The injection molding process is a crucial process with lots of moving parts — but that doesn’t mean you can’t make some simple changes to improve how you do it and safeguard the quality of your final product.
Time is money — but so are professionalism, optimization and attention to detail, as well as other concerns. Here’s how to make the most of each of these to get your injection molding process humming along in no time.
Optimization of the Injection Molding Process
Modest and massive production runs alike require an eye for detail and optimization. Your process should, for example, provide the opportunity for your machines to run as uninterrupted as possible. Machines are machines, though. What about the human element?
Wherever possible, you should have standards in place for loading and unloading molds in a predictable and efficient fashion. If your work requires you to keep to a certain production schedule or produce a certain number of products per hour, optimization could be the missing link.
One key to optimization is effective employee training. The folks you have operating your machines should be able to stay on task without a lot of second-guessing, or the molding dance, as some refer to the art of loading and unloading molds.
Another variable to optimize and remain mindful of is how you cool your products. Optimize the process so it’s consistent throughout your production run — if your cooling process is too harsh, you might suffer from an uptick in avoidable product warping and other defects.
Monitoring Production Rates
Part two of optimization concerns monitoring your production efforts at every step of the way. It’s about creating accountability — and also rewarding excellence.
Having a trained and enthusiastic team is important, but you should have checks in place so you can quickly identify bottlenecks in your production processes or areas where your training perhaps fell short.
Something that usually provides measurable benefit is making incentives available for team members who exceed expectations or who maintain safe work practices consistently without sacrificing efficiency. Some success stories see manufacturing concerns dramatically reduce their labor costs just by rewarding safe and high-quality workmanship.
Efficient Materials Use
Making wise and efficient use of your materials is another key tip for improving your injection molding process and the quality of your finished product.
One thing to try is reducing the shot size. You’re probably tempted to use the largest shot size your equipment will allow, but take a moment to re-evaluate. According to experts, dropping your shot size by just 10 percent of your machine’s maximum capacity will help the application nozzle pull more color and work the check ring more fully. Both actions make later cleanup easier and help reduce wasted material.
Maybe it goes without saying, but making use of the correct thermoplastic for your application is another way to ensure your materials budget is getting stretched as far as it can. ABS plastics provide a good balance between affordability and toughness, for example, but acrylics produce items better-suited to high-UV applications, such as outdoor furniture and other products.
Preventive maintenance is one point here that shouldn’t be overlooked. You know what they say about an ounce of prevention and all that.
Make cleaning your equipment a top priority when you tackle maintenance of the preventive variety. If you haven’t already, take some time to draw up a repeatable process for cleaning your hopper and conveyor areas to make sure they’re free from excess material. Taking this seriously will make sure there’s no colors bleeding in from last time around and helps keep cross-contamination to a minimum.
Design and Materials Tips
Finally, it’s worth mentioning that streamlining your injection molding process is an endeavor that extends even to the art of product design. If you’re working with pure injection molding, your product design will follow accordingly. The same applies for products built using 3-D printers.
Whereas 3-D printing can help you realize complicated and complex geometric shapes and product designs, injection molding does require an eye for detail. The physical qualities of your product should facilitate the smooth flow of plastics into your mold. Getting this right will help you avoid common problems like warping, knit lines, sinking and a variety of other defects that result in wasted materials and time.
Another point to consider is the consistency in thickness of your product’s walls. Uniformity here will help your products cool at the same rate, which further reduces the likelihood of warping. Two useful rules of thumb: Avoid sharp corners in favor of rounded features and keep each of your walls around 40 to 60 percent the thickness of the adjoining walls.
By keeping these fundamentals in mind next time you embark on new product development, you can help keep your waste to a minimum and make the most efficient use of your materials, personnel and equipment.