Plastic Molding Manufacturing
The advent of plastic molding manufacturing changed the production industry and revolutionized how plastic production parts were made. The versatility of plastic injection molding cannot be overstated as you can produce large plastic parts for the automotive industry or tiny plastic parts for toys. The technology behind the production remains the same, the only players that change are the set-ups and the molds used in production. The ease of changeovers in comparison to other production methods also cannot be overstated. It can take a couple of hours to change a regular production line on a progressive die press. Changing a setup and mold line over in a plastic molding manufacturing plant can take as little as 15 to 30 minutes.
Injection Molding Process
A good way to visualize the injection molding process is to watch a 3D printer work on a project. 3D printers are still in their infancy as a vast majority of homes and businesses don’t own one due to the high prices of the units. The 3D printer takes raw plastic (usually in a long continuous string) feeding into the heating unit which heats the plastic up until it’s malleable and liquid. The unit then disperses the liquid plastic onto the programmed area of the printing area. The CAD program will then help shape and form the dispersions into the final plastic product.
A plastic injection mold machine works along those same lines, albeit at a much faster pace and higher temperatures involved. The injection mold machine is set up first via a program that details which part will be made with preset temperature and time controls. The molds are then placed into the machine and this completes the initial setup of the job. To complete one piece, the machine closes the two halves of the mold together in the machine to completely seal the two halves together. These molds are usually constructed out of steel or aluminum which can take the temperatures of melted plastic.
Once the molds are sealed together, small pellets of plastic are then heated near an extrusion point within the vicinity of the sealed mold. The melted plastic reaches a heating point where it’s malleable and liquid, the machine then starts the injection process. The hot plastic is forcefully fed into the sealed mold chamber, filling the mold up completely. The mold then starts to cool as the two halves of the mold open back up and internal pins kick the completed part out to either the operator or a slanted chute for the completed part to slide into a tray or tub. The process can take either 15 or 30 seconds, or it could take a couple of minutes, it’s all dependent on the shape and size of the mold. Larger molds take longer to complete due to the process involved.
Benefits of Plastic Injection Molding
Plastic Injection Molding provides a great help and benefit to production factories due to its consistency of finished products. You’re going to get the same part, time and time again with the rare deviation that needs to be reworked after the fact. The previously-mentioned versatility factor between setups and molds and the wide range of products that you can create from a plastic injection mold.
There’s minimal waste from plastic injection molds compared to other manufacturing methods. The automated nature of the machine and the process means that you won’t need as much labor to run these machines. The tooling maintenance on plastic injection mold machines are nominal and don’t cost that much compared to other methods.
You can use a wide range of colors in the finished product with a plastic injection mold machine as compared to metal production methods. This color option can separate your products from other vendors and make your products stand out. You can also adapt on-the-fly with plastic injection mold machines to account for emergencies and mid-shift changes from the engineering department.
Understanding the Costs Associated with Plastic Molding
There are factors that come into play when figuring out costs when utilizing plastic mold production methods in comparison with others. We will look at a few of these factors below to get a better understanding.
Dimensions Of The Piece
The dimensions of your production piece must be factored in as the larger the mold, the more expensive the mold will be to initially produce, run, and to service. The larger the piece, the slower the production time will be, and you will need to factor the slower production time in with how many parts you can produce per hour.
Compliance regulations vary between industries, and you must adhere to these compliancies when producing plastic parts. Compliance consists of fragility and rigidity of the final piece and these pieces can’t be deemed unsafe.
The raw plastic that is used can be taken from a wide variety of plastics available. Each plastic has its own pros and cons and some are better suited for injection mold than others. The range of price in raw plastics is a wide one and can range anywhere from $1.00 to $30.00 per pound. This will factor into your production costs and your contracted price to produce the parts.
There are other factors that could come into play such as: plating, cell packing, layer packing, painted parts, the need for additional machining, and retail packaging.
Injection Molding Services
Plastic Injection Molds
Plastic Injection Molds can come in a variety of shapes and sizes, and they can be custom-made to your specifications. The molds are made with quality materials that withstand years of use at high temperatures and constant action.
Prototype Injection Molding
These types of molds are usually made by Plastic molding suppliers to do an initial test run of a product to see how the product looks and feels quality-wise. Prototype Injection Molding is a great alternative to those considering employing a 3D printer to do up a mock part or two. The quality of prototypes coming from a prototype injection mold holds up to real-world use and is a better judge of quality than those coming from a 3D printer.
Custom Injection Molding
Custom Injection Molding is a flagship operation of quality plastic molding manufacturers. Not every piece is going to be uniform in shape and size and different projects require different expectations and end results. Custom Injection Molding is the process of designing custom molds to your specifications on your project to deliver a high-quality piece. The molds are just part of the process as the raw materials used can come from a long list of different plastics, each with their own pros and cons that can either make or break your project. The custom molds and the best suited raw materials will come together to make your custom piece the highest of quality and more importantly, repeatable in a production line.
Design Engineering & Assembly Extras
The process doesn’t stop there as a plastic molding company worth their salt also conducts design engineering and those little touches that are needed to separate them from the other molding companies out there. Your project may need professional design and CAD engineering to develop your custom mold. Some other factors to consider are: layer packing, cell packing, poly bagging, and other additional features.