The use of silicone coated fiberglass fabric

Silicone coated fiberglass fabric is made of glass fiber cloth as the base cloth, and is processed by coating or calendering with silicone rubber. Silicone coated fiberglass fabric is a high-quality composite material. Silicone coated fiberglass fabric inherits the dual characteristics of glass fiber cloth and silicone rubber, and is widely used in many fields.

Silicone coated fiberglass fabric’s long term working time is between -70℃ to 230℃. For high temperature resistance, silicone coated fiberglass fabric is widely used in aviation, papermaking, food, environmental protection, printing and dyeing, clothing, chemical industry, glass, medicine, electronics, insulation, construction (roof membrane structure base cloth), grinding wheel slicing, machinery and other fields. It can be used for anti-corrosion coating, lining and liner, anti-sticking conveyor belt, high frequency copper clad laminate, architectural membrane material, insulating material, microwave drying conveyor belt, flexible compensator, friction material, etc.

silicone coated fiberglass fabric

What’s more, silicone coated fiberglass fabric can also be used as heating food gasket, baking sheet, microwave gasket, microwave drying belt like Teflon high temperature cloth.

Silicone coated fiberglass cloth can also be used as anti-sticking linings, gaskets, coverings, etc., carpet tape, etc.

According to the thickness of the silicone coated fiberglass fabric, it is used for conveyor belts of various drying machines, such as drying medicinal materials, tea, food, chemical agents, adhesive tape, sealing tape, etc.

Silicone coated fiberglass cloth is also used for anti-corrosion coating of various petrochemical pipelines, the insulation of electronic appliances, temperature-resistant coating materials, and the environmental protection desulfurization of waste gas from power plants.

The normal color of silicone coated fiberglass fabric: silver grey, grey, red, black, white, transparent, orange, etc.

Pls email to get the free sample of silicone coated fiberglass fabric.

Posted in Product Applications | Comments Off on The use of silicone coated fiberglass fabric

Plant Polyurethane resins for composites

CPA and Purcom launch PUGreen that is a vegetable-based polyurethane resin for composites applications. Its properties meet the main needs of the composites industry, such as lightness, strength, finish and sustainability.

The formulation of PUGreen, details Paulo Macaúbas, responsible for the area of development of new business and products of the CPA, is based on a blend of various vegetable oils.

“It is a resin derived from renewable sources, with a content of 90-100% solids and zero emission of volatiles, which makes it a unique product in Brazil when it comes to vegetable polyurethane,” notes Paulo Macaúbas, who is responsible for the CPA department focusing on development of new business and products. “Thus, in addition to being environmentally friendly and not polluting the atmosphere, PUGreen is odourless, which improves the working condition of the applicator.” he explained.

PUGreen is also said to offer other benefits compared to other composite resins. These include higher elongation and higher abrasion resistance, coupled with good impact properties. A low exothermic peak results in practically no shrinkage and therefore better surface finish.

“Another differential is the weight reduction, which is between 6% and 12%, depending on the type of part,” reports Macaúbas. “This feature addresses the growing trend of the composite industry for the pursuit of lightness.”

Since 2006, CPA has focused on the production of plant resins for industrial flooring. Over recent years CPA has been investing in the development of products for the composites market. This resulted in the creation of PUGreen and the alliance with Purcom, which has been supplying composite moulders for over 15 years.

Since our inception, we have developed polyol from renewable resources, but mainly for the production of foams, not resins. Now, in the partnership with CPA, we have included our portfolio in vegetal polyurethane resin for the most diverse composite conversion processes. Pugreen is a product with CPA technology and purcom expertise,” said Giuseppe Santachè, the company’s commercial director.

Purcom will be responsible for the manufacturing of the novelty, together with the CPA – the commercialization, in turn, will be made by the systems house. At their booth at Feiplar, as well as at CPA?s, visitors will be able to check QuickFloor, the first product molded with PUGreen?.

Created by G12 Innovation and produced by AJB Composites, QuickFloor is a modular and industrialised floor covering ideal for wet areas of buildings, such as bathroom, kitchen and laundry. It is a practical, clean and sustainable solution that contributes to the waterproofing of the area, since the boards manufactured with PUGreen are impermeable and moulded in a single piece.

Future developments will target the transport market, focusing on buses and trucks, as well as in the marine industry.

Posted in News | Leave a comment

Silicone coated fabric flexible connector

Silicone coated fabric flexible connector has the advantage of energy saving, air duct using a variety of high-performance non-metallic organic materials and inorganic materials with several kinds of metal additives, the fire-resistant grade is A1 level (non-combustible), which is acid and alkali resistance, pressure resistance, anti-aging, flexibility, etc. It’s used for flexible connection of air conditioning, anti-corrosion, smoke control, radiation prevention, and purification ventilation systems.
silicone coated fabric flexible connector
The type of connection: Batten connection, flange connection, hoop connection. The connection can be customized.
Silicone coated fabric flexible connector: The material is non-metallic with high temperature, anti-aging, good sealing performance. Material: fluororubber, silicone cloth, glass fiber cloth, steel mesh, steel wire cloth, asbestos cloth and other materials.

Silicone coated fabric flexible connector is specially used for the connection between the smoke exhaust fan and the exhaust pipe, in the case of fire, preventing the fire from burning to ensure the operation of exhaust air duct to achieve the purpose of exhaust. Silicone coated fabric flexible connector greatly reduce the fire caused by personal injury, it’s an integral part of construction, air defense projects, subway projects, public places, ships fire exhaust system. Silicone coated fabric flexible connector has the advantage of anti-corrosion, shock absorption, non-combustible.

Silicone coated fiberglass cloth: high strength, high temperature glass fiber cloth as the base fabric, and curing silicone rubber layer at high temperature, process into finished products. It’s high-performance, multi-purpose new composite materials. Silicone cloth with flame retardant, fireproof, high temperature, anti-corrosion, anti-aging, etc., and the texture is relatively soft, which is suitable for various shapes of flexible connector.

The long term working temperature of Silicone coated fiberglass cloth is at -70℃ (or lower) to + 250℃(or higher). It’s widely used in aerospace, chemical industry, large power generation equipment, machinery, steel plants, metallurgy, non-metallic expansion joints and other fields.

Core-Tex has many years experience of silicone coated fabric flexible connector, if you are interested in our products, please contact, our engineers will serve and answer your questions.

Posted in Product Applications | Leave a comment

Development and performance of high temperature resistant coating

Thermal protective coating is a special purpose coating, which is widely used in the aerospace, electrical and electronic, textile, construction and other fields. Since the 1960s, room temperature vulcanized silicone rubber because of its resistance to oxidation, resistance to high and low temperature alternating, cold, ozone resistance, excellent electrical insulation, physiological inertia, corrosion resistance, moisture resistance and other excellent performance, and it has been widely used and researched.

The selection of base rubber

Thermal protective coating requirements of its film-forming material with high temperature characteristics, and should have a certain mobility. Silicone resin, modified epoxy resin, polyacrylate, organic fluoropolymer, polyphenylene sulfide, etc. are widely used. These resins are resistant to temperatures above 200℃, but curing conditions are harsh, and require specialized equipment. The main chain of dihydro-polydimethylsiloxane Si-O ensure good thermal stability, can withstand temperature -60 ~ 250℃, it can be vulcanized at room temperature, and it’s cost-effective. In theory, the greater the molecular weight of the polymer, the physical and mechanical properties gradually increased more, but the mobility is poor, and unfavorable for construction. After the preliminary screening, the molecular weight of 3×104 of the base rubber is more appropriate.

