Explore the Benefits of 2 Shot Injection Molding

This Molding Method Adds Quality and Diversity to Production

Known by many terms, 2 shot injection molding allows engineers to create multi-material or multi-colored parts without adding extra assembly steps. This opens up a diverse range of possibilities and leads to a host of benefits, particularly when the process is used for high-volume production runs.

As mentioned above, 2 shot injection molding is referred to by several different monikers in the plastics industry. But whether the process is called 2 shot, dual-shot, multi-shot, or double shot, it adheres to the same basic overall framework.

There are two phases of the 2 shot molding process. The first is similar to traditional injection molding: The first shot of resin is injected into a mold and cooled to form a solid part. In the second phase, the molded part is moved to an alternate position via a rotating platen or a robotic arm. After repositioning the first shot, a second shot is injected with the secondary resin or color — in, through, or around certain parts of the first shot depending on the design. The two plastic resins then form a molecular bond and the multi-resin molded part is cooled and ejected.

The process molds a single part using two different plastic resins. This allows the use of two different colors of plastic, or to integrate both a hard and a soft plastic into one part without any post-molding assembly.

It’s critical to find an experienced, well-vetted partner to provide 2 shot injection molding. Higher levels of technical expertise and attention to detail are required as the smallest mistakes can compound into high-cost problems — particularly in high-volume production scenarios. The right partner will have excellent quality control standards and defined processes to mitigate potential issues like flash, flow lines, and short-shots. The right supplier can also add design assistance to your project and engineer value into your final product.

This process is ideal for a wide range of parts and products, with examples found virtually in every industry. Two shot injection molding is essential whenever multi-colored or multi-material components are desired, when descriptions or identifications are necessary, when there is a need for moveable segments or components, and for adding a softer grip to a more rigid substrate. It’s a common solution for power tools or electric toothbrush handles for instance and is instrumental in medical devices and dental products.

With the widespread use and an applicable need in many industries, it’s obvious there are many benefits to this particular injection molding method. Today we’ll be examining three of the biggest and how they can apply to your business.

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Three Major Benefits of 2 Shot Injection Molding

With the ability to produce high-quality parts efficiently, while also opening up avenues of versatility and specialization, 2 shot injection molding is a valuable component for any molding and plastics partner. Let’s dive into the three biggest reasons why this injection method is prized.

Cost-Effectiveness & Efficiency

Because only one machine cycle is used, 2 shot molding allows multiple components to be made with a single tool. This also eliminates the need to join components after the molding process, leading to less operating and labor costs. Because components are joined during molding there are fewer overall components in the finished assembly, which cuts costs in the finished product for development, engineering, and validation. Lastly, the process is efficient — two ‘parts’ made with one cycle — but also less wasteful. The process will lead to fewer defects as there are fewer components to join together later in production.

Better Part Quality

Two shot injection molding allows for tighter tolerances than other molding processes and delivers a high level of accuracy and repeatability — all of which reduce scrap rates. The process eliminates some of the need for secondary processes such as sonic welding or assembly. Because the components are made and joined in the same step, there are far fewer instances of misalignment when compared to over-molding or a more traditional insert process. Finally, the bond is exceptionally strong and is essentially one part, not two; this leads to a more durable product that is both more reliable and has a longer life.

Versatility

Two shot molding expands design possibilities and allows for complex mold designs that integrate multiple materials for functionality that can’t be reached through older molding processes. This leads to enhanced product features and appeal, with the addition of tactile, ergonomic, and aesthetic characteristics. Use multiple colors to add a distinctive look or reinforce brand image on specific components. Molded graphics impart value and worth. Soft-touch layers over rigid components aid in ease of use and mark the product as well-designed and functional.

Best of all, all of these additions come with a process that reduces production steps, cost, and time spent.

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Make Deluxe Plastics Your Partner for 2 Shot Injection Molding

As a full-service custom injection molder, Deluxe Plastics is able to take your project from the initial design to a fully functional, molded part. Our team of engineers will work together with your company to implement your design ideas, select the best material, and offer professional guidance. With three facilities encompassing 290,000 sq. feet of operating space, we perform tool building, maintenance, molding, and any secondary operation your project may require.

Our experienced team can advise you on part design to facilitate 2 shot injection molding and help you select the best materials that meet bonding requirements for the process. Within our 55 injection molding machines ranging in tonnage from 20 to 900 tons, there are three specific 2 shot presses equipped with rotational platens. In addition, most are equipped with Star Automation Robots. We operate three full shifts, 24 hours a day, to cut lead times and ensure your project is molded quickly and efficiently.

Since our inception in 1928, we’ve been governed by our desire to deliver superior service and products to all of our customers. With a robust quality management system, ISO 9001:2015 certification, and more, we are the high-performance injection molding partner you need in a variety of industries, including the commercial, industrial, appliance, and hygiene markets.

Connect with Deluxe Plastics to work with a full-service injection molding and engineering company you can trust for superior products and service.