WO1997004962B1

WO1997004962B1 - Apparatus and method for drying a discontinuous or continuous substrate fed along a feed path of an offset press

Info

Publication number: WO1997004962B1
Application number: PCT/IB1996/000837
Authority: WO
Filing date: 1996-07-25
Publication date: 1997-05-15

Abstract

Apparatus and a method for drying layers of ink applied to the surface of a discontinuous or continuous substrate (5) in a multi-stand offset press (1) comprising a plurality of stands (3A-3D), each having a printing portion for the application of a layer of ink to the substrate as it passes through the stand. A drying assembly (30) is mounted after and adjacent at least part of the printing stand portions and adjacent the substrate for drying the substrate and layer of ink thereon after passage therefrom. The drying assembly comprises an emitter-cooler (40) that radiates energy toward the ink-layered substrate and preferably also a gas duct (31) that directs air toward the ink-layered substrate to dry the substrate and layer of ink thereon contributing to further drying thereof and evaporation of water vapor and solvents arising therefrom.

Claims

AMENDED CLAIMS[received by the International Bureau on 13 March 1997 (13.03.97); original claims 1-24 replaced by amended claims 1-20 (5 pages)]

1. An apparatus for drying a discontinuous or continuous sub¬ strate fed along a feed path through a multi-stand offset print¬ ing press and deposited at the end of the press, comprising: a printing portion in at least half of the stands for applying conventional ink layer to a surface of said substrate and drying means incorporated in the apparatus c h a r a c t e r i z e d b y a drying assembly mounted in at least half of the stands, having a printing portion therein each drying assembly comprising: an emitter for radiating energy toward the substrate surface and the ink layer applied thereto as the substrate moves along the feed path, a pressurized cool gas conduit for directing a flow of cool gas onto the substrate surface and ink layer thereon as the substrate moves along the feed path, the radiant energy from the emitter and the cool gas from the gas conduit serving to dry the substrate surface and ink layer thereon as the substrate moves along the feed path to the next stand of the apparatus end.

2 . An apparatus as claimed in claim 1, wherein there are at least three stands comprising printing portions positioned along the feed path, and wherein at least two of the stands com¬ prising printing portions have a drying assembly mounted therein.

3. An apparatus as claimed in claim 1 or 2, wherein the drying assembly further comprises cooling means.

4. An apparatus as claimed in one of the preceeding claims, wherein the drying assembly further comprises reflecting means.

5. An apparatus as claimed in claim 3, wherein the cooling means includes a reflective surface adjacent the emitter. -

6. An apparatus as claimed in one of claims 1 to 5, wherein the drying assembly further comprises an emitter-cooler comprising cooling means and at least one emitter for radiating energy toward the ink applied to the substrate as it moves along the feed path.

7. An apparatus as claimed in claim 6, wherein the emitter- cooler cooling means is connected to a cooling system.

8. An apparatus as claimed in claim 1, wherein the gas conduit is connected to a cooling system.

9. An apparatus as claimed in claim 2, wherein there are at least four stands comprising a printing portion positioned along the feed path and wherein at least three of the stands comprising a printing portion include a drying assembly mounted therein.

10. Apparatus for drying a continuous substrate in a multi- stand offset press according to one of the preceeding claims, c h a r a c t e r i z e d i n t h a t at least half of the stands having a printing portion for applying a layer of conventional ink to the top surface of the substrate and a printing portion for applying a layer of con¬ ventional ink to the bottom surface of the substrate comprising:

(A) a top drying assembly in at least a portion of the print¬ ing portions of the plurality of stands for applying a layer of conventional ink to the top surface of the substrate, comprising:

(1) emitter means for radiating energy toward the sub¬ strate top surface and layer of ink thereon,

(2) a gas conduit for directing a flow of pressurized, cool gas onto the substrate top surface and layer of conventional ink thereon;

(B) a bottom drying assembly mounted in at least a portion of the printing portions of the plurality of stands for applying a layer of conventional ink to the bottom surface of the substrate comprising: (1) emitter means for radiating energy toward the substrate bottom surface and layer of ink thereon,

(2) a gas conduit for directing a flow of pressurized, cool gas onto the substrate bottom surface and layer of conventional ink thereon.

