Envelopes !!!

I’ve been running windmills since 1988 and for the first time we’ve had jobs for die cutting and scoring envelopes. I’ve used the die cutting plate with matrix for the scoring. It seems there should be a better way to do it. It’s always a problem where scoring and cutting knives come together in the corners. Would appreciate any suggestions or advice. They used to run the jobs on a Heidelberg cylinder and a Kelly C. We no longer have that available.

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What is your problem where the scoring and cutting ruler come together? Puckering, not cutting cleanly, hanging up or catching? There is an answer but it is different depending on your problem. I would think die cutting envelopes one up on a heidelberg would be much easier than running several up on a larger press.

When they were ran on a Kelly they were still ran one up. But on the windmills puckering and not cutting cleanly seems to be the main problem. When die cutting without the scoring it is clean but when I try to get the scoring to show up then the problem starts at the points where the scoring and cutting meet. Hope that clarifies the situation.

If I could do each operation separately it would probably help, but all the knives are on the same wood base.

The matrix is causing the cut rule to bear off. Are you using low height matrix cut with a bevel/ V cut on the ends? Is your cut rule getting dull and needs to be re-knifed? If you don’t have any low matrix you could use masking tape (4-5 pieces) covered with a piece of box tape. Miter/feather the edges on the tape or matrix next to the cut rules to help stop the “bearing off”.
If you want to run it through the press twice, turn the die over and tap the cut rule out, run, replace rule, but you really shouldn’t have to. You will need a raw hide or rubber mallet to tap the rule back in.

If you are using the correct plate on the platen you should have room to shim the back of the knives with 2 thou tape this will then relieve the pressure on the scores .
i leave the last sixteenth of crease in the corners either with no matrix at all or chamfered down a bit , I would be more inclined to think you are trying to use a broad matrix where a very narrow one is most suitable and you are trying to get that little bit too tight to the corner with your crease .

I’ll have to get back on this, as we won’t be back at work till next week due to attending a funeral today. I do want to get a better or correct way of doing this as it appears this is going to be an ongoing thing. Thanks Ron