Keeping Score?

Ran a scoring job this week and was able to get the score looking good…..on top of the stock. However it’s the only time in 20+ years that I can remember the score breaking under the stock. It was a windmill, and tried #32 and 40 matrix, and straight on the bed and on the cutting plate. We did get the job done ok. Could that have been caused by the stock being cut across the grain? I’ve ran multiply paper and really heavy weight stock, but as I said it’s the only time for this problem. Ron

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Had the same problem last year, i’ve been scoring for around 40 years and nothing like this has ever happened. The customer supplied the stock, i cut makeready from old stock i had on the shelf, the makeready scored just fine, the customer stock didn’t work, i even turned the stock and it didn’t matter what way the grain was. Don’t know what kind of stock this was, hope never to see this again. i too used a windmill. Dick G.

Acid based paper never gave much of a problem scoring. I was told by a paper mill QC tech at one of my customers that the old acid based paper was about 75% wood fiber and 25% fillers and so on. The new alkaline papers are the reverse in some cases. That is why alkaline papers feel stiff and crusty compared to the old acid based papers.
So when you try to score these alkaline papers, especially some of the imported sheets, the action of the rule pushing the sheet into the matrix causes the filler fibers to break.
The “curve” at the out side of the score contacting the base of the matrix is a different diameter than the one inside against the rule. This difference is enough to put stress on the filler and make it crack.
You almost need to wet score like we used to do on folders to soften the sheets and keep them intact.
Kinda hard to do on the old windmill though.

Score and crease cracking. If creasing with matrix the rule should hit the outside of the stock. The instructions that come with matrix are based on using good stock. High clay content in some stocks can be dealt with by using 3 pt crease and wider matrix. In a real pinch a cut score looks better than cracked fibers.

. Mike is correct about the clay in todays paper. Try a string score.

I’ll have to check what kind of stock it was. If you’re just folding it, it looked fine…and if you don’t open the stock you’d never notice it, as the breaking is on the inside of the fold.