The power of silicone in textiles: water-repellent, flexible and wear-resistant

The advantages of silicone in coating applications

Silicones are a special class of polymers based on silicon (Si). This element occurs naturally in sand and quartz. Chemically speaking, silicones form a bridge between organic (carbon-based) and inorganic (mineral-based) materials. Their unique molecular structure gives silicones a range of properties that make them exceptionally suitable for coatings, particularly in textiles and technical textiles. We discuss the most important unique properties below :

1. Temperature and weather resistance

Silicones remain stable at extreme temperatures (from -60°C to +200°C) without losing their elasticity or strength. This makes textile materials with a silicone coating highly resistant to all kinds of influences such as UV radiation, moisture, ozone and therefore also to large temperature fluctuations. Silicones are flame-retardant polymers and have a self-ignition temperature of approx. 430 °C. With additives, they can meet strict fire safety standards.

2. Water-repellent and breathable at the same time

Silicones are hydrophobic, which means they are highly water-repellent. As a result, they repel not only water, but also oil and dirt. This keeps the treated fabric dry and clean for longer. A silicone coating can be developed in such a way that the fabric still retains its vapour permeability. This is a crucial property for applications in sports and workwear where comfort is very important. Even with intensive use, the fabric remains comfortable. Even thin silicone coatings make fabrics waterproof (resistant to water columns >10 m according to EN 20811).

3. Flexibility and elasticity

Silicones are naturally very stretchy without tearing or ageing. This makes them perfect for various applications where textiles are often under tension or movement. Think of applications in conveyor belts, airbags, protective covers, etc. They can also be used as a coating for stretchy textiles (such as ELASTAN®) without loss of elasticity or functionality.

4. Chemical inertia and durability

Silicones hardly react with other substances. They are resistant to chemicals, oils, fats and acids. This allows them to maintain their performance in harsh industrial environments. In addition, silicones age slowly: their coatings have a long service life with little maintenance.

We can significantly improve the wear resistance or abrasion resistance of silicone by adding fillers, optimising cross-linking or using combination coatings in which the silicone layer is reinforced with, for example, a PU top layer. In this way, the material enjoys the advantages of silicone (flexible, weather-resistant, inert) and is also more resistant to mechanical wear.

5. Wash resistance

Silicone coatings are known for their excellent adhesion to a wide range of textile fibres, including polyester, cotton, polyamide and elastane. During the curing process, the silicones form chemical bonds with the surface of the fibres. This creates a very stable bond that is resistant to mechanical stress, water, detergents and temperature differences during washing. This wash resistance is crucial in applications such as sportswear, medical textiles and workwear.

6. Anti-slip properties

Silicone coatings are often used to give textiles an anti-slip or grip function. Due to their soft, rubbery structure, silicones provide a high coefficient of friction on the surface without making the material feel hard or stiff.

Silicone coatings at Finipur: expertise and customisation

Developing silicone-based coatings requires specialised knowledge and precise process control. At Finipur, we have advanced production lines and R&D support to formulate coatings that precisely meet our customers' functional requirements. Below, we discuss some areas of application in which Finipur has been active in recent years with regard to the use of silicones in coatings :

• For an industrial (nuclear) application, our customer was looking for a coating that could withstand very high temperatures and therefore had to meet high fire standards. Our R&D team developed a silicone coating that we could apply to the glass fabric to be treated. The coating was applied to the substrate, the glass fabric, using a squeegee coating technique.
• We also had a project involving the coating of a spacer/3D mesh fabric with silicone. In this case, it was important that the breathability was retained. It was to be used in a location subject to high wear and tear, so wear resistance was the most important property in this case.
• For a project involving façade and roof cladding, the customer requested a moisture-variable vapour barrier and airtight layer on the substrate, which was to be used as façade cladding. In this case too, durability, weather resistance, water repellency, etc. were very important.

Silicones therefore offer exceptional added value in textiles and technical textiles: they increase the durability, comfort and performance of materials in a wide range of sectors. Contact Finipur to ask your question or discuss your project.