The selection of color filler
The filler should be added into the coating appropriately, it is to improve the physical properties of the base rubber, on the other hand to strengthen the heat resistance of the base rubber, heat insulation properties. Taking inorganic – organic combination can significantly improve the mechanical properties of the coating, temperature resistance and oxidation resistance. Commonly used fillers include silica, aluminum powder, zinc powder, silica powder and so on. At the same time, the amount of flame retardants, mica powder can be added into the coating, so that the coating has thermal insulation properties. The addition of pigment can improve the temperature resistance of silicone rubber, but not more than 1%.

The selection of cross – linking agent
In this paper, the preparation of single-component room temperature vulcanized silicone rubber, there are three common types of cross – linking agent: First, acetic acid type, such as methyl triacetoxy silane crosslinking agent; Second, oxime type, such as methyl triacetone oxime Silane; third is alcohol type, such as methyl trimethoxysilane and methyltriethoxysilane. Acetic acid and oxime type are corrosive to metal, and it’s smelly; alcohol type is a better choice, but organic tin and other catalysts need to be added , such as dibutyl tin dilaurate.

Formula and process
The optimum formula for thermal protection coatings is shown in Table 1. The preparation process is shown in Pic 1.
Table 1 The formula of thermal protection coatings

Note: 100 parts polydimethylsiloxane as the cardinality.

PDMS→Stirring, heating, vacuum.Inorganic filler (pretreatment)→Stirring, heating, vacuum.Inorganic filler (Coupling agent and crosslinking agent)→Stirring, heating, vacuum(Catalyst)→Finished product
Pic 1 The configuration process of thermal protective coating

Results and discussion
Effect of white carbon black on tensile strength
The data of the tensile test are shown in Table 2.
Table 2 Tensile strength for different amounts of white carbon black coating

It can be seen from Table 2 that the tensile strength increases with the increase of the amount of white carbon black, and when the mass fraction of white carbon black reaches 20%, the tensile strength has a maximum value of 1.4MPa, and then the tensile strength decreases sharply.

From the “structured” theory, it can be seen that the amount of silica filled has a limit value. After exceeding the limit value, the white carbon black will be combined twice to produce creep hardening, which leads to the decrease of the mechanical properties, especially the tensile strength.

Effect of Al (OH) 3 on temperature resistance
According to the mechanism of low temperature volatile heat insulation, the addition of Al (OH)3 can obviously improve the heat resistance temperature of silicone rubber. Al (OH)3 is heated to about 220℃ when the rapid decomposition of the crystal water and absorb a lot of heat, thereby reducing the temperature of the material surface.
The decomposed crystal water reacts with the free carbon produced by the decomposition of the organic material under the catalysis of Al2O3 to produce volatile CO and CO2, which also consumes part of the heat. Pic 2 is the TG curve of the Al (OH)3 sample with 50% mass fraction.

As shown in Fig. 2, the sample was raised from room temperature to 800℃, the weight loss was 40.2%, and the residue was 59.8%. Thus, the coating has a certain residual amount after thermal decomposition, and the gasification fraction is relatively high, which is helpful to improve the ejection coefficient. The thermal decomposition rate of the coating is 5%, 20% and 50% respectively. The decomposition temperature is 290℃, 405℃ and 482℃, respectively, and the thermal decomposition temperature is 354℃. Therefore, the coating can be used under the temperature 290℃ for long term working, it can also can be used at the temperature 354℃within a short time.

Pic 2 The TG curve of A (lOH)3 samples with mass fraction of 50%

Effect of crosslinking agents on tensile properties
Methyltrimethoxysilane is a commonly used cross-linking agent, the cross-linking reaction is as follows:

Pic 3 shows the tendency of the tensile properties of methyltrimethoxylates in different amounts. It can be seen from Figure 3, with the increasing amount of crosslinking agent, the tensile strength also increases, but there is no practical value with excessive amount, because enough construction time should be left in the construction project, adding excessive cross-linking agent of the coating will lead to its rapid curing; and coating costs will increase. After a comprehensive test, 7% to 8% methyl trimethoxy is the best dosage.

Pic 3 Effect of crosslinking agent on tensile properties of coatings

The addition of inorganic fillers and additives improved the mechanical properties of the coating, tensile strength up to 1.4MPa. 20% silica is the best dosage, excessive dosage will lead to the coating material “structured”; the best dosage of methyl trimethoxy is 7% to 8%.

Al (OH)3 improves the temperature resistance of silicone rubber. The coating material has high temperature performance, which can be used under the temperature 290℃ for long term working, it can also can be used at the temperature 354℃within short time, and it has extensive applications.

If you want to know more information of this product, pls feel free to contact our engineer (Email:, we will reply you within 24 hours.

pdfDevelopment and performance of high temperature resistant coating.pdf

Posted in Product Features | Leave a comment

Introduction of fabric organic coating agent

What is fabric organic coating agent?
Fabric coating agent, also named as coating glue, which is a uniform coating on the surface of the fabric that can form a polymer fabric by the coating agent. It can get a unique hand feeling, appearance and a variety of special features, which can greatly enhance the value-added products. At present, the coated textiles account for 30% of the total textiles, while the coating agent consumption has reached about 50% of the total amount of textile auxiliaries.Therefore, the research of coating agent has been paid much attention by people.

What are the types of fabric organic coating agents?
Coating agent can be divided into solvent-based and water-based according to the usage. Solvent-based coating agent has a good film-forming, high water pressure, drying fast, low solid mass fraction, but requires a large number of organic solvents, the cost is high, and it’s toxic and easy to fire, pollute the environment. Due to the increasing price of the international crude oil, the price of the solvent is also rising, which increase the cost. For Water-based coating agent, the water pressure is low, drying is slow, but it’s non-toxic, non-combustible, and safe with low cost. It is also made to thick coating products, it is beneficial to the production of colored coated products. Therefore, many manufacturers are willing to use coating agents according to different chemical structure classification, such as Polyacrylates, polyurethanes, polyvinylchloride, silicone (also named as polysiloxanes).

Silicone coating agent had developed successfully by the German WACKER company in the 1970s, followed by the United States Dow Corning, Shin-Etsu Chemical have also launched their own silicone coating agent and put on the market. This paper introduces the preparation and application of silicone coatings for newly developed fabrics in recent years.

What are the properties of silicone coatings?
Good water repellency and air permeability. The main chain of the silicone is composed of Si and O atoms alternately connected, Si atoms using sp3 hybrid and with organic groups (such as methyl, etc.), is a semi-inorganic semi-organic polymer compounds. When the silicone is coated on the surface of the fabric, the oxygen of the silicon dipolar will point to the surface of the fabric and the methyl outward to the air and form a directional arrangement on the surface of the fabric. The organic groups such as methyl groups convert the high energy, and the surface of the fabric is shielded, so that the critical surface tension of the fabric surface is greatly reduced, resulting in good water repellency; and still maintains good hygroscopicity for the uncoated layer.

In addition, the bond length of Si-O (0.164 nm) is longer than the C-C bond (0.154 nm) and the C-O bond (0.142 nm), the bond angle of Si-O-Si is large (143°), So that the stroma of the lateral rotation on the Si atoms is small, the polysiloxane chain can be free to rotate, and the free space increases, the relative density of the space decreased, so the air permeability improved. If the silicone elastomer is made into a thin film, the air permeability of N2, O2, CO2 and other gases in the air that is 30-50 times higher than that of the natural rubber at room temperature.

