Abstract: A method of contact printing comprising the steps of supporting a film and an original in superposed relationship. A vacuum is progressively applied to the superposed film and original from a first edge to an opposite edge thereof to hold them in substantially intimate contact while simultaneously moving a source of collimated light over the surface of the superposed film and original and exposing the film through the cover sheet and the original.

Abstract: In a contact printer comprising means for supporting a film and an original in superposed relationship, means for providing a source of light for exposing the film through the original, and means for moving the light over the surface of the superposed film and original. The improvement comprises means carried by the light moving means for collimating the light, with the light collimating means comprising a plurality of parallel tubular members having a length to diameter ratio greater than about four and which extend between the light source and the film.

Abstract: An improvement in a contact printer which comprises means for supporting a film and an original in superposed relationship on a vacuum table, means for providing a source of light for exposing the film through the original, and means for moving the light over the surface of the superposed film and original. The improvement comprises means carried by the light moving means for covering the superposed film and original with a substantially impervious flexible and transparent cover sheet as the exposing light is scanned across the film and original whereby the vacuum is applied to the film and the original to remove air from therebetween as the film is exposed by the light through the cover sheet and the original.

Abstract: An improvement in a contact printer which comprises means for supporting a film and an original in superposed relationship on a vacuum table, means for providing a source of light for exposing the film through the original, and means for moving the light over the surface of the superposed film and original. A substantially impervious, flexible and transport cover sheet carried by the light moving means is arranged to cover the superposed film and original as the exposing light is scanned across the film and original whereby the vacuum is applied to the film and the original to remove air from therebetween as the film is exposed by the light through the cover sheet and the original. The improvement comprises means for removing and replacing the cover sheet to assure that the optical path for the exposing light remains clear and unobstructed.

Abstract: A graphic arts contact printer which comprises a vacuum table for supporting a photosensitive film and an original, containing an image to be reproduced, in superposed relationship. A light source provides an elongated beam of photoactive light for exposing the film through the original. A light transport is provided for moving the light transversely of the length of the beam over the vacuum table surface over the superposed film and original whereby the superposed film and original are scanned by the light to expose the film through the original. Means is provided which is associated with the light transport for applying a transparent cover sheet over the superposed film and original as the light is moved over the film and original. Further means carried by the light transport is provided for collimating the light, with the collimating means being disposed between the light and the cover sheet.

Abstract: An improvement in a contact printer which comprises means for supporting a film and an original in superposed relationship on a vacuum table, means for providing a source of light for exposing the film through the original, and means for moving the light over the surface of the superposed film and original. A substantially impervious, flexible and transparent cover sheet carried by the light moving means is arranged to cover the superposed film and original as the exposing light is scanned across the film and original whereby the vacuum is applied to the film and the original to remove air from therebetween as the film is exposed by the light through the cover sheet and the original. The improvement comprises means for contacting the surface of the cover sheet during use and removing dust and dirt thereon to assure that the optical path for the exposing light remains clear and unobstructed.

Abstract: A terpolymer having the formula: ##STR1## wherein R.sub.1 is selected from the group consisting of C.sub.1 to C.sub.20 alkyl groups, C.sub.6 to C.sub.20 aryl groups and C.sub.6 to C.sub.30 alkylaryl groups; R.sub.2 is hydrogen or methyl group, n is about 1 to 60; y is about 2.0 to about 35.0 mole %, and x is about 65.00 to about 98.00 mole %, z is about 0.1 to about 3.0 mole % and n is about 1 to about 60 and M is a metal cation selected from the group consisting of Groups IA, IIA, IB and IIB of the Periodic Table of Elements, wherein said terpolymer has an intri1sic viscosity of about 1 top about 25, wherein said terpolymer is formed by a free radical solution polymerization in the absence of a surfactant or emulsifier and comprises the polymerization of an acrylamide monomer, a metal acrylate monomer and an alkyl poly(etheroxy) acrylate monomer in the presence of a free radical initiation at a temperature of at least 5.degree. C. for at least 0.5 hours.

Abstract: The present invention relates to improved viscosification agents for an aqueous or brine solutions. Typically, the viscosification agents are tetrapolymers of N-vinyl pyrrolidone/acrylamide/salt of acrylic acid/N-alkyl acrylamide wherein said tetrapolymers have the formula: ##STR1## wherein w is about 1 to about 80 mole percent, more preferably about 5 to about 75 mole percent, and most preferably about 10 to about 70 mole percent; x is about 10 to about 90 mole percent, more preferably about 20 to about 80 mole percent, and most preferably about 30 to about 70 mole percent; and y is about 0.1 to about 10.0 mole percent, more preferably about 0.15 to about 5.0 mole percent; and most preferably about 0.2 to about 3.0 mole percent; z is about 1.0 to about 30.0 mole percent, more preferably about 2.0 to about 25.0 mole percent, and most preferably about 5.0 to about 20.

Abstract: The present invention relates to a process for the formation of water soluble copolymers of acrylamide and alkyl poly(etheroxy)acrylate which are finished by a dialysis process and are excellent viscosification agents. Wherein the process includes the free radical copolymerization of acrylamide monomer and alkyl poly(etheroxy)acrylate monomer in an aqueous medium under nitrogen conditions in the presence of free radical initiator at a sufficient temperature and for a sufficient time to effect copolymerization.

Abstract: The present invention relates to improved drag reduction agents which are water soluble copolymers of acrylamide and alkyl poly(etheroxy)acrylate.

Abstract: The present invention relates to a process for the formation of water soluble copolymers of acrylamide and alkyl poly(etheroxy)acrylate which are excellent viscosification agents, wherein the process includes the free radical copolymerization of acrylamide monomer and alkyl poly(etheroxy)acrylate monomer in an aqueous medium under nitrogen conditions in the presence of free radical initiator at a sufficient temperature and for a sufficient time to effect copolymerization.

Abstract: The present invention relates to a composition of water soluble copolymers of acrylamide and alkyl poly(etheroxy)acrylate which are excellent viscosification agents.