A leading security printer and producer of technologies for the hot stamping application of holographic images.
For certain applications, holograms require mechanical strength and the company was trying to apply a hard waterborne polyurethane dispersion onto the aluminium side of the hot stamping foil. Their existing waterborne polyurethane dispersion exhibited poor adhesion to the aluminium and heat activated adhesives.
Incorez introduced the company to their range of Dispurez additive free waterborne aliphatic polyurethane dispersions. Following extensive screening of the selection of hard products within the Dispurez range, the company adopted Dispurez 101 in their formulation.
The use of additive-free Dispurez 101 provided excellent adhesion and the required mechanical strength. Also, the fact that Dispurez 101 is additive free was a real plus, as additives such as silicone free defoamers can cause a fish-eye effect in thin layers.
Dispurez 101 has been designed to allow formulators to produce tough, hard wearing coatings for rigid plastic substrates including uPVC, ABS & HIPS.
The entire Dispurez range is pyrrolidone-free enabling formulators to move away from hazardous materials such as NMP/NEP to hazard free alternatives.
The benefits of Dispurez 101 for this particular application include:
- Excellent adhesion to the metallised side of the film
- Elongation < 300% - a higher elongation reflects badly on the contours of the hot stamped holograms
- Suitable mechanical properties - tensile strength of 40MPa and modulus of 30MPa
- Reduced blocking - this is critical as after the metallised foil is applied with adhesive and dried the metallised foil is tightly rolled
- A clean crisp edge is achieved when the film is cut