Home | English Spanish German
Phone Number
Preco Performance

Standard Tooling and Board Thickness Can Make Your Die Cutting Operation More Efficient

Randy NormanEditor's Note: This is the second in a series of articles about how to set up an efficient die cutting press system. Following are excerpts of a presentation made by Randy Norman, Preco applications specialist, at the 2007 Odyssey Exposition. You can see the first article here.

Standardize Your Tooling
It's very important when setting up an efficient die cutting system to standardize your rule height and feed line height. Using a Preco you can set feed line height by simply adjusting your rollers up and down. This is helpful when changing from a steel rule die to match metal tooling. However, what you want to do is make everything the same, (feedline height, press stroke, etc.) so when you change out a tool, you’re making no other adjustments.

Standardize Your Board Thickness
You'll also want to standardize your board thickness. A dieboard is what supports the steel rule blade. I prefer a ¾" (19.05mm) height dieboard. For example, most manufacturers use .937" steel rule. When the board and rule are combined the cutting edge of the rule sticks out of the dieboard a total of .187" (4.75mm). If you run a thinner die board of 5⁄8" (15.87mm) and a standard .937" rule there is more blade exposed in the dieboard (.312" or 15.87mm). This results in more flex of the rule blade when die cutting, or more lateral movement of the steel rule blades. More movement of the die blade causes more friction when die cutting and accelerates tool wear. This means you will get less die life and increased tooling costs.

If you run both 5⁄8" thick and ¾" dieboards, it creates a problem using the Preco quick change tooling clamps. The quick change tooling clamps are standard for either a 5⁄8" thick or a ¾" thick board. With a 5⁄8" thick dieboard, you will have a 1⁄8" (3.17mm) difference between your die clamps and the dieboard. If you’re running any quick change tooling, in all cases, you have to put a shim in each clamp to change the differences in the tooling heights. A quick fix that avoids having to shim the clamps is to actually mill the sides of the dieboard down to a 5⁄8" (15.87mm) thickness on the side. There’s no steel rule support there, so now if you have to run 5⁄8" (15.87mm) cutting foams, you can run a 5⁄8" (15.87mm) board. If you run anything else, you should use a ¾" (19.05mm) board. This will allow an easier way to change your boards out using quick change tooling.

Use a Proper Storage System for Steel Rule Dies
Stacking dies on top of one another promotes warping. Instead, invest in a proper storage system. A proper storage system will help reduce warping as well as the time you spend looking for tooling. It also eliminates tooling damage from contact with other dies and promotes safety by providing easy loading and unloading of tooling. There should be no need to move several dies from side to side to locate the one you need. Tooling locations should be entered into your information system, which will give you the ability to maintain a tooling inventory and track tooling usage.

Understand the Condition of Your Tooling
Many times I visit a plant and see that the tool is completely shot. I had someone send me a tool the other day because he said he couldn’t get it to cut through. When I got the tool in the mail, it looked like he was using creasing rule not cutting rule; the cutting edge of the dieblade was completely flat, there was no sharpness in the rule at all. The rule had been hit so hard against the cutting plate, it was flat and had cracked in places.

It's pretty easy to tell when your die is bad. Look at the material. When you get a nice, straight, sharp steel rule going through plastic material, it fractures. If you’ve ever split wood with an axe, you know you’re not going all the way through the log. The axe cuts through a short distance, and then it fractures the rest of the way through. It's the same thing with most materials being die cut. With soft materials, you’ll have to cut or hit into something, but most of your plastics and cardboard will fracture when you go through a certain depth rule. Now, when you've got a flat spot on the rule edge, that flat spot will hold the material instead of clean-cutting it. It can’t fracture in a single spot, so it fractures on both sides—and the result is angel hair. When you start seeing that a lot, it’s time to change the rule and re-knife the die.

There is a standard rule of thumb for ejection rubber, too. At a minimum, you want the ejection rubber material at least 1⁄16" (1.59mm) taller than your rule height so when the steel rule blade comes down and penetrates the material, the ejection rubber will hold the material flat as the steel rule blade comes out of the material. If there is no ejection rubber holding the material, the part is going to go up with the tool. When you’re talking about ejection rubber, you really should talk to a supplier that knows how to do it. There are so many different rubber densities now, different bevels and different ideas of how to hold the material down.

There is a science to ejection rubber, and I think many people don't realize that any more. They just take anything they have on the shop floor and they throw it on a die. You need to talk to ejection experts or your diemaker to get some ideas and try experimenting.

Next Issue:
Standardizing cutting equipment plates


back Back to Preco Performance Newsletter

 


© Copyright 1997-2016 Preco, Inc. All rights reserved. Disclaimer.
Made in the USA Veteran Owned