Custom plastic prototypes fulfill a number of needs in the plastic injection mold making process. Inventors, industrial designers, manufacturers and others are constantly seeking ways to develop new products in a short time span, and prototypes are essential in the mold making process.
The need for speed is a powerful driving force behind the custom plastic prototype development. The first one to the marketplace usually gets the lion’s share, which can be quite a motivating force. Now, with stereo lithography, 3D printing, and rapid injection molding it is easier than ever to get there first. Wohlers Associates is a great resource to learn about 3D printing.
Most prototype molds last a lot longer than they are guaranteed to, so you might even get some short production out of the deal.
Creating custom plastic prototypes
You can get a prototype built out of aluminum, pre-hardened steel or even non-metallic composites. Each has their advantage and special features. Aluminum is the most common material used in prototypes because it is very easy to machine, yet is able to withstand the injection molding process.
There are several mold grades of aluminum commonly used, such as Alcoa’s QC-10. This is a remarkable material in that it is relatively hard, able to be machined in great detail, and is 4 times more conductive than steel. This conductivity can help reduce cycle times in molding.
Aluminum, such as QC-10 can be made by CNC machining, WEDM’d, sinker EDM’d and highly polished. About the only thing it cannot do is last as long as steel. A bit more care must be taken when working with it as well, due to the fact that it is still aluminum, not steel.
Another common choice for injection mold prototypes is pre-hardened steel, such as P-20 or PX-5. These, and others steels, are widely used if a higher production is required, or if there are fine details that exceed the ability of the aluminum to be machined
These steels are also fairly easy to machine, especially PX-5. This steel is harder than P-20, but easier to machine and polishes better as well. There are two other pre-hardened steels that are often used: NAK-55 and NAK-80.
These steels are excellent, especially when there is a need for polishing. Many prototype injection molds have produced far more high quality parts than expected, and the quality of the material is a major reason.
Finding a plastic prototype manufacturer that is willing to listen is critical to your success.
How long does it take to get a prototype injection mold?
Naturally this depends on your pocketbook! It is not uncommon to get a quality prototype in 1-4 weeks. Of course, the more complicated you design, the longer it will take. Most injection mold makers can deliver very quickly, especially for a premium.
What are some tips to succeed with prototypes?
Work with the injection mold designer and injection mold maker to make your part as easy to produce as possible. This will speed things up dramatically and reduce your expense. Undercuts, side actions, lifters and such add to the cost exponentially. Often it is possible to achieve the desired part without having necessarily all the features that the final product might contain.