Why Screw Design is Critical to Your Injection Molding Success

ELK GROVE VILLAGE, IL, March 9, 2021 – The proper selection of your screw for any given injection molding application is critical to successful processing. In fact, changing to an optimized screw design has been shown to improve cycle times and reduce part reject rates- all equating to more efficient processing performance.

How can you know you are selecting the proper screw design? When it comes to injection molding you should first consider your application, as some screw variations will allow for superior processing results over others. We are sharing insight into several commonly used screw designs and what applications they are generally used for.

Screw Design Makes a Difference

As mentioned, a specific screw design can be used to enhance performance and even solve processing problems. Several of the most common screw designs to consider include:

General Purpose

Used often because of their highly flexible nature, general purpose screws can be used with most plastic materials. They are a common choice for companies that mold a variety of different materials.

• The single flight screw design works well for most crystalline and glass-filled materials.
• A dynamic barrier general purpose screw design offers a better color mixing ability and ensures a more homogenous melt. This design works well for polycarbonates and clear materials.

High Performance Olefin 

Consider a high performance olefin screw when you need enhanced level of melt control. Designed specifically for polypropylene and polyethylene, the high performance olefin screw design provides the fastest recovery time and uniform melt. 

Mixing 

Mixing screws achieve uniform color, viscosity, and isothermal melt quality while maintaining optimal melt temperature and offer distributive mixing of the melt. Mixing screws allow you to avoid dead spots or hang-up areas that may cause thermal degradation or discoloration.

Additional Applications

Shibaura Machine offers a variety of screws for additional applications. These can include LSR, PVC, and PTFE.

The screw material should also be considered in line with your screw design. With some resins you will want to consider abrasion/chemical resistant or hardened materials to protect from excessive wear. 

Choosing the right injection screw allows you to make quality parts consistently and with maximum production output. Shibaura Machine developed its injection molding machines with screws designs that allow for consistent end-product quality, along with high performance and wear resistance.

Contact us to learn more about the optimum screw design for your application.