The different types of plastics, benefits, and applications (1/2)

In addition to the 3D product design, the injection mold, and the molding process itself, selecting the right plastic material is a critical step in creating your product. Each injection-molded item requires careful consideration when it comes to material selection.

With thousands of plastic types available, narrowing down the right choice can be a daunting task. The selected material must align with the product’s intended use and the environment it will be exposed to. Cost is also a significant factor in this decision.

Typically, engineering plastics offer superior mechanical properties, enhanced durability, and excellent performance during manufacturing. However, these benefits often come with a higher price tag. Making an informed choice in materials can lead to significant cost savings right from the start.

Below is an overview of commonly used plastics and key factors to consider when selecting a material.

Polyethylene (PE)

Advantages:
Polyethylene is widely used across industries due to its favorable properties and affordability, making it the most common plastic today. It is a flexible material that remains durable at temperatures as low as -50°C. PE is highly resistant to chemicals and absorbs very little moisture.

Polyethylene comes in two main types: High-Density Polyethylene (HDPE) and Low-Density Polyethylene (LDPE). HDPE, with its higher density, performs better at elevated temperatures and offers increased chemical resistance. LDPE, being softer, provides greater elasticity.

Applications: Lids, jerry cans, packaging, and seals.

Considerations:

• PE has low stiffness.
• It is unsuitable for temperatures exceeding 80°C.

Polypropylene (PP)

Advantages:
Polypropylene is the second most common plastic after PE. It is relatively inexpensive but offers greater impact resistance than PE. Like PE, it has strong chemical resistance and absorbs minimal moisture.

PP can be categorized into homopolymer and copolymer types. Homopolymers are stiffer and stronger, while copolymers are softer but provide better impact resistance, making them more durable under stress and at lower temperatures.

Applications: Hinges, measuring scoops, trash bins, medical pipette tubes, and fastening clips.

Considerations:

• Thick-walled products may experience sink marks with PP.
• PP has poor UV stability, limiting its use in outdoor applications.
• At low temperatures, PP can become brittle.

Acrylonitrile Butadiene Styrene (ABS)

Advantages:
ABS is a versatile plastic used in various industries such as consumer electronics and automotive manufacturing. It is valued for its ease of processing and glossy finish. ABS is a strong, impact-resistant material with low shrinkage and high dimensional stability. It resists water absorption and performs well under heat.

ABS is also highly suitable for post-processing methods like painting, coating, welding, and adhesive bonding.

Applications: Cosmetic components, LEGO bricks, car bumpers, portable devices, power tool casings, remote controls, computers, and phone parts.

Considerations:

• ABS can cause sink marks in thick-walled products.
• Flow lines, visible streaks on the product’s surface, may appear during molding and are often undesirable.
• ABS has limited UV stability.
• It is prone to stress cracking due to external pressures or exposure to heat and solvents.

What’s next?

In the next part, we’ll dive deeper into materials like Polycarbonate (PC), Polycarbonate/Acrylonitrile Butadiene Styrene (PC/ABS), Polyamide (PA), and Polyoxymethylene (POM). Each material comes with its own set of advantages, considerations, and applications.

If you need assistance choosing the best material for your plastic product, don’t hesitate to reach out! Contact us to discuss your project and ensure you make the right decision.