Why is waterproof canvas waterproof

     Why is waterproof canvas waterproof? Canvas was originally used on sailboats as a waterproof material, hence the name "canvas". It is woven by cotton fabric and hemp fabric, with waterproof properties of a relatively thick waterproof supplies. Canvas can be divided into thick canvas and fine canvas, which are waterproof for different reasons. 

 1. Thick Canvas  

  Canvas is generally made of plain weave, only a few varieties of twill weave, warp and weft yarns are all made of multi-strand yarn. Coarse canvas, also known as canopy cover cloth, commonly used 58 (10 British branch)4 ~ 7 thread weaving, fabric fast resistance to twists and turns, so it has good waterproof performance, so it can be used for the transportation of waterproof vehicles, open warehouse waterproof covering cloth and field waterproof tent cloth. 

2. Fine canvas 

   Fine canvas warp and weft yarn is generally 2 strands of 58 ~ 6 strands of 28 (10 British /2 ~ 21 British /6), used for labor protection clothing and supplies, although this kind of canvas can also be waterproof, but the water resistance is far worse than coarse canvas. Fine canvas, after being dyed, is also used as a material for shoes, travel bags, backpacks and canvas boxes. Some of the fine canvas used to make shoes can be woven into a double layer of organization, the uppers and shoes are combined as a whole, can improve the quality of the upper. 

3. PVC canvas

   The main composition of canvas is polyvinyl chloride (PVC). Some auxiliary materials such as plasticizer and anti-aging agent are added in the manufacturing process of PVC canvas to enhance its heat resistance, toughness, ductility, etc. At the same time, the surface is coated with paste resin and a variety of chemical additives such as increasing agent, mildew proof agent, anti-aging agent, etc. It has non-flammability, high strength, weather resistance and excellent geometric stability, but also has waterproof, mildew resistance, wear resistance, durable, cold resistance, aging resistance, and other natural functions.