Extrusion molding of plastic mesh, plastic tape and cable material
DATE：2022/10/31 8:43:04 / READ： / SOURCE：This station
Extrusion molding of plastic mesh, plastic tape and cable material
Polyethylene meshThe extrusion molding of plastic wire mesh is different from that of plastic wire mainly depending on the special structure of the molding die. The forming method of wire mesh is as follows: when the plasticized molten material in the extruder barrel is pushed into the forming die by the rotating screw, the molten material is divided into multiple molten material flow wires because the die surface of a pair of internal and external dies in the die that can relatively rotate are respectively provided with grooves with the same number and section shape (the spacing of grooves is the same, and the section shape can be semicircle, triangle or shape); When the rotating inner and outer dies are turned to the junction of the two die runner, the two wires are bonded together to form a net knot, and when they are separated, they become net wires; The inner and outer moulds rotate continuously to form a circular net cylinder. As shown in Figure 10-1), it is the schematic diagram of the cylinder mesh molding wire mesh. In addition, there is also a kind of forming mold that is divided into two halves to form a flat structure, as shown in Figure 10-1 (b). The wire mesh formed by the mold with this structure also depends on the parallel left and right movement of the upper and lower templates with grooves to form the wire mesh, but the wire mesh is flat. The cylindrical screen formed by the first mold is also flat if not opened.
The plastic mesh is non-toxic, light, material saving, and has good strength. It can be made into various colors. It is easy to shape, and the price is also very cheap. Therefore, it is widely used in the packaging of various foods, toys, bottles of wine and mechanical parts, and can also be used as shopping bags for fish and silkworm breeding.
(1) The raw material for silk type is low density polyethylene tree finger. For example, D025 grade MFR=025g/10min), Z045 grade (MFR-045g/10min) and Q200 grade (MFR=2.0g/10min) resins produced by Sinopec Shanghai Petrochemical Co., Ltd; It can also be mixed with LDPE and HDPE resins
(a) Cylinder net mold (b) plate net mold
1 - Internal network model; 2 - external net mold 1 - upper plate net mold; 2 Lower plate net mold
Figure 10-1 Forming principle of plastic mesh
(50% each) type raw materials; The process of imported equipment requires the use of high-density polyethylene resin, such as 5000S (MFR-0.9g/10min) produced by PetroChina Daqing Petrochemical Complex and DEMA6158 (MFR-07~11g/10min) produced by Sinopec Qilu Co., Ltd.
(2) Production Process Sequence of Extrusion Molding Wire Mesh
Polyethylene resin pigment and some auxiliary materials → mix evenly → extrude the raw materials into a molten state → mold shape the screen blank → stretch the screen blank in water for shaping → traction → cut open the barrel shaped screen to form a flat screen (or not) → coiling If the screen needs to be stretched, a drafting hot water tank shall be added after the traction process, and then cut open the coiling process after the shaping heat treatment.
The production process sequence of plastic round screen extrusion molding is shown in Figure 10-2.
Figure 10-2 Equipment for Plastic Round Mesh Extrusion Molding
1 - Extruder; 2 - Forming mould; 3 - Stretching cylinder; 4 - Water tank; 5, 7-traction roll;
6 - Sectional spreading device; 8 - Guide roller; 9 - Coiler
Figure 10-3 Equipment for Plastic Flat screen Extrusion Molding
1 - Extruder; 2 - Forming mould; 3 - Cold air cooling device; 4,6,8-traction roll; 5 - Water tank; 7 - Oven; 9 - Coiler
The equipment for flat screen extrusion molding is shown in Figure 10-3
Author：admin