Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41N—PRINTING PLATES OR FOILS; MATERIALS FOR SURFACES USED IN PRINTING MACHINES FOR PRINTING, INKING, DAMPING, OR THE LIKE; PREPARING SUCH SURFACES FOR USE AND CONSERVING THEM
  • B41N10/00—Blankets or like coverings; Coverings for wipers for intaglio printing
  • B41N10/02—Blanket structure
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41G—APPARATUS FOR BRONZE PRINTING, LINE PRINTING, OR FOR BORDERING OR EDGING SHEETS OR LIKE ARTICLES; AUXILIARY FOR PERFORATING IN CONJUNCTION WITH PRINTING
  • B41G7/00—Auxiliary perforating apparatus associated with printing devices

Definitions

• the present invention relates to a method and a device for protecting the blanket of an offset machine when using perforating nets, cutting nets or the like.
• a perforating net is in the form of a strip, generally metallic, having a lateral rim projecting toothed or sharpened, the face opposite to the rim carries an adhesive coating initially protected by a protective tape which remove at the time of use.
• this temporary fixing being carried out by applying the perforating net to the model by its face adjacent to the rim after having removed the protective strip which initially covered the double-sided adhesive, - the passage of the model thus produced in the printing machine, after extraction of the protective strip from the adhesive layer of the different threads so that during this passage, the threads stick to the margin cylinder at the locations they must occupy and at the same time the double-sided adhesive is removed at the same time as the sheet to which it is stuck, due to the fact that the adhesive / metal adhesion of the threads is weaker than the adhesive / paper adhesion.
• the invention therefore more particularly aims to eliminate these drawbacks.
• the other face of the counter-support strips may be coated with a double-sided adhesive so as to be able to ensure installation in a sequence comprising the following steps:
• the sheet used to make the model is previously passed through the printing machine equipped with perforating nets and / or cutting nets so that the perforation and / or cutting lines are visible in relief on the front of the sheet. .
• the counter-support strips can be made of steel.
• Figure 1 schematically shows an offset type printing machine
• Figure 2 is a schematic perspective of a strip of abutment according to the invention.
• Figure 3 is a cross section of the strip shown in Figure 1;
• FIGS. 4 and 5 are schematic representations illustrating a sequence of laying perforating nets on the margin cylinder of the machine, FIG. 4 showing a model carrying the perforating nets on the back and FIG. 5 illustrating the passage of the model between the margin cylinder and blanket;
• FIGS. 6 to 8 are schematic representations of a sequence of laying of counter-support strips on the blanket of the machine, this sequence comprising the production ( Figure 6) of a model ( Figure 7) and then the passage of this model between the margin cylinder and the blanket.
• the invention is intended for machines of the offset or similar type comprising, as shown in FIG. 1, a plate cylinder 1 provided with ink rollers 2 and wetting rollers 3, a blanket 4 and a back pressure cylinder usually called margin cylinder 5.
• the blank sheets to be printed which are initially stacked in a feeding station 6, are transmitted one by one in a margining area 7 before passing between the blanket 4 and the margin cylinder 5, place where the printing takes place.
• the sheets 8 thus printed are then stacked in a receiving station 9.
• perforating nets or cutting nets
• the installation of perforating nets (or cutting nets) on the margin cylinder 5 can be carried out as illustrated in FIGS. 4 and 5 thanks to perforating nets 10 whose lower side (opposite to the cutting or perforating side) is coated with an adhesive layer 11, while the upper side is covered with a double-sided adhesive strip 12.
• the operator first of all prints a sheet 8. Thanks to the double-sided adhesive 12, he sticks the perforating threads to the back of the sheet 8 where perform the perforations, the cutting or perforating elements being oriented towards the sheet 8 (FIG. 4). It then passes the model thus produced in the machine, the perforating nets 10 being placed on the side of the margin cylinder 5.
• the perforating nets 10 are placed on the margin cylinder 5 at the suitable locations. The operator can therefore perform his printing operations with perforation or cutting.
• the invention therefore proposes placing counter-support strips 13 on the blanket 5 at the locations on which the cutting or perforating elements of the threads 10 come to bear.
• these strips 13 may be initially covered:
• a layer of adhesive material 14 covered with a protective strip 15 which can be removed during use - on the other side, by a double-sided adhesive strip 16 (c ' that is to say a flexible strip carrying on its two faces an adhesive covering 17, 18), the adhesive covering 17 opposite the strip 13 being initially protected by a protective strip 19 which can be removed during use.
• the operator passes a sheet 8 ′ through the machine so as to obtain a proof provided with the cutting lines and / or perforations 20, which are visible on the front of the sheet 8 '(here, in broken lines).
• the operator After having removed the protective tapes 15, the operator fixes the counter-support strips 13 on the test 8 ′ by ensuring that their longitudinal axis of symmetry is substantially coincident with the cutting lines and / or perforation 20, the fixing of these strips 13 on the test 8 ′ then being obtained by means of the double-sided adhesive 16.
• the operator passes the test 8 ′ with the machine provided with the counter-support strips 13, these being oriented towards the blanket side 4.
• the double-sided adhesive strip 16 which remains glued to the sheet 8 ′ is detached from the strips 13 (the adhesion of the double-sided adhesive being stronger on the paper than on the strip 13).
• the counter-support strips 13 are placed on the blanket 4 at suitable locations, vis-a-vis the cutting nets and / or the perforating nets 10.
• the operator can then perform his printing operations with perforation and cutting.
• the method described above may also include at least one pressure adjustment phase between the blanket 4 and the cylinder. margin 5. This adjustment can advantageously be carried out at the end of the laying of the perforating nets 10 and / or at the end of the laying of the counter-support strips 13.
• the counter-support strips 13 may consist of a steel strip with a thickness of a few tenths of a millimeter (for example 0.2 mm) and a width of a few millimeters (for example 4 mm).
• the operations of placing the counter-support strips are easy to perform: as with the perforating nets, the installation of the counter-support strips on the model can be carried out flat on a work table.
• the use of the counter-support strips ensures protection of the blankets, and therefore an extension of the life of the latter.

Landscapes

• Printing Plates And Materials Therefor (AREA)
• Perforating, Stamping-Out Or Severing By Means Other Than Cutting (AREA)
• Control Of Cutting Processes (AREA)
• Manufacture Or Reproduction Of Printing Formes (AREA)

Priority Applications (2)

Applications Claiming Priority (2)

Publications (2)

Family

ID=9451393

Family Applications (1)

Country Status (6)

Cited By (3)

Families Citing this family (1)

Citations (3)

Family Cites Families (2)

• 1993
  • 1993-09-24 FR FR9311632A patent/FR2710291B1/fr not_active Expired - Lifetime
• 1994
  • 1994-09-26 EP EP94927779A patent/EP0670782B1/fr not_active Expired - Lifetime
  • 1994-09-26 DE DE69407394T patent/DE69407394T2/de not_active Expired - Lifetime
  • 1994-09-26 AT AT94927779T patent/ATE161225T1/de active
  • 1994-09-26 WO PCT/IB1994/000315 patent/WO1995008444A2/fr active IP Right Grant
  • 1994-09-26 ES ES94927779T patent/ES2113679T3/es not_active Expired - Lifetime

Patent Citations (3)

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events