On a corrugated board die the problem rarely comes from the cut line alone. A crushed edge, a crease that folds badly and waste that will not separate are three distinct symptoms, and each has a different first place to look: flute structure, press pressure or rubbering. Tying the symptom to the right source saves the die from an unnecessary revision.

Flute type changes how the die behaves

E, B, C or double-wall flutes resist cutting and creasing differently: a fine flute behaves close to solid board, a coarse flute carries more air and crushes more easily. The same drawing wants a different crease profile and different rubber on a different flute; a die built without knowing the flute is set up by trial and error at the press.

The first question in diagnosis is flute direction: how was the box form placed relative to the flute, do the creases run along or across it? When the zones sensitive to crushing (narrow panels, lock tabs, flaps) are marked on the drawing, the die is built more carefully there.

  • Flute type and direction are written plainly on the order.
  • Box form and orientation in use (load-bearing panels) are stated.
  • Zones sensitive to crushing are marked on the drawing.

Excess pressure kills the material

A clean cut on corrugated must not crush the structure; most of the flute thickness is air, and a collapsed flute does not recover. Solving an uncut area by raising the pressure crushes the whole sheet: the box looks sound but its edge crush strength drops and the bottom boxes give way under a pallet load.

The right pressure is the lowest value at which the rule cuts through the sheet completely. A local incomplete cut is solved by checking die flatness and rule height, not by pressure. Comparing the edge thickness after the cut with the original thickness is the most practical measure of crushing; that is why the sample is taken on the real material before the production run.

  • Pressure is set to the lowest value that cuts through.
  • A local incomplete cut is solved with die flatness and rule height.
  • Edge thickness after the cut is compared with the original.

Rubbering decides the waste release

On corrugated the rubber is chosen softer and thicker than on board; hard rubber crushes the flute before the rule arrives. Rubber is spread over wide areas so the ejection force is distributed rather than concentrated. In narrow gaps the rubber hardness is checked separately: rubber that is too soft moves sideways and the waste piece stays hooked on the product.

The exit direction of the waste pieces is assessed together with the cut. Wrong placement holds the waste, breaks it or marks the surface; a placement that leaves no mark on the product is the aim. Waste areas that read separately on the drawing let the rubber plan come out right at the first trial.

  • On corrugated, soft and thick rubber is spread over wide areas.
  • Rubber hardness in narrow gaps is checked separately.
  • Waste exit direction and waste areas are shown separately on the drawing.

What is settled together in the file

For corrugated work it is not only dimensions but material and flute type, flute direction, quantity and production machine that raise the quality of the quote. Cut and crease lines come in separate colours; lock tabs and load-bearing panels are marked. When the transport purpose of the product (how many kilos, how many layers stacked) is stated, crease profile and rubber are chosen for it.

When a problem is brought in, a clean and a faulty sample are sent together with the sheet direction marked. Without knowing whether the crushing covers the whole sheet or one position, diagnosis is left to guesswork; a photo and a sample separate a die cause from a pressure cause within minutes.

  • Cut and crease roles are given clearly on the drawing.
  • Flute type, flute direction and machine information are written in the message.
  • If there is a problem, a clean and a faulty sample are sent with the sheet direction.

Quote details we clarify together

When the file, material, quantity and deadline are clear, the quote conversation moves faster and with less back-and-forth.

  • Current revision file
  • Material and quantity details
  • Critical dimensions or production notes
  • Deadline expectation and delivery preference