Chilled fresh foods and ready meals may have made all the retail running over the last decade but freezer foods have by no means been frozen out

It is nearly 80 years since Clarence Birdseye invested just $7 in an electric fan, buckets of brine and slabs of ice to invent a system of packing food in waxed cartons and flash freezing them under pressure. The frozen food sector has since burgeoned into a market that today is worth about £7bn in the UK alone.

The British Frozen Food Federation reports that £3.4bn is sold through the retail sector, £1bn represents ice cream sales and the rest is food service.

Retail sales saw steady volume growth of 2.5% over the year to April. According to Taylor Nelson Sofres Superpanel, this is largely due to the performance of frozen chips and potato products which is the largest sector in volume terms, growing 6.9% year-on-year.

McCain’s and Aunt Bessie’s are two manufacturers pushing the growth with McCain’s Roasts and Wedges “performing particularly well in the last year, as did Aunt Bessie’s Roasts.”

Other growth sectors are ready meals and snacks reports the British Frozen Food Federation. Ready meals are growing at 5.5% in volume year-on-year, driven by retailer own brands and Heinz. Healthy meals are a fast growing sector within this category.

Frozen snacks have seen strong growth (18.8% year-on-year volume), led by Tesco and Asda own label ranges. McCain’s Micro range has also attained good growth in this category. But traditional sectors, such as frozen fish, green vegetables, red meat and pizza are all in volume decline, says the federation.

But this could be set to change if innovative packaging such as Global Sealing Technologies’ award winning self venting laminate bag film for frozen vegetables reaps success.

The company’s Vacsys comprises a 12micron PETP/50micron CPP laminate that has a special valve built into the machine direction of the structure. The first product – brought to the market by Padley Frozen Vegetables for its MicroVeg – was a standup pouch containing a selection of microwaveable portion packs, each of which acts as a mini pressure cooker.

In other words, when the pressure inside the pack reaches 0.2mb over pressure in the microwave oven, the valve opens at each end of the pack allowing the excess steam to escape. At the same time it also maintains the pressure inside, so ensuring rapid healthy cooking of the vegetables.

“The valve consists of a slit in the sealing layer of the film and a special heatseal on the PETP which, while hermetically sealed at room temperature, pressure opens when 0.2mb is reached,” explains Global Sealing’s Dave Moorcroft. The company still extrudes, prints and converts film and laminates.

The pack walked off with a gold star, a technical innovation award and the Listgrove Award for the best design innovation in the recent Institute of Packaging Starpack awards.

“The advanced technology and the developmental expertise demonstrated in this pack are outstanding,” comments Listgrove’s Jason Markham.

According to Dave Moorcroft, a major advantage of the system is that, unlike the competitive valve systems that rely on buttons, this does not need specially converted machines. It will run on any standard VFFS or HFFS machine as well as tray forming and lidding.

Dave Moorcroft told Packaging Today International: “Our first success for vegetables was with Unilever Igloo brand Lust auf Gemuse in Germany last February.”

Sainsbury Easy Steam range was launched in the UK some three months ago and the Padley pack has been on general listing for a few months too.

“The vegetables have been a great success and now it is almost certain that we will be moving into frozen fish and chilled products,” he revealed.

“We are talking with major producers of frozen foods in the USA and in all we have some 30 projects on the go at present. Most look very promising. I believe that the non-ready meal end of frozen foods has been crying out for innovation. This is it.”

A trip down the aisles between the frozen food chests of the major retailers and specialist Iceland revealed a fairly even split between carton and flexible pack styles. All have one thing in common – the print is bright and effective – vying for attention from its cold surroundings.

On the flexibles front the sector has provided the ground for some of the finest quality of flexo print. Amcor Flexibles Venus picked up the best in show gold award in the 2002 European Flexographic Technical Association competition with its print for Marks & Spencer Extra Large Prawns bag.

It was the third year in a row that the company has won the award. “This entry is absolutely unbeatable,” say the EFTA judges. The attention to detail is incredible and it demonstrates good design and origination.”

MCG Graphics provided reprographics for the design and the pack was printed on a Windmöller & Hölscher press at the Ilkeston, Derbyshire plant.

The polyethylene used by the company for these freezer packs is produced by sister company Amcor Flexibles Extrusion. It makes use of special blends of polymer combined to give significant lightweighting opportunities without the loss of performance.

