Today, we use servo injection molding machine to accurately control the material flow; use high pressure water to control mold temperature; use dehumidifying dryer with dew point to eliminate moisture; use hot runner to reduce pressure loss and cost; use cavity pressure & temperature sensor to monitor the whole molding process etc., all these can help us to get more scientific. It is not enough to implement SIM that only know about them, because there are much more other tools like simulation/FEA, Minitab, TRIZ, DFSS, DMAIC etc. can make it more scientific.

Course Summary: Scientific Molder 1 is a one week training program for molders with existing experience who wish to learn Scientific Molding from the Plastics Point of View and apply this knowledge using screw position switchover processing techniques.  The class involves

All critical mentioned above points to plastic resin properties, temperature, melt flow, shrinkage, crystallization, orientation etc. To have a good part, not only the properties in plastic molding process, but also final part appearance and mechanical properties should be concerned. The most important is the heat resistance, chemical resistance, electrical properties etc. during the long-term use. Therefore, resin selection is the first and most important step, especially in insert molding and over-molding.

You have a good tool, efficient cooling and gas venting, suitable and smooth movement structure, reasonable runner size and location etc. You implement scientific parameter setting, get the right drying temperature and time, get the right barrel temperature setting, completely know filling, packing, and holding. All your parameter settings are data and evidence based. But the crack issue, as an example, is still there. What happened? The reason maybe caused by melt flow hesitation, your plastic part wall-thickness here is too thin, and waiting for enough pressure to weld but meanwhile, it is cooling down. It shows that the SIM involves the plastic part design as well.

So, what is scientific injection molding do you think? In my view, it is to effectively prevent plastic defect caused by poor part structure design and poor mold design through in-depth understanding resin properties and selecting the right resin brand & grade with the lowest cost, rapidly find the root causes during mold try-run and then fix it. To achieve a robust and effective process, it also includes to remove the impact of inherent personal experience on products/molds/processes by way of using varieties of monitoring equipment and data analysis tools.

What is scientific plastic injection molding? Scientific parameter setting? If the runner or the gate size is too small, for instance, the sink mark or warpage problem is still there no matter how excellent your process parameter is. So, the tooling design also be included.

Is plastic injection molding a simple work? Yes, do not you see that anyone can inject a plastic part regardless of residual stress inside. Is it complex? Exactly it is, it is related to polymer science, fluid mechanics, material mechanics, metal technics, GD/T ……