11. An apparatus according to one of the preceeding claims for use in a sheet press, wherein the drying assembly is mounted within a housing for movement of the drying assembly into and out of operating position.

12. An apparatus according to one of the preceeding claims, wherein the emitter means generates energy in the range of 0,4 micrometer to 4 micrometer.

13. A method of drying a discontinuous or continuous substrate fed along a feed path from a feeding device at one end through a multi-stand offset printing press to the other end of the press, at least half of the stands having a printing portion for apply¬ ing a conventional ink layer to a surface of said substrate, c h a r a c t e r i z e d b y the steps of:

A) applying in a first stand having a printing portion therein a layer of conventional ink to one surface of the substrate,

B) passing the substrate with the layer of conventional ink thereon past a radiant energy emitter in at least half of the stands having a printing protion therein for drying the substrate surface and the ink layer thereon,

C) passsing the substrate surface with the layer of conventio¬ nal ink thereon past a cool gas flow in each of the stands having a radiant energy emitter therein for further drying the substrate suface with the ink layer thereon, and

D) directing the substrate with the layer of conventional ink thereon to the next stand or the other end of the press.

14. A method as claimed in claim 13, wherein the passing of the substrate surface with the ink layer thereon is past a cooled radiant emitter.

15. A method of drying a discontinuous or continuous substrate according to claims 13 or 14, c h a r a c t e r i z e d b y

(E) applying in a second stand having a printing portion therein a scond layer of conventional ink to said surface of the substrate,

(F) passing the substrate with the first and second layers of ink on the surface thereof past a radiant energy emitter in said second stand,

(G) passing the substrate surface with the first and second layers of ink on the surface thereof past a cool gas flow in said second stand the combination in said second stand of the radiant energy from the emitter therein and the cool gas flow therein drying at least the substrate surface and the second layer of conventional ink thereon.

16. A method as claimed in claim 15 further comprising the steps of:

(H) applying in a third stand having a printing portion therein a third layer of conventional printing ink to said surface of the substrate,

(I) passing the substrate with the first, second and third layers of ink on the surface thereof past a radiant energy emitter in said third stand,

(J) passing the substrate with the first, second and third layer of ink on the surface thereof past a cool gas flow in said third stand, the combination in said third stand of the radiant energy emitter therein and the cool gas flow therein drying at least the substrate surface and third layer of conventional ink thereon.

17. A method according to one of the preceeding claims 13 to 16, c h a r a c t e r i z e d i n that passing the ink printed substrate surface past a plurality of radiant energy emitters is adjacent the application of the conventional ink.

18. The method of claim 17, wherein the passing of the ink printed substrate surface past a plurality of radiant energy emitters occurs adjacent a cooling means.

19 . A method of drying according to one of the c laims 16 and 18 , c h a r a c t e r i z e d b y applying in a plurality of stands a layer of ink on one surface of the substrate.

20. A method of drying, in an offset web press, a continuous substrate according to one of the preceeding claims 13, 14, 15, 16, 17, 18 and 19, comprising the steps of: applying in each stand having a printing portion therein a first layer of conventional ink to the top surface of the substrate and a second layer of conventional ink to the bottom surface, of the substrate, passing in a majority of stands having a printing portion therein, the substrate with a first layer of conventional ink on the top surface thereof and the second layer of conventional ink on the bottom surface past a radiant energy emitter after the application of each layer of ink, passing, in each stand having a radiant energy emitter, the substrate top and bottom surfaces, each with an ink layer thereon, past a cool gas flow, the combination of the radiant energy emitter and cool gas flow in said stand drying the substrate and layers of ink on the top and bottom surfaces thereof, directing the substrate and dried first layer of ink on the top surface thereof and dried second layer of ink on the bottom suface thereof to the next stand or the other end of the press.