Auxetic Technologies Limited

The University of Bolton, Higher Education Corporation a UK Corporation

Kim Lesley Alderson

Andrew Alderson

Virginia Ruth Simkins

Gillian Mary Smart

Graham David Hudson

David Edward Skertchly

Philip John Davies

Phillip Davies

Gillian Smart

A process for the preparation of thermoplastic auxetic foams comprising the steps of: a) taking conventional thermoplastic foam; b) subjecting said foam to at least one process cycle wherein the foam is biaxially compressed and heated; c) optionally subjecting the foam to at least one process cycle wherein the biaxial compression is removed and the foam mechanically agitated prior to reapplying biaxial compression and heating; d) cooling said foam to a temperature below the softening temperature of said foam; and e) removing said compression and heat.

Process for the preparation of auxetic foams

A composite material comprises a layer of fibres conjoined to a matrix, where one of the matrix and fibres comprises a first component which exhibits auxetic behaviour for loading along a first direction, and the other of the matrix and fibres comprises a second component which exhibits non-auxetic behaviour for loading along the first direction.

Composite material

An auxetic material, which has a negative Poisson ratio so that it has the property of expanding or contracting transversely to a direction in which it is extended or compressed, is made in filamentary or fibrous form. A suitable process involves cohering and extruding heated polymer powder so that the cohesion and extrusion is effected with spinning to produce auxetic filaments. Typically the powder is heated to a temperature sufficient to allow some degree of surface melting yet not high enough to enable bulk melting.

Auxetic filamentary materials

An auxetic polymeric material is manufactured in a filamentary or fibrous form. The auxetic polymeric material has a negative Poisson ratio so that it has the property of expanding or contracting transversely to a direction in which it is extended or compressed. The process for forming the material involves cohering and extruding heated polymer powder so that the cohesion and extrusion is effected with spinning to produce auxetic filaments. Typically, the power is heated to a temperature sufficient to allow some degree of surface melting yet not high enough to enable bulk melting.

Growing community of inventors

Liverpool, United Kingdom

Kim Lesley Alderson