Injection Molding Methods

April 19, 2024

Plastic Injection is one of the most common methods for producing plastic parts.

Over the years, this process has been refined and adapted to suit various applications, leading to the development of several different injection molding methods and technologies, each one suited for different materials and may require different preparations far before the heating of any plastic.

When planning to manufacture Injection Molded Plastic Parts, it is always a good idea to be aware of the pros and cons of each technology and their usual material selection and common applications across different industries.

Here are some of the most common types of plastic molding:

Injection Molding Methods

Bi-injection molding

Bi-injection molding, also known as dual injection or two-material injection molding, is a process that allows for the simultaneous injection of..

Compression injection molding

Compression molding is one of the oldest and simplest molding techniques, especially prevalent for thermosetting materials but also used…

Expandable bead molding

Expandable bead molding is a molding process primarily used with expandable polymer beads, most notably expandable…

In-mold labeling

In-Mold Labeling (IML) is a sophisticated technique used in plastic injection molding that integrates the labeling process into the molding…

Micro molding

Micro molding is a specialized form of injection molding that focuses on producing extremely small, intricate plastic parts.

Overmolding

Overmolding is a specialized process in injection molding where a single part is composed of multiple materials, typically two, but sometimes more.

Rotary injection molding

Rotary injection molding is not a distinct molding method per se, but rather a variation of a standard injection molding machine with a rotating platen or table.

Structural foam molding

Structural foam molding is a specialized form of injection molding used for producing parts that have a cellular or foam core surrounded by a solid, outer skin.

Co-injection molding

Co-injection molding, sometimes referred to as sandwich molding or multi-material injection molding, is a process where two different…

Counter pressureinjection molding

Counter Pressure Injection Molding (CPIM), sometimes referred to as Gas Counter Pressure (GCP) molding, is a variation of the traditional…

Gas assisted injection molding

Gas-assisted injection molding is an advanced form of injection molding that uses pressurized nitrogen gas to assist in the molding of plastic parts.

Insert molding

Insert molding is a variation of injection molding where pre-made inserts, typically made of metal but can also be of other materials, are placed…

Multi color injection molding

Multi-color injection molding is a process used to produce plastic parts that have multiple colors in a single component.

Push-pull injection molding

Used for producing parts with varying thickness levels, it involves two sets of molds that move in a synchronized manner to allow varying wall thickness.

Sequential valve gating molding

Sequential Valve Gating (SVG) molding is a specialized technique used in multi-cavity injection molding. It employs a system where each gate…

Thin wall injection molding

Thin wall injection molding is a specialized molding technique used to produce plastic parts with very thin walls.

Cold runner molding

Cold runner molding is a method used in injection molding processes where the molten plastic travels from the injection molding machine’s nozzle…

Direct injection expansion molding

Direct Injection Expansion Molding (often referred to as DIEM) is a more specific molding process related to expandable bead molding…

Hot runner molding

Hot runner injection molding is a system used within injection molds to maintain the molten state of plastic from the injection molding…

Liquid silicone rubber molding

Silicone rubber molding is a process used to produce parts from silicone rubber, which is a flexible, durable, and biocompatible material.

Multi durometer molding

Multi-durometer injection molding is a specialized injection molding technique that allows for the simultaneous or sequential molding…

Reaction injection molding

Reaction Injection Molding (RIM) is a unique molding technique used primarily for producing large, complex parts with specific performance characteristics.

Standard injection molding

The standard injection molding technique is a widely used method for producing parts from plastic materials.

Two shot injection molding

Two-shot injection molding, also known as double-shot or multi-shot injection molding, is a process that produces parts by injecting…

Bi-injection molding

Bi-injection molding, also known as dual injection or two-material injection molding, is a process that allows for the simultaneous injection of..

