A platen (or platten) is a flat platform with a variety of roles in printing or manufacturing. It can be a flat

metal A metal (from Greek μέταλλον ''métallon'', "mine, quarry, metal") is a material that, when freshly prepared, polished, or fractured, shows a lustrous appearance, and conducts electricity and heat relatively well. Metals are typica ...

(or earlier,

wood Wood is a porous and fibrous structural tissue found in the stems and roots of trees and other woody plants. It is an organic materiala natural composite of cellulose fibers that are strong in tension and embedded in a matrix of lignin ...

en) plate pressed against a medium (such as

paper Paper is a thin sheet material produced by mechanically or chemically processing cellulose fibres derived from wood, rags, grasses or other vegetable sources in water, draining the water through fine mesh leaving the fibre evenly distribut ...

) to cause an impression in

letterpress printing Letterpress printing is a technique of relief printing. Using a printing press, the process allows many copies to be produced by repeated direct impression of an inked, raised surface against sheets or a continuous roll of paper. A worker comp ...

. Platen may also refer to a

typewriter A typewriter is a mechanical or electromechanical machine for typing characters. Typically, a typewriter has an array of keys, and each one causes a different single character to be produced on paper by striking an inked ribbon selecti ...

roller which friction-feeds paper into position below the typebars or print head. It can refer to the glass surface of a copier, and the rotating disk used to polish semiconductor wafers.

Gallery

File:Gutenbergpresse 01.jpg, Replica of the

Gutenberg press A printing press is a mechanical device for applying pressure to an inked surface resting upon a print medium (such as paper or cloth), thereby transferring the ink. It marked a dramatic improvement on earlier printing methods in which the c ...

. The platen on the rights holds the paper, and is pressed down onto the typeset File:Large SMG00176993.jpg, Cyclindrical platen on a typewriter File:Star-LC-10-printer-02.jpg, Cyclindrical platen in a dot-matrix printer

Other applications

Office equipment

In office copiers and scanners, the platen is a flat

glass Glass is a non-crystalline, often transparent, amorphous solid that has widespread practical, technological, and decorative use in, for example, window panes, tableware, and optics. Glass is most often formed by rapid cooling (quenching) o ...

surface on which operators place papers or books for scanning. The platen is also called the flatbed. Platens are also used in some printers, such as the

dot-matrix printer A dot matrix printer is an impact printer that prints using a fixed number of pins or wires. Typically the pins or wires are arranged in one or several vertical columns. The pins strike an ink-coated ribbon and force contact between the ribbon ...

Manufacturing and processing

Semiconductor manufacturing

In semiconductor manufacturing, specifically chemical-mechanical planarization, a flat, rotating platen covered with a pad is used to polish semiconductor wafers (see image).

Screen printing

In textile

screen printing Screen printing is a printing technique where a mesh is used to transfer ink (or dye) onto a substrate, except in areas made impermeable to the ink by a blocking stencil. A blade or squeegee is moved across the screen to fill the open mes ...

, a platen is a flat board onto which the operator slides the

garment Clothing (also known as clothes, apparel, and attire) are items worn on the body. Typically, clothing is made of fabrics or textiles, but over time it has included garments made from animal skin and other thin sheets of materials and natural ...

. It is generally made of either a plywood laminate or aluminum with a rubber laminate. Often the platen will be pretreated with a spray adhesive. This allows the garment to effectively become a rigid immobile substrate, especially important when printing multiple colors or utilizing an on-press infrared dryer. The screen is brought parallel and close to the garment (often within 1/32") and the squeegee pressure then brings the screen into contact with the garment so that the ink transfer may occur. There are many special platen types, such as those for printing sleeves or pockets, vacuum platens, platens with clamps to hold bulky materials such as jackets, and even curved platens for printing on hats.

Woodworking

In woodworking, wide

belt sander A belt sander or strip sander is a sander used in shaping and finishing wood and other materials. It consists of an electric motor that turns a pair of drums on which a continuous loop of sandpaper is mounted. Belt sanders may be handheld and mo ...

s use platens to press the sanding paper into contact with the wood being sanded. The platen sits between two steel rolls which deliver the moving force to the sanding belt. Sanding heads with a platen are used on finish sanding with papers of finer grits, when the coarser ones are typically used with contact drum type sanding heads. Stock is fed into and out of the machine on a conveyor belt. Since the abrasive belt creates a substantial pressure on the stock that tends to push the stock toward the infeed, the hold down shoes and rollers hold the workpiece down against the belt while it is moving through the machine in order to ensure uniform contact with the abrasive and continuous movement.

Metal forming

In metal forming processes, a platen is the component that houses the

mold A mold () or mould () is one of the structures certain fungus, fungi can form. The dust-like, colored appearance of molds is due to the formation of Spore#Fungi, spores containing Secondary metabolite#Fungal secondary metabolites, fungal seco ...

for

forging Forging is a manufacturing process involving the shaping of metal using localized compressive forces. The blows are delivered with a hammer (often a power hammer) or a die. Forging is often classified according to the temperature at whi ...

the required shape. The platen tends to be the heaviest and strongest part of the press due to the massive forces that it has to withstand. A platen for a 5000-ton press can weigh up to 350 tons.

Other

In manufacturing, a platen is a flat plate of a press utilized in laminate,

plastic Plastics are a wide range of synthetic or semi-synthetic materials that use polymers as a main ingredient. Their plasticity makes it possible for plastics to be moulded, extruded or pressed into solid objects of various shapes. This adaptab ...

and forest product industries. A platen is typically heated with oil, water, steam or electricity and is used in the production of furniture, tires,

gasket Some seals and gaskets A gasket is a mechanical seal which fills the space between two or more mating surfaces, generally to prevent leakage from or into the joined objects while under compression. It is a deformable material that is used to cr ...

s, particle board, composite heaters and

plywood Plywood is a material manufactured from thin layers or "plies" of wood veneer that are glued together with adjacent layers having their wood grain rotated up to 90 degrees to one another. It is an engineered wood from the family of manufacture ...

. In high frequency

welding Welding is a fabrication process that joins materials, usually metals or thermoplastics, by using high heat to melt the parts together and allowing them to cool, causing fusion. Welding is distinct from lower temperature techniques such as b ...

products, platens are used to put lines on PVC binders and folders down the spine lines. Platens are utilized in impact testing in research; a specimen is crushed between platens. The platen also refers to the fixed part of a linear motor.

References

External links

{{Letterpress Printing