Air etching of polymeric printing plates

Claim 2

Apparatus comprising, in combination 1. a first frame; 2. an air knife assembly comprising a. a second frame affixed to the first frame, b. an air knife carried in said second frame, said air knife consisting of an elongated hollow chamber containing a slit adapted to deliver air under pressure as a thin sheet; c. means to deliver air under pressure to the air knife; and 3. A platen carried movably on said first frame and adapted to hold a relief letterpress plate having liquid polymer thereon; said platen carrying a sink on at least one of its sides to collect liquid blown from said plate by said air knife; 4. drive means adapted to move the platen under the air knife assembly in a work direction and to return the platen to its starting position.

Claim 3

The apparatus of claim 1 in which the platen comprises heating means.

Claim 4

The apparatus of claim 1 comprising means for heating the air delivered to the air knife.

Claim 5

The apparatus of claim 1 which contains a blotting assembly affixed to the first frame, adapted to blot the letter-press plate after it has passed under the air knife, comprising at least one blotting system comprising elements: 1. a supply roll of blotting web; 2. a pressure roll adapted to press said blotting web against the letter-press plate; and 3. a take-up roll adapted to roll up used blotting web.

Claim 6

The apparatus of claim 4 in which the air knife assembly comprises an additional pressure roll.

Claim 7

The apparatus of claim 4 in which the pressure roll is operably connected to means for raising and lowering it.

Claim 8

Apparatus comprising, in combination 1. a stationary frame; 2. a platen carried on said frame and adapted to hold a relief letter-press plate having a liquid polymer thereon; 3. a sink on at least one side of the plate, to collect liquid blown from said plate by the air knife below referenced; 4. an air knife assembly comprising a. movable frame adapted to move over the platen; b. an air knife carried in said movable frame, said air knife consisting of an elongated hollow chamber containing a slit adapted to deliver air under pressure as a thin sheet at least as wide as the letter-press plate; c. means to deliver air under pressure to the air knife; d. a blotting assembly adapted to blot the letter-press plate after the air knife has passed over same, comprising at least one blotting system comprising: i. a supply roll of blotting web; ii. a pressure roll adapted to press said blotting web against the letter-press plate; and iii. a take-up roll adapted to roll up used blotting web; and 5. drive means adapted to move said air knife assembly over the platen in a work direction and to return the assembly to its starting position.

Claim 9

Apparatus comprising, in combination 1. a stationary frame; 2. a platen carried on said frame and adapted to hold a relief letter-press plate having a liquid polymer thereon; 3. a sink on at least one side of the plate, to collect liquid blown from said plate by the air knife below referenced; 4. an air knife assembly comprising a. movable frame adapted to move over the platen; b. an air knife carried in said movable frame, said air knife consisting of an elongated hollow chamber containing a slit adapted to deliver air under pressure as a thin sheet at least as wide as the letter-press plate; c. means to deliver air under pressure to the air knife; d. a blotting assembly adapted to blot the letter-press plate after the air knife has passed over same, comprising at least one blotting system comprising: i. a supply roll of blotting web; ii. a pressure roll adapted to press said blotting web against the letter-press plate; and iii. a take-up roll adapted to roll up used blotting web; and 5. drive means adapted to move said air knife assembly over the platen in a work direction and to return the assembly to its starting position.

Claim 10

The apparatus of claim 7 in which the air knife assembly comprises two blotting systems comprising said elements (1), (2), and (3).

Claim 11

The apparatus of claim 7 in which the pressure roll is operably connected to means for raising and lowering it.

Claim 12

Apparatus comprising, in combination 1. a stationary frame; 2. a platen carried on said frame and adapted to hold a relief letter-press plate having a liquid polymer thereon; the platen comprising heating means to assist in maintaining as liquid the polymer on the letter-press plate; 3. a sink on at least one side of the platen, to collect liquid blown from said plate by the air knife below referenced; 4. an air knife assembly comprising a. a movable frame adapted to move over the platen; b. an air knife carried in said movable frame, said air knife consisting of an elongated hollow chamber positioned at an acute angle to the platen surface and containing a slit adapted to deliver air under pressure as a thin sheet on the letter-press plate and the air knife slit being at least as wide as the letter-press plate; c. means to deliver air under pressure to the air knife; and 5. drive means adapted to move said air knife assembly over the platen in a work direction and to return the assembly to its starting position.

Claim 13

Apparatus comprising, in combination 1. a stationary frame; 2. a platen carried on said frame and adapted to hold a relief letter-press plate having a liquid polymer thereon; the platen comprising heating means to assist in maintaining as liquid the polymer on the letter-press plate; 3. a sink on at least one side of the platen, to collect liquid blown from said plate by the air knife below referenced; 4. an air knife assembly comprising a. a movable frame adapted to move over the platen; b. an air knife carried in said movable frame, said air knife consisting of an elongated hollow chamber positioned at an acute angle to the platen surface and containing a slit adapted to deliver air under pressure as a thin sheet on the letter-press plate and the air knife slit being at least as wide as the letter-press plate; c. means to deliver air under pressure to the air knife; and 5. drive means adapted to move said air knife assembly over the platen in a work direction and to return the assembly to its starting position.

Claim 14

Apparatus comprising, in combination 1. a stationary frame; 2. a platen carried on said frame and adapted to hold a relief letter-press plate having a liquid polymer thereon; 3. a sink on at least one side of the platen, to collect liquid blown from said plate by the air knife below referenced; 4. an air knife assembly comprising a. a movable frame adapted to move over the platen; b. an air knife carried in said movable frame, said air knife consisting of an elongated hollow chamber positioned at an acute angle to the platen surface and containing a slit adapted to deliver air under pressure as a thin sheet on the letter-press plate and the air knife slit being at least as wide as the letter-press plate; c. means to deliver air under pressure to the air knife; d. means for heating the air delivered to theair knife to assist in maintaining as liquid the polymer on the letter-press plate; and

Claim 15

Apparatus comprising, in combination 1. a stationary frame; 2. a platen carried on said frame and adapted to hold a relief letter-press plate having a liquid polymer thereon; 3. a sink on at least one side of the platen, to collect liquid blown from said plate by the air knife below referenced; 4. an air knife assembly comprising a. a movable frame adapted to move over the platen; b. an air knife carried in said movable frame, said air knife consisting of an elongated hollow chamber positioned at an acute angle to the platen surface and containing a slit adapted to deliver air under pressure as a thin sheet on the letter-press plate and the air knife slit being at least as wide as the letter-press plate; c. means to deliver air under pressure to the air knife; d. means for heating the air delivered to theair knife to assist in maintaining as liquid the polymer on the letter-press plate; and

Claim 16

drive means adapted to move said air knife assembly over the platen in a work direction and to return the assembly to its starting position.

Claim 17

drive means adapted to move said air knife assembly over the platen in a work direction and to return the assembly to its starting position.