It also provides enhanced packing machinery speeds, combined with reductions in seal failures and leakers, claims the company.

The production environment needed for packaging frozen foods is harsh. Says sales director of Sandiacre John Edmonstone: “It is pretty cool – around 5 deg C – and machines are subjected to physically rigorous wash downs.” Equipment has to be capable of performing well in those conditions.

Its latest successful offering, the continuous motion TG350-RC, allows flexibility at higher speeds, he explains. “Basically, if you can get it down the tube we can bag it,” he boasts.

The equipment, designed to pack arduous product at high speeds across a diverse range of pack materials, bag sizes and styles, can handle products as diverse as mince, chicken pieces and vegetables. Bag widths up to 350mm can be produced allowing a pack volume from 500g-5kg.

At the heart of the design is the cross seal jaw drive. The jaws travel with the film to give improved seals, consistent bag length and reduced strain on the film itself. “Speeds over 100 bags/min have been achieved when packing frozen foods into polyethylene,” says Mr Edmonstone.

The latest control technology with a colour, windows-based touch screen allows the user to retrieve and analyse production data, assess production performance and diagnose faults remotely. Sales of the machines are already well into double figures since its launch last year.

Visitors to the PPMA show this month will have a chance to see a version of the TG350-RC VFFS machine in its 316 stainless steel livery. In this instance it will be packaging large weights of potatoes at high speed, rather than frozen product.

“It will show the versatility of the equipment,” says Mr Edmonstone. The combination of ‘state of the art’ motion control technology and a specially designed ‘low drop’ former that incorporates a product accumulator system will ensure a soft catch of the product into the bag, minimising the potential for tuber damage. Potatoes in weights up to 5kg can be dropped in one dose without blocking says the company.

With staff retention an issue for product handling in cool climates, automation is increasingly seen as an answer.

Bradman Lake says it has good news for frozen food producers with the introduction of its advanced robotic handling. Under a manufacturing agreement with Propack Packaging and Processing, completely integrated, automatic packaging systems for multipacking and top load cartoning are now available from Bristol for the UK and overseas markets.

Propack LJ vertical racetrack collating machinery with ABB pick and place units and Klöckner horizontal FFS wrapper combined with Bradman Lake HS2/60 carton erectors and Compact or Triliner closers are said to be capable of packing up to 750 wrapped units/min.

But, of even greater interest to the frozen foods producer is the elimination of manual handling. In the company’s robotic top load operation, formed cartons are automatically transferred into the LJ loader while products are flow wrapped and enter fast indexing turbotrain pockets.

The train moves forward for the robot to pick up a designated number of units and place them into a waiting empty carton. This pick and place operation is repeated until a full single or double layer collation is packed and the packs then move again into the carton closer.

The top load system is claimed to be well suited to packing wrapped frozen meat or poultry portions and ice cream bars. Over 30 orders for LJ Series robot packers have been placed in North America. Wrapped frozen chicken portions are packed in the US and one Canadian company is packing 1500 confectionery bars/min, using a two-lane infeed from two flow wrappers.

It is understood that the company is building an LJ loader, HS2/60 erector and compact closer line for its stand at the PPMA exhibition.

For high-speed continuous carto-ning, Bradman Lake has developed the SL904 end loader with an overhead robot loader that runs at speeds up to 160 cartons/min.

By switching traditional horizontal loading to a vertical position above the line of cartons, machine width is dramatically reduced and floor space saved. Access to the loading area is also said to be much improved.

Major player in the European poultry industry Wiesenhof Germany uses 14-head Ishida machines, equipped with 6- or 7-litre hoppers, to weigh large, cooked and frozen chicken pieces into flexible packs, at target weights of 350g, 500g, 750g, 1000g and 2500g at its Lohne plant, near Osnabrück.

The brand is exported throughout the European Union and Eastern Europe, as well as to the Middle East and Far East. As many as 40 different products, ranging from whole legs and breasts to various types of chicken nuggets, are produced in Lohne and sold to wholesalers, retailers and large restaurants.

All the multiheads at Wiesenhof feature error diverting timing hoppers that are designed to reject underweight poultry portions. The weighers are positioned over standard FFS bagmakers.

As the chicken pieces, each weighing between 140g to 190g, are frozen hard and fall through distances of 20-30cm, they have quite an impact on the weigher contact parts.

