blow molding
Blow molding
Manufacturing process to make hollow plastic shapes, internal hollow is made with blowing gas (low pressure gas, ~less than 10atm)
(same method is used to make glass bottles)
Types for blow molding
Type is decided how to make parisons.
Parison: preformed plastic shape to form a final product
Injection blow molding
Premade parison using injection molding
Parison preparation
Parison using injection mold
Blow molding
Hot parison method
Cold parison method
Direct continous process
Parison using injection mold
Blow molding
Stock
Production rate: Injection molding >> Blow molding
Injection stretch blow molding
Mechanically stretching & blowing
Single stage (hot parison method)
Two stages (cold parison method)
Single(hot parison) vs Two stages(cold parison)
Single(hot parison)
Two stages(cold parison)
-Energy efficient
-Longer production time
-Diversity in supply chain
-Energy inefficient
-Large quantity of products
Extrusion blow molding
Parison: preformed plastic shape to form a final product
Extruder
Gas line
Die
Hollow tube
Gas line
Extrusion blow molding vs injection blow modling
Extrusion blow molding Injection blow modling
-Large product
-Delicate/complex product
-More hollow
-Process time is shorter
-Can make it stronger (using high quality of polymers)
Multi-layered structures?
Multi-layered blow molding
Extruder for extrusion blow molding
Vinyl bag?
Inflation without mold
Reviews
Blow molding (by preparation of parisons)
-Injection blow molding
-Hot parison
-Cold parison
-Injection stretch blow molding (mechanical force+gas)
-Single stage (hot parison)
-Two stages (cold parison)
-Extrusion blow molding
-Multi-layered structure
-Inflation without molds