Taking the flexible route

1 February 2012



Demand for different formats and better efficiency drives form, fill and seal machinery development, discovers Andrew Manly


Customer demands for greater flexibility and improved efficiency are not unusual requests for modern machinery suppliers. But nowhere has this had more impact than on the development of both horizontal and vertical form fill and seal (FFS) equipment, which is now used in a much greater variety of applications than was once thought possible.

Modern feeding and control mechanisms, plus very accurate controls, together with open frame construction have enabled both formats to be utilised in areas previously felt to be ‘out of bounds’, such as fresh produce. Indeed, simple definitions of what FFS covers are no longer possible.

Individual machines are also expected to be much more versatile, with different bag or pack formats possible on the same model, together with rapid changeover and easy clean-down – all this plus an inexorable increase in speed requirements.

So little wonder that a sage of the machinery sector, when asked recently for his opinion of the most important development in FFS machinery, simply said “servos”.

However, there appears to be a lot more to it than that; as the addition of zippers, MAP, ultrasonics and ever finer controls to reduce seal widths or improve dwell times make their mark.

Versatility

Alan Jolly, UK representative for US/Czech manufacturer Viking Masek, with a career in FFS systems stretching back 30 years, comments: “Many of the majors now want versatility in their bagging capabilities, without reducing speeds. For example, the ability to readily and easily switch production between bag styles and shapes, such as pillow, block bottom, corner creasing (Stabilo) or Doypack. Our Sigma model was developed specifically to do all of these at high rates of production.”

Chris Bolton, operations director at PFM Packaging, agrees.

“We have looked at our existing technologies and adapted them for new applications. A new in-feed system for our established Falcon flow wrapper enables us to pack tomatoes and other round fruit or vegetables without a supporting tray – saving half the pack weight.”

“An additional feed belt at the base of the forming box helps insert the product into the film, while a flexible overhead brush conveyor maintains the product position during wrapping. Interestingly, the brush conveyor was developed from PFM’s On-Edge technology for handling biscuits.”

Capable of speeds up to 80 packs/min, the Falcon can be changed over between a variety of formats from single items to 2x3 formats, says the company.

Stick packs are now very much seen as an FFS discipline. “The stick pack concept of VFFS (vertical form, fill and seal) is catching on for many products both liquid and solid beyond the usual sugar/ketchupcategories,” adds Jolly. “We are seeing confectionery items being developed specifically to take advantage of the high production speeds available for this format.

Also, new recipe soups and sauces and pastes are already being test marketed. In the healthcare sector there is a significant investment being made into stick packs for powdered energy drink mixes.”

Shayne De la Force, group marketing manager at TNA, adds his view: “Choice will be the biggest factor impacting the future of FFS; if we compare the degree of choice on supermarket shelves today to that of, say, 10 years ago, it is clear that food manufacturers will need to pack a greater variety of products into more formats and sizes.

“To keep up with this trend, FFS systems require rapid product changeovers and reduced downtime. Over the coming years, digitisation of packaging lines is, therefore, crucial to allow food manufacturers to keep up with the demands of their customers. The best way of achieving this is by removing mechanical settings, making systems truly digital.“

Better control

Integration with other equipment is a paramount feature when speed and downtime reduction are important and line efficiency has to be maintained.

Only better controls can achieve this, according to most machinery manufacturers, who can see limits being reached on mechanical functionality, even on servo-driven machines.

New advanced human interface controls on the SVE series VFFS machines from Bosch Packaging Technologies allow users to “independently and quickly adapt to new production requirements without the need for vendor support”, the company clains. Users can program additional functions and integrate new equipment such as labellers, transport belts and dosers into the lines.

With these new controls, operators can automatically vary the machine speed in response to the performance of upstream and downstream line equipment, especially on parallel production lines. If an interruption in any upstream process occurs on one line, the machine stops producing bags and influences downstream processes. Other SVE machines automatically increase their output to compensate for the stoppage, avoiding product jams, eliminating the need for operator intervention and increasing overall equipment efficiency.

Shayne De la Force backs this opinion: “Our latest bagger, the TNA Robag 3c, enables rapid former changes with ‘auto connect’ and ‘unload assist’ features, while the optimised stripper tube closer and film control guarantees seal integrity while reducing waste, at speeds up to 250 bags/min. It can also be seamlessly integrated with other processing and packaging equipment, such as multi-head scales.”

Features add value

New features have enabled machine suppliers to offer FFS solutions in a number of areas that were not previously seen as their ‘territory’. They have also facilitated the development of new pack styles and even improved the machinery’s ‘green’credentials.

