Finding the Process Window for Injection Molding Operations

There are many factors to consider when manufacturing a component: there’s the initial design of the component, mold trials to determine the best material, prototyping, engineering, and eventually, the final production. In order to safeguard the entire molding process, however, there needs to be a way to set limits to help mitigate risk. This is why injection molders create something called the process window.

What is the Process Window?

The process window is the control that molders set during a sampling event that establishes the parameters they want to consistently run at. These include critical processes such as fill time, cushion, screw recovery, hold pressure, and cycle time.

Scientific injection molding helps manufacturers create high and low parameters in which they want to run their process window between. Creating a scientific injection molding book is how manufacturers create the process window, and it’s important for it to be completed ahead of time.

According to Brian Schneider, Technical Manager at Sussex IM, “The most efficient time to create a process window is during the initial run of the tool while doing a scientific molding book. The book creates your window and gives you the optimal set points to run a quality process.”

After a manufacturer creates the scientific injection molding book for their process window, the next steps in the process include:

  1. Picking the parameters suggested to create minimums and maximums for the window from the graphs in the scientific study
  2. Creating the window to operate within the established limits during a production qualification run
  3. Using that process window at all future job start-ups and throughout all runs

The process window is how manufacturers are able to achieve high levels of repeatability for the parts they produce, all without compromising appearance or quality.

Utilizing Effective Process Window Management

The process window is an excellent way for manufacturers to ensure they are creating a part or component within the right parameters.                              However, that means it’s important for manufacturers to ensure the component does not fall outside those constraints. If a component manages to fall outside of a process window, it could be due to an issue with the tooling, the press, or even the cleanliness of the equipment.

The molding experts at Sussex IM recently worked on a press that was running high scrap and a higher-than-quoted cycle time, so the team did a scientific injection molding book. With the book, they were able to recreate the process window to where the mold would run most effectively, and since then, have been able to cut scrap by more than half and improve cycle time by three seconds. By utilizing expert process window management, the team at Sussex IM was able to save a significant amount of time and money on one of their manufacturing processes.

Innovative Molding Solutions from Sussex IM

Sussex IM is a custom injection molder with more than four decades of proven turnkey success in the manufacturing industry. Serving as a resource for automated assemblies, molding, and decorating, Sussex IM delivers a competitive advantage to customers with our expertise in scientific injection molding and process window management. We pride ourselves on our reliable problem-solving abilities, while also supporting integrated value-added operations. Our team is dedicated to ensuring your product is manufactured to perfection.

Want to learn more about how Sussex IM utilizes scientific injection molding for superior process window management?

Contact us today to start a conversation!