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Plastic mold plays a significant role in modern industry and is one of the key equipment for plastic production. Proper and effective plastic mold design can greatly improve the quality and production of products, extend the service life of molds, and reduce costs while increasing efficiency.

Why is it important to design plastic molds?

Reduce the COST.

A good mold design can significantly reduce the processing cost of each part. For example, designing long-life molds, reducing undercut, selecting materials, and designing a series or multi-cavity molds can all help reduce cost. In addition, a high-quality mold, designed accurately and with suitable materials, can last for a very long time while increasing production speed and further driving down costs.

Reproducibility

The goal of injection molding is to make many products in a short time, and the difference between each product is the smallest. Of course, many variables are inherent in the injection molding process, which leads to differences between each product. However, a well-designed mould can help improve the repeatability of the process. In addition, once a mold is designed and installed, it will last for a long time, bringing considerable return on investment (ROI) and additional benefits, such as increasing production speed and productivity.

Faster output

The design, material selection and other factors can increase the time of the injection molding process and the number of parts in each cycle. Reducing the length of each cycle means producing more parts per hour, which allows you to produce a lot of parts faster. Therefore, the more parts are manufactured per hour, the higher the production efficiency.

Please note that this can also affect the cost-higher productivity can further lower the price, especially if the mold quality is improved and the production error is reduced.

Better visual effects

A bad design can cause many visual defects in the final product. For example, war page, shrinkage marks, drag marks and bonding lines can all affect the visual appeal of the manufactured part. A good injection mold design takes all these factors into account, ensuring that the final product looks great.

Visual appearance is more than just “aesthetics” -your customers will undoubtedly notice it, mainly when their customers complain. Although high-quality materials are used, lines and marks will leave traces on the surface, resulting in poor appearance.

Durability

The durability of molds and the parts must be taken into account. Before the mould needs to be replaced, the material and design of the mould itself can affect the number of parts that can be successfully manufactured from the mould. The design of the mold can also impact the durability of the produced parts, reducing breakage. Less breakage and more outstanding part durability mean reduced production costs but also less tangible benefits, such as brand recognition.

If a mold is not designed well, it can cause many issues that can negatively impact the manufacturing process, including:

Increased processing cost

A poorly designed mold can lead to higher processing costs, as it may require more energy, time, and resources to produce each part.

Inconsistent product quality

Poor mold design can lead to inconsistent product quality, meaning that each product may differ in appearance or functionality. This can lead to customer complaints and damage to the brand’s reputation.

Decline in productivity

A poorly designed mold can increase production time, reducing output and resulting in lower productivity.

Visual defects

Bad mold design can cause visual defects in the produced parts, resulting in poor quality, and unsightly finishes

Reduced part and mold durability

Poor mold design can cause parts to break or deform easily, requiring more frequent replacements and increasing overall costs.

What is Involved in the Design Process for an Injection Mold?

Before designing an injection mold, several preparatory tasks are required. These include creating a design task list, understanding the geometry, applications, and raw materials of the plastic parts, and examining the molding process’s feasibility. In addition, a molding process card should be created, detailing product specifications, plastic material details, injection machine technical parameters, and injection molding conditions.

Injection mold structure design involves determining the number of cavities, choosing a split surface, deciding on the cavity arrangement, designing the gating system, determining the demoulding method, structuring the temperature control system, designing the insert block structure, and planning the exhaust system. The overall size of the injection mold is calculated by determining the working size of the part and deciding on the thickness of the different components. A complete structural drawing should then be created to detail the relationship between mold parts, lists, and titles, along with technical requirements, such as performance requirements for the mold structure, push-out and core pulling mechanism assembly requirements, mold assembly process criteria, usage requirements, mold numbers, engraving, oil seals, mold storage specifications, and requirements for trial molding and inspection.

Creating a component diagram follows the structural drawing, focusing on interior and exterior components in order of complexity and first molding parts, then structural parts.

Finally, design drawings should be reviewed to ensure feasibility and ease of manufacturing. By following these steps, an effective and efficient injection mold can be created.

What should be paid attention to when designing a good mold?

Wall Thickness:

It’s crucial to maintain a consistent wall thickness throughout a part to ensure its structural integrity. This helps the part maintain its strength and stiffness while avoiding potential problems like warping or sink marks.

Draft Angle:

A draft angle is a taper added to a part’s design that helps it eject from the mold easily. This essential feature helps prevent damage to the mold and the part itself during ejection.

Undercuts:

Any part features that prevent ejection from the mold are referred to as undercuts. Designers need to consider these features carefully and incorporate side actions, lifters or slides, to help the part eject with ease.

Ribs and Bosses:

Adding ribs or bosses can enhance a part’s strength and reduce its material usage. Ribs are thin sections applied to the part surface while bosses offer attachment points for screws or threaded inserts. Designers need to consider potential issues such as sink marks or deformation of parts when selecting these components.

Gate and Runner Design:

It’s crucial to optimize gate and runner designs in mold designs to ensure effective production, product quality, and cost efficiency. Poorly optimized designs lead to filling imbalances, air entrapment, and defects in final products. Designers should consider gate and runner complexity, maintenance requirements, and production costs when selecting these components for their mold design.

Correlation Designs:

These designs are the mold drawings designed by our company’s engineers according to the product drawings.

To obtain high-quality injection molded parts, it is necessary to collaborate with the most reliable manufacturing company.

Sino Mold Industrial is an advanced manufacture of injection molds. You can enjoy one-stop service with us, where you can customize molds and we will provide you with a five-star mold service. If you have read the above content but still lack confidence in your own design, you can send us your product drawings. We will design the most exquisite injection molds based on your product drawings and manufacture them for delivery within the specified time.

Conclusion

In conclusion, designing high-quality plastic injection molds requires a deep understanding of the plastic material, the product design, and the manufacturing process. By considering each of these factors carefully and strategically, mold designers can create effective and efficient molds that produce high-quality plastic products at a cost-effective rate. In today’s competitive and constantly evolving market, investing in high-quality mold can help businesses stay ahead of the competition and achieve long-term success.

Finally thanks you so much, Anita,Linda,Lina,Bery, Betty, Lucky,Melon, Louise,Irene and Jacky, You all did great job!

We’re getting better because of you all!

Want to say 520 in this special date for you all, To our great Sino Team!