I encountered this question the other day in a training session… Student Our production facility does not use a temperature controller. Is it still important to document the coolant temperature? My Response In this case, it is even more important. If a temperature controller is present, then you can at least assume that the coolant temperature approximates the setpoint. If […]
Category Archives
Plastics Technology
Molding of Magnesium…
I received this question during NPE… BD We have a customer who wants magnesium parts. What is the basic principle to metals injection molding? My Response Essentially, materials such as magnesium are effectively alloyed to create a thixotropic material. This alloy can be shear heated like a polymer to create a semi-solid slurry which can be injection molded. The […]
Polishing Actually Removes Metal…
I heard a die setter make this statement recently… Setter Mold makers get all bend out of shape whenever we touch the mold surface. It’s no big deal to polish out a scratch. My Response First off, polishing takes a long amount of time and is a very labor-intensive process. This person has obviously never […]
Mold Temperature and Weld Lines…
I was discussing a processing issue with a technician and encountered this question… Tech The cause of the poor weld line was mold temperature, but I don’t really understand why since the melt flows from the center and should be hot when the flow fronts meet. My Response This is a true, but the strength and appearance […]
Understanding Jetting…
I was asked this question the other day when discussing molding defects… Student What actually causes Jetting? My Response This defect occurs when the polymer shoots into the mold and does not create a smooth laminar, or fountain, flow as it first enters the mold cavity. A laminar flow occurs when the polymer enters the […]