Manufacture of metallic measuring rule - by adhering negative photosensitive film onto surface by heating prior to exposure

摘要

A metallic measuring rule is manufactured with dark and light graduations. This effected by depositing bright chrome on copper or nickel. Stainless steel is cut into rectangular shapes of required thickness for flexible or rigid rules. The surfaces are positioned by insertion in holes in a conveyor for degreasing and sand blasting. A negative photosensitive film is stuck to the surface by heating and the film is exposed to ultra violet light through a mask containing the graduations to polymerise remaining areas.