WO1991001210A1 - Polymeric materials - Google Patents
Polymeric materials Download PDFInfo
- Publication number
- WO1991001210A1 WO1991001210A1 PCT/GB1990/001081 GB9001081W WO9101210A1 WO 1991001210 A1 WO1991001210 A1 WO 1991001210A1 GB 9001081 W GB9001081 W GB 9001081W WO 9101210 A1 WO9101210 A1 WO 9101210A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- polymer
- process according
- microstructure
- mass
- materials
- Prior art date
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
- B29D99/00—Subject matter not provided for in other groups of this subclass
- B29D99/0089—Producing honeycomb structures
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C55/00—Shaping by stretching, e.g. drawing through a die; Apparatus therefor
- B29C55/005—Shaping by stretching, e.g. drawing through a die; Apparatus therefor characterised by the choice of materials
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B31—MAKING ARTICLES OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER; WORKING PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
- B31D—MAKING ARTICLES OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER, NOT PROVIDED FOR IN SUBCLASSES B31B OR B31C
- B31D3/00—Making articles of cellular structure, e.g. insulating board
- B31D3/002—Methods for making cellular structures; Cellular structures
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B3/00—Layered products comprising a layer with external or internal discontinuities or unevennesses, or a layer of non-planar form; Layered products having particular features of form
- B32B3/26—Layered products comprising a layer with external or internal discontinuities or unevennesses, or a layer of non-planar form; Layered products having particular features of form characterised by a particular shape of the outline of the cross-section of a continuous layer; characterised by a layer with cavities or internal voids ; characterised by an apertured layer
- B32B3/28—Layered products comprising a layer with external or internal discontinuities or unevennesses, or a layer of non-planar form; Layered products having particular features of form characterised by a particular shape of the outline of the cross-section of a continuous layer; characterised by a layer with cavities or internal voids ; characterised by an apertured layer characterised by a layer comprising a deformed thin sheet, i.e. the layer having its entire thickness deformed out of the plane, e.g. corrugated, crumpled
Definitions
- This invention relates to novel polymeric materials, to processes for their production and to devices incorporating said materials.
- This class comprises materials having a microstructure comprising finite sized particles which are conventionally termed nodes connected by fibrils wherein the microstructure is such that the application of a tension 1n one direction causes the nodes to be displaced in the transverse direction. This displacement produces the expansion in the transverse direction which 1s the characteristic of materials having a negative Poisson ratio.
- the discovery enables a variety of polymers to be produced in a form which exhibits a negative Poisson ratio and in consequence exhibit a large shear modulus relative to their bulk modulus. Appropriate selection of the polymer enables materials to be produced which combine this with superior mechanical properties such as the Youngs modulus. This combination of properties can be exploited 1n a variety of useful devices.
- our invention provides polymeric materials having a microstructure comprising nodes Interconnected by fibrils which are characterised in that they exhibit a negative Poisson ratio and have a Youngs modulus of at least 0.2 GPa.
- the materials of this invention may be formed from any polymer which is capable of being produced 1n a form having a microstructure comprising nodes and fibrils.
- the polymer must be sufficiently ductile to form fibrils when expanded, e.g. by drawing and yet must retain the particulate microstructure which provides the nodes. