I. Applicability of dimethyl silicone oil in polyester fabric coating

• Waterproof and anti-fouling (utilizing low surface tension);
• Smooth hand feel and anti-adhesion (reducing fabric friction and pilling);
• Improved weather resistance (resisting aging from ultraviolet rays and humid heat environments).

• Pre-treat the polyester fabric (such as corona treatment or plasma treatment) to improve surface activity;
• Mix with a small amount of adhesion promoters (such as organosilane coupling agents like KH-550 or KH-560);
• If curing into a film is required, use modified silicone oils with active groups (such as hydroxyl silicone oil or vinyl silicone oil) and match them with cross-linking agents.

II. Viscosity recommendation and selection basis

1. Low viscosity (50-300 cSt)

• Advantages: Good fluidity, easy to coat (suitable for dip coating or spray coating), uniform and thin film formation, and the fabric has a soft and non-stiff hand feel.
• Applicable scenarios: Scenarios with low film thickness requirements and the need to maintain fabric breathability/softness (such as light waterproofing or smoothness treatment).
• Note: A single coating results in a relatively thin film; if high waterproofness is required, multiple coatings may be needed.

2. Medium viscosity (500-1000 cSt)

• Advantages: Balances fluidity and film thickness, with strong coating operability (suitable for blade coating or roller coating). The film strength is moderate, and adhesion is relatively stable.
• Applicable scenarios: General functional coatings (such as conventional waterproofing, anti-adhesion, and weather resistance). This range is 优先推荐 for most polyester fabric coating scenarios, as it balances performance and processability.

3. High viscosity (2000-10000 cSt)

• Advantages: Thicker film formation, higher mechanical strength, and better friction resistance.
• Applicable scenarios: Scenarios with high requirements for film thickness, wear resistance, or scratch resistance (such as heavy-duty protective fabrics or industrial wear-resistant polyester fabrics).
• Note: Poor fluidity requires dilution with solvents (such as white oil or toluene, with attention to environmental protection) or high-temperature heating to reduce viscosity; otherwise, uneven coating is likely to occur.

III. Usage suggestions

1. Prioritize pre-treatment: It is recommended to first perform corona or plasma treatment on the polyester fabric surface to improve surface energy and enhance silicone oil adhesion.
2. Compatibility testing: If mixed with other resins (such as polyurethane or acrylic), compatibility testing in advance is required to avoid delamination.
3. Functional supplementation: If water washing resistance needs to be improved, amino-modified silicone oil can be selected (although not pure dimethyl silicone oil, its functionality is better); if film curing is required, mix with organotin catalysts or peroxide cross-linking agents.
4. Environmental considerations: When diluting high-viscosity silicone oil, prioritize environmentally friendly solvents (such as isoparaffins) and avoid using toxic and harmful solvents.

Summary

Dimethyl silicone oil can be used for polyester fabric coating. It is recommended to prioritize medium viscosity models of 500-1000 cSt, which balance coating processability, film uniformity, and functional stability. For thin coating or a soft hand feel, 100-300 cSt can be selected; for thick film and wear-resistant scenarios, 2000-5000 cSt is optional. Surface treatment should be optimized before use to ensure adhesion.