WITH THE LAUNCH OF A NEW LINE FOR THE POLYMERIZATION OF COPOLYAMIDE ADHESIVES, THE MORTARA-BASED COMPANY IS NOW FULLY INTEGRATED WITH THE THERMOPLASTIC POLYMERS INDUSTRY FOR LASTING AND FOLDING.
Alongside the consolidated production lines of co-polyester adhesives, SIPOL® has started a new polymerization plant for the production of hot-melt co-polyamide adhesives in its headquarters in Mortara. An investment with significant impact on the footwear industry with whom the company has very strong ties.
In fact, after having developed the “tin free” co-polyesters of the TECHNIPOL® line, thanks to the introduction of the “Green co-Polyamides” of the TECHNIPOL® PA line, SIPOL® can now offer the footwear industry the complete, integrated range of thermoplastic adhesives: from the basic granules for lasting and folding to the extruded rod cements for lasting operations.
The investment also means that the “Società Italiana POLimeri” can pursue its goal of environmental sustainability: the TECHNIPOL® PA co-polyamides use monomers almost entirely (>80%) from renewable sources (biomass not destined to human consumption).
“The adhesive that is traditionally used for the leather and footwear industry – explains Giorgio Dedè, Technical Sales Manager of SIPOL® – is the co-polyamide. Co-polyester, on the other hand, was introduced later on essentially to increase the production yield. The co-polyester, which is more crystalline, has a quicker setting time so that a higher number of pairs of shoes can be lasted in the same unit of time.
Unlike copolyamides, the co-polyester does not adhere to the hot metal parts of the injector, it does not burn or carbonise, reducing significantly the maintenance on the lasting machine. Beside this, I believe that the use of co-polyamides on lasters fitted with tracers brings not only to a better adhesion, but also to a flexibility and lightness that are more difficult to obtain with co-polyesters.
Another advantage is the extension of the bonding surface: as copolyamides have a slower setting time compared to co-polyesters, when the blades close and the upper is folded onto the innersole, the adhesive can be spread onto a slightly larger area guaranteeing a more efficient and resistant grip”.