Choosing the right resin for creating a custom plastic injection component will ensure it has the necessary characteristics that will allow the component to function as planned. Considering just how many materials there are to choose from, the process of resin selection can become complicated, even for experienced custom plastic injection molders. However, there are certain steps professionals take before choosing the resin that ensure their choice is suitable. Let’s see what those steps are.

How do experts choose the best resin for a plastic injection part?

What additives do professionals use to improve certain characteristicsChoosing the most adequate resin for the particular product requires the molder to be familiar with the characteristics of different resins, but to also have an in-depth understanding of the part they are going to produce.

Here are the three basic considerations experts pay attention to during the resin selection process.

Purpose of the component

Knowing the basic purpose of the component will indicate exact physical requirements the part has to possess. These requirements include withstanding exposure to potentially harmful chemicals, tough environmental conditions, and various stressors.

When assessing the purpose of the component, professionals will choose the resin based on the following criteria:

  • The necessary strength of the component
  • The flexibility of the component
  • Whether the part is going to be under unusual levels of weight or pressure
  • The projected life expectancy of the product
  • Exposure to harsh temperatures and other extreme conditions

Aesthetic considerations

Another important aspect that affects the choice of plastic resin is the visual component of the part. Aesthetic aspect includes paying attention to the color, texture, and transparency of the component. Also, the professionals will base their choice of resin by considering embossing and the final texture of the component.

Regulatory requirements

Finally, but also most importantly, the resin has to be selected keeping in mind the regulatory requirements for the intended application of the component. The material selected for manufacturing has to meet the requirements and standards of the industry it will be used in. Most commonly, plastic molding engineers consider:

  • Different regulatory requirements, including REACH, NSF, RoHS, and FDA
  • Whether or not the product has to be safe for children
  • Whether or not the product has to be food-safe

What additives do professionals use to improve certain characteristics?

Different resins have distinct properties that affect the characteristics of the finished product. However, as favorable the properties of a resin are, manufacturers will still want to make additional tuning to the qualities of the final end-product to ensure it matches the client’s precise requirements.

This is why they will introduce different additives and fillers and imprint additional properties into a plastic molded component. Here are some of the most frequent additive applications:

  • Colorants: These additives add color and different special effects, such as pearlescence and fluorescence.
  • Optical brighteners: They boost the whiteness of the component.
  • Flame retardants: Flame retardants make parts combustion-resistant.
  • Fibers and plasticizers: Fibers add stiffness and strength, while plasticizers improve pliability.
  • Anti-statics: These additives lower static electricity conduction.
  • Antimicrobials: They are mainly used in products for the food industry.

Which custom plastic injection molders should I partner with?

custom plastic injection moldersThere are many different materials used in the process of custom plastic injection molding, and it is up to professionals to choose the most suitable resin for manufacturing a high-quality injection molded component. Combined with the design of the molding process, resins are an essential part of ensuring you receive all the benefits of the automated injection molding. That is why it is vital to partner with a reputable plastic injection molding company.

Wunder Mold is a reputable company with over twenty-five years of experience creating custom parts and components through plastic injection molding. We take time when designing and manufacturing a product to make sure it perfectly matches our client’s specifications. We will carefully listen to your wishes and translate them into a finished product. You can give us a call at (707) 448-2349 or send an email to