Can an injection mold be repaired?

The Toolroom has been providing injection mold services for over four decades. Our molds are designed to last, but that doesn’t mean that a repair won’t one day be necessary. Can you repair an injection mold? What is involved in a repair, and is it cost effective? Our experts are here to answer those questions and advise you on the best solution for your specific needs.

When repairs are warranted, we begin with mold inspection. It is important to assess the condition of the mold by visual inspection of its parts. Metal on metal processes tend to wear the surface. While it might be challenging to see, a dimensional inspection can show tooling surface wear.

Below are some examples of common mold repairs:

Repairing the parting line. The parting line is where two halves of a mold intersect. Parting lines should be adequately sealed while the mold is clamped. With wear or loose fitting, the mold will leak plastic over the parting line during injection molding. The extra plastic is referred to as flash and is an obstacle in the process. To adequately fix this issue, we look at any recent changes that may have been made to the molding process such as material or pressure. We review part maintenance and location of the flash on the plastic product. Repairs to damaged edges and other actions can be performed to rectify flashes.

Repairing gates. Every stage of the injection molding process has one or several gate locations. A gate indicates where the liquid plastic enters the portion of the runner device. Over time, gates can wear slowing gate freeze time or shrinking gate shear. Gates are repaired by welding or new gate insertion.

Repair of ejector pins and holes. Ejection pins are located around the surface of the element, and its assembly ejects the component from the molding board. Due to the nature of ejection system cycling, the guide hold in the tooling surface wears over time. This is made evident with flashing around an ejector pin. Pin malfunction, misalignment, lack of clearance or rust could be to blame.

Eventually, you will find it is time to replace the mold entirely. Here are some signs that changing the mold is an appropriate option:

Changes in dimension over time. If there are an increasing number of noticeable structural variations in the plastic product over time, your material flow could be affected and it is time to replace components.
Cooling issues. It is necessary to maintain and clean cooling lines, and the plastic injection molding process can be significantly slowed with inefficient cooling.
Worn tooling surfaces. We know that tooling services will become worn over time, especially those that provide a textured surface. Avoid issues such as air trapping by having your injection mold repair or replaced. Some injection molds have more moving parts and need replacement as they wear against one another over time.
Ejection system issues. With wear on the ejection system, you may need to replace bushings and/or pins and redrill holes to accommodate for the wear.
Lock damage. Injection molding requires interlocking parts to tooling does not move when under the pressure of injection. Welding and reconfiguration might be required with long-term wear.

The Toolroom has your injection molding repair needs covered. Even if it isn’t a machine we designed, we can help you get back and running with expert machine maintenance, repair or replacement. Our award winning service and design has been helping companies in Missouri and nationwide with state-of-the-art technology and knowhow. Find out more by calling The Toolroom at 573-437-4154 today.