JPS63224948A - Multicolor rotary offset press - Google Patents

Abstract

PURPOSE:To improve a finish of printing by eliminating transfer of printing ink for former printing of matter to be printed onto a surface of a blanket, by a method wherein a transfer surface of a length necessary for printing is made to remain on the surface of the blanket of a printing mechanism on and after the second time and a nontransfer surface which does not come into contact with the matter to be printed is recessed to be provided. CONSTITUTION:A matter to be printed W passes through printing mechanism 1 of two units via a roller 20 and sent out via a drawing feed roller which is not given in a figure. In that case, a nontransfer surface 22 which does not come into contact with the matter to be printed W leaving a transfer surface 21 is recessed to be provided on a surface of a blanket 5 of the printing mechanism 1 in the second time. Consequently, printing ink of printing in the first time is not transferred to the surface of the blanket 5 in this printing mechanism 1 in the second time and does not adhere to the matter to be printed W. Therefore, stains due to printing does not occur and a finish of printing becomes excellent.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a multicolor offset printing press.

[Conventional technology]

Conventionally, this type of multicolor offset printing machine is equipped with a printing mechanism of multiple units in parallel, in which a strip of printing material passes between an impression cylinder and a blanket cylinder that has a blanket transferred from a plate of a rotating plate cylinder on its outer periphery. Structures are known.

[Problem that the invention seeks to solve]

However, in the case of the conventional structure described above, since the blanket of each printing mechanism is a flat surface, during the second and subsequent printings, the printing ink from the first printing material may be transferred to the transfer surface of the blanket surface, causing printing stains. It has this inconvenience.

[Means for solving problems]

The purpose of the present invention is to eliminate these inconveniences, and the gist of the present invention is to provide a belt-shaped printing medium between an impression cylinder and a plunket cylinder, which has a blanket transferred from a plate of a rotary plate cylinder on its outer periphery. It is equipped with a printing mechanism of a plurality of units passing through and a transfer mechanism that sends the printing material while traveling back and forth, and leaves a transfer surface necessary for printing on the surface of the blanket of the printing mechanism that performs at least the second printing and thereafter, A multicolor offset printing machine is characterized in that a non-transfer surface that does not contact a printing material is provided in a recessed manner.

[Effect]

The strip-shaped printing material is reciprocated by a transport mechanism and passes between the blanket cylinder and the impression cylinder of each printing mechanism, and the multicolor printing material is printed in the contact area where the transfer surface of the blanket surface on the outer periphery of the blanket cylinder contacts the printing material. Print.

At least after this second printing, the surface of the blanket of the printing mechanism leaves a transfer surface necessary for printing, and a recessed non-transfer surface that does not come into contact with the printing material prevents printing stains caused by printing ink on the printing material. It can be prevented.

〔Example〕

1 to 6 show an embodiment of the present invention, in which 1 is a two-unit printing mechanism, an inking section 2, a printing plate 3,
The blanket cylinder 6 has a rotating plate cylinder 4 having a blanket 5 on its outer periphery, a blanket cylinder 6 having a blanket 5 on its outer periphery, and an impression cylinder 7.
A contact area θ has a notch 8 on the outer periphery and the contact area θ where the printing target W and the blanket 5 come into contact. and a non-contact area θ.

Reference numeral 9 denotes a transport mechanism, in which a feeding roller 10 is provided on the feeding side of the printing mechanism 1, the printing material W is provided between the feeding rollers 10 so as to be sandwiched therebetween, and the feeding roller 10 rotates intermittently at a variable speed. A rotation mechanism 11, in this case an AC servo mechanism, is provided, and a compensation roller is provided between the feeding roller 10 and the printing mechanism 1 so as to be able to contact and move the printing material W, and the compensation roller holder is provided to prevent the printing material W from sagging. A moving mechanism 13 is provided that reciprocates in the direction and direction in which it is stretched, in this case the up and down direction, and the rising speed is synchronized with the printing speed, and a structure that applies tension to the printing material W on the supply side of the printing mechanism 1, in this case at a constant speed. A motion mechanism is used, and a retiring roller 14 is provided on the delivery side of the printing mechanism 1 so as to be continuously rotatable, and a contact area θ is formed on the outer periphery of the retiring roller 14. It has a suction hole 15 that can suck the printing material W by negative pressure, and the suction hole 15 sucks the printing material W while retiring, and the non-contact area θ
In this case, the suction is released and the printing material W can be pulled back while sliding on the outer periphery of the retiring roller 14.