Excellent heat resistance
The bond energy of Si-O (452 kJ / mol) in the organosilicon compound is higher than that of the C-C bond bond (356 kJ / mol) and the bond energy C-O (358 kJ / mol), so that it has excellent heat resistance. But if the silicone elastomer contains 5% KOH, it begins to decompose at 125 ℃. Therefore, when producing the silicone coating agent, it is necessary to remove impurities such as residual catalyst to ensure that the coating agent can be used in the 250-300℃ environment for long-term.

Good weather resistance
Silicone coating agent has excellent stability, UV resistance and anti-radiation, tear strength, permanent elasticity and good adhesion to the fabric fastness in the environment of -50 ~ 250℃. The brittle point of general-type silicone elastomer is-50 ~ -60℃, the using life is up to 10 years in the out-door environment.

Good mechanical performance
The tensile strength of the silicone elastomer is about 10MPa, and the elongation at break is about 10 times. After coating with the coating agent for the he pongee fabric, the tear strength and the breaking strength are significantly increased.

Physiological inert (non-toxic)
As the silicone is semi-inorganic semi-organic polymer materials, pure dimethyl silicone oil is not toxic, no stimulation of the skin. It can be used in food, cosmetics, drugs, because of these features, it has the performance of physiological inertia.

Preparation and application of silicone coating agent
Silicone coating agent imparts the fabric a strong tear strength, outstanding water vapor permeability, excellent flexibility and resistance to ultraviolet light, it is widely used in raincoats, umbrellas, tarpaulins, nautical clothing, baby pants, hot air balloons, skiing Shirts, protective clothing and other fabric. According to the main components, silicone coating agent is divided into two types, mixed type and modified type.

Mixed type organic silicone coating agent
Such coating agent is generally the active group of polysiloxane and other components in accordance with the proportion of mixing in the system. The method is simple, has been studied in early time and has been deeply concerned by the researchers, but the components and their proportions should be appropriate.

The mass fraction of 10%~85% Polysiloxane, 0.5%~20% acid, and 5%~40% solids (the particle size is 1~5μm, density 0.12~1.8g/mL) were mixed evenly to obtain silicone composition. The composition has non-irritating, non-corrosive, non-combustible properties, and can impart good water and antifouling properties to textiles, leather, glass, ceramics, and metals. The polysiloxane may be methyl silicone oil or hydrogen-containing silicone oil, functional silicone oil, cyclosiloxane (e.g., octamethylcyclotetrasiloxane, hexamethylcyclotrisiloxane). The acid is sulfurous acid or hydrohalic acid, sulfamic acid,etc. The solid particles is mica, graphite, polyethylene, polypropylene and so on.

Using α, ω-vinyl dimethylsiloxy polydimethylsiloxane or terminal hydroxyl polydimethylpolyvinylsiloxane [polymerization degree is not higher than 150, viscosity 4100 mPa·s (25℃)] silicone cross-linking agent (Viscosity 2 ~ 55mPa·s, such as methyl trimethoxysilane, methyltrichlorosilane and so on)) containing at least three reactive groups (Si-H, Si-OH, Si-OR groups), and a catalyst (such as tetraisopropyl titanate, NaOH, chloroplatinic acid) capable of reacting between the two are formulated as a silicone coating composition for use as textile coating. The cured coating is flexible (foldable), flexible, especially suitable for use in airbags. Some people use vinyl silicone oil, hydrogen-containing silicone oil, chloroplatinic acid, tackifiers (such as epoxy silicone oils, alkoxysilanes), silicone resins and crosslinking inhibitors such as tetramethylvinyltetrasiloxane or Unsaturated amine, pyrimidine, acetylene alcohol) is formulated as a silicone composition which is applied to the inner surface of the airbag to form a protective coating which improves its high temperature mechanical properties and adhesion to the substrate.
The olefin-containing polysiloxane, the hydrogen-containing silicone oil, the silicon powder and the hydrosilylation reaction catalyst are formulated into a silicone rubber composition. The elongation of the coated fabric is more than 800%, and it is used as an air bag, inflatable lifeboat and so on. It has a long lasting pressure maintaining characteristic. Olefin-based silicone oil having a viscosity of 100 to 500 Pa·s, a hydrogen-containing silicone oil, an alkoxysilane (e.g., 3-methacryloxypropyltrimethoxysilane, etc.), SiO2 powder, zirconium complex (such as zirconium tetraacetylacetonate) and catalyst (chloroplatinic acid solution or chloroplatinic acid alkenyl compound) made to silicone rubber composition, coated on the, exposure in high temperature and high humidity environment for a long time, finally still contain strong adhesive properties.

The mass fraction of hydroxyl silicone oil 10 to 80% (viscosity: 50 to 1000 Pa·s) and 20% to 50% of methyl silicone oil (viscosity 50 ~ 500 Pa·s) mixed heating to 60 ~ 80℃, stirring 0.5 ~ 1h. Cooling to room temperature, adding 1% ~ 10% hydrogen-containing silicone oil (active hydrogen mass fraction of 0.4% ~ 1.6%), stirring 0.5h, the viscosity of 80 ~ 300Pa·s. And 0.5% to 1% of an organotin catalyst (such as dibutyltin dilaurate, dibutyltin diacetate), 0.5% to 1% of a functional group containing an epoxy group, a mercapto group, an amino group and a ureido group Silane coupling agent (e.g., 3-aminopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, etc.) to prepare a silicone coating agent.

Modified type organic silicone coating agent
The modified silicone coating agent is obtained by polymerizing silane coupling agent and / or reactive silicone oil with an isocyanate or an acrylic monomer. The preparation process of this coating agent is complicated, but can obtain unique property.

Development trend of fabric organic coating agent
Coating processing is a important method of textile treatment, coated fabric production has a broad prospect, its manufacturing and application areas are inseparable from the development of new coating agent research. To develop new varieties to obtain competitive advantage, the development trend of silicone coating agent is as follows: First, the development of special functional products. With the development of high-tech computers and telecommunications, electromagnetic radiation has become the fourth largest pollution threat to human health after noise pollution, air pollution and water pollution. The coated fabric with electromagnetic shielding is extremely important in modern people’s life and work. In addition, with insulation, warming, anti-bacterial, anti-sound, flash, reflective and other special features of the coated fabric should also be concerned. Second, multi-functional product development. Multifunctional coating agent can give the fabric a different style and function, such as waterproof, moisture, flame retardant (or anti-ultraviolet, or resistant to hydrolysis of mildew) triple effect, but also the future development trend of the coating. Third, cost. Silicone coating agents are unique, but more expensive, the cost of materials should be reduced to expand the field.

If you want to know more information of this product, pls feel free to contact our engineer (Email:, we will reply you within 24 hours.

pdfIntroduction of fabric organic coating agent.pdf

Posted in News | Leave a comment

Silicone rubber surface coating compounded with blocking polyurethane

Silicone rubber is a kind of elastomer with excellent heat resistance, low temperature resistance, ozone resistance, weather resistance, electrical properties and high permeability. It is widely used in the buttons of mobile phones, telephones, notebook computers, fax machines, copiers, home appliances remote control and other products. The buttons is high frequency, easy to wear, so need wearproof and good decorative coating. But the silicone rubber surface energy is low, adhesion of the coating is poor, and easy to fall off. At present, the cost of UV curing and organic silicone and other coating is high, it is difficult to meet the rapidly expanding market demand. The blocking polyurethane coating reacts with the functional groups such as the hydroxyl groups on the surface of the treated silicone rubber to obtain a high adhesion, and the polyurethane coating of the layer has excellent abrasion resistance and surface decorative performance. In this research, polycarbonate diol (PCDL) with excellent mechanical properties, hydrolysis resistance, heat resistance, oxidation resistance and abrasion resistance was selected and reacted with excess isophorone diisocyanate (IPDI). The effects of blocking agent type, amount of blocking agent, temperature and time of blocking reaction and synthesis technology on the sealing rate were studied.

