For most of our biggest investments — both in our personal and professional lives — regular maintenance is often at the forefront of our minds. Think about your car, your house, maybe some of your appliances — we want to ensure that we stay ahead of any problems and catch any major issues before they arise, so we engage in regular upkeep and “checkups” to make sure that everything is operating as it should be.
Since its inception, the injection molding process has primarily operated in one traditional way — what is known as a cold runner system. Here, the plastic or rubber substrate is heated to melting and injected into the mold at a fixed point (or several fixed points) called the sprue. A key point to remember here is that the molding material is injected from outside the mold (using a piston or other pressurizing method) through “runners” (or conduits for the material) built into the mold, and then into the cavity itself. The runner in this process cools along with the rest of the part and essentially becomes a part of the finished product itself, and must be ejected, potentially separated from the finished part, and then recycled and reground into reusable substrate.
Injection molding is a complex process with a number of “moving parts” — both figuratively and literally — that should be monitored during production. The process is versatile enough to be the manufacturing method of choice for a broad range of products, but unfortunately, it is rarely as simple as just building a mold and running it through an injection molding machine. Several factors inherent to the process can affect the quality of your end product, and should be monitored and measured as closely as possible in order to maintain the safety and integrity of your parts.