Method and apparatus for drying printed or inked webs by means of heat
OwnerFranz Bohnensiekerinventor
Life of this patent
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Abstract
In a method of and apparatus for heat-drying of webs, especially printed or inked webs, the web is first subjected to a contactless heat shock treatment, for example by hot air at about 300.degree. C. It is then heated by a contact process at a lower temperature, for example by heated rollers at about 230.degree. C., after which it is cooled by a contact process in a third step. Each of the heated rollers may have associated therewith a roller for applying a film of a buffer agent and also a cleaning roller. Energy expended in the processes is recovered by the use of heat exchangers. The apparatus may comprise a closed housing divided into separate chambers within which the sequence of steps is carried out.
Claims13
A method of heat-drying a web, particularly a printed or inked web, which comprises subjecting the web in a first step to a contactless heat shock treatment by a gaseous medium at a temperature of about 300.degree. C., heating said web in second step by a contact heating process by contacting said web with at least two heated rollers at a temperature of about 230.degree. C. and in a third step cooling said web by a contact process utilizing cooling rollers at a temperature of about 25.degree. C., said second contact heating step including the application of a buffer agent to said respective heated rollers to prevent ink from being deposited thereon and application of a cleaning agent to said respective heated rollers for wiping off said buffer agent so as to clean said respective heating roller.
An apparatus for heat-drying of a web, particularly a printed or inked web, comprising a housing divided into at least three treatment stations through which said web is arranged to pass sequentially;
- means at a first treatment station for a contactless, short-term heating of said web by means of a gaseous medium at a first high temperature;
- means at a second treatment station for contact heating of said web at a second high temperature which is lower than the first temperature, said means for contact heating of said web comprising at least a pair of heating rollers, each heating roller having associated therewith an application roller for applying a buffer agent to said respective heating rollers to prevent ink from being deposited thereon and a cleaning roller for applying a cleaning agent to said respective heating rollers for wiping off said buffer agent applied to said heating rollers by said application roller;
- and means at a third treatment station for contact cooling of said web.
An apparatus for the heat-drying of a web, particularly a printed or inked web, comprising a housing divided into a plurality of chambers, a source of hot gaseous medium for contactless shock heating of said web in a first of said chambers, at least one pair of drivable heating rollers for contact heating of said web in a second of said chambers, around which rollers said web is looped in a substantially S-shaped manner, each heating roller having associated therewith an application roller for applying a buffer agent to said respective heating roller to prevent ink from being deposited thereon and a cleaning roller for applying a cleaning agent to said respective heating roller for wiping off said buffer agent applied to said heating roller by said application roller;
- at least one pair of drivable cooling rollers for contact cooling of the web in a third chamber;
- a circulating system for a cooling medium, said cooling medium circulating system comprising said cooling rollers and a first heat exchange means arranged in heat exchanging relationship with a circulating system for a refrigerating medium which has incorporated therein a second heat exchange means, said first heat exchange means being disposed in a fifth chamber and said second heat exchange means in a sixth chamber of said housing;
- and a circulating system for heat transfer medium for heating said heating rollers, said heat transfer medium circulating system comprising heating means disposed in said sixth chamber.
Dependencies are inferred from the claim text.