News

At Interpack in 2005, there was a buzz of excitement about radio frequency. The packaging industry was closely following the progress of Stanelco’s Greenseal technology, which was hailed as a revolutionary breakthrough, owing to its energy- and waste-reduction benefits. The firm secured an exclusivity deal with Asda and joined forces with Proseal to develop a radio frequency tray-sealing machine. Other packaging equipment manufacturers, such as Ishida and Ilapak, said they, too, were examining radio frequency.

Three years on, however, radio frequency has proved to be a bit of a damp squib. After a rocky 2006, in which the company lost three board directors and its share price plummeted, Stanelco admitted last May that commercialisation of its Greenseal product was “unlikely”. Proseal has since confirmed it is no longer pursuing radio frequency technology, and Sealpac’s Marcel Veenstra told Packaging News this month: “Sealing with radio frequency is not at the top of our list for future developments.”

It is a similar story with laser sealing. In 2005, Packaging Automation announced it was working on a project with Loughborough University and several other partners to develop a laser-based tray sealing and inspection system for oven-ready meals.

Spring arrivals
Three years later, there are no signs of this technology coming to market. Instead, it appears Packaging Automation is channelling its energy into conventional heat sealing, launching a patented automatic tray sealer called the Eco-cut this spring.

The new tray sealer is said to reduce the level of film waste created during the operation by up to 33%, and to boost productivity by up to 20%, delivering cost savings to food manufacturers as well as helping the environment.

Packaging Automation isn’t the only firm launching a tray sealer this spring. Proseal is adding a new model to its GT range. The GT1, an enhanced version of the F45, incorporates the same improvements and features as the GT2, which was launched last year. These include touch-screen control, which allows complete machine and tooling set-up to be ‘recipe’ controlled, meaning all settings are easily stored for fast retrieval. Speeds have been increased through the introduction of a servo-driven in-feed conveyor and a tray positioning system. And the machine’s film feed system is said to provide enhanced control of the sealing system for improved seal quality, with easy film threading and dynamic control of the movement of the film throughout the film-feed cycle to maintain constant tension. The machine also incorporates Proseal’s ‘Auto-Tool’ connection system, which enables tool changes to be carried out in around three minutes.  

Ishida Europe, meanwhile, has disclosed that it will preview the third model in its QX range of tray sealers at Interpack, and a seal tester for trays that ensures reliable detection of out-of-spec sealing edges, although the firm refuses to divulge specific details about either innovation until the show.

Ishida will also demonstrate a weighing and tray sealing line for fresh and frozen products. The CCW-R multi-head weigher delivers portioned product to the tray filling system where the portions are deposited into trays. The filled trays are sealed using Ishida’s QX1100 tray sealer. The double-track configuration and use of servo motors enable up to 120 trays to be processed per minute, and sealing can be carried out with inside cut profile to enhance pack presentation.

Like Ishida, Sealpac says it is shifting its focus to a ‘total system approach’, which involves manufacturing auxiliary equipment such as de-nesters and lane dividers in-house. In addition, the company has been developing convenience-led packaging concepts that can be produced on its tray sealers. The A5 tray sealer, for example, can be equipped with a TraySkin system for packaging fresh meat at speeds of up to 70 packs per minute. The system combines the vacuum sealing process with the use of established trays and is said to be especially suitable for beef, which is subject to an advanced maturing and storage process.

Induction sealing
Besides tray sealing, there are likely to be some exciting developments at Interpack in induction sealing.
Induction sealing is commonly used to seal rigid containers such as pots and bottles. The container, fitted with a plastic closure and aluminium foil liner, is placed underneath the machine. The sealer then transmits electromagnetic energy to the foil liner, causing it to heat up and weld itself across the container neck.

According to Peter Tindale, product manager with Pillar Technologies, ‘capless’ induction – direct application of the seal to the container – has become a talking point in the industry.

“In the past, volume producers such as Pillar and Enercon chose not to get involved in capless induction, leaving it to our more bespoke rivals, such as Relco,” says Tindale. “Now that emphasis is shifting, and direct application is of greater interest to us and Enercon, so we are starting to develop solutions.

“The main driver is to take induction sealing into areas where induction was previously not an option, areas where a traditional conduction seal was applied to a container where there would be no closure, or maybe just a light overcap, such as foil-sealed, single-serve products, yoghurts, single-dose ­probiotic drinks, airline water cups and Pot Noodle-type snack foods.”

Tindale claims the benefits of fillers are longevity of sealing heads, quick start-up time (an induction sealing system is ready instantly, whereas a traditional conduction head needs to warm up for several minutes) and power consumption; not only does an induction draw less power, it can be cycled on/off to match the filling sequence, rather than having to run continuously.

There are also benefits when sealing to glass because there is no flexibility/compressibility in a metal conduction sealing head to cope with inconsistencies in a glass container land area, whereas with an induction sealing head a compressible material can be used against the foil seal to create good contact while the induction field is triggered.

At Interpack, Pillar will show a direct sealing unit integrated into a machine produced by the firm’s partner, French company Embatherm.

Improved flexibility
Competitor Relco will also be present at Interpack with a three-head, direct induction sealer that has been manufactured for Avon in Russia for applying foil seals to cosmetic products such as tubs of face cream.

“It is going to the show to be demonstrated before it goes on to the customer for installation,” says Relco sales manager Paul Rollason. “It’s the second machine of its type and probably the ninth machine we’ve sold to the cosmetics industry.”

The Relco FCS-Auto uses the patented Relco Punch&Seal ­single-stroke, foil-cutting, locating and sealing tooling. Foil is fed through the tool, which die cuts it into the required profile, then, using vacuum to hold it on the head, it moves down, transporting the foil onto location on the container neck. Once the
foil is located, the head maintains the pressure required for sealing and the induction cycle is activated.
During this process, heat is generated within the foil, while the head remains cold. When the required sealing temperature is reached, the induction power is switched off, but head pressure can be maintained to allow the seal to cool while still being held against the container.

Pillar says one of the reasons it resisted the move into direct induction sealing for so long was because “the benefits are doubtful in most traditional induction applications”. However, Rollason says one of the first direct-sealing systems Relco installed – at L’Oréal – paid for itself within a year.

Even so, conventional induction sealers account for the bulk of sales, and there are still advances being made in this area. Pillar will use Interpack to launch an automatic induction-sealing system based on a new digital generator.

“The much-reduced size of the induction generator allows the integration of the generator into the coil, offering greater mounting flexibility,” explains Tindale. “Additionally, the digital generator design allows much greater integration within the filling line. Until now, units have had limited integration options – with only start/stop following inputs from a filler or conveyor. Our new unit offers full data capture that can be fed back via a PLC to give more complete batch traceability and external control over machine settings.”

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SNACKS: AN OPEN AND SHUT CASE
CC Products, based in Cologne, Germany, has just been awarded a patent for a new method of resealing bags that overcomes problems that have historically prevented snack manufacturers from going down the resealing route.

Kai Parthy from CC Products says: “Again and again it has come up in market studies that consumers would like to reseal half-empty snack packs. However, the crumbly nature of snacks means existing resealable technologies, such as zip closures and cold seal bags, aren’t suitable, because the resealable coating or zip mechanism tends to get contaminated by crumbs.”

The inventors believe they have solved these problems with their patented technique based on the use of perforated film and a hidden elastic adhesive coating that is only activated when the consumer closes the bag, and retracts again when the bag is re-opened.

CC Products says the process can be integrated into bag-makers’ existing systems without vast expense.