Herma is reducing the obstacles to the further proliferation of pioneering wash-off labels, such as those used for PET recycling: The company, a technology leader in self-adhesive label materials, has now introduced the new wash-off adhesive 72Hpw. “The cost argument against switching from a permanent adhesive to a wash-off variant, which is still frequently cited, is no longer valid,” says Hendrik Kehl, product manager at Herma.
“Thanks to a special formulation, the production costs of the new adhesive are almost on the same level as a conventional permanent standard adhesive. Nevertheless, it makes it possible to generate very pure PET flakes with the usual industrial washing processes, without disturbing residues of labels and the printing inks contained on them.”
At the same time, this adhesive also benefits from the comprehensive wash-off know-how that Herma has now acquired in this field: The new adhesive achieves very good values in the important initial adhesion, i. e. the tack, and in the wash-off rate. They are very similar to the more expensive wash-off adhesives that have already been introduced. “This means that we now offer an interesting entry-level solution that can already cover a large number of applications. This should also convince the label users who have so far refrained from switching for economic reasons,” says Kehl.
Good results in standard recycling plants
Institut cyclos-HTP has already certified the adhesive 72Hpw for wash-off applications in combination with the film Herma PP white super tc (grade 881). This certification enables PET bottles to enhance their visual appeal in various product categories, including beverages, cleaning agents (detergents), cosmetics, and personal care items. They can all be recycled in industry-standard recycling plants. The adhesive 72Hpw has been developed for applications where the label is to be washed off in warm alkaline water. Good results are already achieved at 70 degrees Celsius in a 1% sodium hydroxide solution. Further material combinations are currently still in the test phase. These include, for example, the extra light and therefore resource-friendly films Herma PP 50 white (grade 884) and Herma PP 50 transparent super tc (grade 886).