At Colourhouse Masterbatch, we’re known for producing high-quality materials for industries like automotive. But did you know we help companies across multiple sectors develop innovative new products? To better support our customers, we’ve compiled answers to common questions we get from injection moulding companies and their clients.

In this guide, we’ll use an example project—a fictional outdoor plug socket with a lid—to walk you through the key considerations when purchasing materials for your next project. We hope these steps will help you make smart decisions and achieve the best results for your company.

Step 1: Choose the Right Polymer

Selecting the right polymer is the first critical step in ensuring the durability and performance of your product. Each polymer has its own strengths, so it’s important to match the material to your product’s specific needs.

Common Polymers for Consideration:

• PP (Polypropylene): Lightweight and flexible, ideal for living hinges like the socket’s lid.
• PE (Polyethylene): Strong and durable but less resistant to heat.
• PC (Polycarbonate): Tough and UV-resistant, but comes at a higher cost.
• ABS: Impact-resistant and good for solid parts, but not suited for flexible components like hinges.

From a buyer's perspective, understanding how different polymers impact your product's performance and cost is key.

Key Questions to Ask:

• Will the socket need to resist mechanical stress or impact?
• Does the product require transparent parts?
• How do you balance cost and performance for your chosen polymer?

Step 2: Ensure UV Protection

If your product will be used outdoors, UV protection is essential to prevent plastics from degrading in the sun. Without proper protection, materials can become brittle, fade, or crack.

Considerations for UV Protection:

• UV Stabilisers: Use the right amount of UV stabiliser based on how much sunlight the product will be exposed to.
• Environment: Geographical location can dictate the level of UV protection needed. Stronger sunlight (e.g., in tropical regions) may require higher stabiliser levels than elsewhere on the planet..

Key Questions:

• Where will the plug socket be used?
• Will it be exposed to sunlight for long periods?

Choosing the right stabilisers can make a significant difference in your product’s lifespan.

Step 3: Design a Durable Living Hinge

For a product like a plug socket, the lid’s hinge will see frequent use. Polypropylene is often the go-to material for living hinges due to its flexibility and ability to resist fatigue over time.

Key Questions to Ask:

• How often will the lid be opened and closed?
• Will the hinge be subject to a lot of wear?

Step 4: Achieve Perfect Colour Matching

Colour consistency is not just about looks—it’s about maintaining brand integrity and ensuring the product stands out in the market. Some pigments fade faster than others, so you’ll need to choose the right dye to match the polymer and additives.

Key Considerations for Colour:

• Ensure the supplier can deliver consistent colour across multiple batches.
• Verify that pigments interact well with UV stabilisers and other additives.

Key Questions:

• What colour is required for your product?
• Will different parts need to be colour-matched?

Learn more about our custom colour matching services for your project.

Step 5: Account for Material Shrinkage

All polymers shrink when cooled, and shrinkage rates vary. This must be accounted for during the mould design process to ensure your final product meets exact specifications.

What to Consider:

• Work with your supplier to make sure the mould design considers shrinkage rates.
• Collaborate with the masterbatch supplier to account for shrinkage during production.

Key Questions:

• How precise must the part dimensions be?
• Will multiple parts need to fit together with tight tolerances?

Step 6: Meet Regulatory Standards

Your product needs to comply with safety and regulatory standards in the regions where it will be sold. This can include safety regulations, environmental rules, and specific material restrictions.

Key Regulatory Considerations:

• Ensure compliance with safety and environmental standards like REACH.
• Certain regions may have restrictions on additives such as flame retardants.

Key Questions:

• Are there region-specific regulations that must be met?
• Does the product need specific certifications (e.g., FDA for food contact)?

Step 7: Collaborate with Your Masterbatch Supplier

Working closely with your masterbatch supplier is crucial to the success of your project. You'll need to share details about the selected polymer, UV protection needs, colour preferences, and regulatory requirements.

Addition Rate Considerations:

• Higher addition rates ensure better coverage, colour consistency, and dosing accuracy during production.
• For example, a 3% masterbatch will give better consistency than a 1% masterbatch.

Key Questions:

• What addition rate is ideal for your project?
• Are you using the correct masterbatch to achieve your desired results?

Find out more about our products and services to optimise your project.

Step 8: Test and Prototype

Before you move to full production, test the masterbatch under real-world conditions through prototyping. This allows you to make adjustments as needed.

Testing Focus:

• Mechanical performance: Does the living hinge function as intended?
• UV resistance: Will the product hold up under sunlight exposure?
• Compliance: Does the product meet necessary safety standards?

For more on testing and prototyping, read our article on masterbatch and compound solutions for your project..

Step 9: Avoid the Risks of Cheap Colour Matching

Tempted to save a little by switching to a cheaper colour match? Be careful. It’s important to remember that cheaper alternatives might not provide the same durability or colour stability as the original.

Risks of Switching:

• Cheaper masterbatch might not go through the same testing process, leaving you vulnerable to quality issues.
• Lack of product history can mean inferior UV resistance, colour stability, or mechanical durability.

Key Questions:

• Has the new masterbatch been tested to meet the same standards as the original?
• Are you risking long-term product failure by cutting costs?

Step 10: Manufacturer vs. Distributor

Should you buy directly from the manufacturer or through a distributor? Each option has pros and cons, but working with the manufacturer often provides better pricing, more customisation options, and superior technical support.

Benefits of Working Directly with a Manufacturer:

• Competitive pricing without distributor markups.
• Custom formulations to meet your project’s unique needs.

Key Questions:

• Are you paying extra due to a distributor’s markup?
• Would working directly with the manufacturer provide better long-term value?

Learn more about our expertise by visiting our about us page.

Conclusion: The Importance of a Strategic Approach

As a purchaser, your role goes beyond securing the lowest price. By working strategically and collaborating closely with your masterbatch supplier, you’ll ensure that your product meets high standards, complies with regulations, and delivers long-term value.