Box loses its compression strength and collapses in stacking position.
Keeping corrugated sheets from warping.
Therefore during production we should check the tension of the inner liner and the corrugated board and keep the tension of the facing and inner liners even.
Warp bending of corrugated sheets due to excess moisture.
Focus on corrugated board packaging where high print quality is requested.
Techniques for reducing moisture related warp include.
The present invention makes it possible to determine a warp in a corrugated cardboard sheet in a state in which the corrugated cardboard sheet is nearly finished and at an early stage and to correct the warp accurately and at an early stage on the basis of the warp determination.
Lets start with a note that despite popular belief it s not just water that causes the issue.
Two valmet iq scanners for top and back side moisture measurement.
Diagonal or twist warp board curves along the diagonal of the sheet.
There are very simple gauges made that are twelve inches wide with a small stylus in the middle to measure the deflection from the plane of the substrate.
Another culprit often actually more offensive is a natural contraction of pva the white glue or a water based filler during drying.
Similarly excessive tension of the gluer will also lead to such a problem.
Major problems caused due to moisture gain in box.
Reusable and paper faced on only one side.
Yes warp is linear and can also be considered diagonal when measuring a corrugated sheet.
Gum which is drying fast need not have moisture resistance and vice a versa.
Fourth the main cause of warping the cause of warping is very complex summed up is due to the fact that noodle paper ie corrugated paper paper and paper in the production due to a variety of reasons caused by their expansion and contraction differences.
Up warp board bows up convex.
The causes of cardboard warping.
A warp determination device for a corrugated cardboard sheet manufacturing device is provided with.
Increase corrugator speed if possible adjust web and liner wrap either reduce double back wrap or increase.
Down warp board bows down concave.
Corrugated board for demanding customers the corrugated board we produce is often aimed at packaging requiring high quality printing which needs flat sheets and minimal impact on the outer liner to avoid washboard that effect on the print quality says ola lindberg process engineer at stora enso packaging in jönköping.
Stable and consistent process and totally flat sheets of corrugated board coming out of the corrugator with more frequent quality changes and smaller order sizes.
The nature and type of paper 2.
As the tension of the single corrugated board and the facing liner is not even the tighter side will retract.
If your longest warp is 15 yards order quantity would be 45.
The causes of warpage are.
Order by the foot enough for your longest warp.
You need to consider the worst case of dimensional deformation.
Easy to use as you separate your warp layers.
This corrugated warp separator is perfect for keeping your yarn in line.
