Perforation

As perforation ( perforation also, from the Latin foramen = hole ) refers to a perforation of hollow or flat objects. Regular arrangement, quantity, shape and size of the holes play a role, particularly in the art.

Photography and film

In the context of film and photography is called the regular perforation perforation of photographic films and feature films for the purpose of transporting and positioning.

When cine attributable to the height of each frame one perforation in Kleinbildfilm it to the width of each picture eight.

The perforation of roll film used for the first time Dickson for his cinematograph in 1893, where he had run through horizontally in the apparatus along halved 70 - mm film. The Lumière Brothers used a perforating machine for their 35 mm film, but they let him run vertically through the apparatus.

In photography, the first time took Oskar Barnack motion picture film in 1914 for the development of the Ur-Leica, which was then marketed as the first modern film camera from 1924.

Philately

In philately perforation refers to the teeth or piercing a stamp sheetlet for easier separation of individual stamps. ( See also stamp separation).

Medicine

In medicine perforation denotes the breakthrough or the puncturing of a tissue or hollow organ such as the stomach and intestine (bowel perforation ). A perforation of an abdominal organ usually leads to peritonitis with the symptoms of an acute abdomen. Many of the causes and consequences are listed.

Wood preservatives

In the chemical pressure impregnation, the problem is that our primary timber, the spruce, can be impregnate very bad. The small penetration depths of usually only a few millimeters are not sufficient for an effective protection of wood components in the rule. In order to improve the impregnation of spruce, the perforation has been used since the 50s of the last century. This method is to bring in relatively tight grid slots or holes in the wood surface, that is, up to a desired depth " perforate " the wood. The perforation of the timber increases the uptake of the wood preservative.

Printing / paper

Slotted and punched holes in paper or cardboard for the separation of a leaf or leaf part. Produce in Perforating, in continuous printing machines or in letterpress machines (eg Heidelberg platen or cylinder), partly also in offset printing machines by sticking the perforation lines on the impression cylinder and the blanket used as a counter-mold. A perforation is measured in teeth / inch.