Improve repeatability of injection molding plastic
ISO 9001:2008 recommends taking PROCESS APPROACH to quality Management.In an Industrial Injection molding plastic set up which parameters one should watch to improve the repeatability of Molding.
Assuming you have already developed a molding process that yields an acceptable part, you're halfway to your answer. The Big 8 key process input variables (KPIV's) include injection pressure and speed, transfer position, melt temperature, cooling time, mold temperature, holding pressure and holding time. Monitor these regularly. Use your molding machine's SPC capabilities (hopefully it is so equipped) . The more stable these outputs are the more consistent your process is. And assuming again that you properly developed the process, you can be more confident that your product will consistently meet specification.
First part of your comment is perfectly understood. Now a days machines have PLCs and the parametres like temp. stroke & time can be stored in memory and can be recalled every time we reload the mold. Your suggestion of SPC ,we have choce of parameters to be monitor during the production such as Injection(Fill) time, switch over position, cushion, refill time , peak pressure etc.These are not set but achieved due to combined effect of mold temp. melt temp. machine repeatability etc. Which of these you will suggest to monitor so that one can judge the process quality and also it will suggest us about quality of our parameter setting. I hope I am clear in my explanation.
Edaran and GCP will always remember you. We do applied cavity pressure Transducers for
One of North American Project; however in my experience it is just a Measuring Device.
Feedback device/ Method, which fine tunes the molding Process is, statistical Process control.