injection molding

January 8, 2021

Hansen Plastics’ Two Shot Molding Process Guide

Utilizing injection molding for manufacturing parts has inherent benefits, such as reduced production costs, and increased innovation to manufacture complex parts faster. One process Hansen Plastics uses that exemplifies both of these benefits is two shot, or 2-shot, injection molding. By using a technique that can inject two materials into the same mold, manufacturers have access to a wider range of material combinations for their parts — without dramatically increasing the production time, and eliminating secondary operations, saving money while more efficiently crafting the parts.  

The process for creating a part using 2-shot injection molding is fairly straight forward, but what it lacks in complexity, it makes up for in precision and timing. 

  • First, the press is sealed with the first mold in place, and resin is injected into the mold, forming the initial part. Then, the press is opened, and the part is transferred — either via rotation, or with a robotic arm — to the second mold before the press is sealed again. 
  • Once re-sealed, a shot of resin is injected simultaneously into both molds, with the first forming a new, second initial part, and the second shot being injected in, on, or around the first initial part to complete the fully molded part. 
  • After the two resins bond through cooling, the press is opened, allowing the finished part to be ejected, and moving the newly formed part into place to receive its second injection.  

As can be seen, the 2-step process relies on precise coordination of the molds and injections to be completed successfully, without undue flashing or short shots. Because of this, it’s necessary that the process be undertaken by skilled professionals with experience with the two shot molding technique. 

If utilized by an expert team, such as the engineers at HPC, the 2-shot molding process can be a major value add for manufacturers. Creating parts using 2-shot molding reduces the number of components used during molding, and greatly reduces waste and assembly time. By using two materials in the same molded part, not only can manufacturers enhance the cosmetic details of the part, they are also able to craft more complex parts with greater efficiency, expanding the functionality of their designs. And with high-production run parts, the 2-step process ends up saving money, and more importantly, time, without sacrificing quality.

Collaborating with an injection-molding team with the technical knowledge and expertise to master the 2-step molding process, such as Hansen Plastics, can be a game-changer for manufacturers in all industries. For over 40 years, Hansen Plastics has been committed to building long-lasting relationships, which requires unwavering dedication to quality and consistency in injection molding, to help establish and retain trust with all HPC customers across industries and applications. If you are looking for a trusted, experienced plastic injection molder to handle your products, reach out to HPC today, or visit for a full view of Hansen Plastic’s capabilities.