Compression molding is a versatile manufacturing process used by small and large production companies alike for creating a wide variety of parts, from large airplane parts to small baby-bottle nozzles.Get more news about compression moulding machine,you can vist our website!
In this guide, we’ll provide an introduction to compression molding, its benefits, and applications. Then, we’ll show how anyone can use this process to create prototypes, mass produce parts, and everything in between.Compression molding is a manufacturing process where a measured amount of molding material that’s generally preheated (typically referred to as a charge) is compressed into the desired form using two heated molds.
Compression molding and injection molding are very similar, but they have one major difference. In compression molding, molds are closed around the charge, and in injection molding, the charge is injected into a closed mold cavity.
Today’s manufacturers frequently use both compression and injection molding but for different types of parts. Injection molding is typically a better choice for more complex parts, while compression molding is a great option for relatively simple designs, including ultra-large basic shapes that cannot be produced using extrusion techniques.
Injection molding requires a shorter cycle time than compression molding, so it’s often faster and more cost-effective if you need to produce a large number of parts. However, compression molding is a lower-pressure production method, so the tooling costs are often lower. It also wastes little material, providing an advantage when working with expensive materials.
As a general rule of thumb, high volume production is better suited for injection molding, while compression molding is used rather for low and medium series of part production.Compression molding is often the most cost-effective manufacturing method if you need to produce simple, mostly flat, large parts. Some curves and pockets in designs are acceptable, but extreme angles and deep draws can be challenging to achieve through compression molding. Due to the lower pressures, tooling costs are affordable, and molds typically last a long time without warping or needing to be replaced. To offset the cost associated with compression molding’s long cycle times, manufacturers can use a mold with multiple cavities to produce multiple parts in the same cycle.
Compression molding produces solid parts that are free of flow and knit lines. The structural stability of compression molded parts is very high. Compression molding is also used to manufacture parts using composite materials, which means that durable, corrosion-resistant parts and products can be produced easily through this method.
Compression molding is also a great manufacturing tool for engineers and product developers. For example, prototyping can be done using low-cost compression molding. Simple compression molds can be designed in computer-aided design (CAD) software, 3D printed, and then used to form various types of materials with a simple tabletop vise. You’ll find an example of how OXO does prototyping this later on in this article.
While there are many benefits to using compression molding, it does have its limitations. Compression molding doesn’t work well for manufacturing complex parts, such as those with severely slanted angles or small details. The cycle time, which can be several minutes long, is slow in comparison to high-volume molding methods. Injection molding, for example, often has cycle times of just seconds.
The labor cost associated with compression molding can be relatively high as well due to the slow cycle time that correlates with more working hours. Flash and burrs need to be manually removed from compression-molded parts, which takes up more time and creates waste. All these limitations aside, compression molding is still an important manufacturing method that is used to produce a wide range of products that we use every day.