Is coated webbing waterproof?

The short answer is “yes“ – coated webbing is inherently waterproof. But understanding ”why“ and ”to what extent“ requires a closer look at how this versatile material is constructed and the different coating options available.

Coated webbing is a composite material that combines a strong inner fabric core – typically made of high-strength polyester or nylon – with an outer layer of polymer material applied through an extrusion or coating process. This outer layer creates a seamless, non-porous surface that completely seals the fabric fibers, effectively preventing moisture from penetrating the internal structure. Unlike traditional woven webbing that absorbs water like a sponge, coated webbing repels liquids and remains dry even in wet conditions.

The waterproof performance of coated webbing depends primarily on the coating material used. The three most common options are TPU (thermoplastic polyurethane), PVC (polyvinyl chloride), and silicone.

TPU coated webbing is widely regarded as the gold standard for waterproof applications. TPU's molecular structure provides inherent waterproof properties while maintaining excellent elasticity, flexibility, and tear resistance. The TPU layer completely seals the webbing's fiber gaps, effectively blocking moisture penetration. Whether in sudden rain or humid storage environments, TPU waterproof webbing keeps straps and handles dry, preventing mold, odors, and material aging caused by dampness. TPU also performs exceptionally well across a wide temperature range, remaining flexible from -30°C to 80°C without becoming brittle in cold or sticky in heat. It is environmentally friendly, biodegradable, and free from harmful plasticizers.

PVC coated webbing offers good waterproofing and chemical resistance at a more economical price point. Its smooth surface prevents water droplets from adhering easily. However, PVC has its limitations: it relies on plasticizers for flexibility, which can migrate over time, and it tends to become brittle in low temperatures. Under prolonged UV exposure, PVC may also discolor and lose flexibility. For general industrial binding or budget-conscious applications where extreme conditions are not expected, PVC coated webbing can be a practical choice.

Silicone coated webbing provides superior waterproofing and heat resistance, making it suitable for extreme weather conditions and demanding environments. It offers better waterproof performance than other materials along with excellent aging resistance. Silicone is also non-toxic, soft, and biocompatible, making it ideal for medical devices, infant products, and food-grade applications. The main trade-off is higher cost, which typically limits its use to high-end products and extreme environments. More and more brands of baby strollers, baby chairs and baby carriage choose silicone coated webbing for the straps.

Waterproof performance is commonly evaluated using the IP (Ingress Protection) rating system, where the second digit indicates the level of water resistance. Common ratings for coated webbing include: IPX4 (splash-resistant), IPX5 (water jet-resistant), IPX6 (strong water jet-resistant, suitable for harsh rain), IPX7 (short-term immersion resistance – can be submerged in up to 1 meter of water for 30 minutes), and IPX8 (long-term immersion resistance). For outdoor gear like backpacks and tents, IPX6 or IPX7-rated webbing is typically recommended. For pet leashes and collars frequently exposed to rain, mud, or moisture, IPX5 or IPX6-rated waterproof webbing ensures dryness and hygiene during daily use.

Take Sunmolin as an example. This Dongguan-based company is not merely a manufacturer of coated webbing; it is a professional elastomer coating extrusion solution provider. Its product portfolio covers TPU coated webbing, silicone coated webbing, PVC coated webbing, as well as TPU piping cord and TPU coated rope – a diversified product line. More importantly, Sunmolin not only offers standardized extrusion-coated products but also maintains a professional service team capable of providing full-process solutions for customers during the development and production of waterproof products – from material selection and formulation optimization to process commissioning and mass production. Whether you need a pet leash with specific hardness and texture, or outdoor equipment webbing requiring high tensile strength and weather resistance, Sunmolin can deliver practical, tailored solutions based on its accumulated expertise in elastomer coating extrusion technology.