Multi-Shot Injection Molding with Sussex IM

At Sussex IM, we strive to solve our customers’ problems in the most efficient way possible. Backed by our proven injection molding expertise, one of the ways that we deliver solutions is through two-shot or multi-shot injection molding. As your injection molding experts, Sussex IM is always looking for new ways to address our customers’ needs. To maintain this responsibility, we have continued to expand our medical injection molding capabilities with the addition of our new Class 8 clean room.

If you have a medical device application, multi-shot injection molding can benefit your needs and the advantages this manufacturing capability provides.

What is Two-Shot or Multi-Shot Injection Molding?

Two-shot, or multi-shot injection molding, is a highly efficient manufacturing process in which molded parts from two or more different materials are combined to build a single product.

This versatile manufacturing process produces complicated molded parts that may have different colors, components or materials. Usually, those factors are limited to two different types, but with customization of the molding machine and mold construction, a part could utilize up to three materials. Additionally, the use of multiple injection molding machines can create an even larger combination of materials.

The necessary double injection is carried out on one machine, built and programmed to perform two injections in one cycle. While the process can also occur with two or more molds in multiple injection molding machines, using one mold and one injection molding machine ensures reduced handling and guaranteed cleanliness. The single press method is also the lowest cost.

Benefits of Multi-Shot Injection Molding

There are numerous benefits of multi-shot injection molding. Providing the simplest and most cost-effective way to produce parts with multiple materials, as the process only requires one machine cycle, multi-shot injection molding delivers reduced costs and needs for labor. The efficient process will also produce higher output levels compared to other manufacturing processes.

Beyond the ability to seamlessly create multi-color or multi-material parts, two-shot injection molding also is a flexible process that allows for added creativity and complexity in part design, opening up part complexity possibilities. The unique capabilities of two-shot injection molding are especially beneficial for the medical market as medical device designs continue to advance and have become increasingly intricate.

Material Selection – Key to Success

As the case with any manufacturing process, material selection is a critical part. In multi-shot injection molding, the selection process becomes even more vital as the resin not only has to be a fit for the end-use application, but the materials have to be a fit, chemically, with each other. Otherwise, bonding will not occur. Another way to overcome this challenge is through part design, mechanically bonding the two materials via internal channels and interlocking features. Typically, to aid in this decision-making process, a material compatibility chart is available to determine which resins may work together for this particular kind of injection molding.

When examining the end-use, it is vital to understand if the device will require higher durability, protecting against being exposed to fluctuating temperatures and the resilience required. For medical applications, considerations of FDA regulations the product will need to meet, especially if the device will be inserted into the human body or in contact with bodily fluids, will be critical.

Material selection is always complicated, and given the recent shortages and price increases, finding your first choice can be nearly impossible, meaning material replacement is a growing need. At Sussex IM, our knowledgeable team is happy to help guide you through the material selection process.

Multi-Shot Injection Molding and the Medical Industry

With the recent increased demand for medical products, multi-shot injection molding is as popular as ever. The multi-shot injection molding manufacturing technique offers several favorable qualities that appeal to the medical market including, the opportunity for increased sterilization, molding precision and cycle time.

With the combination of different properties into one part, two-shot injection molding also provides value through improved aesthetics, functionality and quality. While any market will enjoy the benefits of combining materials to improve part integrity and greater visual appeal, as this process improves color and eliminates painting in secondary operations, the medical market has several applications where this manufacturing process is unmatched.

For example, a medical device housing would require a material that is both durable and aesthetically pleasing. Two-shot injection molding can also offer an end-product that features a rigid plastic housing with a soft-touch grip.

The Sussex IM Difference

At Sussex IM, we recognize the nuances necessary for medical injection molding. To continuously serve the increased demand for medical manufacturing and new product development, we have strengthened our capabilities to support medical injection molding with our ISO Class 8 clean room.

To enhance all of our injection molding expertise, Sussex IM has complete service offerings including, design for manufacture, dedicated 3PL capabilities and inventory management to round out our full-solutions service. From start to finish, we are the comprehensive partner to ensure success – that’s the Sussex Solution.

Ready to find out how we unite different technologies together to provide complete solutions? Contact us today.