Stretching methods for plastic products
Containers made by stretch blow molding are better than those without biaxial orientation in terms of transparency, gloss, permeability, stiffness and impact resistance, because the increase in stiffness can reduce the wall thickness of the product. The improvement of impact resistance can reduce or eliminate the need for impact modifiers, thus achieving better economic benefits.
In the biaxial orientation process, the most important thing is to control the thermoelastic temperature and stretch ratio. According to Junk research, during the heating process of hard PVC, as the temperature increases, the strength (σB) decreases, while the elongation (ε) increases, and then decreases after passing the maximum value (εmax).
Stretch blow molding methods include two types:
Extrusion blow blow (ESB)
ESB places the extruded parison in a blow mold for pre-inflation and end sealing (bottle bottom), and adjusts it to a temperature suitable for stretching. Then the pre-inflated parison is placed Longitudinal stretching, blowing and cold setting are carried out in the forming mold.
The ESB unit is generally composed of an extruder, a parison die, a top blow mold, a forming die, a temperature regulating device and a mold clamping device. The VKI-3ESB unit introduced by the Gansu Leather and Plastic Research Institute from Baucn-feld Fisher Company produces PVC bottles.
ISB uses the injection molding method to inject DVC material into the prefabricated parison mold and cool it; after opening the mold, place the prefabricated parison in the pre-blow mold, adjust the temperature, and perform pre-inflation; then place the pre-inflated parison in It is longitudinally stretched, blown and cooled in the forming mold; it is then demoulded.
The ISB unit is composed of an injection molding machine, a top parison mold, a temperature regulating device, a pre-blow mold, a forming mold and a mold clamping device. Such as VK4-0.7 (Battenfeld Fisher), ASB-250 (Nisei), etc.
HUATAO provides blow molding equipment. Including:
Plastic Mold Equipment
Automatic Blow Molding Machine
Semi-automatic Blow Molding Machine
PS Foaming Machine
EPE Foaming Machine
PU Foaming Molded Machine
Horizontal lnjection Molding Machine
vertical lnjection Molding Machine
All-electric Injection Molding Machine
Thick Sheet Blister Machine
Thin Sheet Blister Machine
Color Plastic Masterbatch
Plastic Recycle Machine
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