Smurfit Kappa introduces diagonal flute

Smurfit Kappa has designed a diagonal flute box.

Smurfit Kappa introduces diagonal flute box

The corrugated firm said technical experts in the design department of its offices in Herzberg, Germany, were recently presented with a challenge to optimise the existing transport packaging for premium hair care products.

According to the firm, it said no part of the construction could be changed – so the challenge was tricky.

In a statement, the firm said: “To offer the best solution, the product designer at Smurfit Kappa went against convention and rotated the direction of the corrugations on the E-corrugated board.

“The twisted arrangement of the cuts on the punching sheet resulted in a considerable improvement in the layout. This led to customer savings of 20% in the packaging. In addition, the improved technical characteristics meant that the diagonal corrugation achieved a roughly 13% higher BCT value (stacking compressing resistance, measured by a Box Compression Test).”



  1. This is a great idea if it maximises the sheet utilisation, but I can’t get my head around how it would increase BCT!

    • BCT could be increased if the previous design was formed with horizontal fluting ? Thus,diagonal fluting would improve box compression.

    • Dear Phil,

      In relation to your question, a spokesman from Smurfit Kappa said: “That’s the secret and trick behind it! You reduce the stacking strength in the long sides a little, but you maximise the strength in the short sides, where you now have double layers carrying load. And those layers are glued together which arise the BCT by fare more than you reduce on the long side.”

  2. Unless I completely have missed the point cutting on the angle of the flute has been used in the cosmetic liner industry for many years!!

    • Dear Alan,

      A Smurfit Kappa spokesman said: “We know that there is diagonal cutting used in open flute for decoration reasons, as well as for cushioning. However, we did not know, until now, that it could be used for better utilisation, better BCT, better run ability on erecting machines and simply for outer transport boxes.”

  3. It is a good material sheet utilisation but how is supply the BCT?

  4. This is a fantastic idea in terms of maximising the sheet and saving the customer money and it should be applauded. I make the assumption that the box itself does not contain a great deal of weight and therefore was originally conceived to be cost effective and was therefore quite rightly designed with the fluting at a 90 degree angle to the one which would maximise the strength (after all the product needs to be designed to be fit for purpose). The additional BCT would therefore come from the extra strength gained by moving the fluting by a 45 degree angle to be more in line with where the fluting would ideally need to be to attain it’s greatest BCT strength. The designer of this needs to be given recognition for “outside the box” thinking of these alterations and by increasing the BCT in this way which could potentially allow the board grade to be lowered and the maximisation of the sheet thus allow a major cost saving to the customer.

  5. I was expecting to see something amazing when I read the title to this article. I’m a little disapointed. Angling the flute can’t possibly increase the verticle stacking strength, only distribute it evenly over all directions. The box may feel stronger overall, but would be more likely to crush under pressure. The problem with wastage on the board is due to the style of box they’re using. There are lots of similar style boxes that create far less wastage in the first place.

  6. I have to echo Alan Leeming’s thoughts on this – we have used this technique regularly over the years to optimise material usage and improve fold quality, (as have many others), so I’m surprised to see it treated as an innovation.

  7. its not a new idea and i’m surprised they weren’t aware of its possibilities. Most time served design engineers know this can improve BCT in certain circumstances.
    Nothings new in corrugated. Its all been done before but usually ahead of its time