Because of the special mechanical and specific properties of paper, many operations can be performed only with the aid of vacuum or compression.
Paper Cutter Table
An air cushion makes it easier to move and straighten stacks of paper when cutting. For this purpose, small nozzles are built into the table surface and sealed with spring loaded spheres. The weight of the paper stack pressing down on these spheres opens up the nozzles and releases compressed air under the paper.
During the screen printing process, the blower on the vacuum table generates a vacuum that holds the sheets of paper in place so they can't shift during printing.
Powdering on Printing Presses
Immediately after printing, the still wet sheets of paper are dusted with powder to prevent the fresh ink from smearing and keep the sheets from sticking together. A vacuum pump serves to spray the powder through an injector and apply it to the paper.
Turning Bars and Tables
For double-sided printing, paper webs must be turned on suitable bars or tables. This is done by blowing air through a perforated pipe to generate an air cushion. The paper web can then glide across this cushion without making contact with any surface. When printing is finished, a similar air cushion ensures that the printed paper webs can be air-dried and then stacked without smearing the still wet ink.
Many processes in the printing procedure require vacuum or compression, including printing, folding, collating, binding, trimming, packaging and labeling. It is not necessary to provide a vacuum pump for each individual production machine. A central vacuum system generates the vacuum required by all the individual processes, thus saving space in the production area and reducing employee's exposure to noise and heat.
Using several compressors in a central system allows maintenance work to be performed without interrupting production because the other compressors in the system can take over for the deactivated machines. In addition, an optimal, cost-effective utilization of the central system can be achieved by selectively switching the individual compressors off and on.
Book Binding Bachines
Automatic book binding machines are made up of a combination of many individual machines, each incorporating different vacuum applications. Compressed air helps transport books or parts of books via suction rollers and to press on the spines after glue has been applied. Vacuum pumps and compressors are also used to dry the glue and blow away waste paper.
Digital Printing " High-Performance Copiers
During the reproduction or copy process, the blower on the vacuum table generates a vacuum that holds the negatives or sheets of paper in place so they can't shift during printing.