Polyurethane hot-melt adhesives for the production of cork stoppers
OwnerUwe Franken, Hartmut Primke +1inventors
InventorsUwe Franken, Hartmut Primke, Carlos De Alvaro
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Abstract
Reactive hot-melt adhesive with a softening-point between 90° C. and 160° C.—in particular reactive polyurethane hot-melt adhesives—are suitable for the adhesion bonding of mouldings made of agglomerated cork to discs made of natural cork. In this way it is possible for high-quality cork-stopper composites for the sealing of beverage bottles to be produced in very efficient and cost-effective manner.
Claims4
Use of a reactive hot-melt adhesive with a softening-point according to ASTM E28 between 90° C. and 160° C. for the production of cork stoppers.
Process for the production of cork stoppers, characterised by the following essential process steps:
- a) application of a reactive polyurethane hot-melt adhesive with a softening-point between 90° C. and 160° C., preferably between 100° C. and 150° C., in particularly preferred manner between 110° C. and 130° C., with the aid of a die or a punch, in the manner of screen printing, through appropriately shaped perforated plates pertaining to the application punch onto at least one end face of a moulding made of agglomerated cork,
- b) joining of a cork disc made of natural cork onto the adhesive-wetted end face(s) of the moulding,
- c) optionally, mechanical aftertreatment of the bonded moulding by grinding or cutting.
Dependencies are inferred from the claim text.