K - Polymer Processing Glossary of Terms

Knockout - Any part or mechanism of a mold used to eject the molded article.
Knockout bar - A bar that ejects the molded article from the mold. It is usually activated automatically while the mold is opening.

Comments

Post a Comment

Popular posts from this blog

Bimodal high density polyethylene, HDPE

Image
We will try to imagine how bimodal molecular weight distribution rise. We will focus on two main properties: processing and mechanical . We start from normal (unimodal) molecular weight distribution (please, start to analyze the graph). Macromolecules with short chains , are easiest to process, polymer has lower viscosity , long chains are responsible for mechanical properties the grow. Considering, what left (middle), can be replaced. The idea was simple, eliminating average properties, we receive polymer with key properties. Return to the most important, processing and final product properties , considering molecular weight distribution . Short fractions or single monomers are gaseous substance, waxes, their impact is questionable (easy degradation, responsible for bad odor) and appear for unimodal distribution , changing the distribution we eliminate them. Long fractions generally affect mechanical properties , e.g. stiffness , it is possible to reduce wall thickness (sho
Read more

Safety precautions for injection molding

Safety is everyone's responsibility in the workplace. Safety is most often related to good maintenance and good housekeeping. Safety needs to be an attitude that if always present in your daily activities. Employees should not be hesitant to voice safety concerns in the workplace. Management is just as committed to safety as the operators on the floor; the primary difference is that the operators are usually the closest to unsafe conditions; keep management advised of unsafe conditions. The following list includes items which should be maintained to assure a safe working environment: 1. Floor and machine should be kept free of oil 2. Floor and machine should be kept free of pellets. 3. Never reach over or under machine guards. 4. Never climb between the bars when pumps are running. 5. Retract injection. unit before entering the bar space. 6. The front gate should have an electrical, hydraulic and mechanical safety device preventing clamp from closing when the front gate is open. 7
Read more

Injection mold validation procedure

To validate an injection mold, there are numerous items one must take into consideration before the mold is completed and work is ready to begin. First, it is advisable to hold a mold design review meeting with all involved parties prior to tool manufacture. Invite the mold builder, hot runner supplier, steel supplier, press supplier, resin supplier, and a strategic molder for the design review. Involving everyone early on in the process and keeping them informed throughout the building of the mold avoids needless complications. Once all the suppliers have been identified it is vital that they are all given training on the injection mold validation procedure , IMVP. The training should be done well in advance of the first mold qualification, if you have a pilot tool stage this is an ideal time. It could be done whilst the production tools are being manufactured. It is strongly advised the tool builder is made aware of the requirements of mold certification (steel measurements) before
Read more