A platen press is a type of industrial press that is used primarily to manufacture composite materials. For example, most commonly, platen presses are used to condense forest products and wood material in order to create such composites as plywood and particle board. Powered by hydraulics, platen presses condense, crush, form and mold products with the help of two large, heated plates. In addition to the forestry industry, platen press users are found in industries such as: research and testing, automotives, aerospace and aircraft, marine, transportation, plastic packaging, appliance manufacturing, furniture and military and defense.
In research and testing facilities, researchers use platen presses to conduct impact testing. They do so by placing a test object in between the two platens and measuring the impact as they crush it. In the automotive industry, platen presses form a variety of products, such as car bodies, tires and mats. Aerospace and aircraft industries use them to make a variety of airplane parts, including doors, seating structures, noses and nacelles, while they also make ship parts and components in the marine industry. In general transportation, platen presses can be used to produce freeway signs and honeycomb panels. They are also used widely in rubber and plastic packaging, in which they create rubber and plastic products like sheets and mats. Interestingly, in this industry, vacuum molding machines are also considered platen presses, since, in order to seal the plastic around the product, they crush and melt the product’s plastic edges between their heated metal plates. Platen presses are also used to help create appliance parts, stainless steel kitchen sinks, some kitchen furniture and even the conveyor belts upon which many other appliances are produced. They are indispensable in military and defense, where, since the combination of force and heat they employ allows them to work with even the strongest and densest materials, they are used to make and test body armor, bullet-proof helmets and other strong structural components.
Platen presses are made up of two large, flat and heavy metal plates, called the top and bottom platen. Most likely, they are made from stainless steel, as all components of platen presses are made from some type of strong, structural steel. These platens are stacked on top of each. To form a new product or shrink the size of scraps, the top platen moves up and down, applying extreme pressure, while the bottom platen remains still, allowing products to compact. Platens, considered to be the strongest and heaviest part of platen presses, generally weigh several tons each and they work via the power of hydraulic pressure. In fact, platen presses may be categorized as a type of hydraulic press. A hydraulic press uses a hydraulic cylinder, also known as a linear hydraulic motor, to generate compressive force. A hydraulic cylinder consists of a barrel, a piston, a piston rod and some sort of pressurized hydraulic fluid. The cylinder barrel, which is essentially an enclosed seamless tube, contains both the cylinder pressure and the piston. In order to reduce the likelihood of corrosion and wear, the piston may undergo coating processes like chrome/nickel plating or thermal spraying. Either way, the piston is fitted with metal or elastomeric seals and bearing elements, which prevent the pressurized fluid from leaking. The piston is connected to the piston rod, which moves back and forth based on the pressure, by nuts, bolts or threads. The hydraulic fluid, which is usually some sort of oil, is what powers the whole process. The fluid is incompressible, which means that when it is pressurized, instead of deforming, it pushes against the piston and displaces it. The displacement of the piston causes the displacement of the piston rod, which, connected to the press, causes the proportionate movement of, in this case, the top platen.
In addition to the platens, many platen presses have rapid cooling systems added to their system, to facilitate an expedited forming time by decreasing the amount of time it takes for a new product to dry and cure. If a platen press is being used to mold a product, such as a kitchen sink or a set of tires, it must have molds, or dies, attached to the platens. In addition, when they are molding products, platens must be heated by electricity, steam, water or oil in order to raise the temperature just enough so that the material they are molding becomes malleable, but not plasticised. To create a quality, uniform product, operators must make sure that their platen presses radiate temperature uniformly and in a stable range throughout, even under extreme pressure. Additionally, they must have display an even load distribution.