In manufacturing, molding is a process that involves shaping a pliable material or liquid using a rigid mold or matrix. Plastic injection molding, a popular molding technique, involves melting raw polymer resin granules into a liquid and injecting them into a mold to create a desired shape. The molding process may involve varying levels of heat and pressure to achieve the desired profile.
The plastic injection molding process involves the following steps:
- Plastic resin materials are placed in a barrel.
- Heat melts and mixes the plastic, which is then injected into a mold cavity.
- Shot sizes are created to determine the volume of material injected into each mold.
- The mold closes, and the melted plastic is injected into the mold cavity.
- The material cools and solidifies while the injection molding machine prepares for the next cycle.
- The mold opens, and the part is ejected.
- The process repeats when the mold closes again.
Plastic injection molding is a versatile process used in a wide range of industries to create everything from automotive body parts to synthetic human body parts. There are several other types of plastic molding available, each with unique features and benefits. Manufacturers choose the molding process based on the application's specifications and requirements.
Some of the most common types of plastic molding include:
- Blow Molding, used to create hollow, one-piece objects like bottles and storage containers.
- Compression Molding, ideal for high-strength parts like automotive components, clothing fasteners, and body armor.
- Extrusion Molding, suited for long, hollow-formed applications like tubes, pipes, and straws.
- Injection Molding, the most versatile molding process that can create a wide variety of parts, from large automotive parts to small surgical equipment parts.
- Rotational Molding, used to create large, hollow, one-piece containers like tanks.