Print Qualification Trial J-1 35# Opaque

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Paper : 35# Opaque, 35”

Roll #1 : BC5H25242X (St. Helens control paper)

Roll #2 : BC5E24982D (St. Helens control paper)

Roll #3 : BC8N14861E (Jackson)

Roll #4 : BC8N14861F (Jackson)

Graphics

1 color 16 page signature from an existing Darby file including text, solids, halftones (120 line) and 50% screen tints (120 line). Two versions of the Boise logo were added.

Plates

Agfa polyester analog – changed to Agfa aluminum analog due to unacceptable print quality from the polyester plates.

Press

DGM 435-3

35” open web with 2 – 2/color units delivering into a signature folder.

Prints blanket to blanket.

Water system brush type.

Registration Control

QTI auto register system.

Manual ink control. Ink fountains fed from central tote system.

Speed

Normal operating speed web 50# or 60#).

Trial Run Speed : 12,000 IPH (normal for running single web LWO)

Roll Stand : 2 Martin roll stands.

Press Set Up : First print tower used.

1st Unit : bypassed

2nd Unit : Black

Infeed : Infeed tension 40lbs.

Ink : INX

Ink tack : Black : 9.5

Densitometer : N / A

Fountain Solution : Prisco 2451+2

Manually mixed using RO filtered water.

pH of 4.0 and conductivity of 1100.

Stand alone recirculation tank.

Blankets : DYC compressible .067 thicknesses.

Observations

Press appears to be well maintained and all settings, pressures and adjustments are within normal operating specs.

All of the test rolls looked to be in good condition. Rolls 1 & 2 were unwrapped and in the press with rolls 3 & 4 still wrapped and staged next to the press.

Press Run

St. Helens 35#

Plates were on and the press was already webbed up when we arrived. The crew pulled up on roll #1 and began setting color. Print quality was poor and after working with water and ink settings for a while, it was determined that an expectable print quality could not be achieved using the polyester print plates that had been made for our trial. Also, the blankets on the press had been running 50# and 60# offset for over a week and were worn a bit too much to produce a clean sharp print job on 35#. The crew was instructed to order a set of conventional aluminum plates for our job from their pre-press department and to mount fresh blankets during the 1/2 hour of down time waiting for the new plates.

With new plates and blankets mounted, the press was started back up. Ink and water adjustments were made to attain a satisfactory print density. This consultant made few small adjustments to balance the work across the web as well as front to back. A wrinkle was noticed on the web coming out of the festoon section and was determined to be an unwinding issue with roll #1. Roll# 2 was spliced into and the wrinkle problem went away. After running about 2/3 of roll #2, and while maintaining a good clean and sharp print quality, 300 samples were pulled and marked as St. Helens paper. Print quality and run ability remained good throughout the roll, producing no picking or print issues. While roll #2 was running, the crew was instructed to flip and remount roll #1 in the roll stand for a second try. Roll #2 was run out and roll #1 was spliced into again. With the roll flipped, it ran well with no wrinkling problems. Ink and water balance was maintained with print quality and run ability being equal to the previous St. Helens roll. At the finish of this roll, blankets were inspected and found to be clean and free of any debris.

Jackson 35#

Roll #3 was spliced into with no infeed or web guide issues. Print quality and run ability were equal to the previous 2 rolls. Show through was slightly more on the Jackson sheet and the paper had more of a blue white color. Ink density was checked and 300 samples were pulled and marked as Jackson paper. Roll #3 ran out with no problems.

Roll #4 spliced with no infeed or web guide issues. Print quality and run ability were equal to Roll #3. Roll #4 was not quite finished (about _ of the roll left) when it was time for the press crew to quit for the day so it was decided to end the print trial at that time. Blankets were completely clean and free of any debris.

Final comments

The Jackson paper ran clean and produced a sharp print quality. No significant ink adjustments were necessary to maintain print density when transitioning from the St. Helens sheet to the Jackson sheet. xxxxx commented that the Jackson sheet ran and printed as good as any other 35# opaque he has seen. The Jackson 35# trial paper is a good quality opaque sheet needing only a slight improvement in the show through.

Folding : It is worth mentioning that the folding characteristics were excellent on the Jackson sheet, producing a crisp 16 page folded signature that lies flatter than the folded signatures of the SH sheet. This folding quality is highly valued by most financial printers.

To see the resume of the expert associated with this case study, see the link below.