Plastic molds are used to create so many of the things we use today. Most of the products we use on a daily basis are created by injection molding plastic or metal parts that will later connect to build our appliances, machinery, and so much more. When a part becomes compromised or takes excessive time to create (and thus increasing production costs) we all suffer the consequences. That’s why it’s so important to choose the right mold release process for the most effective and efficient demolding practice.
Compatibility of Mold Release Agents
When choosing a mold release agent we have to be absolutely sure the lubricant doesn’t affect the item being demolded. This means checking that the agent is compatible with the material. Some mold release agents are also able to produce matted or shiny results, so it’s important to check this before using an agent.
Some materials will stick to the inside of the mold a little more than others. In such cases, the slip capabilities of the agent will need to be increased. In the case of materials that have a complex chemical structure, such as cross-linked polymers, a combination of mold release agents will need to be used with varying slip levels on different areas. Be aware to use an agent that doesn’t create unsightly build up on the surface of the mold or item.
The Application of Release Agents
Mold release agents are generally applied with aerosol cans although there are a number of agents that require thicker coats and different drying periods. In these cases, paintbrushes may be used to get the optimum consistency. Some agents are used by workers directly while others are set up using machines and hoses. Be aware of safety considerations such as smells and allergenic chemicals. There are mold release agents that are odorless and hypoallergenic, facilitating a safer environment for demolding. Companies are also working to make demolding agents more eco-friendly.
Innovations in Demolding Processes
In some cases, demolding is done using ejectors, air or a stripper plate. In these instances, issues can occur. The part often shrinks too tightly to the core and high ejection and stripping forces can deform and wrinkle the part. Undercuts or textured outside surfaces can make it exceedingly difficult to remove the part without damaging the surface.
Paul E. Allen, president of Logic Corp, has patented a new mold release process he calls Incremental Cavity Ejection (I.C.E.), a method that demolds without causing distortion or damage. It’s designed to reduce the adhesion of the cooling and shrinking process and allow the item to shrink radially, away from the cavity wall. The patent was issued in August of 1999. Logic Corp. licenses the process, including the system for determining when to activate core and ejector movements and/or the air system. A variety of plastic production companies now use similar systems.
As you can see, there are a few mold release processes available. Whether you choose a demolding agent or an ejector, air or stripper plate, there is always a way to get the process working best for you and your needs.