Main raw material
IPDI, PCDL, dibutyltin dilaurate, toluene, di-n-butylamine, trimethylolpropane (TMP), diethyl malonate, chemically pure. Acetylacetone; ethyl acetoacetate; ethyl acetate; isopropanol , Phenol; methyl ethyl ketone oxime, purity 98%, all of the above is AR.

The synthesis of blocking polyurethane
A certain amount of PCDL, dibutyltin dilaurate and ethyl acetate were added to a four-necked flask equipped with a collector-type magnetic stirrer, a reflux condenser, a thermometer and a nitrogen inlet and outlet, and IPDI was added dropwise at 80℃, reacts 2 hours. After cooling, the NCO group was added and reacted at 60℃ for a period of time. The residual NCO group content was measured. Then, the crosslinking agent TMP was added for 2 hours to obtain a blocking polyurethane solution with a solid mass fraction of 46%.

Analysis and testing
The determination of NCO content: Test by dibutylamine re-titration method.
Measurement of the blocking rate: The blocking rate of the NCO group was calculated according to (W1-W2) x 100% / W1, and W1 and W2 were calculated as the NCO group contents of the prepolymer before and after the blocking.
Resistance to yellowing test: the obtained blocking products evenly coated on the slide, until the solvent volatile, put into 160℃ oven for 1h, observe the appearance of the product.
Alcohol resistance test: impregnated with cotton group of anhydrous alcohol, wrapped in a dedicated test head (after wrapping with cotton, the test head area of about 1cm2), applying 500g load to 40 to 60 cycles per minute, 20mm around, wipe back and forth on the surface of the bottom, 3 samples, the coating thickness of 0.06 ~ 0.09mm. The number of falling off cycles is the test result.

Resistant to sweat test: clean cloth soaked in the ammonia containing 1. 07%, sodium chloride 0.48% of the mixed water solution, which stick on the surface of the product, and sealed with a plastic bag, placed in the room temperature after 24 hours. After the test is completed, the test solution on the surface of the product will be wiped clean and the coating adhesion will be tested after 2h or more at room temperature. 3 samples, the coating thickness is 0.06 ~ 0.09 mm.

Using CMT4340 electronic testing machine to test the tensile strength : the tensile speed is 50mm/min, the sample made of the thickness of 1 ~ 2mm dumbbell shape, after standing at room temperature for 24 h, according to GB / T 528-92 standard determination.

Using the Spectrum Fourier transform infrared spectrometer (FT-IR) of Sprectrum from United States, after pure KBr tabletting, the solution was dropped onto the KBr sheet with a capillary and tested after evaporation of the solvent.

The decompression temperature of the blocked product was measured by a differential thermal analyzer (DSC821e) manufactured by METTLER. The flowing rate of N2 was controlled at 80 mL/min, from 20℃ to 160℃, and the heating rate was 10℃/min.

Results and discussion
Effect of blocking selection on blocking rate

The requirement of silicone rubber surface coating decorative effect is high high, the selected blocking agent required resistance to yellowing and has a low decapsulation temperature. In this study, phenols, oximes and dicarbonyl compounds were used as blocking agents. The molar ratio of blocking agent to NCO group (-H: -NCO) was 1: 1, and reacted at 60℃ for 4 h to synthesize blocked polyurethane solution , the experimental results in Table 1.
Table 1 Effect of blocking selection on blocking rate

In Table 1, the sealing rate of phenol and methyl ethyl ketoxime is very high, but the high temperature curing release of the blocking agent is toxic, and the coating is yellowing. The resistance to yellowing of the products of three β-dicarbonyl compounds, such as diethyl malonate, acetylacetone and ethyl acetoacetate, was relatively good. Although acetylacetone and ethyl acetoacetate are able to achieve higher blocking rate than diethyl malonate, the first two are significantly higher in the decapsulation temperature and are accompanied by slight yellowing and are difficult to meet the high decorative requirements of the coating. Therefore, in this study, the prepolymer was blocked with diethyl malonate without yellowing.

Effect of the amount of blocking agent on the blocking rate
The reaction temperature was 60℃ and the reaction time was 3 h. The effect of the molar ratio of blocking agent to NCO group on the blocking rate was investigated, and the experimental results are shown in Pic 1

The molar ratio of —H :—NCO Blocking rate/%
Pic 1 Effect of the amount of blocking agent on the blocking rate

In Pic 1, when the molar ratio of -H: -NCO is 1: 1 in the blocking reaction, the blocking rate of the blocking reaction is only 35%, but with the increase the molar ratio of -H: -NCO , the blocking rate is improved. After the molar ratio is more than 1.9, the rise of the blocking rate tends to ease. This largely depends on the reactivity of active hydrogen (-H) in diethyl malonate, because the active hydrogen on the methylene group in the diethyl malonate is affected by the strong absorption and symmetry structure of the dicarbonyl, the activity is far less than active in phenolic, amine-based sealants. Secondly, when the coating of small molecules contain a high proportion of the blocking, it will seriously affect the coating solvent resistance and other properties. Thus the fixed molar ratio of -H: -NCO is 1. 9.

Effect of reaction temperature on blocking rate
The reaction time is 4h, the molar ratio of -H: -NCO molar ratio is 1. 9, and the effect of the blocking reaction temperature on the blocking rate is investigated and results are shown in Pic 2.

Pic 2 Effect of closed reaction temperature on the sealing rate

In Pic 2, when the temperature rose from 40℃ to 80℃, the blocking rate showed a trend of rise and fall, the suspension of NCO is the exothermic reaction, the reaction of diethyl malonate is very low under the low temperature conditions, and affecting the blocking efficiency. However, the high temperature will inhibit the exothermic reaction in the direction of positive reaction, and the high activity of IPDI will produce many side effects, which will affect the blocking effect of the product. The suitable reaction temperature is 60℃.

Effect of blocking reaction time on blocking rate
The molar ratio of -H: -NCO was 1.9, and the blocking reaction temperature was 60℃. The blocking rate of the reaction time was from 1h to 6h. The reaction results are shown in Pic 3.

Tim/h Blocking rate/%
Pic 3 Effect of blocking reaction time on the blocking rate

In Pic.3, when the blocking reaction is 1 h, the blocking rate has reached 45%, and in the flowing few hours, the closure rate increased by only about 15%, within 1 h after feeding, the initial reaction concentration of the blocking agent and NCO group reached the maximum, so that sufficient contact between the reactants, completed most of the reaction. When the blocking reaction is carried out for 4 hours, a dynamic equilibrium state is reached, and the effect of increasing the reaction time on the reaction degree is very small. Generally, the appropriate blocking reaction time is 4h.

