Stereotypy

(redirected from stereotypies)
Also found in: Dictionary, Medical.

Stereotypy

 

the process of preparing stereotypes— duplicates of relief printing surfaces. The process consists of ma-trixing, preparing the stereotype from the matrix, and trimming the stereotype. Stereotypy is used in printing large numbers of copies, printing newspapers simultaneously at several locations, reprinting, and printing on rotary presses. Stereotypes may be prepared by casting, electrotyping, or molding.

In the casting process, the cardboard matrix is placed on the bottom of a built-up casting form, and molten type metal at a temperature of 300°-320°C is poured into the form. The matrix can produce 15–17 castings; the thickness of the stereotype depends on the type of printing press to be used. After casting, the stereotypes undergo mechanical finishing: the thickness is reduced by removing excess metal on the reverse side of the stereotype, the side edges are trimmed, and large blank areas are recessed by milling. The majority of flat and curved stereotypes are cast by semiautomatic equipment with an output of one piece every 2–3 min or by automatic equipment with an output of 2–3 pieces per min. Major newspaper printing plants use production lines equipped with facilities for the automatic, high-speed casting and mechanical finishing of stereotypes. Because type metal is not very strong, special measures are taken if the quantity of copies to be printed exceeds 40,000. In this case, the printing surface of the stereotypes is electroplated with a layer of stronger metal, such as iron, nickel, or chromium, having a thickness of 0.01–0.03 mm.

In electrotyping, the stereotype is produced by depositing a layer of metal, usually copper, on the matrix. After separation from the matrix, this layer is strengthened on the nonprinting side with type metal or plastic. The mechanical finishing of such a stereotype is similar to that of cast stereotypes.

In the molding process, the matrix is used as a die to mold a ductile material, such as plastic or rubber, into the required relief form. The matrices are usually made of a thermosetting plastic, and the stereotypes, of some thermoplastic, reusable material. The matrices are mounted in a special press in which the lower plate is heated, to 170°-190°C, and the upper plate is cooled. Several stereotypes can be made from a single matrix; they require very little mechanical finishing. Unvulcanized rubber is used as the raw material for rubber stereotypes. After molding, the material is vulcanized under pressure. A process for producing polymer stereotypes by casting molten plastic materials has also been developed; the process is several times more productive than the molding process.

The choice of process is determined mainly by publication deadlines, by the required quality of printing, and by economic considerations. Cast metal stereotypes, which can be produced quickly and simply, are the most widely used. However, they do not print as clearly as other stereotypes. Cast stereotypes with supplementary electroplating are particularly prone to severe distortion. They are used to print newspapers, books, journals with few illustrations, and tear-off calendars. Electroplated stereotypes are much more expensive because their labor costs are higher. However, they withstand long printing runs (up to 300,000 copies) and very accurately reproduce all details of the original. They are widely used for printing long runs of illustrated publications, including those with multicolored illustrations, such as encyclopedias, reproductions of oil paintings, and multicolored inserts in books and journals. Plastic stereotypes can be used for printing large numbers of copies (approximately 200,000). They are also used for printing various texts and publications with monochromatic illustrations. Rubber stereotypes yield the lowest accuracy of reproduction but have high wear-resistance. For this reason they are used for printing large quantities of packaging materials, wrappers, and forms. They can also be used to print long runs of books without illustrations.

REFERENCES

Shaposhnikov, S. I. Slereottpiia. Moscow, 1966.
Valershtein, I. Ia., I. A. Davydov, and O. P. Trofimova. Polimernyestereolipy. Moscow, 1972.

N. N. POLIANSKII

References in periodicals archive ?
These behaviours persist, it's just the person learns to have more control over it or learns to do it in private or under the table," Dr Harvey Singer, professor of neurology at Johns Hopkins School of Medicine and specialist in childhood stereotypies, explained.
Like displacement behaviors, stereotypies appear functionless in the context in which they occur, but are "repetitive behaviours induced by frustration, repeated attempts to cope, and/or central nervous system dysfunction" (Mason, 2006, p.
Research has shown that sick cows follow a different behavioral pattern, such as stereotypies, anorexia, lethargy, decreased exploratory, reproductive activity, water consumption, grooming, and other social and nutritional behaviors, may indicate that the animal is not in good condition (11).
RS individuals demonstrated that 99% had stereotypies, 86% do not speak, 70% have scoliosis, 56% have seizures, and 45% do not walk.
More complex, apparently meaningless movements may fall into the category of stereotypies.
Paclawskyj, Matson, Rush, Smalls, and Vollmer (2001) evaluated the convergent validity of the QABF using analog functional analysis and the MAS for adults with profound intellectual disability who displayed self-injury, aggression and stereotypies.
Problem behaviors such as self-injury, aggression, disruptive behavior in school settings, and motor or vocal stereotypies occur in over 60% of people with developmental or intellectual disabilities (Lowe et al.
Such children may also use stereotypies or occasionally echolalia to make their speech seem fluent.
Problem behaviors displayed by children with developmental disabilities include stereotypies, noncompliance, aggression, and self-injury (Griffith, Hastings, Nash, & Hill, 2010).
Herein, our purpose is to present scientific data sans judgmental stereotypies.
Cases relate to Parkinson's disease and other Parkinsonian disorders, tremors, chorea, dystonia, ataxia, tics and stereotypies, myoclonus and startle syndromes, and psychogenic movement disorder presentations.