Injection blow molding is the production plastic products The first step will be plastic The bottom of the parison and the parison are formed when the plastic is injected around the core of the preform, and the parison is conditioned at the temperature and then the parison is moved to the In the blow mold, the air is introduced through the mandrel to blow the parison into the shape of the mold, and after the bottle is finished, it is transferred to the discharge section.
The advantages of injection molding blow molding are many:
No scrap, size is accurate, the bottle is made without secondary processing.
The weight accuracy of the finished bottle can be controlled in soil 0.l grams.
The shape of the bottle and the shape of the bottle inside and outside the forming accuracy of up to ± 0.004 inches.
The weight and size of the bottle are suitable for matching and are easily connected to the filling line.
Due to a certain degree of biaxial orientation, can make a variety of different materials to improve the transparency and strength in the discharge section of the bottle controlled by a certain direction, which can be automated online decoration and filling the operator's workload is very small The
equipment
With the existing injection molding machine for the production of profitable plastic bottles, the size and shape of the bottles are limited. There are several types of injection blow molding machines available on the market. They are transferred from one section to another , Which are of the same type as those of the three or four rotary rotors. Can be divided into two categories: the blow molding assembly components, this component can be installed in some industrial injection molding machine; and complete sets of injection blow molding equipment, with a plastic mill, hydraulic devices, control devices and other supporting parts These devices can be further divided into: with vertical reciprocating screw mill, and with a horizontal reciprocating screw mill.
The vertical type is much simpler than the reciprocating type. When the injection volume is the same at the same filling speed and lower injection pressure (if necessary), its components are small, the energy consumption is small, the area is small and the maintenance is simple.
Reciprocating screw mill is mainly developed for injection molding; although its structure is more complex than the vertical, but the reliability of the operation is better.
The current molding machines, including large standard production units, can produce larger bottles at higher production speeds; the perfection of the injection device makes the PVC and acrylic resin easy to process; ) Development work is continuing.
Often, the pharmaceutical industry and the cosmetics industry are 16 centuries and smaller injection molding blow molding plastic bottles market. Specifically developed for this process raw material Has been made into the injection molding plant to enter other markets.Polypropylene copolymer processing is easy, transparent, and forming fast, it has actually replaced the cough with cold medicine and mouthwash glass bottles.
Other new resins are injection molded blow molding grade PVC homopolymers and polycarbonates. These crystalline transparent materials have been relatively easily machined on vertical screw machines and also on horizontal screw machines with continuous plunger screws Processing.
The new streamlined manifolds with improved acrylonitrile-containing resins and polyvinyl chloride resins have made multi-chamber operations a reality, although these resins are thermosensitive. A 8-chamber mold has been successfully used for PVC processing, Several 12-chamber molds have been used in the production of acrylic-containing resin bottles.
Several companies are using the production of PVC bottles with 8-chamber molds, which are modified to reduce their heat sensitivity.It is now evident that larger machines, higher mold clamping pressures and The larger platen area will be able to economically produce plastic bottles up to 4 liters. The advantages of precision bottlenecks and no scraps will be able to gradually compensate for the higher costs of tooling.
Due to the development of the machine (the number of segments) and the innovation of the mold design, the future development work will focus on the improvement of the orientation of the resin. The progress of the mold design technology has been able to manufacture the plastic bottles, With a precision groove, and reduce the thickness of the entire bottle wall, shortening the production time.
The development of mold design will make injection molding gradually into the home chemicals, toys, especially plastic products Food container market.