Custom molded rubber products are so diverse that it would be virtually impossible to name all of the applications of these products worldwide. These products are used in everything from farm equipment to jetliners, the oil & gas industry, railroads, trucking and countless other industries. In addition, these products play a part in everything from bowling alleys to beverage containers, hospitals, breweries, elevators, canning factories – and the rubber molding process is also critical to producing a multitude of products from garden hoses to drinking straws. Suffice it to say that rubber products are everywhere – and they play a tremendous part in everyday life across the world.
While the range and applications of custom molded rubber products is obviously immense, for the purposes of this discussion we will focus on the processes by which these products are manufactured for use in the industrial sector.
Three of the most common techniques for manufacturing custom molded rubber products are compression molding, injection molding and extrusion. The type of process utilized depends upon both the materials used and the intended application of the finished product.
Compression molding utilizes an uncured rubber compound, often pre-shaped and measured to a specific weight. The rubber is placed into a mold that has been designed to produce a finished product of exact specifications. The mold is then closed, and the rubber is compressed using both pressure and heat. The combination of heat and pressure causes the rubber to flow and fill out the entire cavity of the mold – thus forming the finished rubber component. Depending upon the type of rubber utilized and the specific part being manufactured, an exact cycle time is established to determine how long the rubber must be cured. Upon completion, the molded rubber is ejected from the mold and are ready for use.
Injection molding is a process that dates back to the 1960s – although it has been improved somewhat since then. This process gets its name from the fact that it utilizes pre-heated rubber that is injected under pressure into a pre-formed mold. The process begins with a metal mold that is manufactured to the exact specifications of the finished rubber part. The mold is then placed into a press. Heated rubber is then injected into the mold, with the press applying pressure to ensure that the rubber is forced into every cavity within the mold. Upon curing, the rubber separates from the mold – and a perfectly shaped rubber product is produced.
Extruded rubber products differ from molded products in one basic way – the extruded product is forced through a die which forms the rubber into a tube-like shape to form products such as rubber pipes, hoses and other tubular products. Extruded parts can be manufactured to include continuous lengths of up to 60 feet or more.
While there are a multitude of companies that manufacture custom molded rubber products, one company that stands out in the field of industrial products is MARK Tool & Rubber Company. Founded in 1954, MARK Tool has earned an excellent reputation in the field of downhole cutting tool service – including the development of SplashTRON® pipeline coating. From the oil & gas industry to valves, electrical, railroad and much more – MARK Tool is an industry leader in custom molded rubber products.