December 9, 2022
Main materail of Plastic woven bags is PP or PE. The main recycled material is the admixture of PP, PE and other melt resinou. How to select material will directly effect the quality and capability of woven bags.
Can the stretch PE flat wire add 20%PP material to reduce the cost?
Normally can't add about 20% PP material, especially for screws with small length and diameter. The melting point of 5000s high -density PE is about 125℃, while the melting point of PP is about 168℃.
Add a small amount of PP to the PE raw material. During the wire drawing production process, the temperature of the middle and last section of the extruder machine barrel has reached the temperature of PE plasticization (about 230℃). At this time, the plasticized melting point temperature of PE has been reached above 125℃. PE plasticization is already very good, however, it contains a small amount of PP but it is not completely plasticized, because the temperature of the PP melting point is about 168℃, which is about 40℃ higher than the PE. Therefore, there will be PP unspecked particles in PE melts. PP unspecked particles will block the filter screen, and the wire is broken when drawing, and it is prone to broken silk when drawing.
If the plasticization temperature of the extrusion is increased, and the PP is fully plasticized, the temperature of the PE is too high.
If about 20% PE material is added to the stretched PP flat wire, it mainly controls the PP plasticizing temperature, although PE is plasticized in advance, the overall melt viscosity will be slightly reduced, but there will be no unblied PE particles and will not block the filter screen.