![Flatbed Letterpress Diagram](https://upload.wikimedia.org/wikipedia/commons/6/64/Flatbed_Letterpress_Diagram.svg)
A platen (or platten) is a 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 typicall ...
(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 th ...
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 distributed ...
) 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 selectivel ...
roller which friction-feeds paper into position below the
typebar
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 selectively ...
s or print head. It can refer to the glass surface of a copier, and the rotating disk used to polish semiconductor wafers.
Applications
Office equipment
![Epson stylus cx4200](https://upload.wikimedia.org/wikipedia/commons/a/aa/Epson_stylus_cx4200.jpg)
In
office copiers and
scanners
''Scanners'' is a 1981 Canadian science fiction horror film written and directed by David Cronenberg and starring Stephen Lack, Jennifer O'Neill, Michael Ironside, and Patrick McGoohan. In the film, "scanners" are psychics with unusual telepathic ...
, 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) of ...
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
Chemical mechanical polishing (CMP) or planarization is a process of smoothing surfaces with the combination of chemical and mechanical forces. It can be thought of as a hybrid of chemical etching and free abrasive polishing.
Description
The proc ...
, 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 human body, 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 ...
. 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 which i ...
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
Lamination is the technique/process of manufacturing a material in multiple layers, so that the composite material achieves improved strength, stability, sound insulation, appearance, or other properties from the use of the differing materials ...
,
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 c ...
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 manufactured ...
. In high frequency
welding
Welding is a fabrication (metal), 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, fusion. Welding is distinct from lower ...
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
Specimen may refer to:
Science and technology
* Sample (material), a limited quantity of something which is intended to be similar to and represent a larger amount
* Biological specimen or biospecimen, an organic specimen held by a biorepository ...
is crushed between platens.
The platen also refers to the fixed part of a linear motor.
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 right holds the paper, and is pressed down onto the typeset.
File:Large SMG00176993.jpg, Cylindrical platen on a typewriter
File:Star-LC-10-printer-02.jpg, Cylindrical platen in a dot-matrix printer
See also
*
Jobbing press
A jobbing press, job press, or jobber is a variety of printing press used in letterpress printing.
The press is meant to be operated by a pressman working on small jobs, as opposed to long print runs or newspaper work, or jobs that require less ...
References
External links
{{Letterpress
Printing