Full-servo machines for flexible packaging

MORE AND more products now come in flexible packaging, in particular, stand-up pouches. Yoghurt, fruit purée and energy drinks in single serve formats are among the biggest growths in the sector mainly due to the spouted pouch which makes “on the go” consumption much easier. The pouch also ensures hygiene and leak-proofing, and may be opened and closed as needed.

In supermarkets, products in vividly colored pouches are more attractive to consumers. Moreover, the reduced size and weight of pouches, as well as the raw materials, allow for easier and cheaper transportation and storage, compared to rigid packaging formats.

Among providers of full-servo machines for flexible packaging is Bossar. According to the company, the technical advantages of its series include:

- Total independence of the different motion stations, processes and phases in the machine. The single shaft and fixed timings have come to an end.

 - Immediate correction of timing, pressure and sealing for every speed, impossible to be done in a cam shaft machine.

- No more flaws in the cutting and sealing, producing perfectly centered pouches and sachets without peaks on their edges, which make them hard to differentiate from pre-made pouches.

The full servo HFFS machines are manufactured for clean and ultra-clean applications, are totally manufactured in stainless steel and provided with laminar flow cabinets to keep the filling area free of particles, mid-pressure UV light for film cleaning, and sanitizing of the spouts and caps with peroxide to achieve high levels of sanitization.

Whenever thermal treatment with or without high pressure processing, pasteurization or “retort” autoclaving is to be undertaken after the filling and sealing of the pouch, the sealing and safety offered by the manufacturer is fundamental. Thus it is necessary to install a sealing group controlled with numerical parameters to guarantee the safety of the spout and the pouch film.

The width correction group installed in the sealing group, is a system patented by Bossar that guarantees that the seals will have always the same width even in the case of an error occurring on the eye mark regardless of the centering of the printing area.

In these full servo machines is an independent ultrasonic sealing system for both pouches formed by a single film or two different films.

Additional control mechanisms are provided, like optical guides to check that the pouches are correctly opened before filling the product, and vision cameras to control that the spout or valve was inserted in the correct position, so that the pouch is rejected before filling to avoid product wastage.

The space available and the setup of the machines at customer’s premises were taken into consideration in the design of the Bossar Motion Servo (BMS). Bossar machines can work either from the right or the left hand side. Working from the left hand side enables to set one machine opposite to the other, and a single person can operate both machines ergonomically, which translates into time and personnel savings.

When filling baby food, fruit purée and products that need the highest reduction of residual oxygen to prevent oxidation, it is necessary to provide the HFFS machine with a controlled atmosphere system with inert gas injection units (Nitrogen) in the auger filler, or the dosing tank. Gas is injected from the area where the pouches are opened before filling, to the top sealing.

There are many pouch shapes available for product customization. These are made with total or partial shape dies and special cutting knives. Not only an attractive and distinguishing visual impact is achieved by shaped pouches, but also the removal of any chards on the cut edges of the pouches that may damage other pouches or indeed the consumer.

The electrical consumption of the full servo machine is far lower than mechanical machines, enabling the feedback of any energy surplus, which is sent back to the grid through the power sources.

Every mechanism in the full-servo machine works autonomously and synchronized by the PLC and software. So when undertaking a controlled stoppage of production or when the product in the hopper is exhausted, the pouches in the walking beam in the filling area finish the top sealing process while the other parts in the machine stop their activity and movement, thus no waste of product or film occurs.

Furthermore, as no cams, shafts and springs exist in the full servo machine there is little or no potentially contaminating lubricants involved in the process.