What Materials Are Used in Injection Moulding?

Injection moulding is a widely used method for making many different plastic products, from small medical gadgets to large car parts. It’s a quick and flexible way for product development.

But what kinds of materials are used in this process? Let’s take a closer look at the common materials that make injection moulding work.

1. Thermoplastics

Thermoplastics are the most commonly used materials in injection moulding. These plastics can be melted, shaped, and then cooled to form solid products. The best part is that they can be re-melted and re-moulded multiple times without losing their properties. Here are some popular thermoplastics:

• Polyethylene (PE): This is one of the most widely used plastics in the world. It’s known for its flexibility and strength, making it ideal for products like plastic bags, bottles, and toys.
• Polypropylene (PP): Known for its toughness and resistance to chemicals, polypropylene is used in automotive parts, food containers, and household goods.
• Acrylonitrile Butadiene Styrene (ABS): ABS is strong, durable, and resistant to impacts. It’s commonly used for making LEGO bricks, electronic housings, and automotive parts.
• Polystyrene (PS): This material is clear, hard, and brittle. It’s often used for disposable cutlery, plastic models, and CD cases.
• Polyvinyl Chloride (PVC): PVC is known for its durability and resistance to weathering. It’s used in plumbing pipes, flooring, and medical devices.

2. Thermosetting Plastics

Unlike thermoplastics, thermosetting plastics can’t be re-melted once they’ve been moulded. These plastics are permanently set into shape using heat or chemical reactions. Some common thermosetting plastics are:

Epoxy: This material is known for its excellent mechanical properties and strong adhesive qualities. It’s used in coatings, adhesives, and composite materials.

• Phenolic: Phenolic resins are heat-resistant and strong. They’re used in electrical components, kitchenware, and automotive parts.
• Melamine Formaldehyde: This plastic is known for its hardness and resistance to heat. It’s commonly used in laminates, dinnerware, and electrical insulation.

3. Elastomers

Elastomers are rubber-like materials that can be stretched and then return to their original shape. They are used in injection moulding to make flexible and durable products. Some common elastomers are:

• Silicone: Silicone elastomers are known for their flexibility, heat resistance, and non-reactivity. They’re used in medical devices, cookware, and seals.
• Thermoplastic Elastomers (TPE): TPEs combine the properties of thermoplastics and elastomers. They’re used in automotive parts, toys, and soft-touch grips.

4. Biodegradable Plastics

With more focus on protecting the environment, biodegradable plastics are gaining popularity in injection moulding. These plastics break down more easily in nature, which helps cut down on plastic pollution. Some examples are:

• Polylactic Acid (PLA): Made from renewable resources like corn starch or sugarcane, PLA is used in packaging, disposable cutlery, and medical implants.
• Polyhydroxyalkanoates (PHA): These are naturally occurring polyesters produced by microorganisms. They’re used in packaging, agricultural films, and medical devices.

What are the factors to consider in choosing the Right Materials?

Choosing the right material for injection moulding depends on a few key factors:

• Mechanical Properties: The material should have the required strength, flexibility, and durability for the intended use.
• Chemical Resistance: Some products need to withstand exposure to chemicals, so the material must be resistant to corrosion or degradation.
• Cost: The material should be cost-effective for mass production.
• Environmental Impact: With sustainability becoming more important, the environmental impact of the material is also a key consideration.

Injection moulding is a flexible process that uses different materials to make everyday products. Whether it’s thermoplastics, thermosetting plastics, elastomers, or biodegradable plastics, each material has its own special qualities.

Knowing about these materials helps you pick the best one for your product needs, ensuring the quality, durability, and fit for their purpose. If you would like to know more about injection moulding services, talk to our experts now. Send us an email at info@hlhprototypes.com  or upload your CAD file here.