Rubber is a very common material that everybody knows its properties very well. Countless objects are being used in day to day life. It is soft and strong, versatile and has elasticity that when pulled back it can stretch to certain extend. Because of these qualities, it is used as fastening material like rubber bands and other fasteners. It can grip the items strong and will not let loose in the package. Though the natural material is available man uses synthetic, the artificial one, for all his creations.
With molding it can be finally shaped out into any product. Molded rubber products are widely used in all fields, particularly in medical, commercial and industrial fields. It is the most useful material in manufacturing industries due to its properties. It is durable, force can be applied without worrying about change of shape, extremely flexible, cannot be fractured, can be airtight, waterproof, good insulators and easy for coloring.
Molds are containers into which, melted material is poured and when it solidifies, the material inside is separated from original containers. When melted material is poured into molds, molded rubber products are produced. Tires used in automobile industries are the most common example of rubber molded products. Tires pass through a complex process of production and in its final stage threads for friction are created by a molding process only.
Rubber itself can be used as molds. They are greatly used to create any type of design in engineering fields. Whatever application needed, they can be invented using these molds. Boots, seals, bellows, valves and vibration mount are to name a few. Since these molds handle pressure and temperature changes with ease, the efficiency of the machinery is increased.
Various Types of Rubber molding
- Injection molding: This type of machine is suitable to produce small parts that demand high degree of precise measuring. An example of this is the press shop. The concept behind this process is very simple. A metal mold with the exact size and shape of the rubber part is first created. Then, this is inserted into the press and attached to this injection system. Pressure will be applied by the press so that it can hold the top and bottom portions together. With the help of a screw, heated rubber will be injected inside the cavity using force and injection nozzle. It gets separated from the mold after it is cooled. The press opens and releases the part. The resulting piece will retain the exact details, size and shape.
- There is no heating element in this process. The inserted material is already heated. Molds used for this purpose are made with stainless steel which does not retain heat. Within a very short time, it gets cooled. These types come in horizontal and vertical modes. The only difference between them is the use of robotics in horizontal type to eject the completed parts. However, in vertical type there is no need for anything like this. The resulting parts just slip into the allotted container. Since this is expensive and is a natural product, it must not be wasted and methods to curb wastage must be implemented. This is ideal for mass production since it is cost effective.
- Compression molding: In this method, mold is divided into two halves. Uncured rubber is placed at the bottom portion of the mold and two halves get closed. It fills the cavity. The excess material will come out and after the curing timing is over the product is removed from the cavity. This process is ideal for producing expensive parts since it produces low volume only.
- Transfer molding: In this process, uncured material is placed on top of a transfer pot contrary to compression type. It goes inside the spores and fills in the cavity. It is vulcanized through pressure and heat and is later on removed successfully from the cavity after getting cold. Cost involved in production using this method is not at all expensive and hence it is ideal to create complex parts.
There is also a possibility to use hybrid mold which is a combination of injection and transfer molding types. An experienced manufacturer will know exactly which type of mold to use for each type of production.
Rubber can be recycled and hence manufacturers who use these molds can proudly declare that they are being Eco friendly. Still want to know more? Click here for more information about rubber molds and rubber moulding.