Reference numeral 16 denotes the original web, and the printing material W enters the feed roller 10 via the roller 17 and roller, passes through the two units of the printing mechanism 1 via the roller 19, the compensating roller and the roller luff, and then passes through the retiring roller. 14.

In addition, in this case, the surface of the blanket 5 of the second printing mechanism 1 is provided with a recessed non-transfer surface n that does not contact the printing material W, leaving the transfer surface ■ and the transfer surface 21, as shown in FIG. 5.6. There is.

n is a clamp plate, and U is a clamp bolt.

Since this embodiment has the above configuration, the blanket cylinder 6,
The impression cylinder 7 and the retiring roller 14 are continuously rotating as shown in FIGS. 1 to 4, and the contact area θ where the blanket 5 and the impression cylinder 7 in FIG. feed roller 1
0 stops and stops feeding the printing material W, and the moving mechanism 13
The compensation roller n moves in the direction of slackening the printing material W, and in this case rises, and the printing material W moves toward the blanket cylinder 6.
The feeding roller 10 is sandwiched between the roller 7 and the impression cylinder 7 and is further pulled and fed by the retiring roller 14, and the feeding roller 10 is rotated by the rotating mechanism 11 in the non-contact area θ in FIG. 2 between FIG. 1 and FIG. 3. to replenish the printing material W, and the compensation roller tensioner moves in the direction of stretching the printing material W by the moving mechanism 13, and in this case descends, and the printing material W passing through the printing mechanism 1 and the retiring roller 14 is pulled back. , the difference between the amount of rotation of the feeding roller 10 and the amount of retraction by the compensation roller.The printed material W is continuously fed, and in this case, when the feeding roller 10 does not rotate in the non-contact area θ, the printed material W is the full feeding amount. Since it is designed to go back by minutes,
The amount of rotation of the feeding roller 10 is the amount of replenishment and feeding of the printing material W, so that the printing material W can be continuously fed while going back and forth. The feed amount can be adjusted by changing the speed of the
Accurate feed amount can be easily obtained and work can be done faster.

In particular, since the transfer surface 21 of the length necessary for printing is left on the surface of the blanket 5 of the printing mechanism 1 after the second printing, and the non-transfer surface n that does not contact the printing medium W is recessed.
The printing ink from the previous printing of the printing material, in this case the first printing, is transferred to the surface of the blanket 5 and does not adhere to the printing material W and cause printing stains, thereby improving the printing finish.

〔Effect of the invention〕

As described above, the present invention leaves a transfer surface of the length necessary for printing on the surface of the blanket of the printing mechanism after the second printing, and a non-transfer surface that does not contact the printing material is recessed. The printing ink from the previous printing on the printing material is transferred to the surface of the blanket and does not adhere to the printing material and cause printing stains, thereby improving the printing finish.

As described above, the intended purpose can be fully achieved.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is an explanatory diagram immediately before the start of the non-contact area, FIG. 2 is an explanatory diagram in the middle of the non-contact area, and FIG. 3 is an explanatory diagram immediately before the start of the contact area. 4 is an explanatory view of the middle of the contact area, FIG. 5 is a perspective view of the blanket for second and subsequent printing, and FIG. 6 is an assembled sectional view thereof. W: Printing material, 1: Printing mechanism, 3: Plate, 4: Rotating plate cylinder, 5: Blanket, 6: Blanket cylinder,
'7...Impression cylinder, 9...Transfer mechanism, ■...Transfer surface, n...
Non-transfer surface. March 14, 1986 Applicant: Sanjo Machinery Co., Ltd. Inventor: 1) Masato Fuku 1) Kazuyuki 74'
/j17A

Claims (1)

[Claims] A printing mechanism including a plurality of units in which a band-shaped printing material passes between an impression cylinder and a blanket cylinder having a blanket transferred from a plate of a rotary plate cylinder on its outer periphery; and a transporting mechanism that transports the printing material while traveling back and forth. , the blanket of the printing mechanism that performs at least the second and subsequent printing leaves a transfer surface necessary for printing, and is provided with a recessed non-transfer surface that does not come into contact with the printing material. Color offset printing machine.