Adhesive bond using different adhesives

Abstract

A method for adhesively bonding shaped elements made from wood-based materials to flexible film substrates, in which i) the side that is to be bonded is mechanically processed, ii) a reactive one- or two-component polyurethane adhesive is applied to the center regions of this side, iii) an aqueous adhesive based on EVA, PVAc, PVOH is applied at least to the outer region of this side, and iv) this side is bonded to a flexible substrate as an edge coating.

Claims

1. A method for adhesively bonding a shaped elements made from wood-based materials to flexible film substrates, comprising: providing the shaped element which is to be adhesively bonded, the shaped element having a side including an outer region surrounding a center region, wherein the shaped element is mechanically processed, applying a reactive one- or two-component polyurethane adhesive to only the center region of the side, applying an aqueous adhesive based on ethylene vinyl acetate (EVA), polyvinyl acetate (PVAc), polyvinyl alcohol (PVOH) to at least the outer region of this side, and bonding the side adhesively to the flexible substrate as an edge coating.

2. The method according to claim 1, wherein a flowable one-component polyurethane adhesive is used as the polyurethane adhesive.

3. The method according to claim 1, wherein the polyurethane adhesive is applied in an amount from 20 to 300 g/m.sup.2.

4. The method according to claim 1, wherein the aqueous adhesive is applied to the entire side of the shaped element and/or to the surface of the flexible substrate that is to be adhesively bonded.

5. The method according to claim 1, wherein the flexible substrate is heated prior to joining.

6. The method according to claim 1, wherein the wood-based material is selected from wood, particle-board panels, MDF panels and/or that the flexible substrate is selected from decorative films, plastic films, or plastic edge strips.

7. The method according to claim 1, wherein the substrates are adhesively bonded under pressure.

8. The method according to claim 1, wherein a liquid at 23 C. polyurethane adhesive is used as the polyurethane adhesive.

9. The method according to claim 1, wherein the the aqueous adhesive is applied to the outer region and the center reqion.

Description

EXAMPLES

(1) PU adhesive Makroplast 7221 (Henkel) Solvent-free, contains NCO groups, viscosity approx. 9000 mPas, 25 C. Aqueous adhesive Dorus AD 096/2: Solids content approx. 50%, viscosity approx. 10,000 mPas, 25 C.

Method Example 1

(2) A commercial particle-board panel is mechanically shaped along its narrow side. A one-component PU adhesive is applied to the inner surface of this side (approx. 80 g/m.sup.2). Immediately thereafter an aqueous adhesive based on PVAC is applied to both substrates to be bonded (approx. 80 g/m.sup.2).

(3) Immediately thereafter the CPL laminate is adhesively bonded to the panel surface by pressing with rollers. The pressing time is approx. 5 seconds.

(4) After 24 hours the adhesive bond is assessed.

(5) The pores in the substrate are no longer visible.

(6) The running of the surface is smoother and quieter than a corresponding comparison without PU adhesive.

(7) A possible contamination of the longitudinal edge can be removed by cleaning with water.