1. Any shape can be formed
Just like in mechanical engineering, part designs must be manufacturable. Impossible to shape any shape. Plastic parts should be moldable to a large extent. If something goes wrong, or if the formability is poor, you can find yourself running into all kinds of production issues and quality issues in the mold making process.

The misconception that plastics of any geometry can be formed perfectly is incorrect and misleading. Most designs need to be revised if they are not at least 90% of the original idea. Perfection depends on the balance of melt flow and heat exchange channels. It’s logical that if the plastic doesn’t freeze evenly, the mold will be useless for all intents and purposes.

2. Plastic injection molding is not suitable for prototyping
Plastic injection molding is notorious for being unsuitable for prototyping for a variety of reasons. Often, it’s considered a resource-intensive technology, in the sense that it’s “not cost-effective” and “takes too much time.” Often, other techniques are used for prototyping, but the main problem is the lack of similarity to the final product.

In fact, the injection molding method offers the most cost-effective solution for creating samples that resemble the finished product. It creates high-quality prototypes faster and more accurately represents the final product than any other option at your disposal. This will give you a feel for the finished product so you can make necessary changes without affecting the cost.

3. Short mold production cycle
The durability of your mold and its production cycle largely comes down to your requirements. For example, steel molds are built and developed for long-term production. On the other hand, molds developed using other materials are used for prototyping and other short-run production. That being said, regardless of the material used, the mold is extremely durable and can operate consistently over hundreds of thousands of cycles without failure. This, in turn, will produce thousands of parts for you.

4. Mold manufacturing produces a lot of waste
We all know that working with CNC machines requires highly trained professionals, but the job is sometimes given to engineers with minimal training. Experienced CNC operators are often responsible for many tasks, including workplace loading, unloading, cycle activation and monitoring, workpiece measurement, evaluation, adjustment, and more. So it only makes sense to hire an experienced CNC operator who can minimize scrap and equip them with the best machines in the business.

Additionally, injection molding and mold making produces minimal waste compared to other traditional manufacturing processes. Older, less advanced processes often eat up a significant portion of the virgin plastic flakes or clumps.

Four key areas of the machine are responsible for small amounts of plastic waste – gate locations, runners, gates and cavities, where excess material can leak out.

5. Only injection parameters can solve quality problems

This is wrong. Injection molding parameters are not the only way to correct the molding process. Constraints such as dimensional inaccuracy, warpage, sink marks, and shrinkage can be partially resolved with the help of mold design.

A job that worked perfectly before may not always run perfectly. Using the most efficient mold and part design is just as important as setting the injection molding parameters. Therefore, it is safe to say that the quality of your final product can be largely determined before production begins.

Final thoughts
Now that you know the most common mold making myths, you know what not to do. Get the right people involved in the job, find competent programmers who understand the process, and use reliable machines from well-known companies. Optimizing your manufacturing process will be a breeze if you follow this simple advice.