A clear trend was detected in the direction of ultrasound: conventional heat sealing in the packaging industry is being replaced more and more by ultrasonic seals and welds, which is clear from the number of enquiries.

The main indicators for selecting ultrasound include to date:

• the ability to weld moistened packaging,
• pack contents are not damaged or affected by heat,
• use of mono-films without heat shield (2nd film layer) to protect against heat sealing
• indirect monitoring and documenting of the weld result through energy analysis and
• format-free Cut’n’Seal applications for simultaneous separation and welding on Sonotrode table applications for high quality, tight, peelable weld joins and soft, burr-free separation edges.

Alongside these advantages, ultrasound is also increasingly becoming established in the packaging industry to the detriment of heat sealing, because of the potential material savings of ultrasound resulting from seam widths which are reduced by up to 90%. Customers and potential customers calculate the high capital investment of ultrasound technologies against material savings, meaning that machine and tool concepts are optimised in order to benefit from smaller seam widths.

What was now clear at Interpack was that the niche demand for ultrasound is expanding very dynamically, because the technology has a very big future. For example, the energy requirement is reduced by up to 75% because of the cold ultrasonic sealing tools. In addition, the eminent suitability of SONOTRONIC ultrasonic tools for series production, in combination with all the marketing activities, speaks for itself. SONOTRONIC is an integration partner in the areas of mechanics, ultrasound and laboratory work. We have been working successfully for years with, amongst others, Gerhard Schubert GmbH, Crailsheim, Widmann Maschinen GmbH, Schlierbach and CFS B.V., Bakel. Again and again real results were achieved with unique selling features. This was also achieved with the latest Interpack product innovation, the C-motion from CFS.

The vertical tubular bag machine (VFFS) is the only machine in this market sector, which is directly geared towards ultrasound. It is suitable for large salad bags with film thickness up to 35 µm, a seal length of 320 mm and 30 kHz ultrasonic equipment. The sealing unit was developed in co-operation between CFS and SONOTRONIC and also by including the results of more than 50 million bags already produced, of the same size and with 35 µm film thickness. Initial test evaluations already show that outstanding results can be achieved here in the short term, with millions of fault-free welds. The same applies to sealing thin, 30 µm salad film.

Overall, Interpack 2011 proved to be an attractive industry get-together with great interest in ultrasound technologies. As the leader in ultrasonic plastics processing, SONOTRONIC is looking forward to welcoming you again at future trade fairs or at its company for a personal meeting.