Polypropylene (PP) woven bag coating special material preparation technology

1. Application and Preparation Introduction:
Polypropylene coating special materials are mainly used for the coating of polypropylene woven bags and woven cloths. After being coated, the woven bags produced by the coating do not need to be lined with polyene bags and can be used directly. Due to the direct coating of the polypropylene flow-through film on the woven bag, the strength and overall performance of the woven bag are increased, and the use is convenient, and the manufacturing cost is also reduced.
In November 1997, the National Building Material Bureau established the word <1997> No. 079 that the packaging of cement and other products must use laminated woven bags. At the same time, with the development of the domestic packaging industry, the scope of use and the amount of coating grade PP have been gradually expanded. 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. Estimated economic benefits:
The price per ton of coated special material is higher than raw material price by about 2,000 yuan. After deducting the cost of 150 yuan for auxiliary agent, artificial labor for water and electricity, and depreciation for machinery, the net profit per ton of special material is 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.
Main performance index: Add 1~5% cooling masterbatch to polypropylene resin for processing; The following points can be achieved: All grades of polypropylene resin can produce high quality C-round fine denier fiber; it can reduce spinning and Plastic processing temperature from 20°C to 50°C; improving the quality of polypropylene fibers and plastic products; increasing production efficiency; and reducing environmental pollution.
Applications: polypropylene spinning, polypropylene blown film, polypropylene woven bags, monofilaments.