Preforms are made by a pet injection molding machine. Beverage bottles, mineral water bottles, oil bottles, cosmetic bottles, plastic packaging boxes, and so on, which are often seen in daily life, are made of preform blow molding.
A water bottle manufacturing machine is a piece of equipment that processes molten plastic through a mold. Before using a pet injection molding machine to process raw materials, you first need to customize injection molds of pet preform. Inject the molten plastic raw materials into the pet preforms mold through the pet injection molding machine, resulting in the pet preforms product.
The application of bottle preform making machine:
Beverage industry: PET bottle blanks for the production of carbonated beverages, bottled water, fruit juices, etc.
Food packaging: PET bottle blanks for the production of edible oils, condiments, etc.
Personal care and cosmetics: PET bottle blanks used to produce shampoo bottles, lotion bottles, etc.
Pharmaceutical packaging: PET bottle blanks for the production of pharmaceutical bottles, etc.
Chemicals and petrochemicals: PET bottle blanks for the production of various chemical products.
Below we will focus on what is a pet injection moulding machine. 5 Steps for PET bottle production process, blow molding machine, and pet preform making machine/pet preform mold price.
What is the process of making preforms?
5 Steps for the PET bottle production process:
- Step1: Designing and manufacturing the preform mold
- Step2:: Injecting the plastic into the preform mold
- Step3: Cooling the preform mold
- Step4: Blowing preforms into bottles
- Step5: Testing for PET bottles
The manufacturing process of PET preform involves several key steps, including raw material preparation, injection molding, cooling, and blow molding. The following is the detailed pet preform manufacturing process production process:
The PET pellets are first dried and usually dried at a temperature of around 40°C for about 10 minutes. These dried PET pellets are then fed into the hopper via a vacuum-sealed conveyor system. Mix PET granules with masterbatch and other auxiliary materials evenly, usually at a temperature of 70°C~80°C for 6~10 minutes to ensure that PET granules are heated evenly. The mixed PET material is fed into the injection molding machine and injected into the mold at high temperature and pressure to form a tubular preform.
The production of preforms requires a preform injection molding machine and a mold, the plastic is melted and injected into the preform mold, and when the plastic in the mold cools down, the preform product is ejected by opening the mold. Turning preforms into bottles requires one more process – blow molding. Blowing up the preforms with a blow molding machine results in the final bottle product.
Step1: Designing and manufacturing the preform mold
(1). The first step in the design and production of a mold is to define the size of the neck of the preform, the weight, and the output each day. With this information in hand, we will design
(Preform Drawing)
(Preform mould)
The injection mold consists of two parts: the moving mold and the fixed mold.
The molten PET material is hydraulically injected under pressure into the mold to cool and form, and after the mold is opened, pet will be obtained. Different sizes of pets require different molds.
Common preform sizes are 28mm, 30mm, 48mm, 120mm, and more. And we have 12,16,32,36,48,72 Cavities Mold. We ultimately customize the mold according to the size of your preform.
(2). After the customer has negotiated the product information of the preform, our designers start to design the molds, and after the molds are completely designed, we start to manufacture them.
(3). After making the molds, we test them thoroughly. Like checking the cooling system, geometry, surface roughness, common indentations, etc.
Step2: Injecting the plastic into the preform mold
Before making plastic bottles, use an injection molding machine to produce the preform. And melting the plastic, a screw mechanism injects the molten PET plastic into a preform cavity in the shape of a preform. PET preforms are much more compact than fully molded bottles.
Step3: Cooling the preform mold
Inject and fill the plastic to the preform mold cavities. Cooling and shaping the product inside the mold. After cooling, the preforms are hard enough to be ejected from the mold.
However, the point to note here is that if the cooling effect is not good, the preforms will appear to be whitened. If the injection pressure is small, with low injection speed, the first injection fails to fill the cavity, the first injection of the material flow front will be because of poor contact with the mold wall so that the temperature does not fall below the glass transition temperature, thus forming a large number of nuclei.
Step4: Blowing preforms into bottles
The process of blowing the preforms made by the injection molding machine into bottles is called blow molding.
Place the preform in a blow mould. Inject compressed air into the preform to inflate it until it is close to the cavity wall, and maintain the blowing pressure until the bottle cools.
Step5: Testing for PET bottles
Rigorous testing of PET bottles on the production line is the final step before packaging to ensure compliance with industry standards. Tests include:
- Impact Test
- Pressure Test
- Permeability test
- Transparency check
Manufacturers also test the final product before packaging and shipping it to its final destination to ensure consistency in size, shape and finish.
Haichen’s specialized PET Preform injection molding machine
As an injection molding machine factory with rich experience and mature PET preform cases, Haichen’s preform machines export to many countries. We have bottle preform injection molding machines from 170T to 600T specialized in making bottle preforms.
We can provide you with professional advice and solutions, including the selection of pet bottle machines and precise customization of molds. Our PET injection molding machines have helped many factories achieve success through efficient production.
Preform Injection molding machine units
- Full computer control system for preform making machine
PET computer control system: The computer control system consists of a highly reliable computer, various control modules with reliable performance, motor drives, and various sensors. Handle every detail line more precisely.
- Ultra quiet hydraulic circuit for PET machine
- Stable high-speed, high-pressure compression injection for high-precision and high-density forming of preform products.
- Real-time injection process curve display
- Enlarged preform mould clamping stroke to meet the requirement of larger stroke.
- Set the 4 levels of injection speed, 3 levels of holding pressure, and 4 levels of metering stage set according to product requirements.
- Optimized platen design with cast elbow joints together with the platen improves the rigidity of the mechanical system and hence the dimensional accuracy of the PET product.
- Screws and barrels are made of high-quality new materials, which prolongs service life.
- We source all hydraulic components and seals from internationally renowned manufacturers.
Successful PET Preform cases
We have many successful cases of preforms.
Case1:Size: 28 mm 12g
Material: PET
Cavities: 32 cavities
Machine: HCK 250
Cycle time: 14s
Case2: Size: 83 mm 60g
Material: PET
Cavities: 4 cavities
Machine: HCK 200
Cycle time: 27.5s
Haichen has more than 20 years of experience in this field, and we have well-trained workers, experienced engineers, and service teams to manufacture molding machines. We can provide each customer with professional advice and machine tooling options. Come and consult us.
