Flow Wrapped packaging has been around for a long time and it is fair to say that the main features of Flow Wrapping machines are fundamentally unchanged. However user expectations of simple controls, automatic product feeding, minimum servicing, maximum production reliability and product specific configuration, can present challenges to machine manufacturers.
Multi axis machine drives and control systems have become the expected norm allowing greater control and flexibility of machine configuration to suit the products that are to be wrapped. This technology enables end users to interact with the machine by entering product settings on a screen display for product to product change over. The latest displays have colour touch screen technology with enhanced diagnostic interrogation and diagrammatic representations of machine functions. The electronic control also enables some adjustments to be made whilst the machine is in motion, for example print registration settings.
As well as the improvements in machine control there has been a demand for product feed innovations and infeed design to reduce or eliminate the need for hand loading. Automatic feeding can be simple or very complex dependent upon the product type. Phase feeding for example, which is in essence a series of conveyor belts that synchronises the product feed to the end crimp jaws, is a relatively inexpensive automatic feed system that removes the need for operator loading. Phase feeding is particularly effective for goods that are flowing along a conveyor from the production process, for example biscuit bars, or from being loaded into a punnet for example cherry tomatoes. At the opposite end of the spectrum a feed system for multi-packing crisps is very complex as the primary packs are not consistent, are relatively fragile and contain product that is easily crushed. Furthermore the logistics of auto-feeding have to be considered, if a flow wrapper is multi-bagging a 6 pack of crisps at 60ppm then the feed system has to be able to deliver consistently and in the correct orientation 360 primary ppm to the flow wrapper infeed. Improvements to infeeds are not only to accommodate automatic feeding because it is often essential that delicate product is handled gently to avoid damage.
A recent development by Redpack Packaging Machinery is a good example of this; they have developed a machine to wrap apples without a tray and the infeed that they are manufacturing transports the apples without friction or contact with hard surfaces. Apple producers are very happy with the outcome because not only are they getting their fruit wrapped without damage but also at 4 times the speed of their old wrapping machines.
Of course improvements in feeding and production throughput bring other challenges for instance production has to be halted when the film reel needs to be changed but periodically stopping the machine flow is very disruptive and costly to a constant production process. Developments to auto-splicing the film have negated the need to stop the production flow and in most instances can take place without reducing the machine speed. Redpack advise that their new auto-splice:
“not only saves time but can splice and synchronise print registration at full speed with the loss of only one bag; production throughput is enhanced and substantial savings and improvements made by preventing film wastage”
Automatic processes and high production rates mean that machines are fully utilised, especially where production requires a minimum of human intervention. To accommodate 24/7 operation machine manufacturers are aware of the need to design machines such that they require a minimum of maintenance, advances in machine drives have assisted this by eliminating much of the old mechanical drive arrangement.
Reel handling has been improved by replacing mechanical shaft braking reel with a geared motor drive that synchronises film speed with product throughput, and the mechanical reel clamp has been discarded in favour of a fast and positive pneumatic clamping system. Continuous production has necessitated improvements in hygiene control; machines have to be more accessible for clean-down, as an example Redpack provide an opening infeed so that the conveying mechanism is easily accessed this can be combined with a cantilever machine design to allow clean down at the seam and end crimp film sealing areas.
It can be seen that end user demand has brought about significant changes in the technology and design of flow wrapping machinery and it has become vitally important for anybody who is about to purchase a new machine to carry out a thorough investigation of the market place before committing to a manufacturer. Designers, such as Redpack Packaging Machinery, will be more than happy to carry out a product/production review and to provide advice on the best solution to a particular application.