The factor that affects overprint precision in gravure is very much, be like, use advocate electric machinery and the stability that its control a system and dependability, the transmission form of gear case reachs precision, guide paper roller touchs static balancing stand or fall, the sensitivity of electrical system reachs dependability, equipment is using the operation of violate the rules and regulations that appears in the process, mechanical system maintains not archives causes wear away, local be out of shape etc all is the element that overprint forbids. Basically analyse a few elements related to edition roller in this.
(One) the mechanical precision of edition roller
The precision of edition roller machinery that at present plate making business leaves factory all should achieve the following requirement commonly:
The ±0.2% with long roller of length extreme deviation
±0.02mm of diametical extreme deviation
6mm-12mm of mural large range
Extreme deviation of keyway breadth depth 0.3mm
±1 of extreme deviation of taper hole taper°
Cylinder is spent do not be more than 0.03mm
11mm of ～ of 7mm of flange round horn
Dynamic balancing 80g is the following (1200r/m)
Out of tolerance of edition roller precision is one of causes that cause overprint to forbid. At present plate making has single sunken opportunity two kinds of forms edition of a kind of tape spool, a kind of hollow edition.
Edition of 1. tape spool
Cost of tape spool edition is high, but treatment precision is tall also. When be being machined because of business of plate making of tape spool edition, want to pass an entrance to MDC car is ground and be become, on one hand the car grinds the precision of machine tall, the datum mark when on the other hand the car is ground and the datum mark when pressworking are identical, precision of machinery of roller of the edition when pressworking so is tall.
2. hollow edition
Hollow edition charge slightly low, but because the treatment when plate making is standard,presswork together hard fiducial and identical, although plate making is the same as,presswork next fiducial search consistent, non-standard or the axis that wear thick line is long-term when the jockey when returning existence to presswork wears an axis disassemble, especially cruel disassemble cause axial loss, make after wearing an axis actually, edition roller controls jumpy out of tolerance, out of round is spent exceeding mark to wait all is the main reason that overprint forbids.
(2) the influence of direction of paper silk detailed to overprint
Generally speaking, paper fibrous is transverse expand should compare paper fibrous fore-and-aft expand to be gotten greatly much, it is 2~8 commonly times. Accordingly, paper fibrous is transverse and stretchy also compare fore-and-aft and stretchy get greatly much. Paper of straight silk detailed pressworks is to show direction of black-and-white paper fiber and platen turn direction agrees. Abb detailed paper pressworks is to show paper fiber direction and direction of drum shaft line are consistent. Paper of straight silk detailed from switch on the mobile phone to imprint, the adjustable change of paper is transverse be more than fore-and-aft, paper graph article appeared to produce transverse overprint easily to forbid after pressworking. After abb detailed paper pressworks, the adjustable change of paper is fore-and-aft be more than transverse, article of the graph after pressworking produces fore-and-aft overprint easily to forbid. Why to because this is used,plant filar detailed paper pressworks, the adjustable change quantity of this detailed paper all should provide plate making company.
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