Pet Preform Machine

PET preform machine series is specially designed and manufactured according to PET material molding technology, such as special design of screw and cylinder, precision controller for cylinder heating, pull rod space, nozzle, injection system,amplification motor and oil pump. Our ZOWEITE® PET preform machine is widely used in different PET molding products, including PET water preforms, soft drink bottle preforms, edible oil bottle preforms, 3 gallon and 5 gallon PET preform, etc.

Precautions for injection molding of PET preform machine

1. Treatment of plastics.

Because PET macromoleules contain lipid groups and have certain hyfrophilicity, the pellets are sensitive to water at high temperature. When the water content exceeds the limit, the molecular weight of pet decreases during processing, and the products are colored and brittle. Therefore, the materials must be dried before processing. The drying temperature is 150 ℃ for more than 4 hours, generally 170 ℃ for 3-4 hours. The air injection method can be used to check whether the material is completely dry. Generally, the proportion of recycled materials shall not exceed 25%, and the recycled materials shall be dried thoroughly.

2. election of PET preform machine

Due to the short stabilization time after the melting point and high melting point of pet, an injection system with more temperature control sections and less self friction heat generation during plasticization shall be selected, and the actual weight of the product (water containing mouth material) shall not be less than 2 / 3 of the injection volume of the machine.

3. PET preform machine mold and gate design

PET bottle embryo is generally formed by hot runner mold. It is best to have a heat insulation plate between the mold and the injection molding machine template, with a thickness of about 12mm, and the heat insulation plate must be able to withstand high pressure. The exhaust must be sufficient to avoid local overheating or fragmentation, but the depth of the exhaust port shall not exceed 0.03mm, otherwise it is easy to produce flash.

4. Melt temperature

5. It can be measured by air shooting method. 270-295 ℃, and the reinforced gf-pet can be set to 290-315 ℃.

PET preform machineInjection speed

Generally, the injection speed should be fast to prevent premature solidification during injection. However, too fast and high shear rate make the material fragile. The ejection is usually completed in 4 seconds.

6. PET preform machine Back pressure

The lower the better to avoid wear. Generally not more than 100bar. Usually not required.

7. Retention time

Do not use too long residence time to prevent molecular weight reduction. Try to avoid temperatures above 300 ℃. If the shutdown is less than 15 minutes. Only air shooting is required; If it exceeds 15 minutes, clean it with viscosity PE and reduce the barrel temperature to PE temperature until it is started again.

8. Precautions

a. The recycled material shall not be too large, otherwise it is easy to "bridge" at the blanking place and affect the plasticization.

b. If the mold temperature is not well controlled or the material temperature is not properly controlled, it is easy to produce "white fog" and opacity. The mold temperature is low and uniform, the cooling speed is fast, and the product is transparent if there is less crystallization.

ZOWEITE® have 30 years experience in this industry, id you are a novice or not have more experience in PET preform machine production, we can also help you completer the Turn-key project, including machine, mold, plant design and auxiliary equipment.

According to material properties and molding requirements of PET, our experienced engineering team has specially designed PET preform machine for application. Its mature design meet all customers of PET preform machine production. Also ZOWEITE provide production line test service. When the customer’s machine is completed, we will arrange to test the production in the our factory before shipment. Customers can also come to the site to watch and check the trail operation of the mold. If the customer cannot come, we will also help take clear photos and video of test , and then send them to the customer for inspection.