Guy Levy, managing director of Ilapak UK, explains: “Our latest Vegatronic 2000 OF bagger incorporates ultrasonic sealing technology, while the open-frame design and minimal number of moving parts allows easy accessibility for fast washdown and maintenance. This makes it ideal for products packed in a wet environment, such as prepared produce, frozen food or grated cheese.”

The company successfully replaced the traditional heatsealing system with ultrasonic sealing, achieving high quality, leak-proof packs even with extremely challenging products and harsh working environments, it says. It can operate at up to 120 bags/min.

The machine’s ultrasonic jaws are able to operate even if the sealing area is contaminated with product (eg, salad leaves). This minimises product and film waste, increases the production speed and can result in an increase in production efficiency of up to 5%, claims Ilapak.

Adding a zipper or re-closable option is now common. PFM has recently introduced a new hook-to-hook tape system which is available on both its vertical and horizontal FFS ranges. The Plix-Pack tape re-seals itself over a typical width of 10mm simply by pressing the bag top together with no need to line up the front and back accurately.

“The new re-closure tape also offers technical advantages,” says PFM’s Chris Bolton.

“The tape is much lower gauge than some alternative re-closure solutions, making bag edge sealing through the tape much more reliable.”

Among the features offered by Bosch is a ‘long dwell’ sealing head on its Pack 301 LD horizontal machine, to produce air-tight seals. It is applicable for a great variety of products, says the company, particularly fresh or perishable goods where MAP is necessary. Also, products packed in thick film such as medical goods can be accommodated.

“As consumer focus on product safety intensifies, technologies for hermetically sealed seams are in demand,” says Daniela Thiele, director product management and marketing for Bosch.

“The machine’s longer sealing time and high productivity meets the manufacturer’s needs for efficiency and quality.”

While a sealing time of up to one second is possible, the flow wrapper is capable of producing 150 packs/min. Seal quality is further ensured through a feature that allows temperature to be independently controlled on both the top and bottom sealing jaws. There is also a detection system for product caught in the seal, which rejects the pack to avoid damage to the jaws.

Material benefits

Many of the improvements in speed and seal integrity have been possible only with the development of laminates with better heat conductivity. Alufoil laminates or metallised films have not only improved sealing techniques but also helped to reduce the width of seal necessary and the temperature required at the jaws to perform it. Indeed, jaw temperatures have been reduced considerably in some cases.

Ilapak has taken a creative approach to this particular problem with its Carrera 4000 eco, which has shaft and bearing patents for the sealing jaws that thermally isolate them from the jaws themselves. The rollers are also isolated from the heat around the sealing heads, which means there is a significant energy saving of around 60% compared with other horizontal machines. The warm-up time for the machine is also reduced from about 30min to just 8min, and there is less heat loss during major changeovers.

The future

Have limits been reached in performance and flexibility? Opinions differ. But speeds of 250 bags/min are now common. And all FFS suppliers are continually developing machines to do it quicker and better, as they have done for the past two decades.

Most machine suppliers believe the demand for more speed will not go away, as ROI factors mean customers want more and more out of every line.

Weighing and feeding systems are also getting faster, so provided servos and digitisation do their job and multi-laning is possible, the boundaries are probably not yet in sight.

The last word goes to Shayne De la Force of TNA, who sums up the feelings of most FFS machinery manufacturers: “Stand-out FFS equipment must deliver the highest levels of performance, flexibility and simplicity. Some machines boast high levels of one or other of these attributes, but it is a combination of all three that is essential to exceeding customer demands.

“Performance refers to the number of good bags per minute and uptime, whereas flexibility extends to everything from product changeovers to upstream and downstream equipment integration. And, lastly, simple but sophisticated design is crucial for operational ease, service/maintenance and all things in-between.”


Bosch Pack 301 LD horizontal machine with long dwell sealing head Bosch Pack Bosch SVE VFFS Bosch SVE VFFS Ilapak Vegatronic 2000 OF Ilapak Ilapack Vegatronic has ultrasonic sealing techlogy Vegatronic TNA Robag 3c Robag A new in-feed system on PFM’s Falcon flow wrapper allows tomotoes to be packed without a tray Falcon

Ilapak Ilapak
Vegatronic Vegatronic
Falcon Falcon
Bosch SVE VFFS Bosch SVE VFFS
Bosch Pack Bosch Pack
Robag Robag


Privacy Policy
We have updated our privacy policy. In the latest update it explains what cookies are and how we use them on our site. To learn more about cookies and their benefits, please view our privacy policy. Please be aware that parts of this site will not function correctly if you disable cookies. By continuing to use this site, you consent to our use of cookies in accordance with our privacy policy unless you have disabled them.