What is Molded Textile Rubber?
In order to fabricate rubber in a variety of shapes, sizes and colors, manufacturers process the material using a wide range of molding technologies. Molded plastic parts are useful in various industries, such as those that employ printing, plumbing and hydraulic processes. Generally, molded parts are installed as either part of machinery (rollers for printing presses) or as individual units (caps). Standard parts can be pre-made to order, though customizing dimensions and shades is also an option. The three primary types of technologies that are used to create an array of molded products are: injection molding, compression molding and transfer molding.
Molded Textile Products
There are numerous amounts of rubber molded products that are fabricated. Some standard products include O-Rings, rubber hoses and tubing, isolators and rollers, all which have various functions.
O-Rings are generally used for sealant purposes and can be fabricated in an assortment of different sizes. Variations of rubber that are used for ring fabrication include silicone, neoprene and polyurethane.
Rubber hoses and tubing are frequently constructed with an inner tube that provides a layer of reinforcement. They can be customized to be either conductive or semi conductive and they are manufactured in both natural and synthetic rubber variations.
Isolators are typically installed inside equipment to decrease the noise and vibration in machinery. They are processed using various synthetic rubbers and are an example of rubber bonded to metal.
Rollers are used in applications that command friction and holding power. They are often found as part of machinery, such as printing presses and are distinguished for their heat resistant capability and resistance to high-pressure compression. They are manufactured in an array of rubber variants, including neoprene, polyurethane and hypalon.
Textile Molding Technologies
- Compression Molding
Compression molding is a traditional form of casting rubber that is efficient for its low tooling cost and minimal waste production. The process involves a preformed cavity, which is pre-shaped (shaped like the part to be fabricated). Various forms of rubber, such as urethane, silicone and neoprene, can be manually placed in a press-heated cavity mold, which compresses the rubber matter with its plates. The combined pressure and heat of the cavity forces the rubber to take the shape of the mold.
- Transfer Molding
While it is comparable to the compression molding process, transfer molding is better suited for producing smaller rubber parts and pieces with intricate detail or design. During this process, uncured rubber is forced by a piston through the sprue holes of a transfer pot to the cavity. This method is commonly applied to processes that require rubber molded on metal inserts, as the cavity is typically enclosed and capable of processing “insertable” pieces. Generally this process is more costly than compression molding due to the tooling rates, but it is associated with superior dimensional aesthetic and a shorter processing cycle. The rubber variants that are typically processed in this cycle are similar to those processed in the compression molding cycle.
- Rubber Injection Molding
This process involves a ram that functions by heating and measuring rubber before it is injected into the cavity mold of the injection press. Typically, the rubber is injected through the nozzle to the machine’s runner system. It is pushed through the cavities, where the molding takes place. As with the transfer molding process, injection molding is suitable for applications that involve rubber molded on metal. This process generally involves fewer cavities than in transfer molding and produces less waste material.