Evaluation of Plastic Waste Management in Thailand Using Material ...

Table 2.3 Plastic Formation Processes and Its Raw Materials and Products in
Thailand (PIT, 2013)
No. Formation process Raw material Product
1 Blow molding PP, PE, PET, HDPE Shampoo bottle, oil tank
2 Stretch blow molding PET, PP, HDPE Water bottle
3 Injection molding PP, PE, HDPE, ABS, PS, PC Housewares, automotive
parts, electronic devices
4 Blow film extrusion HDPE, LDPE, LLDPE Carrier bag
5 Film extrusion PP, PE, LDPE, HDPE Thin film, adhesive tape
6 Sheet extrusion PP, PE, PS, PMMA Sheet, document case
7 Pipe/tube extrusion PVC, PE, PP Water and wastewater pipe
8 Profile extrusion PVC Rigid, HDPE Window frame, rain gutter
9 Rotational molding PVC, HDPE, PP Water tank, bin, box
10 Thermoforming PS, PE, PP, PET Food tray, water cup
11 Laminating PE, PP Snack bag, multilayer bag
12 Tape yarn/filament PP, HDPE, PA6, PA66, PET Woven sack, jumbo bag
13 Compressed molding Melamine Kitchen sets
From the above Table, each formation process is different and consists of the specific
machine and technical operation. The details of the major plastic formation processes are
described as below:
1. Blow molding: First, the plastic resin is melted at the extruder by heat from the
electrical heater. Second, the screw compress the liquid/melted plastic throughout
the die head, and then the parison will be generated from the die head. This step
based on the movement between screw and open-closing of mold with the
hydraulic system. Third, the mold adjacent and blow the parison until fulfilling the
parison in the mold. Finally, cooling water from the chiller are used to make the
products set followed by the mold. Figure 2.2 presents the blow molding process.
Figure 2.2 Blow molding (PIT, 2013)
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