Equipment feature: flexible form, fill and seal

Suppliers to the major retailers are under increasing pressure to not only come up with novel packaging concepts but to also produce a variety of different pack styles and sizes.

Trying to meet these demands can start an internal tug-of-war, with the sales and marketing departments eager to forge ahead with new packaging formats and the production and finance departments worried that changes will mean more expense and disruption to production.

Thankfully, manufacturers of horizontal and vertical form, fill and seal (FFS) machines have been busy coming up with equipment that keeps pace with these demands and challenges the assumption that new packs has to mean new packaging kit.

One of the biggest headaches for manufacturers is when they are required to package the same product in various pack styles. In many cases some of the packs will need to be produced continuously at high speed and others – often larger family-sized packs – can only run at slower speeds.

Sandiacre Rose Forgrove has come up with a solution to this dilemma in the form of the Novus line of vertical bag makers (pictured). These are designed to operate both intermittently and continuously, depending on the product and pack style. “Our customers gain an enormous advantage from purchasing such a flexible bag maker compared to the cost of being forced to make an ‘either/or’ decision,” says the company’s Marc Koetzle.

Keeping your options open
Bags with fin seal corners have become very popular with marketers. However, taking the decision to produce these packs can restrict the range of products that can be filled and the variety of pack styles that the vertical FFS machine can offer.

That was until Sigpack Systems, part of the Bosch group, launched its SVE series, a range of modular continuous motion machines capable of changing between corner sealed bags and pillow, gusset and stand-up bags.

The system incorporates patented corner seal technology; the corner folding and sealing process is done in the film web before the forming shoulder rather than in the forming tube area, as is the case with most conventional bag makers.

Sigpack has also come up with a novel packaging format which cashes in on the trend for on-the-go consumption. Pull Pack is a flow wrap that can be opened with one hand. “You hold the product in one hand and use your teeth to pull on the seal fin along the shorter edge of the packaging,” explains the company’s Holger Botsch. He says a Pull Pack module can be easily fitted to an existing Sigpack flow wrapper.

Fresh produce
The fresh produce industry has been a major focus of innovation for flow wrapping technology in recent years, with machinery manufacturers working hard to design systems capable of packing fruit and veg of all shapes and sizes.

Redpack has addressed the problem of packing delicate and hard-to-handle produce like fresh herbs and lettuces by developing a top-sealing machine with an inverted seam crimp and film flow in-feed.
“Product is placed directly onto the film and carried into the flow wrapping module with no mess or bruising,” explains Redpack sales executive Peter Smith.

Another notable innovation in the packing of fresh produce is the variable bag length top-seal flow wrapper from Record Packaging Systems. The Gazzella uses sensors to measure product length and cuts the bag to fit.

“If you’re packing sticks of rhubarb,” says Mike Atkinson, sales manager with Record, “they are not necessarily cut to the same length. This machine detects the size of the product and makes each bag correct for that size.”

The benefits include lower material costs and better presentation than traditional flow wraps made to suit
the longest product. Speeds of up to 60 packs per minute are achievable with these machines.

The trend towards flushing packs with gases to prolong shelf-life has turned attention onto pack seal integrity, with FFS equipment manufacturers coming up with sealing techniques that minimise the occurrence of leaky packs.

Record, for example, can supply its Jaguar and Panda horizontal FFS machines with long seal jaws which produce a seal of higher integrity than standard.

“Originally the only machines that could create a high integrity seal were box motion sealing heads, which are restricted in terms of speed and are complicated technically,” says Atkinson. “The long dwell has revolutionised that.”

Similarly, Kliklok Woodman’s Cyclone vertical bag makers incorporate a patented sealing motion based on a hypocycloidal geometric path to provide extended seal dwell time with a smooth trajectory motion.
It looks like there could soon be a completely different solution to the problem of leaky packs. Stanelco, the radio frequency application group, has successfully integrated its GreenSeal radio frequency (RF) technology into vertical FFS equipment for bagged salads.

RF sealing, possibly a world first, is already being trialled by Asda for sealing own-label ready meals. Stanelco has now adapted the technology in response to a request from a customer in the produce market, a market which Stanelco says is potentially even larger than tray lidding.

Current sealing methods for pillow packs use heated jaws, which transfer heat to the film so the PE layer adheres to the other side of the film. The problem is that if salad leaves stray into the sealing area or the weld line gets wet, the bag won’t seal properly. Stanelco claims GreenSeal overcomes these issues.

“With our system we are exciting molecules within the plastic itself. Anything that comes into contact with the tooling will become energised and will warm up,” says sales and marketing manager Rob White.
As well as resolving problems with leaky packs, RF is said to result in significant material cost savings, by eliminating the need for a PE layer.

White admits that the initial capital outlay for GreenSeal won’t be cheap, but the net gain is worth the expense in the long-run. “We’ve done some sums and the cost to install the equipment on a salad bagging line would be far less than the amount a company will currently be losing on product wastage. We would expect to see payback within a year.”

Trials so far have been carried out on a vertical FFS machine purchased by Stanelco. However, White says it hopes to start working with a machinery supplier that is interested in trialling the technology in the next few months.

Bagged pipes
Pipe fittings are not a product you’d normally associate with vertical bag makers. However, Sandiacre’s TG600-L vertical FFS is proving the ideal packaging solution for Wavin, a UK supplier of plastic pipe systems.

Wavin wanted to reduce the amount of labour and material it was using to pack its four-inch plastic pipe connectors, which were being packed manually into pre-formed bags.

George Poynton, engineering manager at Wavin’s Chippenham facility, had previous experience in the biscuits and snacks industry and immediately thought that a bag maker might be the answer to improving productivity.

After discussions with Sandiacre, Wavin settled on the TG600 VFFS. The system produces 600x900mm pillow packs, each containing five or 10 pipe-fittings, at a rate of three bags per minute.

The company did have concerns that as the fittings dropped 2.5m from the forming set, they may get damaged in the process. To ensure product integrity, a product catcher located half-way suspends the fall for a moment and then allows the fitting to continue into the bag, which is held by a special bag support.
As a result of installing the system, Wavin has reduced packaging material costs by 20 per cent. In the future it hopes to run biodegradable film on the machine, which will help meet its obligation to reduce the amount of waste it sends to landfill.

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