Compression molding a vital molding process that utilizes compression force and heat to shape raw materials into designed patterns and geometries depending on the client’s specifications. The molding process is mostly used in the rubber sector.
The metal molds are usually made using either pneumatic or hydraulic seals. In lay man’s terms, the whole process pertains to the heating of the raw-materials till they are molten, and they are, in turn, closed for a specific period.
Once it removed, the mold will have excess materials; this is quite normal as a result of being compressed and heated. To get the exact dimensions and shapes, flashing commences, and it’s done by specialized designers at LT century, bringing to light the ideas and specifications of the client.
Basics of compressions molding
The following factors need to be taken into account before the commencement of the compression molding process:
- Curing time
- The pressure to be applied
- The shape
- Raw materials
Typically, two main types of raw plastic commonly used in compression molding.
- Thermoplastics- There are mainly four types acrylics, polystyrene, polypropylene, and polyethylene
- Thermoset plastics- They also come in four types silicones, phenolics, unsaturated polyesters, and polyurethane.
Thermoplastics and thermoset plastic are quite exceptional to compression molding; for thermoplastics, they harden when heated to liquid molten and can also be cooled and reheated as many times as you want.
For Thermoset plastics, they fall in the category of pliable plastics, which means once they are heated and forms a shape or part, it’s permanent; they cannot be changed. The amount of heat required for both sets varies depending on the desired results and client’s specifications.
Other vital factors that are critical determinants in the time taken to make molds include the thickness of the product, time, material. Note that, for compressions, molding makes sure that the materials you select will fill the crevices in the mold resulting in even distribution forming the perfect part or product.
The initial process of compression molding starts with:
- Placing of the material into the mold
- Heating of the product till its pliable and soft
- Using the hydraulic tool to press your material against the mold
- Once the molten material has hardened and forms a shape of the mold, it’s removed
- The resultant product undergoes additional services such as cutting the excess materials.
For some products, they will be market-ready after ejection from the mold. Compression molding is advantageous to manufacturers as it is quite economical and cost-effective when mass-producing parts/products. The method is very effective, resulting in minimal material wastage.
Compression molding future
A lot of manufacturing products are made from raw-materials; thus, compression molding is going to be around for decades to come. The only change in the future is mold products will be produced without the need for flashing.
With advancing technology, everything is being automated; thus, we are going to see a drastic reduction in skilled personnel. It’s not far-fetched to say that all aspects of the molding process will be done without human input.