Effect of crosslinking agent on polyurethane coating
In order to overcome the shortcomings of linear polyurethane water resistance, solvent resistance and heat resistance, the blocked residual isocyanate groups and cross-linking agent react together, the polyurethane molecules to form a cross-linked network structure, but the introduction of cross-linking agent will increase the viscosity of the early polymerization system too fast, it’s easy to gel. In this study, TMP was used as an internal crosslinking agent to synthesize a suitable cross-linked polyurethane solution. Because the blocked reaction has a low blocking rate under the premise that the coating is not yellowing, the free NCO groups still exist in the system, which affects the stability of the system. Moderately crosslinking can not only improve the solvent resistance of the coating, but also can improve the blocking rate of closed reaction. The crosslinked and uncrossed polyurethane prepolymers were characterized by FT-IR after the end of the blocking reaction. The results are shown in Pic. 4.

In Pic. 4 that there is still a characteristic absorption peak (2264 cm-1) of the NCO group in the polyurethane prepolymer without the crosslinking agent after the end of the blocking reaction, mainly due to the blocked reaction efficiency. After the cross-linking, the characteristic absorption peak of the NCO group disappears, and the NCO group has completely reacted by the crosslinking agent.

Wave number/cm – 1
1 – non crosslinked product, 2 – crosslinking products
Pic 4 The reaction product FT – IR of pre polymers before and after blocking and crosslinking

Performance test results before and after crosslinking
—H: —NCO is 1. 9 :1, the reaction temperature was 60℃ and the reaction time was 4h. To investigate the effect of the amount of crosslinking agent on the properties of the coating, curing on the surface of the silicone rubber treated by plasma, place it for 24 h to test its performance, the results shown in Table 2.

Note: The crosslinker content is the mass fraction of PCDL in the prepolymer.
In Table 2 that the tensile strength and the alcohol resistance of the coating gradually increase with the increase of crosslinking, meanwhile, the content of the NCO group decreases with the increase of the crosslinking. And the silicone rubber surface groups to reduce the probability of reaction, resulting in resistance to hand sweat after coating adhesion decreased.

The molar ratio of -H: -NCO was 1.9, the reaction temperature was 60℃, the reaction time was 4h, and the cross-linking was achieved with TMP to obtain the closed polyurethane solution. The decarburization temperature of the prepolymer was tested to be about 116℃. The tensile strength and the alcohol resistance of the coating gradually increased with the increase of the crosslinking, and the adhesion decreased after the sweat resistance test.

If you want to know more information of this product, pls feel free to contact our engineer (Email:, we will reply you within 24 hours.

pdfSilicone rubber surface coating compounded with blocking polyurethane.pdf

Posted in Production Process | Leave a comment

The production of silicone coated glass fiber fabric covered nickel-chromium heating sheet

Nickel-chromium heating sheet is commonly used in a heating element of Aviation equipment, instrument, it is also named heating zone, the larger product called electric heating blanket. Its role is to rely on power through the heating sheet itself after the heat generated by the temperature control system to control the instrument’s operating temperature, because its small size, light weight, long using life, good process, safe and reliable, easy to use, Which is widely used in aviation and aerospace industrial equipment, instrumentation, temperature control system. Due to using various types of nickel-chromium heating sheet, to ensure that equipment, instruments to work in requested temperature for long time.

In general, there are two processing methods to manufacture the nickel-chromium heating sheet. namely molybdenum wire cutting method, and lithography etching method. The former process is simple, easy to process, suitable for stereotypes of large-scale production of products, the latter which cartographic flexibility, it can be changed while using, and it is suitable for small batch development. Our processing of nickel-chromium heating sheet, which is produced by the two methods.

The performance and features of nickel-chromium heating sheet
It can be designed according to user requirements, also can be designed into a variety of shapes and sizes, and can be flat or bent wrapped in the instrument.
Using silicone coated glass cloth as the cover, temperature performance is good, can be in -50 ~ 200℃ temperature range of long-term normal work.
Insulation performance is good. It does not occur flashover breakdown phenomenon under the voltage of 500 volts, the power of 0.5 KVA, anti-electricity 1 minute.
Its lead wire connected firmly, at least to withstand 0.2kg of tension. The insulation resistance between the lead line and the end ≥ 200MΩ (checked by 500V megger).
Resistance values can range from a few ohms to several hundred ohms. Through the DC or AC power can work long-term.
Anti-wet performance is good. The bonding strength between Silicone glass fiber cloth and nickel-chromium alloy sheet is high, will not fall off.
Long service life, which can work continuously for 1000 hours. With the GPS-4 or GD402 adhesive bonding, it bonded firmly with aluminum, copper, steel and other metal, and it is not corrosive to metal.

The structure and materials of nickel chrome heating sheet
It is composed of a resistive material – nickel chrome alloy sheet, lead wire, substrate and cap layer and other components. Making the nickel chrome heating sheet, according to different working temperature, conditions of use and requirements, the appropriate choice of various types of raw materials.
Resistance material. Ni-Cr alloy sheet is an important part of the heating film, according to the use of requirements, should be used high resistivity, corrosion resistance of the precision resistance alloy sheet.
Leads. From the end of nickel-chromium alloy sheet leads to the two fine insulated wire, using high temperature resistance of PTFE insulated installation line, model AF-250 (110 volts), the nominal cross-section of 0.013 mm2.
Substrate and cap layer. The substrate is used to maintain the geometry and relative position of the nichrome sheet, the cap layer protects both the shape and the relative position of the nichrome sheet and the nichrome sheet.

The substrate and cap layer are different with respect to the function of the heating sheet. In fact, the material used for substrate and cap layer is the same. In order to meet the production requirement of the curved heating sheet, besides selecting thinner nickel alloy sheet, the substrate and cover materials should also be also selected. Thus, it will not only meet the needs of the heat resistance and electrical insulation, but also have a certain deflection performance. Therefore, taking the silicone coated glass fiber cloth as the substrate and cap layer materials, the thickness of 0.18 ~ 0.20mm. Since the material is not vulcanized, so that taking the sticky performance of silicone rubber which coated on the glass fiber cloth, fix the shape and the position of a nickel-chromium alloy sheet, there will be strong bonding force between the silicone coated glass fiber cloth and nickel-chromium alloy sheet after heating vulcanization .

Production of Ni – Cr heating sheet by lithography etching method
Lithography etching method, through photochemical, corrosion and other means to print the desired shape of the line on the Ni – Cr heating sheet. The steps of the surface processing technology are as follows:
Graphic design→surface treatment of alloy→copy graphics→solid film processing→paste silicone glass fiber cloth→chemical corrosion→cleaning→measurement of welding wire and resistance→cover glue.
Graphic design. The thickness, the shape and the voltage of the required nickel chrome heating sheet in the instrument are used as the basis to calculate the required resistance value to determine the density, the direction and the length and width of the line on the heating sheet and draw 2: 1 ~ 5: 1 enlarged drawings of line, keep the negative film after photographing.
Pre-treatment of plate and nichrome sheet. Pre-treat the nickel-chromium alloy plates, firstly, the nickel-chromium film according to film size, the appropriate amplification on each side, cut with a cutter. And then using the magnesium oxide powder to remove oil on the surface, and placed in ferric chloride solution for weak corrosion treatment, so that the surface roughness, to improve its surface adhesion.

Copy graphics
The preparation and coating of photoresist, we use polyvinyl alcohol (PVA) as a photoresist material, the formula as below:
Polyvinyl alcohol 100 g
Water 1000ML
Ammonium dichromate 12 g
Preparation Methods: Firstly, PVA mixed with water, and then placed in a water bath to about 90℃, so that the PVA dissolved fully, remove and cool to room temperature, after the aqueous ammonium dichromate solution was poured, the mixture was sufficiently stirred. In order to remove the photoresist in the impurities and air bubbles, should also through net light filtering. Generally with three or four gauze filter for twice, then with the centrifuge to spin coating on the sensitive adhesive. And placed near to the oven until the glue is not sticky.

