In carton production the most expensive fault usually appears not on the cut line but in the folding and release behaviour: a cracking crease, a perforation that tears as it breaks, or a piece that stays on the rule. The die components that decide these three are the creasing rule, the perforating rule and the rubbering; the job and selection criteria of each are explained separately below.

Why creasing is critical

Creasing is the scored line that lets board fold in a controlled way: the blunt-edged creasing rule, working with the channel opposite it, compresses the board to form the fold line. A crease that is too weak makes the box hard to close; one that is too hard cracks the surface or breaks the fibres.

Board thickness, grain direction, film, varnish or ink coverage change the creasing decision: thick board widens the channel, a fold across the grain raises the cracking risk, a varnished surface does not forgive the wrong channel. The crease channel is therefore chosen from the measured thickness rather than the grammage, and cracking on printed board is checked on the sample.

  • Creasing lets board fold without breaking; the channel is chosen from thickness.
  • Grain direction and surface finish change the creasing decision; they are written on the order.
  • Cracking on a printed surface is checked on the folded sample.

When perforation is needed

Perforation forms a controlled tear or opening line with a cutting strip of teeth and gaps: hang holes, tear strips, detachable coupons and easy-open service packaging are its typical uses. The parts it cuts make tearing easy, the bridges it leaves hold the piece in place.

The tooth-to-gap ratio sets the behaviour: fine teeth tear easily, coarse teeth leave a bond that survives transport. The right ratio follows the product’s job; it must not break on the shelf and must separate cleanly when the user pulls. That balance is confirmed in a trial on the real material, not on paper, and is noted on the drawing as a tooth specification.

  • Ease of tearing and transport strength are considered together.
  • A tooth/gap note is written on the perforation line.
  • The final ratio is approved in a trial on the real material.

What rubbering does

Rubbering pins the material at the moment of cutting and pushes the cut piece off the rule as the rule withdraws; it also helps the waste drop in a controlled way. The wrong rubber comes back as marks on the product, hard release, double feeds or machine stoppages; a die without rubber seems to “work” at low speed and produces sheet wrap and stoppages at production speed.

Hardness and placement are chosen for material thickness, detail density and machine speed. Soft sponge goes on open areas, harder profile rubber along narrow channels and around perforations; small inner windows are filled completely. Rubber has a shorter life than rule; wear tracking is part of die maintenance.

  • It gives a clean release from the die and a controlled drop of waste.
  • Hardness is chosen by zone: soft on open areas, hard along narrow channels.
  • Collapsed or hardened rubber is renewed locally; the die is not replaced.

A practical check for the carton die

At die approval the folded product is checked as well as the flat dimensions: lid lock, glue flap alignment, the effect of the crease line on the surface and waste separation are assessed together. The sample is cut from the production board and several products from different positions on the sheet are examined together; a single sample does not represent the whole sheet.

The perforation line is torn by hand, the lid and lock are opened and closed a few times, and waste gaps are tried with machine speed in mind. This check takes minutes and reduces the waste risk before the production run; the approved sample is kept with the file number and becomes the reference for the repeat order.

  • Flat dimensions and the folded product are checked separately.
  • Lid, lock and perforation line are tried by hand.
  • Waste separation is assessed with machine speed and the real material in mind.

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