Polypropylene (PP) woven bag coating special material preparation technology

1.Application and Preparation Introduction: Polypropylene coating special material is mainly used for the coating of polypropylene woven bag and woven cloth. The woven bag made by coating does not need to be lined with a polyethylene bag and can be used directly. Due to the direct application of the polypropylene flow-through film to the woven bag, the strength and overall performance of the woven bag are increased, and the use of the woven bag is convenient and the manufacturing cost is also reduced. In November 1997, the National Building Materials Bureau required the construction of the word No. 079 to require cement and other products. The packaging must use laminating woven bags, and with the development of the domestic packaging industry, the scope and amount of coating-grade PP are gradually expanding. The original plastic manufacturers have purchased the production line of plastic and woven compound bags, which changed from the original PE inner bag + PP woven bags to the two-in-one covered bags and three-in-one paper-plastic composite bags, making the market demand for coating-grade PP increasingly increasing. , Domestic coating grade PP supply tighter. In view of the above situation, we used general-purpose T30S and 2401 (MFR = 2 ~ 4g/10min) as the base material, and through controlled degradation after blending, successfully developed coating grade PP special material (MFR = 20 ~ 32g/ 10 min, tensile strength 24.0 MPa). During the development process, several experiments were performed on the selection of the molecular weight regulator and other excipients, the mixing and plastification of the raw materials, and the related process parameters. After optimization and screening, the formula and production process of the PP coating material were determined. Form a production line for mass production. Through a number of applications, satisfactory results were achieved, which consistently reflected the product's stable quality, good melt flowability, uniform film formation, low shrinkage, high peel strength, and high adhesion.
2. Estimation of Economic Benefits: The selling price per ton of coated special material is higher than raw material price by about RMB 2,000. The net profit after deducting the auxiliary agent cost of RMB 150 and the artificial labor and machinery depreciation expenses can be estimated by themselves. More than 1,500 yuan. The annual output of a production line (calculated with an extruder with a screw diameter of 65) is 350-450 tons, and the annual net profit tax can be more than 500,000 yuan. If you have a large screw extruder, you're more productive. At present, there are more than 1,000 large-scale woven bag factories in China, and there are countless townships and private enterprises. The project has broad prospects. Second, polypropylene cooling masterbatch preparation technology Polypropylene cooling masterbatch is a polypropylene-based masterbatch, mainly used to reduce the polypropylene spinning and plastic products in the processing temperature, especially in polypropylene spinning Excellent results, but also for the production of polypropylene blown film, textile bags, monofilament, injection molding products, also received good results. The project won the national invention award in 1980. Polypropylene cooling masterbatch won the silver medal at the Tenth World Invention Fair in Geneva in 1986 and won the gold medal and grand prize performance index at the Eureka International Invention Fair in Brussels in the same year: Adding 1 to 5% to polypropylene resin Cooling masterbatch for processing can achieve the following: All grades of polypropylene resin can produce high-quality C-round fine denier fiber; can reduce spinning and plastic processing temperature from 20°C to 50°C; increase polypropylene fiber and The quality of plastic products; improve production efficiency; reduce environmental pollution. Applications: polypropylene spinning, polypropylene blown film, polypropylene woven bags, monofilaments.