H.S. Boyd wants you to achieve the best run possible. To help you reach that goal, and to save you time and money, we offer these general production/installation guidelines.
Proper preparation of the impression cylinder is essential to ensure the rule’s adhesive backing correctly adheres to the cylinder surface each time. Clean the impression cylinder to remove any oil or grease, and be certain the surface is dry before you apply the rule.
Although careful handling and controlled pressure settings will minimize damage to the blanket, many printers prefer to use an old blanket or protect their blanket surface with Perf Mate, an H.S. Boyd-designed protection sheet that can be used by itself or in connection with the blanket. When an old blanket is reused, always check the position of the previous perforating job on the blanket to ensure any previously perforated blanket area does not interfere with the current job requirements. And remember – on longer runs the cost of a blanket is nominal compared to the savings gained by on-press finishing.
Guidelines for positioning the offset perforating rules should be clearly placed on the plates. Before beginning, make sure you can position the rule in precise accordance with the artwork. Be certain you also have the appropriate type and size of rule to complete the job correctly.
PROVEN METHODS OF APPLICATION
The following methods of applying Boyd rules have proven extremely effective. No matter what application you use, remember to overlay the rule with the clear tape provided in the product package. This tape is resistant to press conditions and will not slip during the run. The working edge of the rule will cut through the tape on the first impression.
DIRECT APPLICATION TO CYLINDER
In this method, you will transfer the plate image directly to the impression cylinder to serve as the guide for positioning the rules. The first step is to ink up and run through one printing cycle without paper. When the image has been transferred to the cylinder, make sure the rule guidelines are clearly visible.
Measure and cut the rule to the designated lengths and remove the paper backing to expose the adhesive surface. Carefully align the rule with the guidelines on the cylinder and press down firmly on the face of the rule. Add a length of clear tape over the rule to secure its position.
You are now ready to begin the run; however, certain precautions should be included in your preparation. Be certain that all press parts clear the rule as you set the pressure to begin. You may find it useful to run through some make ready sheets to check the accuracy of rule placement and the pressure against the printed surface.
Too much or too little pressure will affect the performance of the rule, so the pressure may need to be adjusted before you begin as well as during the run.
APPLICATION TO CARRIER SHEET
This method of application secures the rule to a carrier sheet, which is then secured to the impression cylinder by spray adhesive or other adhesive material. With the carrier sheet lying face up on a table, apply the rule along the guidelines. Use a straight edge for exact lines. Overlay the rule with the clear tape. Apply a coat of spray adhesive to the impression cylinder to prepare the approximate area the carrier sheet will cover.
Next, place the carrier sheet onto the feeder table aligning with the head stop and the side guide. Inch, or manually turn, the press forward and feed the sheet into the press. During the application procedure, only allow the unit being used to perf to go onto impression.
As the carrier sheet runs through the blanket and impression cylinder, the unit will go on impression and the carrier sheet will be adhered to the impression cylinder. Stop the press when the carrier sheet is halfway through the unit and cut off the gripper bite. Secure the leading edge of the carrier sheet with tape. Back off pressure and adjust as desired. On completion of the job, the plastic sheet may be removed and stored for future use. The removed gripper bite will need to be replaced to run the same job again.
HS BOYD REFERENCES