Notes for coating:
(A) The thickness of the photoresist has a great influence on the development and coloring of the subsequent exposure. Too thin to take off easily, and no protective effect, too thick will be insufficient, and lines blurred easily.
(B) The dryness of the photoresist also has a certain impact on the quality. If it’s not dry completely, the film will tend to stick to the film in the exposure, so the film damages, on the other side, it will make the Ni-chrome graphics incomplete, and for long time baking, it will cause later in the coloring and cleaning Process, it will difficult to show a complete graphics on the nickel-chromium alloy sheet.
(C) Coat sensitive glue on the Nickel-chromium alloy sheet, after baking, it should be placed in the dark place to avoid light, so that the development of lines blurred., should be placed in the dark to avoid light, so that the development of lines blurred.

Exposure. Put the sensitive glue coated nickel-chromium alloy sheet on the baseplate, which close to emulsion side of negative film (Attention to prevent light scattering, so as not to cause blurred lines), then put it under the cold light. The lamp power of 250 ~ 300 watts, the light source from the film is about 20 cm, time is 3 minutes, in addition, the sun light be used in hot days, time is 3 to 5 minutes, thus forming the required graphics of the “latent image.”

Solid film. The exposed nickel-chromium alloy sheet was washed with warm water and colored in 0.5% eosin water solution immediately. Rinse with warm water, remove the photosensitive part of the photosensitive glue from the metal sheet, when the line is clear, immerse it in the fixing solution immediately.
The fixative formulation is as follows:
Chromic anhydride 5 g
Water 100ML

Take the the nickel-chromium alloy sheet out after 20 seconds. After rinsed with water thoroughly, dry the surface with a hair dryer, and then put it into the electric oven, bake it under the temperature of 140℃. The baked nickel-chromium sheet, the color of line color was brown, and the film is very strong. Remove the extra part of the line on the nickel-chromium sheet, the incomplete part is filled with white nitrocellulose.

Paste silicone glass fiber cloth. We take the nickel-Chromium heating sheet as the base plate, which the glass cloth is coated with vinyl silicone rubber compound without vulcanization of semi-finished products.

The processing of silicone coated glass fiber fabric
(A) Dewaxing: Silicone coated glass fiber cloth thickness can be selected according to the request of product. We use the glass cloth of 0.06mm thick twill E-glass cloth, treated under 250 ℃ temperature for about 10 to 15 minutes, until smoke up. Thus, the wax on the glass cloth is volatiled completely.
(B) Chemical treatment: the dewaxing glass cloth immersed in the treatment solution for 3 to 5 minutes, dry it after removing.
Treatment solution formula:
Vinyltriethoxysilane 4 g
Industrial alcohol 50 g
Water 50ML
(C) Coating: After dewaxing and chemical treatment, glass cloth can be well integrated with silicone rubber, after coating the two sides by the coating machine, the total thickness is 0.19 ~ 0.20mm.
Vinyl silicone rubber 100 units
Diphenylsilanediol 3 units
Fumed white carbon black 30 units
2,4-dichlorobenzoyl peroxide (DCBP) 4 units

The surface treatment of nickel-chromium sheet. Place the sheet for 5 minutes after cleaning the bottom of the nickel-chrome sheet with acetone, then coat 2 layers chemical tackifier evenly. The formula of tackifier:
Vinyl triethoxy silane (referred to as A-151) 10 g
Boric acid 0.05 g
Dichlorobenzoyl peroxide (DCBP) 0.5 g

A-151 PH value of which is adjusted to 2 ~ 3 with hydrochloric acid, and the general PH value of A-151 is 5 ~ 6, effect of tackifying is poor. The nickel-chromium plate coated with the tackifier was allowed to stand at room temperature for 30 minutes and then placed in an electric oven at 60℃for 1 hour. Take treated nickel-chromium sheet out, the sheet and the silicone coated glass fiber cloth fit together tightly, And caught between two layers of Teflon film, and then taking the bovine bone scraper to remove bubbles in the sandwich.

The bonding of nickel-chromium sheet and silicone: carry the one side of nicker-chromium sheet with silicone coated glass cloth into the 135℃electric oven, blast insulation for 10 minutes, so that nickel-chromium and silicone coated glass fiber cloth firmly bonded together.

Chemical corrosion. The nickel-chromium heating plate after washing with water, FeCl3 solution used for a weak corrosion. Then FeCl3 Mixed with water to adjust to the Baume’s reading on the table for the 36 ~ 38, temperature control in the 60 ~ 70 ℃, through the compressed air for chemical corrosion. Time is about 10 minutes, remove any unnecessary parts. Be noted that, besides the fluidity of the solution, the cleanliness of the surface of the nickel-chromium sheet have a great impact on the corrosion rate and quality .

Cleaning. Wipe off one layer yellow film of the nickel-chromium line with banana oil, or concentration of 60% sulfuric acid water solutions, and immersed for 30 seconds at temperature of 70℃ to remove the surface yellow film and then rinsed with water.

The resistance measurement of lead wire. In the beginning of nickel-chromium alloy sheet welding lead wire (design the length of wire as requested). The resistance value of heater sheet is determined by Wheatstone bridge. If the resistance value is greater than the index value, it will be removed, and the qualified one will be glued.

Cover glue. For the qualified nickel-chromium heating sheet, covered with a layer of the same size silicone coated glass fiber cloth on the side of wire, and then . After pressing, and then taking the bovine bone scraper to remove bubbles from the sandwich, and then into the electric oven temperature of 135℃, the blast insulation for 10 minutes, and then take it out.

Take the GPS-4 adhesive to pate the nickel-chromium heating sheet on the metal shell. Before the adhesion, cleaning the adherend (shell) surface with solvent, then coat thin layer surface treatment of NO1〜NO8. The mixture was placed at room temperature for 1 hour and then baked at 80℃ for 10 minutes. After being dried, coat the glue on the surface of the treated metal and non-metal surface (shell), the thickness of coating is about 0.2 ~ 0.3 mm, paste after a few minutes. And it can be parked at room temperature for 3 days to get enough adhesive strength. If it is allowed to stand at room temperature for one day, the vulcanization is carried out at a temperature of 80℃to 90℃ for 4 hours, so that the adhesion strength can be improved.

The experimental situation: We produced 22 heating plate totally, the maximum is 66.90Ω and the minimum is 49.1Ω, the difference is more than ten ohms, of course, the majority of nickel-chromium alloy sheet can adjust the resistance value, but the production efficiency is low.

Process of manufacturing nickel – chromium heater by molybdenum wire cutting method
The design of the heating sheet, the selection of material as the above 4.1, the image should be 1 : 1.

The production of the heating sheet.
(1) The processing of nickel-chrome alloy sheet. According to line shape and size, using wire cutting technology to cut out the required nickel-chromium sheet. This batch of 31 pieces of a cutting, the resistance is about 36.9Ω (design resistance of 36±1.5Ω).
(2) Welding wire. In the beginning and end of nickel-chromium alloy sheet, welded PTFE insulated installation line.
(3) Cleaning. Clean the lead with the nickel-chromium alloy tablets with ethanol, gasoline, acetone and other solvent, in order to improve the dry bonding strength. Special attention should be paid to the solder at the solder joint, otherwise the acidic substance of the residual flux will corrode the wire.
(4) Coat surface treatment agent. To increase bonding effect between the nickel-chromium alloy sheet and silicone coated glass fiber cloth. The treatment agent coating on the nickel-chromium alloy sheet placed 40 to 60 minutes, with vulcanization.
(5) Put the nickel-chromium alloy sheet on the substrate, cover layer, remove the bubbles between substrate and cap layer.
(6) The pasted heating sheet on the electric oven at 135℃within 10 minutes of heat preservation blast, remove it, and to be requested silicone coated glass cloth heating sheet. Because decomposition of DBP is 2.4 dichlorobenzoic acid and 2.4 dichlorobenzene, relatively less volatile, so the pressure is not vulcanized to avoid bubbles.

With the further development of space technology, the application range of nickel chrome heating sheet is expanding. Besides of the heating element used in aviation, the large nickel-chromium heating sheet is also used in technology equipment. Practice has proved that the use of wire cutting technology to produce nickel-chromium-clad heating sheet is a high-efficiency, good quality method. While the use of lithography etching method manufacturing heating sheet, although there are some shortcomings, such as low pass rate of quality instability and so on. But taking a series of remedial measures, the quality of products can be improved a lot. In general, in the processing of nickel-chromium heating sheet, taking the method of using lithography etching for small batch production as possible. Once the product is finalized, should use molybdenum wire cutting method to the mass production.

In addition, because the welding wire is still used brazing method commonly , so the thickness of the solder joint is still large. The flat fluorine plastic wire should be used in the future, and to replace the current circular wire, thereby reducing the thickness of the solder joints, and improving the bonding strength. In the future, in order to use thinner heating sheet and the use of a wider range of heating temperature range, the polyimide film as the substrate and cap layer can be considered, through the flexible accelerometer silicone coated glass fiber cloth wrapped nickel chrome heating sheet, and open up various types of temperature control heating sheet manufacturing methods.

If you want to know more information of this product, pls feel free to contact our engineer (Email:, we will reply you within 24 hours.

pdfThe production of silicone coated glass fiber fabric covered nickel-chromium heating sheet.pdf

Posted in Production Process | Leave a comment

Application Of Silicone Rubber In Textiles

Buffer air bag
The United States used the silicone rubber as a cushioning balloon coating material launch Pathfinder Mars probe in the end of 1996. On the one hand, the lowest temperature of the surface of Mars is -83 ℃, thus requiring balloon coating material has good low-temperature rigidity; On the other hand, when the airbag inflator discharges high-temperature gas at a high speed, the strength of the airbag material is able to withstand an instantaneous strong impact load in a high-temperature environment. Practice has proved that silicone rubber successfully resisted the harsh space environment, the detector successfully delivered to the surface of Mars. Silicone rubber has excellent weather resistance,it is also used in the car’s airbag, so as to effectively prevent the aging of the balloon coating to reduce the function of the balloon, the balloon in place after a long time can still be effective work. In addition, the buffer airbag is a precision airdrop, unmanned aerial vehicles landing areas of important components, at present, many people have carried out related research on this subject, the same balloon coating materials made of its stringent requirements, compared to other rubber Or coating materials, silicone rubber is the ideal choice.

Softening agent
Softening agent is a kind of textile auxiliaries that can adsorb on the fiber surface, improving the smoothness of the fiber, making the fabric have a comfortable feeling. Silicone softening agent originated in the the end of the 1950s, so far, the development has gone through four stages: (1) the United States Dow Corning emulsified polymerization directly to produce hydrocarbon-based silicone oil firstly, that marked the birth of the first generation of silicone softening agent, but because of its use of mechanical emulsification method directly to emulsify the silicone oil, silicone oil does not contain active groups, which combined with the textile is not strong, and not washable. (2) On this basis, the researchers developed the metal as a catalyst, with a hydrocarbon-based seal of the second generation of silicone softener, which is still a single function, easy “Floating oil and demulsification”, in the beginning before the industrialization of the third generation silicone softener replaced, before the start of industrialization was substituted with the third generation of silicone softeners; (3) Third-generation silicone softening agent is incorporated into the silicone backbone by the presence of reactive groups, these reactive groups can improve the soft effect, increase the fabric washable ability.(4) With the improvement of clothing requirements, the researchers introduce more active groups into the silicone main chain, so that softening agent really applied to all kinds of fabric. At present, some people have been modified silicone softening agent, and its role in the textile industry is growing.

Fire – resistant insulation materials
The principle of thermal insulation cloth in textile products is different, but there are two kinds of: One is the use of functional particles plus resin for processing; the other is the use of coating materials coated on the fabric surface. Silicone rubber as a high temperature resistance material, is an important insulation coating material.Some people had researched silicone rubber aluminum insulation cloth in the early 1980s, fiberglass as base fabric, coated with silicone rubber in the surface, and then through the vacuum spray technology to foil an aluminum layer. This insulation cloth can be in -60 ℃~ 250 ℃ long-term working, generally used in aircraft cockpit, umbrella cabin and booster cabin and other parts need to be insulated. Silicone coated glass fiber fabrics can be used as high-temperature anti-corrosion conveyor belt, some high-temperature protective gloves, asbestos insulation blanket, insulation blanket, high temperature service fabrics, glass fiber fire cloth and other products.

Insulation Materials
Silicone rubber coated fabric has a high electrical insulation level, which can withstand high voltage load, so as to be made of insulating cloth, sleeving and other products. In the electrical industry, insulating tape is a commonly used material, a lot of insulating tape is produced by rubber coated fabric, but there are many kinds of ordinary rubber can not meet the stringent requirements of the electrical industry, such as resistance to high voltage performance, adhesive properties, adhesion of hot air aging and anti-corrosion properties of metal, but the silicone rubber has advantages in these areas .

Silicone printing for textiles is a new hot spot in the textile industry in recent years, through the screen printing, silicone can be firmly attached to the fabric surface. Screen printing Silicone is widely used, its design has a strong three-dimensional, soft, printed pattern has a high peel strength, abrasion resistance, brightness, also has a waterproof, anti-skid and high temperature resistance. As the silicone rubber are easy to color, bright color, solid, its clothing, clothing accessories, shoes and hats, luggage and other handbags and other textile products are widely used.

Lace / ribbon dripping
For some clothing, especially women’s underwear, stockings, etc., need to do some anti-skid treatment, to prevent clothing slippage. Lace has become an important decorative women dress, high-grade women’s underwear, stockings roots will be modified with lace, but this part often occurs slippage, the use of silicone rubber dispensing process came into being. Silicone rubber treatment can achieve rounded, right-angle effect, three-dimensional sense of strong, excellent tear resistance, and contact with the human body comfort, both to ensure the beauty of clothing, but also to ensure its functional role.

Silicone cloth
Silicone cloth is a kind of high-performance and multi-purpose textile composite material, which is made of high-temperature resistant and high-strength glass fiber fabric and compounded by special technology. It is widely used in aerospace, chemical, petroleum, Equipment, machinery, metallurgy, electrical insulation, construction and other fields. Silicone cloth can also be used as the aforementioned fire-resistant insulation materials and insulation materials used, in addition to high temperature insulation, its main performance characteristics has high strength, soft and toughness, tailorability, chemical corrosion resistance, oil and water resistance. Some people had researched the performance of silicone cloth as a thermal gasket, and found that silicone cloth can not only ensure the insulation, but also can improve the thermal conductivity of insulation gasket, coupled with the strength of silicone rubber itself, making it a good performance in all aspects. Silicone glass fiber cloth coated with nickel chromium can be made into the aviation equipment, instrumentation often used in heating elements, in some of the more large products called electric blanket, its role is to rely on energy heat, by temperature control system to control the operating temperature of the instrument.

other aspects
The silicone rubber surface has a high friction, it can be coated on the surface of some anti-skid pad, anti-skid effect is better, such as the bath mat, car mats, etc. In addition, in some special clothing, the body needs to focus on the protection of parts coated with a certain thickness, a certain shape of silicone rubber can improve people’s wear safety, such as racing suits knee, elbow, shoulder and other parts.

