Cellulose acetate is distinctly different in mechanical properties when compared with polypropylene, which means that the film needs to be handled with more care.
In particular, the acetate film is more rigid and less extensible. Therefore, you should follow the following recommendations.
Rolls for lamination are usually packed in cartons, suspended on wooden end-pads and have an outer wrapping of polyethylene film. The rolls should be carefully unpacked, avoiding damage to the ends of the rolls. This is best done either by carefully slitting the four corner edges of the carton so that the sides fold down or by opening and folding back the top of the carton and carefully rolling the carton over so that the roll slides out on its end pads. We recommend keeping the original cartons and re-using them to store the partially used rolls.
The rolls should be lifted from the middle, avoiding contact and possible damage to the edges of the film. Similarly, rolls should never be placed or stored on edge. In fact, a slight nick or bruise on the edge of an acetate roll can cause repeated tearing during processing.
If only part of a roll is used in a lamination run, the residual roll should be carefully re-wrapped in polythene film, tucking the ends into the core to "seal" the roll. The roll should then be stored, preferably suspended via a bar through the core, or as in the original packaging. Again, do not store a roll on its ends. During storage, excessively high temperature and humidity values should be avoided. A temperature range of 15° to 25°C and relative humidity rate of 30 to 60% is recommended.
When applying the adhesive, which can be either water-based or solvent- based, it is recommended not laying an excessive amount of it, especially when using water-based adhesives. In fact, water-based adhesives can cause the edges of the film to lift. This problem is further accentuated by systems equipped with an air oven rather than a heated drum.
When loading acetate film into a machine, the film should be taped full width to the preceding film and carefully pulled through at slow speed. This helps avoid tearing. Acetate film cannot be knotted together to haul through a machine, as it is sometimes done with BOPP.
At the start it is recommended reducing to a minimum the quantity of adhesive applied on the film and to rapidly increase the lamination speed until the expected speed is reached (in any case lower than the one usually set when working with BOPP). By minimum quantity of adhesive we mean the sufficient quantity of adhesive to let the acetate run in the machine without creating friction or tensions.
During the acceleration phase of the film it is then necessary to restore the right amount of adhesive up to the optimal value. Please note that Clarifoil shows on the labels the side of the film on which it is recommended applying the adhesive. The glossy acetate is always wrapped in a way that leaves free the side on which to apply the external adhesive. For a perfect adhesion, we recommend using a two-components adhesive, an adhesive with a solids content of 50% and a cross linker.
It is highly recommended carrying out tests before starting processing in order to check whether the adhesive chosen to laminate the film is suitable or not. Finally, please note that Clarifoil acetate does not require pre-treatments (if necessary, be careful not to over-treat the surface).
Mag Data Spa is at your disposal for further clarifications regarding the use of the acetate.
Notes: the information provided represents the best of our knowledge. It is provided in good faith and are not binding. We decline any responsibility regarding the specific conditions of use. The responsibility of checks is left to the end user.
Mag Data Spa
Stefano Galderisi