High Speed Injection Molding
How do you achieve high-speed production of complex parts?
The key component is an understanding of the volumes required. If the volumes are a million pieces per year, sometimes a four-cavity mold is needed or a high-quality tool. For high-speed or high-volume production, using high-quality tools is important. The tools should hold up with very little maintenance in this process.
Given a million pieces per year, a four-cavity small part is appropriate. To reduce the price of the parts as much a possible, hot-runner systems are needed to run high-speed molding. These systems eliminate the scrap from production; therefore, the parts are the sole result of the process.
Given five to seven million pieces per year, multi-cavity molds (eight-, sixteen-, twenty-four, thirty-two-cavity molds) are needed. Hot-runner systems and high-volume tools become very important. It is critical money be invested upfront in the development of this process. Based on the performance of these high-speed tools, the costs will be recovered in the future.
How does involving your mold-maker early in the process impact your engineering and development of new plastic molding products?
The mold-makers involved in the trade of high-quality tooling must have several years of experience. The majority of mold-makers go through apprenticeship and training programs sponsored by the state.
Not only have they received state certification, they have trained on the production floor. By observing the production staff, mold-makers gain an understanding of the process and the end result of the types of products manufactured. Performance results are obtained during this exercise.
Getting the plastic mold maker engaged in the beginning also brings up a lot of ideas and develops the thought process for production. Based on their years of experience, it can be systematically determined how to produce high-quality tools with a very small margin of error in molding.
This lends itself to the best product possible with the least amount of down time. It incorporates the types of steels used, the types of molds used, as well as the types of engineering required. Any aspect of the process is accentuated by the experience of the mold-makers and their recommendations. It is crucial they be consulted at the very beginning of product development.
How do you move tools from overseas or execute mold transfers?
When transferring plastic molds from overseas, the best practice is to find a facility that has an in-house tooling capability. It is important the facility is able to accomplish large-scale repairs on molds. Therefore, the skills required for execution are available within the company itself.
Since the company receiving the tools or the mold transfer is highly trained, the tools are sent there to be taken apart and examined. This step in the transfer process allows the manufacturer to assess if the tools were properly built. In numerous cases, tools are shipped with a combination of U.S. and European (metrics) supplies mixed together within the same molds.
These are some of the issues that need to be addressed to ensure proper procedures are taken to straighten the tool out. Otherwise, it cannot be made into a moldable product. Another concern is standardization of the molds. The molds should run in standard molding machines built for the industry.
The type of material needed to run in a particular plastic mold – engineering or otherwise – must be a consideration as well. The molds must be capable of meeting the volumes required for the materials involved. Some tools may not have the capacity to run the necessary volumes for the entire duration of the process.
A lot of tooling that comes from overseas may be prototype, not production tooling. The type of steel or engineering used during production may not be standardized or in line with manufacturer expectations. Prototype tools are not designed for high-volume production. It is important the tools are assessed properly.
What are the best practices in new product mold design?
After product development has been secured and generation of plastic parts has begun, the best practice is to have those plastic parts designed by an expert. Generally, this would be a trained plastics engineer specializing in the various aspects of the process: tooling, molding, and plastics.
The engineer reviews the product line to confirm the plastic parts are moldable, the material used is appropriate, and the types of machines required. The results of the engineer’s assessment can be interpreted as to whether the product line is capable of being molded or not.
In order to save costs on the front end, work with a plastics engineer that specializes in tooling and molding. Based on this expert opinion, the feasibility of the product line may be determined.