Torque Values For The Clamp Bolts…

I got a multi-part question the other day regarding a couple aspects of mold clamping… Rob Do you have a suggested torque specification for 5/8-11 and 3/4-10 bolts? I know you are suppose to refer to the manufacturers torque specification, but does that apply to a clamp bolt and clamp? The clamp is a lever […]

Compressive Stress vs. Orientation Stress

Yesterday, I received this question from a frequent blog contributor… Milan What is the difference between molded-in compressive stresses and molded-in orientation stresses? My Response I will first define the two concepts in practical terms, and then address the differences between the two… Molded-In Compressive Stress – As the polymer fills the mold and cools, the polymer begins […]

Finding the Location to Vent…

I just got this quick question from one of our blog readers… Larry We have a small nozzle mold (0.2oz of Lexan PC) that traps air, but we can’t seem to find a way to vent it. The only success we have had is to reduce the clamp tonnage. Can you briefly state a procedure for […]

Mold Texture and Part Shininess

This e-mailer had a long question about texture and shininess. I have shortened it to include the critical portions… Nathan The largest part quality issue is shininess in the textured portion of the part. A particular part is molded out of PC/ABS C6600, we have performed some studies and came up with the following conclusion:  The draft […]