Compression Molding Precision by Davies

Compression molding is an ideal method for molding plastic and composite parts because it offers benefits over traditional injection molding. Some of the benefits of compression molding includes:

  • Choice of different types of material
  • Parts that are exceptionally strong
  • Parts that are heat resistant
  • Parts that maintain their shape even under harsh conditions
  • Little excess material in production.

Compression molding involves the use of both heat and pressure Compression Molding Diagramto shape and cure material into a desired shape. This process is ideal for complex parts, parts that require a high level of strength, and parts that must withstand harsh conditions. There are many companies that are able to do injection molding, however most companies lack the know-how to excel in compression molding. Success in this particular molding method depends on finding a molding company with a substantial level of skill and experience.

The first step in the compression process is to choose  the molding material that would best fit the project. Usually, Thermoset materials are utilized in one of the subsequent forms.

  • Granules
  • Putty-like masses
  • Preform 

When these materials are subjected to heat and pressure they will cure and harden, resulting in a strong and durable final product.

What is the compression molding process?

To begin the compression molding process, the mold is preheated to a desired temperature which is determined based upon the material being molded. By preheating the mold we ensure that the molding material will flow easily and freely within the mold. This step is important to minimize any defects or inconsistencies in the final product.

After the mold is heated to the required temperature, the preheated material is added to the mold. The mold is then closed with top pressure or plug member, which applies pressure forcing the material into contact with all areas of the mold. By adding pressure we ensure that the material fully takes the shape of the mold filling all of the details or features of the mold.

Along with compression, heat is applied to the mold to initiate the curing process of the Thermoset resin. By combining heat and pressure we accelerate the chemical reaction within the material, causing the material into a process caused crosslinking. Crosslinking makes the parts stronger, less flexible and resistant to becoming soft in warmer environments. The duration of the heating and curing process varies depending on the specific resin along with the desired properties of the final product.

What are the benefits of compression molding?

Compression molding is known for its ability to mold large and fairly complex parts with excellent surface finish and accuracy. Compression MoldingAlso, the absence of shear forces during the molding process reduces the formation of what are called knit lines. Knit lines are lines on the product that occurs when the resin meets and joins together. The benefit of this process is a stronger and more structurally sound compression molded part as compared to other molding methods such as injection molding.

An additional advantage of compression molding is that the fibers are less likely to degrade in the composite materials. Fiber reinforcements, such as fiberglass, play a critical role in improving the strength and stiffness in the molded parts. During compression molding, the fibers are subjected to less shear stress, as compared to injection molding, preserving the length and alignment more effectively. Having less stress on the fibers allows for leads to an improved final product.

Compression molding allows for a wide range of materials, including thermoset and other plastic or composite material. These materials can be in the form of:

Davies capability to mold these types of materials allows for creating lightweight, high-performance components for a wide range of industry partners.

In the case of thermoset molding and transfer molding, there is an advantage in the use of high-temperature thermoset materials. These materials exhibit a superior ability to maintain their shape compared to thermoplastics. There is minimal shrinkage throughout the molding process. When these composite parts will not degrade if they are subjected to extreme environmental conditions such as being exposed to high heat. This stability of these molded part is particularly valuable when the wall thicknesses of the part varies, minimizing the chance of warping or distortion in the end product.

Moreover, high-temperature thermoset materials offer excellent heat resistance and can withstand extreme operating conditions. They are ideal for applications where maintaining its shape is crucial, such as under-the-hood components in the automotive industry, aerospace structures, and electrical insulation parts.

This type of molding is an ideal solution for its ability to mold large, complex parts with minimal knit lines. There is also little degrading of the fibers during the molding process ensuring a durable product. It is a preferred choice for industries that require with high-strength and heat resistance. The molding process allows us to control the forming process, allowing for more accurate and reliable parts. 

Choose compression molding as an ideal technique due to its ability to make complex durable parts that fit most applications.

Questions and Answers about Compression Molding

2Which materials are commonly used in compression molding, and what are their advantages for specific applications?
Compression molding typically uses thermosetting polymers, such as phenolic and melamine, along with composite materials. The key benefits of using these materials includes having tolerance to extreme heat, durability, and the parts maintain their shape even under harsh conditions. These materials are widely used in applications such as automotive parts, electrical components, and even aerospace applications due to these benefits.
3Can compression molding be used for creating parts with complex designs?
Yes, compression molding can produce parts with complex designs based upon the way compression molding works. The material is heated prior to entering the mold, this allows the material to flow better into the detail crevices in the mold when a consistent pressure is applied.
4What are some common applications of compression molding in everyday products?
Compression molding offers a versatile, high-quality, and cost-effective way to produce custom parts making it a popular choice in many industries. Compression molded parts can be found in kitchen utensils, electrical outlets, and components of automobiles.
5What is the compression molding process?
Compression molding involves the use of both heat and pressure to shape and cure material into a desired shape. It is a fairly straightforward method where a material is pressed between two heated molds, and once it cools down, it turns into a shaped part. It usually involves a rather large press and heated molds. This type of molding is ideal for complex, high-strength components.

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