Plastics Business

Raw material procurement and precision molding services

List of precision molding resins we handle

Type of molding

Injection Molding

The word ‘injection’ in injection molding has the meaning of filling a substance. Injection molding is done by filling heated molten resin (plastic) into a mold. It is mainly used for molding thermoplastic resins, but is also used for thermosetting resins in rare cases. It is suitable for mass production because it can mold a variety of resin products with thin walls and complex shapes at high speed.

Applications for injection molding include small and medium-sized products such as smartphone covers, electronics housings, plastic models, bath chairs, toilet seats, and even large parts such as automobile bumpers. As it is used for molding and mass production of a wide variety of plastic products, this is regarded as a basic plastic molding method.


Blow Molding

Blow molding is a technology based on the traditional glass bottle manufacturing process, and is suitable for the production of hollow plastic products. It is also called ‘blow molding’ or ‘hollow molding’ because air is blown into the molten resin from the inside, causing it to expand.

For example, when manufacturing containers for liquids, depending on the liquid in question, a resin with gas barrier properties is used to prevent oxidation due to oxygen permeation. In the manufacture of containers for chemicals, multilayer blow molding is used, in which multiple molding materials, including chemical-resistant resins, are molded in layers.

Applications include containers for PET bottles, liquid cosmetics and liquid detergents, as well as automobile gasoline tanks and exhaust manifolds.


Extrusion molding

Extrusion molding is a continuous molding process in which heated molten resin (plastic) is literally pushed out like a cocotte. Unlike other resin molding methods, the resin is not cooled or solidified inside the mold. The molten resin passes through the die (mold), which is the extrusion port, and is molded into a certain cross-sectional shape. After it is extruded from the die, it is cooled and solidified.

Applicable products include pipes, ducts and tubes, as well as optical fibers and other wire rods, sheets used in automobiles, electrical products, and construction materials, packaging films, and surface protection films for LCD screens.

Extrusion molding is also applied to granulation of pellets, a common molding material for thermoplastics. Pellets are made by melting and mixing single or multiple material resins, extruding them, and cutting them into granules. Melting and kneading with an extruder is also an important step in pellet production when compounding fillers and masterbatches.


Extrusion molding (T-die method)

The ‘T-die method’ is a type of extrusion molding in which resin (plastic) is extruded from a die at the end of an extruder.
The T-die is also called ‘hanger die’ because its shape resembles a hanger.


Extrusion molding (inflation method)

A type of extrusion molding, specialized in forming films for plastic bags.The word ‘inflation’ means ‘expansion’: molten resin is extruded from a ring-shaped die into a thin film.
At the same time, cold air is blown in to inflate it to a certain size and form it into a bag shape. With co-extrusion, it is possible to make multi-layered films as well as single-layered ones.

In the past, molding of plastic bags made of polyvinyl chloride (PVC) was mainstream, but today, molding of plastic bags made of polyethylene (PE) is more common.


Vacuum forming and pressure air forming

In vacuum forming, a sheet or film of extruded plastic is used as the forming material. The heated and plasticized resin is placed on top of the mold, and a vacuum is created between the resin and the mold so that the resin is sucked into the mold for forming. In some cases, vacuum suction and compressed air are used together.
Since the mold can be formed with either a male or female mold, it is relatively low cost and suitable for small lot production.

Vacuum forming has a wide range of applications, from thin-walled plastic containers such as egg cartons and food trays to large products such as bathtubs, automobile dashboards and bumpers.
Smaller products can be formed continuously, but for larger products one molded product is produced per forming.


Compression molding

Compression molding is mainly used for molding thermosetting resins and is widely used because of its simple operation. The resin, filler, reinforcing material, curing agent, etc., are blended. The resin is then spread to every corner of the recess (cavity) of the molding die, and then pressed to harden and shape the product.
Compression molding is conventionally used to mold various types of laminates, such as melamine veneers, laminated tubes, and laminated rods, and more recently, laminates used as printed circuit boards and insulating materials are being used in the molding of home appliances and industrial electronics. Generally, compression molding is used with thermosetting resins such as unsaturated polyester, epoxy resin, phenol resin, and melamine resin, but it is also used with thermoplastic resins for small-scale production and for molding FRP (fiber reinforced plastic) materials. A simplified diagram of the compression molding method is shown below.


Rotational compaction

This is one of the powder compaction methods. Thermoplastic powder resin material is placed in a mold and rotated 360° in a heating furnace to melt the material evenly on the inner surface of the mold, and then cooled and solidified to obtain a molded product.

  • This method is less expensive than injection molding, blow molding, and other molding methods.
  • Moreover, the mold production time is short and the mold weight is light. Rotational molds can be made from sheet metal, casting, electric casting, machining, or a combination of these methods. We can propose a mold manufacturing method that is best suited for your product.
  • Large-volume products can be manufactured with this molding method.
  • It is also easy to change materials and colors using this method.

Request for Quotation

Please feel free to request a quotation, even for small quantities.
We will make arrangements for smooth and reliable molding.

If you have any questions, please feel free to contact us.