What are the Coating Methods for PTFE Coated Fiberglass Fabric?

As a professional manufacturer of PTFE coated fiberglass fabric, Jiangsu Aokai New Materials mainly adopts dip coating and knife coating for this continuous flat product. (Traditional spray coating is not suitable for mass production due to low efficiency and high material waste.) Based on its core manufacturing technology, Aokai New Materials uses different processes for different products. The advantages and disadvantages of the two coating methods are analyzed below.

I. Dip Coating Process

Dip coating is the most traditional and widely used method for manufacturing PTFE coated fiberglass fabric.The process: fully immerse the fiberglass base fabric into PTFE emulsion for full absorption, then go through metering, drying and sintering to obtain the finished product.

Advantages for PTFE Coated Fiberglass Fabric:

· Excellent full impregnation: PTFE emulsion penetrates into every fiber of the fiberglass base fabric, realizing full inside-out encapsulation. This provides outstanding corrosion resistance and air-tightness, making it ideal for PTFE fabric used in chemical pipeline wrapping.

· Suitable for continuous production: Easy to realize continuous production. Through multiple dip-coating and sintering cycles, large quantities can be stably produced with low unit cost.

· High bonding strength: Full impregnation ensures strong interlayer adhesion and high resistance to delamination.

Disadvantages for PTFE Coated Fiberglass Fabric:

· Limited single-coat thickness: A single dip coating produces a very thin layer (only a few microns). To produce thicker PTFE fabric (above 0.2 mm), 5–10 or more repeated dip and sinter cycles are required, resulting in long production time and high energy consumption.

· Relatively average uniformity: Compared with knife coating, slight longitudinal streaks or edge-thick and center-thin variations may appear. For applications requiring extremely low friction coefficient, this may affect the uniformity of non-stick performance.

II. Knife Coating Process

Knife coating is the preferred process for high-end PTFE coated fiberglass fabric.It uses a precision doctor blade to apply a metered amount of PTFE emulsion onto the surface of the fiberglass base fabric, forming an extremely uniform coating.

Advantages for PTFE Coated Fiberglass Fabric:

· Accurate and controllable coating thickness: By adjusting the blade gap, the wet film thickness can be precisely set in one pass, and the desired dry film thickness is obtained after sintering. This is critical for products requiring strict thickness control such as food-grade conveyor belts and PTFE fabric for heat sealers.

· Excellent surface uniformity: Produces an extremely smooth and dense surface free of pinholes or streaks, ensuring highly consistent non-stick and low-friction properties across the entire width.

· High material utilization rate: Almost no splashing or dripping of PTFE emulsion; all coating material forms the film, resulting in outstanding cost efficiency.

Disadvantages for PTFE Coated Fiberglass Fabric:

· High equipment and process requirements: Requires precision coating machines, tension control systems and clean environments. Equipment investment is higher than dip coating lines.

· Sensitive to substrate flatness: Uneven weaving, broken filaments or knots in the fiberglass base fabric will be magnified by knife coating, causing local coating unevenness.

· Mainly for flat products: Only suitable for flat products like PTFE coated fiberglass fabric, not for 3D workpieces — which is not a problem in PTFE fabric production.

Summary

· Dip coating is preferred for high continuous production efficiency and cost advantages.

· Knife coating is better for superior coating uniformity and precise thickness control.

In practice, Aokai New Materials uses a combined dip + knife coating process:First, dip coating ensures full PTFE encapsulation of fibers; then knife coating achieves a perfect surface. This combines internal strength and surface performance.

The above information is provided by Jiangsu Aokai New Material Technology Co., Ltd.

For more details about parameters, applications and custom solutions of our full product line including PTFE coated fiberglass fabric, PTFE high-temperature tape, PTFE high-temperature mesh belt, laminating machine seamless belt, single-sided PTFE fabric, high-temperature resistant conveyor belt and high-temperature resistant fiberglass cloth, please contact us:

· Service Hotline: Mr. Guo 18944819998

· Mr. Liu 13705266308

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