Pros And Cons Of Thermoset Injection Molding

Weighing the pros and cons of the molding process for your composites can help you determine whether it is the right choice for your project needs. Manufacturing plastic or composite parts requires heating and pouring the raw materials into a mold that has been specially made for the part. The four most common molding processes are:

Compression

Injection

Transfer

Extrusion

Different molding processes are used to create different works. In this article, we will weigh the pros and cons of the injection molding process for thermoset composites.

Advantages of thermoset injection molding

Injection-molded parts may be the most suitable one for several reasons:

Many different types of materials can be used for injection molding, including thermoplastics and thermosetting resins, polymers, and elastomers. This provides engineers with a lot of control over which hybrid material will produce the best results, especially when it is necessary to meet specific performance requirements.

Very suitable for high-volume operation.

Precision and low waste. Due to the specific mold and material combination, compared with other processes, there is less waste of injection molded parts.

Short cooling time-the injection molded parts cool quickly, reducing the time required for the injection molded parts to be released from the mold.

thermoset injection molding

Disadvantages of thermoset injection molding

For the above reasons, injection molding is an excellent process, but it also has certain limitations and defects. These disadvantages include:

Mold costs-these costs can be very important because precision-made molds are required.

Flash-Flash is inevitable when injection molding thermoset plastics. Once the part is created and ejected from the mold, the next step is to automatically or manually remove the flash (excess material). Due to the high viscosity of liquid plastics, a flash of thermoplastics is not a problem.

Part size-The size of the part being created is very important in the molding process. Typically, smaller part sizes (0.1 lb to 6 lb) are injection molded, while larger parts are transfer or compression molded. The number of orders will also determine which molding process is best for the project. Compression molding may be used for smaller parts with a low (or high) volume, while transfer molding may be used for medium to high volume projects. Injection molding will be ideal for large-volume running smaller pieces.

Finally, when choosing a molding process for your part, it is always recommended to talk to a thermoset composite or thermoplastic engineer. After assessing your needs, they will be the most capable and able to make suggestions for your work and provide the highest quality products at the most reasonable cost.

We are a thermoset injection molding supplier. Please feel free to contact us if you are interested in our thermoset injection molding or other products.

Two-Shot Molding vs. Overmolding

What is two-shot molding?

Two-shot molding, also known as dual-shot, multi-shot, or double-shot molding is a subcategory of injection molding that allows engineers to create multi-material or multi-colored parts without adding additional assembly steps.
The two-shot injection molding process is best understood, where different material layers or colors are created by the injection molding machine. The first material is injected into the mold to create the substrate, and other materials or materials around the substrate will be molded. The substrate solidifies and cools before being transferred to another cavity of the mold by hand, a robotic arm, or a rotating plane.
Engineers should know that the speed of two-shot injection molding can be accelerated or slowed down depending on how the substrate is transferred to other cavities of the mold. Hand and robot arm transfer takes longer than rotating planes, but rotating platen molding is more expensive, and is usually just an efficient option for high-volume operation.
In addition, it is essential that the materials of the mold will be easily combined and the molds are properly aligned to prevent deformed parts.
Advantages and disadvantages of two-shot molding
Two-shot plastic injection molding is efficient and economical manufacturing technology. This process can also produce highly durable end parts and assemblies.
From a design point of view, two-shot molding provides designers with a lot of flexibility, because this process can create complex geometric shapes and accommodate multiple colors to make parts more beautiful.
In addition, since one machine manufactures the entire part, no post-processing is required, engineers can drastically reduce manufacturing time, thereby keeping costs low. However, it is worth noting that the cost of the initial two-shot mold may be very high, and the two-shot molding machine is more expensive than the standard injection molding machine. Fortunately, these costs are usually offset by saved labor and assembly costs for mass production.

What is overmolding?
Overmolding, like two injection molding, is a multiple injection molding process that uses two or more different thermoplastics to produce a single final product. This process is ideal for engineers who want to build components that are strong, functional, beautiful, and that will not separate over time.
In order to start the over-molding process, engineers injected a harder over-molding material. Then, the substrate is placed in a complex mold or a complex cavity in the same mold. The molten overmolding material is sprayed into the substrate, or onto the substrate, or sprayed around the substrate. After the molten material is cooled, the substrate and the mold are bonded chemically or mechanically. The entire over-molding process only takes 30 seconds.
Advantages and disadvantages of overmolding
Overmolding and two-shot injection molding have many of the same advantages. They are ideal for the rapid manufacture of durable, reliable, and shock-resistant parts with complex geometries, but over-molding is best suited for low-volume production runs.
Compared with two-shot molding, the design of multiple molds is also easier to carry out, because engineers can use any standard injection molding machine to carry out this process.
In terms of disadvantages, the tolerances of parts manufactured by overmolding are often lower than those of two-shot molding that can be achieved. It is also important to remember that plastic compatibility requirements may limit designers.
We are two-shot molding suppliers. Please feel free to contact us if you are interested in our products.