Co-injection molding

Co-injection molding, sometimes referred to as sandwich molding or multi-material injection molding, is a process where two different…

Cold runner molding

Cold runner molding is a method used in injection molding processes where the molten plastic travels from the injection molding machine’s nozzle…

Compression injection molding

Compression molding is one of the oldest and simplest molding techniques, especially prevalent for thermosetting materials but also used…

Counter pressureinjection molding

Counter Pressure Injection Molding (CPIM), sometimes referred to as Gas Counter Pressure (GCP) molding, is a variation of the traditional…

Direct injection expansion molding

Direct Injection Expansion Molding (often referred to as DIEM) is a more specific molding process related to expandable bead molding…

Expandable bead molding

Expandable bead molding is a molding process primarily used with expandable polymer beads, most notably expandable…

Gas assisted injection molding

Gas-assisted injection molding is an advanced form of injection molding that uses pressurized nitrogen gas to assist in the molding of plastic parts.

Hot runner molding

Hot runner injection molding is a system used within injection molds to maintain the molten state of plastic from the injection molding…

In-mold labeling

In-Mold Labeling (IML) is a sophisticated technique used in plastic injection molding that integrates the labeling process into the molding…

Insert molding

Insert molding is a variation of injection molding where pre-made inserts, typically made of metal but can also be of other materials, are placed…

Liquid silicone rubber molding

Silicone rubber molding is a process used to produce parts from silicone rubber, which is a flexible, durable, and biocompatible material.

Micro molding

Micro molding is a specialized form of injection molding that focuses on producing extremely small, intricate plastic parts.

Multi color injection molding

Multi-color injection molding is a process used to produce plastic parts that have multiple colors in a single component.

Multi durometer molding

Multi-durometer injection molding is a specialized injection molding technique that allows for the simultaneous or sequential molding…

Overmolding

Overmolding is a specialized process in injection molding where a single part is composed of multiple materials, typically two, but sometimes more.

Push-pull injection molding

Used for producing parts with varying thickness levels, it involves two sets of molds that move in a synchronized manner to allow varying wall thickness.

Reaction injection molding

Reaction Injection Molding (RIM) is a unique molding technique used primarily for producing large, complex parts with specific performance characteristics.

Rorary injection molding

Rotary injection molding is not a distinct molding method per se, but rather a variation of a standard injection molding machine with a rotating platen or table.

Sequential valve gating molding

Sequential Valve Gating (SVG) molding is a specialized technique used in multi-cavity injection molding. It employs a system where each gate…

Standard injection molding

The standard injection molding technique is a widely used method for producing parts from plastic materials.

Structural foam molding

Structural foam molding is a specialized form of injection molding used for producing parts that have a cellular or foam core surrounded by a solid, outer skin.

Thin wall injection molding

Thin wall injection molding is a specialized molding technique used to produce plastic parts with very thin walls.

Two shot injection molding

Two-shot injection molding, also known as double-shot or multi-shot injection molding, is a process that produces parts by injecting…

The different materials, number of cavities, type of mold opening, and feed system are aspects that directly impact the structure of the mold itself, movable components such as sliders and automatic demolding processes may also be employed depending on the type of injection or used material.

For example, plastic injection molding automotive parts may require weather or chemical-resistant materials such as HDPE, PVC or PLA. When in comes to medical parts, plastic injection molding medical parts commonly use polyethylene (PE), Polypropylene (PP), Polystyrene (PS) and Polycarbonate (PC).

The health industry has a regular demand for plastic injection molding medical parts, in these cases each project needs to be designed to meet the challenges of industry standards, such as ergonomics and aesthetics, ruggedness, UV resistance, excellent flame and water resistance, ease of repeated cleaning and disinfection, and safety of use.

Each of these injection molding methods has its advantages and is suited for specific applications that also depends on the material properties required, the part design, production volumes, and the specific industry needs.

Choose Cindre for Plastic Injection Molding

We offer support at every step of your injection molding manufacturing program, starting from design from manufacturability all the way to creating mold tooling, prototyping, obtaining first approval, validating the process, conducting full-scale production of injection molded plastic parts.

Have Questions about Plastic Injection Molding?

Please contact us, and we shall be happy to answer them!

Injection Molding Methods

Plastic Injection Molding Methods

Injection Molding Methods

Standard injection molding

Standard injection molding

Choose Cindre for Plastic Injection Molding

Have Questions about Plastic Injection Molding?