- •Изучаем технологию полиграфического производства на английском языке
- •Lesson 1
- •2. Конверсия.
- •Герундий
- •Конверсия
- •Vocabulary Notes
- •Text 1a
- •Text 1b
- •Text 1c
- •Text 1d
- •Oral Practice
- •Lesson 2
- •Инфинитивные обороты
- •Vocabulary Notes
- •Text 2a
- •Offset Printing
- •Text 2b
- •Letterpress Printing
- •Text 2c
- •Text 2d
- •The anodized aluminum plate
- •Multi – metals
- •Oral Practice
- •Lesson 3
- •Составные предлоги
- •Составные союзы
- •Vocabulary notes
- •Text 3a
- •Text 3b
- •Intaglio, Gravure or Photogravure Printing
- •Text 3c
- •Sheet – Fed Gravure and Rotogravure
- •Text 3d
- •Gravure Plates and Cylinders
- •Photography and Retouching for Gravure
- •Photomechanics for Gravure
- •Lesson 4
- •Цепочка определений
- •Vocabulary Notes
- •Text 4a
- •Paper: beneath the surface
- •Text 4 в
- •Text 4 с
- •Text 4d
- •Paper Properties
- •Lesson 5
- •Словообразование
- •Vocabulary Notes
- •Text 5a
- •General characteristics of inks
- •Text 5b
- •Printing Ink
- •Text 5c
- •Notes to the text:
- •Text 5d
- •Drying Principle
- •Additional Texts Properties of Water-Based Gravure Inks
- •Paper Improvements
- •Two main systems
- •Processing photopolymer plates
- •Negatives for photopolymer plates
- •Moulding photopolymer plates
- •Photopolymer flexo plates
- •Laser plates
- •Rubber and plastics stereotypes
- •Waterless lithography
- •Litho Platemaking
- •Direct image and electrostatic Direct image
- •Electrostatic
- •Chemical transfer
- •Ink series in web offset
- •Библиографический список
- •Содержание
Moulding photopolymer plates
Some photopolymer plates are suitable for newspaper and all types of commercial printing; some are concentrating mainly on the newspaper market, book printing and business forms; others have been produced specifically for the flexographic industry. The volume markets are considered to be newspaper and flexography.
Photopolymer flexo plates
The most recent development in the photopolymer field has been the introduction of new plates for flexographic printing. Although they are initially more expensive than rubber plates it is significant that some of the companies now manufacturing plate materials for flexography have been traditional suppliers of the materials for the production of rubber duplicates.
Laminates control the relief depth. For example, the first layer is laminated to the base plate, exposed to a line positive, washed out in a spray machine and then, after drying, the operation is repeated until the necessary relief layer thickness is achieved. The average mould requires six to seven minutes to produce.
After the relief has been formed on the final laminate the mould has to be cured in a special oven for six to eight hours before being used.
The vertical relief duplicate rubber plates produced from Foto-Flex moulds allow much longer press runs with no loss of quality because as the relief wears
down, there is no thickening of the image. The company used one set of plates for a 10 million press run on cartons and although the rubber relief had worn down by 0.152 mm there was no thickening of the image as there would normally be with rubbers produced from original photoengravings.
Laser plates
Several manufacturers of photopolymer plate materials have for some months been experimenting in the field of lasers, which will allow direct copy-to-plate exposures, thereby eliminating the camera. The first commercial operation in this field is in Elmira, New York State, where a system known as Laser-Graph is producing all the full-page plates for the local daily newspaper.
Two main items of equipment are being used to produce a Laser-Graph plate direct from the compositor’s paste-up, a Scan-Scriber unit and an Ablation unit. The planned page, protected by a sheet of clear foil, is placed on a vacuum base at the scanning end of the Scan-Scriber and at the scribing end is placed a blank Laser-Plate, which is made up of the following: a 0.254-mm thick aluminium base to which is laminated a 0.508-mm thick layer of plastic material which forms the relief in the finished plate; an extremely fine layer of copper foil (non photosensitive) is laminated to the plastic relief layer.
As the paste-up page passes into the unit a helium-neon laser scans the copy and simultaneously an argon laser removes the copper foil covering the future non printing areas of the blank plate. The Scan-Scriber operation takes two minutes for one full newspaper page, and at this stage the plate has a visible copper image but no relief. The plate is then transferred to the Ablation unit, where a carbon dioxide laser vaporizes the plastic non-image areas of the plate in four minutes to form the relief. It is then punched and crimped at both ends, and without requiring to be pre-curved is ready for the press room. Total plate production time is six minutes.