When talking about rubber products manufacturing, there are various manufacturing processes that do exist. With each procedure, it comes with its own set of benefits that make it the right choice for the manufacturing of specific product. Being able to make yourself aware of different manufacturing processes help to understand tradeoffs and cost implications.
Few of the commonly used rubber products manufacturing include extrusion, molding, latex dipping as well as calendering.
Extrusion – this process begins with unvulcanized compound that is then fed into the extruder. After it’s inside the extruder, it’ll be carried forward to the day; a specialized manufacturing tool to mold the rubber. As soon as the compound has reached the dye, the pressure forces it through the extruder’s opening. The extruded product will be vulcanized before it can be deemed usable.
Latex dipping – for this, it takes place when a thin walled mold is immersed to the latex compounds and slowly withdrawn. The thickness of dipped product can be increased easily by just re-dipping the product in latex compound. When the dipping process has occurred, the product is now finished in vulcanization. Depending on finished dipped product, it may require post treatments.
Molding – it’s composed of 3 major manufacturing processes namely transfer molding, injection molding and compression molding. For the latter, it’s the least expensive and at the same time, the oldest technique. With this procedure, rubber compound is formed into blank or chunk of rubber. The blank gets placed into mold cavity for it to be shaped. There’s a slow heating time leading to long curing time. The heating may vary from 90 seconds for thin walls to few hours for thicker walls.
Transfer molding is the natural progression in development to be able to limit the drawbacks of compression molding. This procedure starts with blank being loaded in chamber. Once done, it’s scattered in several cavities. In early stages, preheating takes place in rubber which forces the rubber to flow through channels. Through this, the curing time is reduced and the rubber can flow easier to fill in mold cavities with improved efficiency.
For rubber products manufacturing, injection molding is the most common procedure used. With this procedure, the press units as well as injection unit function as separate entities which come with a separate control as well. With such kind of molding, blanks handling is eliminated and processes could be automated and difficult cavities as well as flow channels can be filled easily.
Calendering – this one functions by forcing softened materials to center of counter rotating rollers. The rollers then compact the materials and overall thickness of product is set by gap distance between cylinders.