【Knowledge】Double Shots Injection Molding

What is double shots plastic injection molding?

Double shots plastic injection molding is the process that two resins (or two different color resins) are injected into the mold then make one object. This way can enhance the productivity and visual aesthetic. Besides, it ensures the quality consistency by tow shots injection molding. This method is widely used in automotive parts, home appliances, audio equipment and living products.

By rotating the platen, first shot and second shot are separately injected into different parts of mold, as the picture below. 



The pros and cons of double shots injection molding


  • Reduce assembly cost – Traditionally, the designer will adopt assembling or insert molding to put two different materials together. However, it can easily combine two resins through double shots injection. Reduce the time of assembly and lower the cost of assembler.
  • Enhance the product quality – Compare with single shot injection molding, the product made by double shots injection molding has better bond strength and water proof because it is one integrated part. For mass production, it can reduce the possibilities of human error and achieve on-time delivery.
  • Add more product value – By combining different colors or materials, it can improve the appearance and the texture of products. For those require strict standard, double shots injection is the best solution. 
  • Flexible Design – Assembling two single-shot parts requires spaces for tooling or worker to assemble. However, double-shot design can save more space then achieve compact design, which is a trend nowadays.


  • Higher plastic molding cost – The design for double-shot injection mold is more complex because there are two molds in the same injection machine. Besides, due to mating issue for these two resins, it requires a high level of accuracy.  
  • Material compatibility – Two materials should be compatible in order to bond successfully. 

Double-shot Injection Molding Applications

  • Combine hard and soft materials – It is applied to soft-touch surface products like handles, grips, knobs and other portable equipment. This kind of design can make products comfortable to use and lower the influences of vibration or shock.
  • Transparent and Non-transparent – You can see this combination in control panel for automotive, lighting cover and others. Transparent parts are more difficult to produce since they are easily influence by impurity, which will affect the appearance and the degree of transmission. 
  • Higher standard for appearance – Double shots injection molding can overcome the shrinkage problem. Thus, it can meet higher appearance quality and reduce the problems to surface treatment. 
  • Brand Identity – Create focus on brand logo or important text.  

Products Display

Car Dashboard Panel


Car Central Panel


Car Knob






Protective Housing


Audio Equipment Knob


Audio Equipment Knob


Washer Knob