The question never ceases to amaze our organization on whether it makes more sense to perform operations outside or inside a plastics injection mold as it relates to assembling or creating a product that requires a secondary step such as over molding or assembly itself.
It has been our experience, along with many others across the world, that if you can do it in the mold while holding the part, it is better for several reasons.
The advantages range from, but not limited to;
- One may have the ability to create immediate tamper evidence that cannot be achieved thru external automation.
- One may have the ability to create mechanical assemblies that cannot be achieved thru external automation.
- One has less handling of the product thru the manufacturing process.
- One does not have to deal with re-establishing the part onto another fixture since you already have the part being held on a core, cavity, or insert.
- One does not have to deal with part warpage due to the cooling process when loading it into another tool.
- One has increased part quality on multi-cavity tooling for part 1’s secondary process will always mate with part 1’s first process. Example: An 8 cavity 2 shot part using 2 separate molds has 8×8=64 combinations to make the final product. In the case of using in mold tooling technologies, the combinations are reduced down to 8 combinations for they never get mixed and matched. This can allow in fine tuning dimensions and sizes to achieve a higher quality product.
- One has less physical equipment to achieve in making the final product which equals less manufacturing space utilization.
Granted, not every product / application has the ability to utilize this approach, but when it can be applied, there is no question to the value added benefits of in mold tooling technologies.
Another point to consider when evaluating manufacturing solutions is the environment of where the technology will be ran at. There have been cases where people, culture, or internal equipment limit the ability to apply the best manufacturing solution for the application.
For us, it is important to evaluate the scope of the application along with understanding the environment in which the product will be manufactured in to ensure that a proper balance for success is achieved.
Educating the industry on what can be done using technology is key for continued innovation in the marketplace.
Written by: Ron Cisliek, Gram Technology