Mitsubishi Heavy Industries Technical Review Vol. 46 No. 3 (Sep. 2009)24

New 57H-V Slitter Scorer for a Corrugating Machine

PAP E R & P R I N T I N G M A C H I N E RY D I V I S I O N
PAP E R C O N V E R T I N G M A C H I N E RY
D E PA R T M E N T|1. Product Overview
Mitsubishi Heavy Industries (MHI), Ltd., has developed the new 57H-V slitter scorer series.
In addition to the basic functions of the existing 57H-III slitter scorer series, which include sharp
slitting performance and quick setup for short orders, MHI added the following new features to the57H-V to better meet customer requirements: (1) reduced paper loss, (2) improved workability andserviceability, and (3) easy installation in a smaller space.

|2. Main Features
2.1

Reduced paper loss

(1) In place of the existing air cylinder, MHI adopted a servomotor for the lifting mechanism of
the slitter knife and the scoring roll. As a result, variation in lifting timing can be minimized,
thereby significantly reducing paper loss that occurs on order changes (Table 1).
 Cost reduction compared to MHI 57H-III: approximately 600,000 yen/year Cost reduction compared to MHI 57G (model subject to replacement):
approximately 1,700,000 yen/year
Table 1 Comparison of cost resulting from paper loss, due to order changes
for different MHI slitter scorers
Machine type
Waste sheet length
Waste sheet width
Slitter unit change
Paper loss upon order change
Annual paper loss upon order change(250 days/year)
Annual paper loss cost
Difference in annual costunitsmm
times/ daym2/day
m2

57H-V
0.70

57G
1.10

213

57H-III
0.851.52200258

53 25064 50083 5001 000 yen
1 000 yen

3 035－

3 677
642

4 760
1 725

334

Note: Order change speed: 250m/min, sheet unit price: 57 yen/m2(2) A steering guide device incorporated in the slitter scorer controls the web skewing. This
prevents losses due to defective products that occur when the slitter knife is misaligned withthe web.
Furthermore, the steering guide is synchronized to move inversely with respect to the lateraladjustment of the slitter scorer, thereby improving the phase alignment response between theslitter knife and the web (patent application filed).

Mitsubishi Heavy Industries Technical Review Vol. 46 No. 3 (Sep. 2009)25

2.2

Improved workability and serviceability(1) The 57H-V slitter scorer precisely adjusts the slitter knife height to cope with the change inthe knife diameter due to automatic grinding of the knife on the machine. The heightadjustment is automatically carried out by a mechanism that combines the slitter knife lifting
servomotor and positioning laser sensor, thus eliminating the manual adjustment by anoperator (patent application filed).
 Adjustment time for the existing model: more than 30 minutes for manual adjustment
 Adjustment time for the 57H-V: 2-3 minutes for automatic adjustment(2) Fixing of the knife for trim slitting and the incorporation of a trim head hitting device in theslitter scorer ensure that trim comes into the trim chute during an order change, thus
eliminating some checking work by an operator (patent application filed).

2.3

Easy installation in a smaller spacePreviously, the large machine dimension in the flow direction has been a disadvantage of
double-frame slitter scorers. In the 57H-V, the dimension was reduced by modifying themachine mechanism and optimizing the maintenance space. Thus, the new slitter scorer can beinstalled in a smaller space, providing a convenient alternative for an existing single-framemachine.
 Required dimension in the machine flow direction
 MHI 57H-V: 2,700 mm (minimum)
 MHI 57G (Single-frame machine): 2,500 mm
 MHI 57H-III (Double-frame machine): 4,080 mm|3. Main Specifications
Figure 1 shows a cross-sectional view of the new 57H-V slitter scorer, and Table 2 lists its
main specifications.

Figure 1 Cross-sectional view of the 57H-V
Table 2 Specifications of the 57H-V slitter scorer
Item
Maximum machine speed
Maximum paper width
Machine mechanism
Shaft arrangement
Number of boxes out
Slitting method
Head positioning method
Head lifting method
Knife height adjustment
Steering guide device

Specification
400 m/min
1800, 2000, 2200, 2500 mm
2 units/2 frames (tandem alignment)
Scorer-scorer slitter/1 unit
4-7 boxes out
Lower blade slitting system with a single blade
1 head/1 motor system
Servomotor method
Automatic adjustment
Optional