What determines the quality of tarpaulin? is the tarp material, thickness, mesh count, denier weight, lamination process, and stitch reinforcement. Generally speaking, the materials used to make tarpaulins are as follows:
1. Polyethylene. These covers are made from woven polyethylene terephthalate (PET) mesh or scrim. They are coated with polyethylene or polyvinyl chloride (PVC) film laminates. Poly tarps range in mass from light to heavy.
2. Vinyl. These tarps are made of PET and PVC scrim, double-layered with PVC film laminate. Often used for grain trailer covers, vinyl tarps are heavier, more expensive, and durable in their service. In terms of price, they can be 2 to 10 times the size of a polyethylene tarp of relative size.
3. Canvas. This is the tarp your grandfather or great-grandfather used to use. Made from highly durable plain weave fabrics, these tarps have largely been replaced by vinyl tarps as trailer covers. However, these extra-heavy and highly durable mulches still have their place on farms.
The actual thickness of the tarp is measured in mils (1 mil is 1/1,000 of an inch). The higher the number, the thicker the tarp. Lightweight tarps are 5 to 6 mils. On the other hand, heavy-duty tarps can be 20 mils or thicker. The weight of the tarp, expressed in ounces per square yard, is a real testament to its quality. For example, vinyl tarps are two to three times as heavy as light- or medium-weight polyethylene tarps. Weight alone isn't a complete indicator of quality, however, but it does indicate that the tarp has a denser weave count and thicker thread used to make the scrim.
The scrim or mesh of the tarp has a weave count, which is listed as threads per square inch (PET or PVC) placed vertically and horizontally. For example, a 12×12 braid counts 12 threads per square inch in both directions. The higher the weave number, the heavier the tarp, and the more tear-resistant it is. Daniel is a measure of the thread weight (grams per 9,000 feet of thread) of the scrim used to make the tarp. The larger the denier, the more resistant the tarp is to tearing and abrasion. Denier is also known as the linear quality of a tarp.
Most tarps have coatings that help them resist UV degradation. These treatments include hindered amine light stabilizers (HALS), butylated hydroxytoluene (BHT), and carbon black. Polyethylene and vinyl coatings on tarps are naturally waterproof and are also resistant to mildew and rot. The vast majority of tarps do not contain flame retardants. If you need flame retardancy, ask for a flame retardant-treated tarp. Finally, the awning cloth is made with an additional layer of black polyethylene to create a light-blocking material.
Seams on laminated tarps should be sewn and heat sealed to prevent leaks. A good hem ensures the stability of the tarp. The preferred hem is a wide seam, containing at least two rows of lockstitches with five to six stitches per inch. A higher-quality tarp will have extra reinforcement around its perimeter to help prevent tearing. Reinforcement may include perimeter rope and grommet reinforcement.