Design Principles for Injection Molding Suggestions¶

The quality of the component design and mold design will play a significant role in maintaining the efficiency of the process when it comes to developing a new part that will be manufactured using injection molding. However, it will be explored later. Another factor to consider is the kind of material used to make the mold. Let’s spend a moment concentrating on design first.

1. Consider Corner Geometry¶

Sharp corners should, wherever feasible, be avoided, just as they should be avoided in conventional or CNC machining. Sharp edges may raise the cost of making molds for injection molding as well as hinder flow during the molding process. As a result, they raise both current and future expenses.
Choose a radius or chamfer rather than leaving sharp edges. Compared to a sharp corner, both of these characteristics will be simpler to machine into the mold. However, it is important to remember that a radius is the preferred choice. The greatest option to guarantee adequate injection molding flow is this. While a sharp corner is still preferable over chamfers, a radius will actually improve material flow. A greater radius is often less expensive to manufacture into the mold as well.

2. – Use Appropriate Draft¶

In designing a mold, draft is vitally essential. The ejection step of the process will be much improved by adding this little bit of taper to flat areas in the mold. Ejection becomes very difficult if these flat surfaces aren’t kept exactly upright. Proper cycle times often disappear when the process’s ejection step is disrupted.
Make sure that correct draft is incorporated in the mold design since short production times are one of the most important benefits that injection molding delivers. Parts should eject smoothly and effectively when the mold has a suitable amount of airflow.

3. – Consider the Wall Thickness¶

When molding, uniform wall thickness is crucial for effective heat dispersion. If heat is not dispersed equally, it will be visible in the finished product. The wall thickness is crucial in avoiding several faults that are easily preventable. Since the machine regulates the material’s temperature, this is more about enabling heat to escape uniformly over the whole mold.

Inadequate heat distribution may cause warping and blisters, both of which lead to scrapped components. One of the easiest methods to lessen or get rid of flaws like these is to consider consistent wall thickness throughout the design stage.

4. Utilize Every Available Square Foot¶

One of the finest aspects of injection molding is that several cavities may be made in a single mold. Additionally, the cavities need not produce the same component. Four distinct pieces might be produced simultaneously using a single mold. However, a mold might very simply produce several copies of the same component.
Since there are so many options here, be sure to utilize every square inch of the mold to its fullest potential. Make careful to use all of the mold’s area, whether those entails expanding or shrinking the existing cavities.

5. Included Functions¶

Depending on the component or product, extra characteristics can be required for it to operate correctly. Anything from a hinge to hardware that enables the part to be connected to another component might fall under this category.

This may be included into the design of a hinge using a live hinge. It is possible to reduce secondary procedures by incorporating features into the design. Overall expenses are decreased if ancillary activities are scaled down or eliminated.

Consider insert molding if the characteristics you need call for a material that is incompatible with injection molding. When using insert molding, the object is fitted with screws or other components as it cools in the mold.

6. – Use symmetry to your advantage¶

Design for Manufacturing contains a concept that makes use of symmetry and self-mating elements. Injection molding is a perfect example. Costs can be cut if it is feasible to adapt left and right components so that you only need to create two times as many of a part that can fit in both places.
Mold-making costs may be decreased by designing pieces to be self-mating or symmetrical. Don’t forget the fact that making injection molds might be rather expensive initially.

7. Take Production Quantities into Account¶

The amount of components that are estimated to be required is a crucial aspect. Should manufacturing be eased by constructing a single mold with several holes generating a whole batch of the same parts? Is it OK to use more than one mold at once? Is it more probable that this project will need 5,000 components or 500,000? When creating the molds, consider the intended manufacturing volume.

8. Consider Tolerances and Finishes¶

Regardless of the techniques employed in production, finishes and tolerances remain a sensitive topic in manufacturing. Costs might easily increase if the standards for finishing or tolerances are set too high. In the case of injection molding, this should be taken into consideration when the mold is being constructed.

The tolerances and finish specifications of the mold will define the best techniques, as well as how long it will take and how much it will cost, to create it. In certain sections of the mold, a poorer grade finish could be acceptable depending on the purpose of the molded component.

The portion of the component that the consumer design service won’t view would be the finest illustration of this. The perceived quality of the product won’t be much impacted if the mold doesn’t have a nice finish in the region that creates that surface.

If you want to prevent this problem from occurring, you need to look into the injection molding company available and choose the best one for the molding procedure.