Switchable adhesive and objects utilizing the same

Abstract

A carpet material with at least one of its components made easier for recycle by use of an adhesive which can be selectively altered to change the adhesion strength to allow component carpet layers to be separated.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application claims priority to United Kingdom No. 0914377.7 filed Aug. 17, 2009, herein incorporated by reference in its entirety.BACKGROUND OF THE INVENTION[0002]The current invention relates to a means whereby an object can be rendered more readily adaptable from a first form suitable for a first use to a second form suitable for a second use, and to an adhesive, in particular, but not necessarily exclusively, a hot aqueous solvent switchable adhesive comprising or essentially consisting of a plasticized esterified expanded starch obtained by at least expanding starch to provide an expanded starch, esterification of the expanded starch to provide an esterified expanded starch, and plasticization of the esterified expanded starch to provide a plasticized esterified expanded starch. In particular, the current invention relates to a method of using such hot aqueous solvent switchable adhesive as the agent for allowing the adaptability...

AI Technical Summary

Benefits of technology

[0019]A carpet material with at least one of its components made easier for recycle by use of an adhesive which can be selectively altered to change the adhesion strength to allow component carpet layers to be separated.

Problems solved by technology

Carpets or carpet tiles are the floor covering of choice in many households and businesses in the world but unfortunately carpet or carpet tiles have a limited lifespan and must eventually be replaced, with the resultant used carpet waste generally being sent to landfill.

These vast quantities of carpet waste have a negative impact on the environment, and the recycling of materials, like nylon and bitumen, comprised in the carpet is currently limited.

The quantity of used carpet or carpet tiles discarded thus amounts to significant economical losses in potentially reusable materials.

Recycling carpet or carpet tiles, however, is difficult because the components that are used to build up carpet or carpet tiles are chemically and physically diverse.

Unfortunately, recycling of the components of carpets or carpet tiles are hindered due to the residual presence of adhesive, for example SBR latex, when the layers have been mechanically separated under great tensile stresses.

In other words, adhesive might still be present both in the yarn of the carpet face layer and in / on the backing layer, thereby providing contaminated materials not suitable for proper reuse.

This method will however not solve the problem of residual presence of the adhesive attached to for example the yarn or the backing.

This method has however the drawback that high amounts of energy have to be spent in a process using vast amounts of chemicals, while in addition the problem of residual presence of the adhesive in / on the yarn / fabric is not solved satisfactory.

Although various modified (latex-based) adhesives for carpet tiles have been described, in general these are not easily separated or removed from carpet fibres.

However, none provide a satisfactory solution to the problem discussed above with respect to efficient recycling of objects such as carpet or carpet tiles, and none provide a satisfactory adhesive that can be suitably used in a carpet or carpet tiles that can be recycled.

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