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I received a few questions from a blog reader the other day, this is one of them… Nathan Regarding the Cavity Balance Test – which is preferable, 50% or 90% full. note: this test uses different injection speeds to determine which provides the most balanced fill during a 1st stage short shot. My Response It is preferable to use a […]

I received this question this morning… MK After establishing the injection molding process for particular part, which parameters should we keep constant during the next subsequent production run? Whether it is Injection time, injection speed, or switch over position, or any other parameter.  My Response Actually, the focus should not be on the machine inputs, but the […]

I was asked this screw design question last week… JG What is the optimal length for the feed zone of the screw? note: this is for an injection molding machine My Response Generally speaking, the feed zone of the screw should be at least 1.5 times the total injection stroke. This allows the material in front of […]

I was having a discussion with a colleague about material drying and asked this question the other day by his co-worker… Technician You guys keep referring to hydrolysis, what is it and how does it affect the material? My Response Basically, hydrolysis is the process of breaking the water molecule into a positive hydrogen (H+) atom and a negative hydroxide (OH-) molecule. These […]

I received this interesting question earlier this week… KD We are changing some of our tools to cylinder nozzles that decompress hot runner tools using carriage retract – closer to the manifold. Is this good? note: these cylindrical nozzles are designed to insert into the sprue bushing while being allowed to slide in and out as a seal is […]