PVC laminated tarpaulin and PVC knife coated tarpaulin are both PVC-coated, fabric-based composite materials, but there are significant differences in their structure, process, performance, and they also have their own focus in application scenarios.
PVC knife coated tarpaulin is made of polyester filament as the backing cloth. It is high density plain or twill woven fabric. The base polyester filament has no mesh, so it has higher density. PVC paste is directly coated on the surface of the base fabric by knife scraping coating process, the coating is deeply bonded with the base fabric fibers without obvious delamination. The thickness of the coating is controlled by a precision knife squeegee, and the PVC is plasticized at high temperature to make the PVC material integrated with the base fabric, which is a more complex process focusing on the uniformity of the coating and the bonding strength.
While PVC laminated tarpaulin’s base fabric is woven mesh cloth. It is mostly polyester filament and mesh is diamond-shaped or square, aperture 0.5-5mm ranging. Mesh cloth on both sides of the film is made through the film or calendering process composite PVC film (thickness 0.1-0.5mm). The producing process is similar to a "sandwich" construction. The mesh substrate is "sandwiched" and bonded by two layers of PVC film. It's a relatively simple process with a focus on rapid mass production.
In terms of performance, the gap between the two is also large. In the aspect of tensile strength, because the base cloth of PVC laminated tarpaulin is grid-like, the strength in the warp and weft direction is not uniform, and the overall strength is medium. While the high-density base cloth of PVC knife coated tarpaulin fabric is combined with the overall coating, which has a more balanced strength and better tensile performance.
On the tear resistance, the grid node of PVC laminated tarpaulin is the weak point. That makes it is easy to be broken after the force which shows poor tear resistance. PVC knife coated tarpaulin’s coating layer and polyester base cloth are combined closely, which can withstand the external force together and shows better tear resistance.
In terms of waterproofing performance, the PVC film splicing of PVC laminated tarpaulin may have gaps, so it is easy to seep water. And the water pressure resistance is generally not more than 1,000 millimeters; the coating of PVC knife coated tarpaulin is continuous and without pinholes, so it is waterproof, and the water pressure resistance is usually more than 3,000 millimeters.
In terms of weather resistance, the PVC layer of the laminated tarpaulin is easy to age and may crack in 2 to 3 years of outdoor use; the coating layer of the knife coated tarpaulin has been treated with special treatment and has a strong resistance to ultraviolet rays, so its outdoor service life can reach 5 to 8 years.
In terms of thickness and weight, laminated tarpaulin is thinner, with a thickness of 0.3 to 0.8 mm, and lighter, with a weight of 300 to 600 grams per square meter. At the same time, the knife coated tarpaulin is thicker, with a thickness of 0.8 to 2.0 mm, and heavier, with a weight of 600 to 2,500 grams per square meter.
In terms of surface flatness, the surface of laminated tarpaulin may be wrinkled when it is laminated, and its flatness is average; the surface of knife coated tarpaulin is smoother after being scraped by the scraper and shaped at high temperature.
In the aspect of usage, because of lightweight and low cost, PVC laminated tarpaulin is suitable for scenes that do not require high strength and durability, such as temporary awnings, advertising light boxes, inflatable toys, lightweight packaging and so on. PVC knife coated tarpaulin is suitable for long-term outdoor or high-intensity use because of its high strength, waterproof and durability, such as truck covers, large outdoor tents, open storage tarpaulins, industrial tarpaulins, high-end advertisement spraying fabrics and so on.
In short, PVC laminated tarpaulin is more on lightweight and low cost, suitable for temporary or light use; PVC knife coated tarpaulin focuses more on high strength and durability, suitable for long-term outdoor or high-intensity use, the choice can be judged according to the specific needs.