Most of you probably have heard of the option “Core Pull” with Injection Molding Machines. Simply put, core pull allows a cavity to be put in the product parallel to the clamp. A simple example that you may be familiar with is PVC pipe connectors. You’ve probably seen them at your local hardware store. There 45 degree elbow connectors, straight connectors, connectors to go from 2” pipe to 1” pipe, etc. To accomplish this hollow product on an injection molder you need core pull.
Hydraulic pins are inserted into of the mold while clamp closes. While clamped, the plastic is shot and formed around the pins creating the hollow point in your product. Core pins are then released from hollow point areas of pipe, clamp opens, and your PVC pipe connection is created! There are many products that are made with core pull. The important component is that the product being create must need a place devoid of plastic that cannot be accommodated by the mold itself.Advantages:
- Low overall cost
- No post-injection molding work in creating hollow points in product
- Time saving
- Cincinnati Milacron
- Van Dorn
- Krauss Maffei