Planatol HM 2941 Hotmelt Adhesive Declared Perfect for Binding by KOLBUS

Planatol Adhesive GmbH, one of the leading suppliers of adhesives for the graphic arts industry, launched four new thermoplastic adhesives for perfect binding on the market last year. The performance of the new hot melt and PUR adhesives was confirmed with impressive results by different test runs at the Information and Training Centre of the book binder machine manufacturer KOLBUS GmbH & Co. KG in Rahden, North-Rhine Westphalia recently.

The new Planatol HM 2941, a light-coloured, yet reasonably priced hot melt, is just as suitable for general perfect binding as it is for the two-shot procedure, which is recommended by experts for very high machine speeds. For the two-shot procedure, HM 2941 is applied as a primer at 170°C at a viscosity of approximately 1000 mPas in order to achieve ideal sheet edge wetting. As a primary glue, the glue is applied at 130°C at approximately 3000 mPas. Using this process the KOLBUS Information Centre was easily able to produce perfect bindings on the high-speed KM 412E perfect binder at 18,000 cycles per hour.

The new Planatol HM 2959 side glue, produced in the shape of small pads, can also be processed with excellent results and without spraying. Its high tack and long open time result in a uniformly thin adhesive coat. "We are very pleased with the good results attained right away. The brochures, which were produced using a 50 g/m² gravure paper, produced pull values consistently above 7 N/cm, and even a heavy paper that is normally bonded with a PUR thermoplastic adhesive produced these good pull values," Udo Beitans, head of KOLBUS information workshops and user training.

Likewise, the Planatol S-PUR 2954 (Safety PUR, VOC-exempt) and PUR 2880 W thermoplastic adhesives were tested at KOLBUS with good results on the KM 600 perfect binder with a Nordson EP 48 V bookbinding gun at 7,000 cycles. Both glues were easy to use. Planatol Safety PUR in particular did well due to its excellent hot tack and quick crystallisation. This VOC-exempt PUR glue does well even during offset stacking of thick brochures and provides a good pot life, yet quickly sets when exposed to humidity. PUR 2880 W is appealing due to the fact that it sets very quickly and has good reactivity, which also makes this PUR suitable for very high machine speeds.