The Impact of Hot and Cold Lamination on the Breathability of PVC Fabrics

The Breathability Problem of PVC Fabrics

PVC (polyvinyl chloride) is a polymer material with tightly arranged molecular chains, making it almost impermeable to air at room temperature. Traditional PVC fabrics, due to their lack of porous structure, tend to be stuffy and prone to odor buildup when worn or used, especially in summer or high-humidity environments.

Core reasons for insufficient breathability

Dense molecular structure: Strong intermolecular forces in PVC make it difficult for gases to penetrate.

Limitations of coating processes: Traditional coating processes (such as hot and cold lamination), if not designed with pores, will further block air permeability channels.

Hot Lamination Process

The hot lamination process involves melting PVC paste at high temperatures (usually 150-200℃) and then laminating it to the base fabric, forming a dense coating. The key to optimizing its breathability lies in foaming technology and pore design:

The role of foaming agents:

Using AC powder foaming agents with a fineness of 5-8 microns and a decomposition temperature controlled at 180-220℃, uniform micropores (pore size 100-500 microns) can be formed, allowing air to pass through but blocking water.

Higher foaming ratio results in higher porosity and stronger breathability, but a balance between strength and breathability is needed.

Practical application examples

Functional clothing (such as miner's uniforms) uses the hot lamination process to improve breathability through foaming pores while maintaining waterproofness.

Cold Lamination Process

The cold lamination process does not require high-temperature melting; it directly laminates the PVC film to the base fabric using adhesive. Its breathability is limited by the following factors:

Adhesive permeability

If the adhesive penetrates the base fabric fibers, it may block natural pores, reducing breathability.

Low-viscosity, high-permeability adhesives should be selected, or breathability additives should be added to the adhesive.

Coating thickness control

An excessively thick cold-laminated PVC film will completely block air permeability channels. A thickness of 0.1-0.3mm is recommended, along with the design of a microporous structure. Practical Applications and Recommendations

Outdoor Gear:

Tents and raincoats utilize heat-sealing technology, achieving "waterproof and breathable" properties through foamed pores, and incorporating antifungal agents to extend their lifespan.

Functional Clothing:

Athletic wear uses cold-laminated PVC film paired with a breathable base fabric to prevent stuffiness.

Home Decor:

Furniture PVC coatings use embossing techniques to increase breathability, reducing the risk of mold in humid environments.

Conclusion

Heat-sealing and cold-laminating processes have their own advantages and disadvantages regarding the breathability of PVC fabrics: heat-sealing more easily achieves high breathability through foaming technology, while cold-laminating requires overcoming limitations through adhesive and structural design.