5.Introduction of extrusion blowing technology, stretch blowing technology and injection blowing technology

Extrusion blowing technology, stretch blowing technology, and injection blowing technology are widely used. I hope this article can give some inspiration to friends who want to understand this knowledge.——-Vito.

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Because the injection-blown bottle is first injected out of the tube blank and then blown into a bottle, the bottle wall is more uniform, and it is brighter and has no seam line, which can better show the grade of the product. The bottom of the squeeze-blown bottle has a seam line. Points of Attention and Differences in the Development of Squeeze Blow and Injection Stretch Blown Plastic Bottles.

Difference 1. Differences in production of raw materials:
The commonly used plastic raw materials for extrusion blowing plastic bottles are: HDPE LDPE PP PVC PETG
The commonly used plastic raw materials for injection plastic bottles are: PET PP HDPE PMMA

Difference 2. Process difference:
Squeeze and blow plastic bottles without preforms
Injection stretch blow plastic bottles need to be injected first and then blow molded

Difference 3. Differences in production:
Extrusion and blowing process bottles need to be mechanically or manually removed after the mold is released, and some need to be polished and trimmed.
Injection-stretch-blow process bottles can be directly packed into boxes or carried out to other processes after they are out of the mold, without the need for secondary processing.

Difference 4. The appearance difference of the bottom of the bottle:
Squeeze-blown plastic bottle with a clamping line at the bottom of the bottle
Injection stretch blow plastic bottle, no parting line at the bottom of the bottle

Difference 5. Mold difference:
Squeeze blowing plastic bottle needs: two pairs of blowing molds, of course, sometimes one can also be made, depending on production needs
Injection stretch blowing plastic bottles need: a pair of preform injection molds (in most cases of the two-step method, the manufacturer directly purchases the preforms from the preform supplier), and a pair of blowing molds

Difference 6. The selected material application market:
1. Application of extrusion blowing plastic bottle material in the plastic bottle industry:
HDPE (low-pressure high-density polyethylene): general-purpose packaging bottles for daily chemicals such as shampoo bottles, shower gel bottles, laundry detergent bottles
LDPE (High-Pressure Low Density Polyethylene): eye drop bottles, e-liquid bottles, hose bottles, seasoning bottles, and other products that need to be squeezed
PP (Polypropylene): Food, medicine plastic bottles, more mainly injection-stretch-blow one-step method and injection molding process
PETG (the name is too long, just look it up on Baidu): cosmetic packaging bottle

If you have any specific questions about the process outlined or would like to discuss your needs in more detail,

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