The amount of time that it takes to manufacture a plastic injection mold depends on the type and size of the part.
The manufacturing process can be as little as two weeks for simple plastic parts. At Zetar, 80% of the molds can be completed within 25-35 days, but more complex molds will require significantly longer times like 40-60days. It’s important to consider how quickly you need your injection molds so that you can plan accordingly.

The process of making an injection mold

To know how long it takes to make an injection mold, we need to have a general understanding of the steps of making an injection mold.

1.Process analysis of plastic products

Get the sample or product drawing of the plastic products to be molded by the customer. If you get the sample, scan it into a 3D drawing first.

Before the mold design, the designer should fully analyze and study whether the plastic products are in line with the injection molding processing principle, which requires careful consultation with the designer of the products and has reached a consensus.

This includes the necessary discussion on the geometry, dimensional accuracy, and appearance requirements of the product to try to avoid unnecessary complications in mold manufacturing.

2. Mould structure design

Do mold modeling, such as molds with hot runner, design the hot runner well too. A set of mold, not only need to have good processing equipment and skilled mold manufacturing workers, another very important factor is to have a good mold design, especially for complex molds, the good or bad mold design accounts for more than 80% of the mold quality.

An excellent mold design is: under the premise of meeting the requirements of customers, make the processing cost low, processing difficulty is small, processing time is short. To do this, not only to fully digest the requirements of the guests, but also to understand the injection molding machine, mold structure, processing technology and the injection mold factory‘s own processing capabilities.

Therefore, to improve the level of mold design, the following points should be achieved.
a. Understand every detail in each set of mold design, and understand the purpose of each part in the mold.

b. Refer to previous similar designs when designing, and understand the situation in its mold processing and product production, and learn from the experience and lessons learned.

c. Learn more about the working process of injection molding machine to deepen the relationship between mold and injection molding machine.

d. Go down to the factory to understand the process of processed products and recognize the characteristics and limitations of each processing.

e. Understand the test mold results and mold changes of the molds you designed to learn lessons.

f. Try to adopt the previous more successful mold structure in the design.

g. Learn more about the effect of mold water entry on the products.

h. Study some special mold structure and understand the mold technology.

3. Mold design confirmation

After the mold drawing is designed, we need to confirm with customers whether it meets their requirements.

4. Purchase mold material and choose standard parts

In the selection of mold material, besides considering the precision and quality of the product, we also need to give the correct choice with the actual ability of processing and heat treatment of the mold factory. In addition, to shorten the injection mold manufacturing cycle, use the existing standard parts as much as possible.

5. Roughing, that is, rough machining

Including dynamic and fixed mold wire cutting, CNC milling, and milling machine processing.

6. Finishing

Including medium-wire, slow-wire, high-speed milling, EDM, and deep hole drilling.

7. Surface treatment

Surface treatment according to customer’s requirements, including polishing or skinning.

8. Die Matching

The so-called mold matching is to assemble the machined parts in an orderly and correct way after the machining is done. Machining is the error, not 100% accurate, so in the assembly is not smooth, then you need to grind the parts a little, or by other means so that the parts can be assembled in order. This process is called mold matching.

9. Test mold

A set of molds from the design to the assembly is only 70% to 80% of the total mold manufacturing process.

For the error caused by the inconsistency between the intended shrinkage and the actual shrinkage, the smoothness of the mold release, the cooling effect, especially the influence of the size, position, and shape of the gate on the accuracy and appearance of the product, etc., must be tested through the mold trial.

Therefore, a mold test is an indispensable step to check whether the mold is qualified and to choose the molding process.

Factors Affecting the Production Time of Plastic Injection Molds

In-mold making, customers want to make the mold quickly, but the mold-making time usually depends on the process difficulty and order quantity.

1. Process Difficulty

It refers to the difficulty of making the plastic part sample provided by the customer. Generally speaking, it is understood that the more complex the shape of the plastic part, the more difficult it is to make the mold. From a technical point of view, the more parting surfaces a plastic part has, the more difficult it is to process and the longer the mold manufacturing time.

2. Number of customer orders

When it comes to this factor, many people find it hard to understand why the number of customer orders is related to mold making.

The number of customer orders determines the number of cavities in the mold. The number of cavities in the mold: that is, a set of mold has several cavities, a set of mold production out of several products, depending on the customer’s product market is large or not, do two products and a product is certainly different, the processing time will also be different.

Normally, for new products, since the market is not fully open and the market demand for the product is not that big, the number of cavities in the injection mold is not that many, and the market supply can be guaranteed, so the cost performance is relatively the highest.

Of course, after the market of the product is cultivated and mature, the number of cavities of the mold will be increased, which depends on the market demand to determine whether to make changes in the number of cavities to feedback the market demand.

If the order quantity is high, the corresponding number of mold cavities will be higher and the time required to make the mold will be longer because the cavities will be longer accordingly. In addition to faster production, it increases the productivity of the product, thus reducing the cost of the product, and the individual product will be cheaper.

If the order quantity is small, the cavity time is shortened and the mold-making time is reduced. So generally we will recommend the optimal number of mold cavities to meet the production requirements and ensure the highest cost/performance ratio after our calculations based on the customer’s order quantity requirements in our quotation.

3. Product Size

The larger the size, the longer the cycle time for plastic mold processing, and the longer the parts processing time.

4. Product requirements

Different customers have different requirements for the products, whether the designed surface is sub-surface or glossy, or mirror surface, which affects the production cycle of plastic molds.

5. Product material performance

Often our products have special requirements, the requirements of the mold steel and processing technology requirements are also different, the follow-up processing links will be more complex, naturally will take a little time, and some molds require anti-corrosion or soft rubber mold, the requirements will be different, the manufacturing and processing process will be more complex.

Summary

Through this article, we have learned about each step of the injection molding process and the factors that affect the production time of injection molds, and the length of each production process is determined by the size, structure, requirements, and order quantity of the product.

So if we have an injection molded product that needs to be realized by the injection molding process, we should evaluate the complexity of our product before the mold making and arrange the project planning time reasonably.

To shorten the time to make the mold, communicate early and often with your mold designer and mold maker so that they can help you with your design requirements and allow ample time to make the injection molds so that the injection molding can be done more smoothly later.

After all, there is no way to skip each step of the production of injection molds. Only when you make a good mold can you produce satisfactory products that will be loved by consumers.