(1) In addition to silicone rubber has excellent temperature resistance, weather resistance, good water repellent properties and corrosion resistance, but also has a very good electrical insulation, compression elasticity and vibration absorption capacity, these excellent properties of silicone rubber In many areas are widely used. In the textile field, silicone rubber can be applied in three categories of textile products, silicone rubber has become an important raw materials in textile industry.

(2) Silicone rubber is nontoxic, it does not cause pollution, and also suitable to replace the additives( will cause pollution) of the finishing process, while improving product quality, so silicone rubber will be widely used in textile finishing processes.

(3) The current technology can dye the color for silicone rubber,and it can change the color of silicone coated fabric to change the clothing color. Silicone surface is not easy to contaminate, it’s suitable for winter garments fabric. It’s believed that through the development of scientific research, this technology can be applied in textile products.

If you want to know more information of this product, pls feel free to contact our engineer (Email:, we will reply you within 24 hours.

pdfApplication of Silicone Rubber in Textiles.pdf

Posted in Product Applications | Leave a comment

The basic properties of the silicone rubber

Low temperature performance
Rubber has high elasticity, due to the thermal motion of rubber molecules weakened in low temperature environment, macromolecules and molecular chain segments are frozen, which will gradually lose elasticity. Two important factors affecting the low-temperature properties of the rubber are the glass transition temperature and the crystallization temperature. For all current rubber products, silicone rubber has the lowest glass transition temperature. Russian scientists made non-crystalline silicone rubber at -60 ℃, -90 ℃, -100 ℃ and -120 ℃ low temperature and rubber products can work long-term in the air, inert gas and vacuum environment. Some people improve the low-temperature performance of silicone rubber by copolymerization modification in the polydimethylsiloxane molecular chain on the introduction of other large volume groups. The principle is to destroy the regularity of molecular chains by using the large volume of structural units. This modification can make the glass transition temperature of silicone rubber increase slightly, but it can reduce the crystallization rate of silicone rubber, inhibit its crystallization, thereby improving the low temperature silicone rubber properties. With the study of silicone rubber properties, Ethyl silicone rubbers with the lowest operating temperatures of -120 ℃ to -90℃ were present. The minimum operating temperatures for various silicone rubbers are dimethyl silicone rubber (MQ) -60℃, methyl vinyl silicone rubber (MVQ) -70℃ to -60℃, phenyl silicone rubber-70C, methylphenyl Vinyl silicone rubber -100℃ to -70℃, methyl ethyl silicone rubber -100℃, ethyl silicone rubber -120℃ to -90℃, fluorosilicone rubber (FMVQ) -60℃.

High temperature performance
There are two main processes for the thermal aging of silicone rubber: Firstly, the side chain of the main chain of oxidative decomposition, resulting in excessive crosslinking, the silicone rubber becomes brittle, hard. Secondly, the main chain scission, generates low molecular weight cyclic and linear polysiloxane oligomers, silicone rubber soft, sticky, which is mainly related to its main chain, side chain groups, terminal structure and the type of additives are closely related. Therefore, many scholars have made a lot of research in this field. It is proposed to improve the thermal aging resistance of silicone rubber by changing the main chain and side chain structure of polysiloxane, using new curing system, adding additives, adding silicon nitrogen compounds to improve the thermal aging properties of silicone rubber. At present, RTV silicone rubber has been able to work continuously at 150 ℃ for a long time, and can work continuously for 10 000 h in the environment of 200 ℃, even some silicone rubber products can work at 350 ℃ for a short time. Although silicone rubber products are superior to other rubbers in heat resistance, they need to be able to work continuously at higher temperatures for a longer period of time, so the future development of the normal work at 300 ℃ silicone rubber as the focus of the study.

Weather resistance
Silicone rubber has excellent weather resistance, and it is not sensitive for ozone aging , even if a long time in the wind and rain, ultraviolet radiation and other conditions exposed to its physical properties will not be substantial damage. The silicone rubber nitrile rubber and styrene-butadiene rubber together placed in natural light, the first time to observe the rubber surface crack the time required, the results showed that nitrile rubber only six months to a year, while the styrene-butadiene rubber takes two years to two and a half of the time and the silicone rubber will take about 10 years. Another test is to expose the above three kinds of rubber under natural light to calculate the elongation to reduce the original half of the time required, the results show that nitrile rubber takes about 7 years, styrene-butadiene rubber takes about 4 years, while the silicone rubber It takes more than 10 years. These data indicate that silicone rubber has better Weather resistance than other rubbers.

Water resistance
Excellent water repellent properties of silicone rubber, which was soaked in water for a long time, can only absorb about 1% moisture, and will not cause damage to its mechanical properties and electrical properties. The water vapor test of silicone rubber found that under normal pressure, the water vapor will not cause damage to silicone rubber, but with the pressure increases, the impact of silicone rubber will become increasingly evident. The data show that: 150 ℃ under high pressure conditions, polysiloxane molecular chain fracture, the performance of silicone rubber decreased, this situation can be selected by adjusting the appropriate intermediate material to improve the structure of silicone rubber, there are many modified silicone rubber products can withstand high temperature steam.

Corrosion resistance
Silicone rubber has a good resistance to oil, even at high temperatures, can also be a good resistance to oil erosion. In some common organic rubber, nitrile rubber and chloroprene rubber at 100 ℃ below also has excellent resistance to oil, but at a higher temperature silicone rubber can show than their excellent oil resistance. In addition, silicone rubber also has excellent resistance to organic solvents and chemical reagents, it is basically free from polar organic solvents, in non-polar organic solvents, silicone rubber will be swelling phenomenon, but unlike other Organic rubber degrades, and when the silicone leaves the solvent, it returns to its original state. Silicone rubber is poor on the strong acid resistance, thus should make attention when using it .

Other properties
In addition to the above-mentioned characteristics of organic silicone rubber there are other important properties. Silicone rubber is a good insulating material, the resistivity can reach 1~100 TΩ•m, and the insulation in a large temperature range can remain stable so it is ideal for some electronic components insulating material. Silicone rubber thermal conductivity rate is about 0.2W / mΩ•K, slightly higher than other rubber, is conducive to the production of friction surface with its equipment, such as textile machinery on the rubber roller. When the silicone rubber close to the flame is not easy to ignite, but once ignited will continue to burn down. By adding fire protection ingredients can make it self-extinguishing, and some silicone rubber products have passed the United States UL94 combustion performance standards. In the use of rubber gasket, due to high temperature, gasket deformation recovery ability is particularly important, silicone rubber compression deformation recovery ability to be stable at -60 ℃~250 ℃. Vibration in some mechanical products, rubber vibration absorption capacity of the gasket is also very important that the actual performance of silicone rubber gasket absorption vibration is also very good. In addition, silicone rubber also has good sealing, can be applied to the air bag airbags.

If you want to know more information of this product, pls feel free to contact our engineer (Email:, we will reply you within 24 hours.

pdfApplication of Silicone Rubber in Textiles.pdf

Posted in Product Features | Leave a comment