Understanding Velocity-Control…

I received this question from a previous contributor… Rafael When you write velocity-controlled injection, what do you mean? My Response A velocity controlled process uses a velocity setpoint to control the rate at which the polymer is injected into the mold. Usually this is represented on the control panel as in/s or mm/s.  On a hydraulic machine, […]

About Safety Glasses…

I was recently at a facility in which the employer did not require safety glasses because ‘the machines are already guarded’… My Thoughts Although there are many regulations, and interpretations, most manufacturers and regulatory groups can agree that safety glasses should be worn under the following machine conditions… 1) Whenever a safety gate is opened, it is considered violated, and […]

Complications With 1st – 2nd Stage Transfer…

A technician encountered this interesting problem yesterday… Kevin We have been working to achieve 95-97% fill during first stage fill with zero hold time and pressure. As soon as I apply hold pressure and time, the screw continues at speed after transfer. My machine has a hold speed minimum setting, but no option to turn this setting off. I […]

Balancing Family Molds…

A common blog reader asked this question regarding family molds… Jim What is the best way of balancing a family mold? My Response When balancing family molds, it is best to approach it in two steps. Step 1 – Balance the runner system – When possible, try to balance the runner system so that each gate starts filling the […]

Same Supplier… Same Grade… Bigger Dimensions…

I received a follow-up question regarding a blog entry last week… ED We switched our product line over to 4710 PE 100 extruder grade PE about 2.5 years ago. The material was produced in Belgium. We sized all of our new tooling to this material.In February they started making the material in Texas. The supplier says the […]