Handling about 50 weighments/min at the 1kg pack weight, each of the 14-head Ishida machines is hit by about 25 tonnes of these chicken missiles every working day. This amounts to 6500 tonnes each year or about 40 000 tonnes over six years.

To cope with these constant impacts, and to guarantee trouble-free operation throughout 15-hour shifts, 260 days a year, the dispersion table at the top and the timing hopper underneath each weigher outlet have been specially strengthened.

“I am very pleased with the ability of the Ishida multiheads to give accurate results, day after day, year after year,” says Bernhard Ströer, general manager at the Lohne plant. “In my view, they are clearly worth the price difference in this respect.”

The machines were installed by Optima, Ishida’s distributor in Germany, which has its own specialised Ishida sales and support division. With a production schedule like Wiesenhof’s, clearly downtime has to be kept as low as possible. Downtime associated with product changeover has also been minimal, says the company.

With the easy-to-clean design and the quality of the control interface, the process takes less than half an hour, it adds.

“We rarely have to call in the Optima-Ishida people,” says Mr Ströer. “This is because the machines are reliable and also operator friendly. Also, Optima thoroughly trained our people at the outset.”

Twin advantages of reduced downtime and lower packaging costs have justified Devon-based Lloyd Maunder’s investment in SWF tray formers, reports DS Smith Packaging Systems. The meat and poultry packers supply major supermarkets with chilled and frozen portions, packed individually into B Flute 2-piece boxes supplied by DS Smith’s Bristol plant.

The introduction of tandem SWF 400V tray erectors, one forming bases, the other forming lids, has increased efficiency by 4% through the versatility, reliability and precision of the machines, it is claimed.

With blanks fed vertically from the magazine, the forming head ejects the tray onto a flat belt conveyor that passes the second erector forming the lids. Bases and lids are then manually nested onto pallets for packing of the poultry products.

Easy changeability has been designed into these US built machines, for which DS Smith is sole UK agent, as Lloyd Maunder changes sizes on average three times a day. Covering the two machines this changeover takes a maximum of five minutes and is a major contributory factor in increasing productivity.

The accuracy of tray forming has meant that full depth square corner posts can be designed into the pack, creating a flush fit against the top rim of the tray.

This has substantially increased the vertical compression strength of the pack, so allowing a reduction in board specification and subsequent packaging costs.

Each erector operates at 14 trays/min (maximum speed: 60 trays/min). Ron Hancock of Lloyd Maunder says: “As soon as the SWF machines were installed, we saw immediate productivity gains and reductions in down time. Their obvious reliability has encouraged us to switch other products into machine erected trays, so reducing costs still further.”

The standard SWF 400V tray erector can accommodate trays with a maximum footprint of 914x768mm, although the wide base version can extend this to 1092x1267mm, making the machine suitable for heavy duty distribution packs.

In the fiercely competitive world of ice-cream the hunt is always on to scoop the competition and bring new concepts to the marketplace.

Claiming the global number one position in the ice-cream packaging market is rapidly expanding Huhtamaki. Among recent innovations is a pack for an impulse buy product.

Says Huhtamaki’s Markku Pietinen: “Unilever Chupster is a push-up ice cream with a bonus lollipop inside the plunger. We make most of the components, insert the lolly and assemble the packaging for Big U.”

Another company with a history of providing the industry with new ideas has been RPC Bebo Plastik. One of its latest offerings, a transparent ice cream tub thermoformed from a special low temperature polymer, further underlines its focus on innovation.

The German plastics packaging producer developed the container in conjunction with ice cream manufacturer Humana Milchunion eG, of Evcerswinkel, as an alternative to heavier and less transparent injection moulded versions.

“In packaging, the most challenging demands often lead to the most innovative solutions,” comments Roland Schultz, sales manager ice cream packaging at RPC Bebo.

“This ice cream container was made possible by the strength of the creative partnership between us and Humana.”

Success of the project depended on finding a material that would combine qualities of excellent clarity and lightness of weight, while remaining effective at freezer temperatures, he added. RPC’s solution was to use a specially formulated, low-temperature resistant PS for the container. The pack was completed with a lid of transparent PET.

The 1-litre container is being supplied to the Dia chain of supermarkets in Spain, part of the Carrefour group, for their own label ice cream.

Transparent labels feature colourful designs of the ingredients of the three flavours in the range – Frutos Silvestres, Stracciatella and Tiramisu – alongside the Dia logo, to create a printed, no-label effect on the sides of the pack sides and its lid.