In 2019, SML decided to step into the market for cardboard packaging for liquids launching a completely new machine with its aseptic TRIPLEX coating and lamination line. Mario Höllnsteiner is the product manager in charge of the TRIPLEX coating lines. SML TechReport talked to him about customer requirements, the advantages of in-house developed machine control and how well TRIPLEX is accepted in the market today.

Mr. Höllnsteiner: What triggered SML’s decision to develop the TRIPLEX line for liquid packaging board? 
"On the one hand, we recognised the market’s demand for an alternative supplier of extrusion coating lines for liquid packaging board. On the other hand, we realised that the reuqirements suit to our own product range down to the ground. And the third, and probably most important, reason to develop this line was simply that we have the skills to do it better than the competition."

The technical requirements for this type of line are quite demanding…
"Yes, I would even go so far as to say that the construction of extrusion coating lines for liquid packaging board is the supreme discipline in the engineering of extrusion lamination systems. SML has everything that it takes in-house, to further develop this type of highly advanced machinery – above all the technological knowledge."

What are the most striking characteristics of the TRIPLEX coating line? 
"A key characteristic, the one that most people first become aware of, is the robust set-up and the strong dimensioning of the line. This guarantees the long lifetimes, especially with regard to the use of heavy cardboard grammages, for which SML’s TRIPLEX lines were especially designed."

Which effects does the machine control system have on the line performance and efficiency? 
"The length of our TRIPLEX lines, and with it the number of drive systems, requires the rather complex control of the web tension. Since we ourselves developed the machine control system that handles the drives completely on our own, we were able to reduce the times for line ramp-up and ramp-down significantly. This minimises scraps while raising the overall line efficiency."

How have the ongoing discussions about the recyclability of packaging materials affected the development of the TRIPLEX line? 
"These discussions, of course, did not end with liquid packaging board although this type of packaging has been well-established in the market for a very long time. Manufacturers are required to substitute the aluminium in liquid cartons with an alternative co-extruded barrier film. We managed to arrange five extruders on one carrier by specially designing the movable extruder carriage. Despite this high number, each of these extruders is freely accessible. At the same time, the arrangement of the extruders helps us to keep the melt pipes relatively short. This in turn is a huge advantage when processing materials which are sensitive to long residence times in the system – like EVOH for example that can replace aluminium."

Finally, in what way has the TRIPLEX series been further developed since it came on the market three years ago, and how are you assessing the decision to step into the market for liquid packaging board from today’s perspective? 
"First of all let me say that we are, of course, constantly optimising all of our machines. The biggest innovative step in the TRIPLEX series was the increase in line speed. The TRIPLEX line was originally designed for a line-speed of 400 m/min. In the meantime we offer machines with speeds of up to 600 m/min. We took the decision to step into the market for liquid packaging board three years ago and it was most definitely the right call. Today, we have three customers who already placed their trust in SML’s lines for liquid packaging board, and there is strong interest from well-known manufacturers and brand owners all over the world."

Redlham, 29.11.2022