The objective therefore was to find a way of sealing films under better temperature and pressure control in a way which reduced film usage and delivered hermetic seals. IFP approached Ceetak Ltd, a UK company specialising in sealing systems and rubber products and asked them to develop a sealing technology which would guarantee hermetic seals.
Key factors in the design brief were also reliability, low cost , ease of operation and maintenance.
The designs should also be easily retro fitted to the wide range of existing machine types used in the industry., for example Ilapak, Sandiacre, Bosch, Rovema, CFS, GIC, etc.
The designs must also be capable of coping with film tracking which is an inherent feature of all bagging machines. As the film is pulled from the reel through the tensioning rollers and across to the product tube the lateral position will wander from time to time and change the amount of overlap in the back seal. Although the objective was to reduce film usage and make a narrow seal the limit was governed by the variability of this overlap.
Another objective was to improve the appearance of the seal. Flat bar and band seals do not look very attractive when set incorrectly because the flat surface is not very tolerant of excessive temperature. It was therefore proposed to use embossing as a means of improving both the seal appearance and performance.
Operator safety was also taken into consideration.