You, our core audience, know more about injection molding than most. Some of you don't know anything about it at all. Whichever camp you're in, you should watch this video by Bill Hammack, a/k/a Engineer Guy, explaining the process because I guarantee you'll learn something new; not only does he provide clear explanations of the machines both inside and out, he reveals the history. (Which injection molding mavens among you knew it was pioneered in the 1800s—and was tangentially related to elephants and billiards?!?)
Current industrial design students: Did your current professors explain injection molding to you, and if so, using what methods? And if you don't mind sharing, what year are you, and what program do you attend?
Current industrial designers: Did you learn about injection molding on the job, or at school? If the former, who explained it to you and how?
Create a Core77 Account
Already have an account? Sign In
By creating a Core77 account you confirm that you accept the Terms of Use
Please enter your email and we will send an email to reset your password.
Comments
Following are some of the common defects in Injection Molding(https://www.scientificmoldingsolutions.com/scientific-molding-resources). The solutions mentioned are possible solutions and must be tried out with safety in mind. Please always follow the material manufacturer and machine manufacturer's guidelines for safety.Paragraph.
Molten Plastic is not reaching the mold cavity section
Increase melt temperatureIncrease mold temperatureIncrease injection speedIncrease injection pressure if process is pressure limited
Plastic is shrinking as it cools but additional plastic cannot be for further compensation of the shrinkage
Increase pack and hold pressuresIncrease pack and hold times
I was fortunate enough to have my first job as a CAD Engineer making mold designs and 3D plastic models for production of automotive car lamps. I understood well how each specs in the 3D and DWG affect the result of the product. This video however clearly explained the actual reasons behind each style, but to fully understand the whole concept, a real experience on how injection molding works is needed. Awesome video, will really look out for more of your stuff. :)
The video is nicely done. The rendering of the spoon mold however likely wouldn't be setup that way in real life as you would want all parts of a multi-cavity tool to complete filling at the same time to improve product quality.
Being a transplant into the plastics industry, I learned this stuff largely by examining the broad range of items being made from my company's materials. What's most fascinating, is seeing failed components and designs as they tend to be the best learning examples. The world that makes things is a pretty neat place to be a part of. Thanks for sharing this.
We also had a class called Materials and Processes. Every week we took a field trip to a different kind of manufacturing facility, and one week it was where they injection-molded cases for Zip drives. Now I'm surprised that things were being molded in the US.
We had a mandatory class at Georgia Tech called "Materials and Processes". The instructor did an amazing job of teaching us the basics of common manufacturing processes for different materials, and the relevant engineering and design rules around each.
My introduction to injection moulding was on the job during my first solo product. I had a whole new appreciation for the phrase "baptism by fire" after that project. Thankfully my tool maker/manufacturer was a total champion and was very patient/helpful through the process. IM is more of a dark art than science that really needs to be taught through experience - my toolmaker once said "I can't tell you what you can do, but I can tell you what you can't". That back-and-forth process probably thought me more than any classroom could have. I was very lucky and had an openminded toolmaker that let me push the boundaries of what he and I both thought possible to achieve beautiful finish quality in some challenging shapes using a very finicky material.
Those two links are my go-to resources for injection molding.