Manufacturing Process of Plastic Containers
3 kinds of molding are used for plastic containers.
If a customer desires a sterilization /a packaging service, we will correspond to the request. Please do not hesitate to ask us.
If a customer desires a sterilization /a packaging service, we will correspond to the request. Please do not hesitate to ask us.
Injection Blow Molding
- Pre-form Molding (Injection Molding)
- The most suitable shape for a container is pre-formed by thermoplastic resin. The pre-form material is heat controlled on the area of ”elongation-desired-part”/”elongation-undesired-part”by a direct heat controller.
- Blow Molding (Stretch)
- The pre-form material is surrounded with a pair of mating-molds and a bottom-mold. When the temperature distribution of the pre-form is the most suitable state, the air is blown until the inflated pre-form touches to the inner surface of the mold. In case of stretch blow molding, simultaneous stretch is performed and
- Taking Out of Products
- After finishing the blow molding, the product is taken out from the mold. No post-process is required.
Direct Blow Molding
- Parison Molding (Extrusion Molding)
- Cyrindrical parison is molded through a die by the extrusion of plasticized resin.
- Blow Molding (Stretching)
- A parison is placed between a pair of mating-molds, and after that the upper and the lower parts of parison are closed. Then air is blown through a blow pin of which is inserted into the mouthpart until the inflated parison fully touches to the inner surface of the mold.
- Taking Out of Products
- The fully touched and stretched parison is solidified naturally to a blow-molding product. After removing the air, the mold is opened and the product is taken out.
- Post-Process
- When an unnecessary burr is generated on the product, the burr is removed from the product. As for another post-process, there is a cutting-work for the finishing.
Injection Molding
- Mold Clamping
- When a mold is clamped, the clamping is performed at low pressure and changed to high pressure just before the finish. This will make the clamping strong. This method is concerned with checking foreign substances on the surface of mold. Making the motion faster will become the causes of deformation and abrasion of the mold, we will perform the mold clamping through several steps.
- Injection (Filling)
- After finishing the mold clamping, the screw is moved forward and melted resin within the cylinder is injected to the mold. 【General Knowledge】 The injection pressure to fill the melted plastic into a mold is called“the first pressure”.
- Keeping Pressure
- After finishing the injection and filling the melted resin within the mold, the keeping pressure is performed for a certain period of time. 【General Knowledge】 The keeping pressure is called “the second pressure”. Due to putting the injection pressure to the melted resin filled in the mold, molding shrinkage will be controlled without occurring sink and bow.
- Cooling/Weight-Saving (Plasticizing)
- For the purpose of solidifying a melting plastic, cooling is performed within the mold, and at the same time plasticizing a resin is done before the next stage of jnjection molding. Due to the rotation of screw, the resin within hopper is moved to a ditch of screw and goes forward within a cylinder. Within this process, the resin is compressed with the rotation of screw. After that the resin is heated, mixed and melted by the cylinder.
- Mold-Opening, Demolding and Taking Out
- The mold-opening is performed after finishing the cooling of injection product and the plasticizing resin. Just after the mold-opening, the molding product is demolded by the demolding apparatus. Taking out the product, the whole operation of one cycle is finished.
- 【Injection Molding】
- From the cold clamping to the taking out by repetitive motion, this molding method is able to make a complicate shape in a sort period of time, cheaply by large scale production. Most of plastic products are made by this molding method.
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