Pet Blow Molds

Summary: Injection-stretch blow molding Injection-stretch pet blow molding machines have two basic processes: Single stage a...

Injection-stretch blow molding

Injection-stretch pet blow molding machines have two basic processes: Single stage and double stage processes. Both methods utilize a series of three or four station machines to complete the process. The single stage process is the most common type of PET stretch blow molding machine, but there are other options available.
The process of injection-stretch pet blow molding involves the preblowing of a PET preform. After this, the PET preform is stretch-blown into a bottle in a blow mold. The stretch-blow process then imparts heat resistance to the PET bottle.
Injection-stretch PET blow molds are available in a variety of sizes and shapes. The preform is a small tube, bottle, or vial. After initial molding, the preform is rotated 90 degrees and heated to a specific temperature. Constant heating reduces the elasticity of the preform and creates a void. Injection-stretch PET blow molds are ideal for making PET bottles.
Two-stage stretch blow molding is also an option. The first stage uses a telescoping mandrel and a core pin to form a preform. The second stage involves filling the preform with plastic. Once the liquid is filled, the preform is transferred within the mold. The finished product is then cooled and removed.
Stretch blow molding uses polymers and preforms to create hollow objects. After injection, the preforms are heated and stretch into the final shape.
Continuous blow molding
Continuous pet blow molding requires a continuous flow of air through pneumatic valves, which have to function within milliseconds. Typically, blow molders have six pneumatic valves, referred to as pre-blow, high-blow, recovery, exhaust, and air sweep. These valves must be clean and free of debris because leaks can affect the final product shape and size.
Continuous pet blow molding is most effective for small and medium-sized products. It requires less investment and is relatively simple to operate. For larger products, however, plastic with the right viscosity and melt strength is essential. This ensures that the product will not sag, which could have a negative impact on quality. Continuous blow molding is also suitable for heat-sensitive plastics, such as PVC. It also has a short cycle time, which minimizes the possibility of degradation or undesirable curing.
The process of continuous PET blow molding starts with a designed preform. This preform should be designed to match the finished bottle's dimensions. The material must also be properly heated and conditioned for optimal results. Once the preform has been conditioned, it is placed inside the blow mold. The blow mold will then introduce low pressure air that will cause minimal initial expansion.
PET is a polyester material that is commonly used in blow molding. It is used for making water and soft drink bottles. The recycling rate of PET is rising. PET is also recyclable in the recycling code, making it a good choice for many industries.
Integrated two-stage process
The Integrated Two-Stage Process is an innovative way to manufacture PET bottles. Previously, PET bottles were only made using single-stage machines. In this process, the preforms are injected into a special machine, which is then stretched and blown into a bottle. The two-stage process has advantages and disadvantages, and the two machines should be used according to your production needs.
The first step of the process involves creating a preform made of PET or a similar material. The second step involves producing two walls, one made of virgin PET material, and the other from non-contaminated PET material. This inner wall acts as an insulating barrier. The outer wall may also be made of recycled material.
The Integrated Two-Stage Process involves two processes, one of which involves filling and another for stretching. In the filling phase, the PET bottles are heated up to 260°C, while during the stretching stage, they are heated using infrared light. The two-stage process is a very efficient way to produce PET bottles, as it can reduce the costs of the production process.
After a batch of preforms has been filled, they are passed to the stretch blow mould machine. Then, the preforms are reheated to the proper transition temperature. The non-expandable part of the preform is shielded from the reheat process, such as the ring or stem. The temperature transition zone is likely to be in the region 30 and 31 in FIGS. 5A and 5B.