Injection Mold Types: Production Molds


As their name suggests, production molds are used in the final stages by the injection mold makers. Unlike prototype molds, production molds are meant to be used repeatedly for long periods of time, so they must be durable and able to handle harsher conditions. Since it is the final stage of the process, the end product is meant to meet all of the project requirements and specifications.

Custom mold makers will skip the prototype mold if customers request that a project only goes through to production instead of working with a prototype. While the prototype can save money, it can also require more time as the production of the first few parts is meant to be a test run. Custom injection molds that go straight into production molds are given a much longer duration for the design process to ensure the first product is nearly perfect.

Production molds are not meant to be modified or changed. If the first product is too far off of the necessary requirements, you may need to start from the beginning. However, without the additional time for modifications, these injection molds can actually save time as long as the design process goes smoothly.

If you want to avoid using prototype molds, you need to find expert injection mold makers. New companies do not have the knowledge or experience required to create a final product that is nearly perfect on the first round. A number of things can go wrong and many considerations can be missed in the design stages. These are problems that expert injection mold makers have already encountered and learned to fix before moving to the production mold. In the event that there is a problem with the production mold, the experts can make modifications to avoid starting over again.


Injection Mold Types: Shuttle molds

Shuttle molds are made through the shuttle injection molding process. It is one of the more complicated types of molds and requires injection mold makers who understand more than just the basics of that process. Where injection molds usually produce a single product at the end, shuttle molds typically produces two bottom halves with a single top half.

The shuttle mold process creates a single unit – the top half and the first bottom half are made simultaneously. At the same time a second bottom half is being processed to include all of the additional aspects, such as inserts. Once the process is complete, the completed mold is moved further down the assembly line. The lower half with the added inserts is then worked with the top half to ensure it fits like the first one did.

Custom mold makers then begin the process again, closing the mold so that the bottom can be adjusted to align with the top as the second lower half is assembled.

The primary purpose of shuttle molds is to reduce the amount of time required to process each mold. Because the more complex portion of the mold is done at the same time as the top and bottom half are aligned, the custom mold makers do not have to wait for the inserts and other additions to be completed before completing another one. Since the top half does not require additions, it only needs to be included in the first round of the process.


Injection Mold Types: Insert Molds


Insert molds are one of the more difficult types of injection mold types. Injection mold makers have to consider several different areas to complete the final mold. Insert molds can combine plastics and metals (and some other types of materials) so that the final part can connect to different parts of the final product. Custom mold makers typically have to ensure the insert mold is wear resistant, has a reduced weight, conductivity, and tensile strength.

Insert mold makers must create parts that can be molded into other plastic components. There are a wide range of applications for insert molds, such as screws, studs, pins, rivets, tubes, bushings, and surface mount pads. The custom injection molds have to be able to create parts that are more durable and sturdy than other molds because they will be used with metal, which can be very harsh on plastics.

The purpose of insert molds is to reinforce the final product. They reduce the amount of time required to assemble parts, the cost of labor, and improve the strength of the final product. As they are meant to be made of durable plastics, they also help to reduce the weight of the part.

This particular mold type follows the same process as other injection molds. The primary differences are the design and QA processes. The design has to meet strict requirements to ensure the insert will be able to function as intended. The following are the two most common considerations during the design process:

  • Determine the means for holding the insert during the custom injection mold process
  • Any required undercuts or bosses required to strengthen the final product

Insert molds also tend to have a more rigorous QA process to ensure the final part provides the necessary durability and strength.


Custom Injection Molds


Custom injection molds provide manufacturers with a way to utilize one of the quickest processes to mass produce a product. While most plastic injection molds are customized, it is possible to use existing designs to quickly create molds that are basically recycled instead of customized.

The reason that most plastic molds are customized is because of the requirements and standards that every part and product must meet. If you already have a mold for a 1.25” screw, but you need one that fits a 1” screw, you have to create a new mold to produce the different size. Seldom can a manufacturer work with existing mold designs without having a custom injection mold made to complete the project.

Custom plastic molds offer more than just a way to meet specifications though. If you aren’t sure what method of assembly a product will be best for, or if a tolerance can be met with a particular type of rib, a custom injection mold can be a way of testing different designs to see which product is best for the intended purposes.

Custom injection molds can also be used to test out different plastics to see which ones work best under various conditions. For example, if you have been working with a metal mold that now needs to be replaced, a custom injection mold can be made to see if a plastic mold will be able to tolerate the harsh conditions that the metal mold had undergone. If the custom injection mold can handle the temperatures and other harsh conditions, you can save a considerable amount of money by making the change.

Custom injection molds are sometimes compared to 3D printing as well. There are times when 3D is more cost effective, but on the whole, plastic molds tend to be better for longer term projects as the process tends to be much faster and the final product more durable. Custom plastic molds can typically produce much larger parts than 3D printing.

Experienced custom injection mold makers can help you determine what mold type is best for your current project by reviewing your specifications and the final requirements for the finished product.