Molds are appropriately hollowed out blocks, based on patterns, which will take the desired shape when materials in viscous form are poured into it and later made to solidify. There are different materials used to make moulds like rubber, plastic, glass, plaster of Paris, and even metals. There are many industries in which moulding method is used to obtain multiple copies of the same pattern. The rubber industry is one of them, and in this field, different types of moulding methods are applicable.

So, what is rubber moulding? It is a process through which usable products of rubber is created. The rubber used in this case is usually an untreated one; which is also known as elastomers. This naturally occurring polymer features excellent elasticity. It means, when this kind of rubber is stretched or compressed with the application of external force, it can revert to its original shape and size. This very property of rubber is exploited when using moulds with rubber to use in places where shock absorbing is necessary, mainly in the automobile industry and metal furniture, etc.

Types of rubber moulding process

  • Compression moulding- Among the many moulding methods, this is the simplest one. Compression moulding techniques feature different shapes and sizes, and they also comprise of singe cavity. But, what makes this technique so simple? Well, in this process, all you have to do is place the untreated rubber in the mould cavity. Once you place it inside, you just have to close the mould and wait for the rubber inside to cool down. However, external pressure is also applied to get better results. By compressing the top and the bottom plates, the air trapped inside the mould is driven out. So, this is how the compression moulding technique works.
  • Injection moulding- In this process, the injection machine is used. The injection machine is accompanied with a barrel assembly and a nozzle as well. The rubber is injected into the machine, and the category of rubber used in this process is commonly recognized as gum stock. The rubber is placed inside a stuffing box, which in turn is put into the injection barrel. The high amount of pressure is used during the process of moulding, which keeps the mould closed all through the curing as well as injection cycles. In this process, a screw is also used for injecting the rubber via the nozzle into the mould. Quite obviously, the process involved in injecting moulding is a complicated one.
  • Transfer moulding- The process of transfer moulding usually varies according to the shape and size of the mould. The shape of the mould in turn decides the complexity of the process. In this process, the rubber is put inside a transfer pot. The pot is placed right above the cavity region. The box is then pressed into the cavity with the help of a piston. Both heat and pressure is applied for treating the rubber here, and the transfer of moulding in this case remains quite like that of the injection system. The end product developed through this process is somewhat cheaper in price when compared to the above-mentioned processes.

So, those were the three main methods available for rubber moulding. The selection of the process is certainly a complicated task. For this reason, before you avail the services of a company that moulds rubber on behalf of its clients, it would be better to seek expert advice as to which moulding process would be most desirable for your manufacturing needs. Only an expert can help you figure out the best moulding method per your requirements. In this regard, you can seek recommendations from people you can trust. In addition, going through the online reviews can also prove to be helpful for you.