THOMPSON'S PERFECT RULES
Offset perforating, scoring & cutting rules, an economical way to print & perf at the same time.
With Perfect Rules, you can perf, score, or cut on press in-line while your print. Perfect rules will eliminate bindery steps and are designed for use on sheetfed, web or continuous forms presses. Heat treated for longer life, these rules can be used for long runs or again and again on short runs. With Perfect Rules, you can perform many finishing steps economically in your own shop.
GENERAL GUIDELINES FOR USE:
There are two primary methods for applying Perfect Rules that are
both equally effective. One method is to apply the rules directly on
the impression cylinder and the 2nd is to use a carrier sheet. Both
are explained in detail below.
To obtain best results with Perfect Rules, it is suggested you use a hard 3-4 ply non-compressible blanket. However, it should be noted the blanket will be damaged and many printers prefer to use an old blanket. When a blanket is re-used, always check the position of the previous job to ensure the current job will not be affected.
INSTRUCTIONS FOR DIRECT APPLICATION TO CYLINDER:
All rules are coated with double sided tape. This feature allows you to apply the rules vertically or horizontally to the impression cylinder. The following steps are suggested for proper application and location of the rules to the cylinder:
- A perforation guideline indicating the exact placement of the rules should be included on the printing plate.
- Make certain that the impression cylinder is clean and free from oil or grease.
- Transfer the plate image directly to the impression cylinder by inking up and running one printing cycle without paper.
- The rule guidelines should be clearly visible on the impression cylinder, so measure and cut the rules to the proper lengths, then remove the paper backing to expose the adhesive surface.
- Carefully align the rule with the guidelines and apply to cylinder. The adhesive will hold the rule in position.
- Overlay the rule with the clear film tape furnished with the rule. On the first impression the cutting or scoring edge will puncture through the tape.
You are now ready to begin the run, however it is advisable to reduce the pressure between the impression cylinder and blanket cylinder and gradually increases until the desired printing and perforating results are obtained. You may find it useful to run through some spoil sheets to check the accuracy of rule placement and the pressure against the printed surface.
INSTRUCTIONS FOR APPLICATION TO CARRIER SHEET:
Instead of applying rules directly to impression cylinder, this method secures the rules to a carrier sheet which is then secured to the cylinder. The carrier sheet can be a thin sheet of plastic or paper. The main advantage to this method is the job can be removed intact and used again. Or is sometimes easier and can save time by preparing the entire perf job off press. The following steps are suggested for best results:
- Apply rule to carrier sheet in same manner as direct application method above. If needed, use a straight edge for exact lines and be sure to overlay the rule with clear tape provided.
- Place the sheet in the press feeder and open the sheet detectors wide enough to allow passage of the metal rule between cylinders.
- Coat the impression cylinder with rubber cement or spray adhesive to the approximate size of the carrier sheet.
- Slowly feed the sheet through the press. As it enters the grippers turn off the press and continue the cycle by hand.
- Cut the sheet directly behind the grippers with a sharp blade. The sheet will now stay fastened to the cylinder. Using the adhesive, fasten any loose corners or edges.
The job can now be run, but before turning on the press make certain there is clearance between press parts and the applied metal rules. Adjust pressure if necessary to allow for the extra sheet.
Perfect Rules are manufactured to perforate, score, and cut on different weights of paper or card stock. Many factors can affect the choice of the specific rule to run the job at hand. The type of paper and grain direction, type of press, experience of press operator and application techniques are examples. See our separate product listing for a complete list of products for your particular job. If you are having problems, then it may be necessary to make a simple adjustment as described below:
|Paper is sticking to teeth on the perf.||Grippers need to be adjusted or replaced. Lay a piece of clear tape over the perf. Possibly apply a silicone spray to the blade teeth.|
|Perf is not perforating as desired||Add pressure or change blade to special high product.|
|Perf is sitting instead of perforating the paper||Back the pressure off, or try changing to a special low product, or overlay the blade with a piece of clear tape.|
|Rule is not perforating at all.||Use a good hard 3 - 4-ply non-compressible blanket. Check the pressure. Does this particular press have spring-loaded cylinders designed to release under pressure as a safety precaution?|
|Teeth are bending or breaking off.||Back off the pressure and make sure the correct height of perf for the stock is being used.|
|Perforation is straying from guidelines. Back off the pressure.||Try using a good 1/2" - 3/4" masking tape to overlay the perf (especially in high-speed web operations that generate heat).|
|Indention or shoulder mark in paper is appearing adjacent to the perforated line.||Back off the pressure, Try center-mounted blade to distibute pressure evenly to both sides of blade.|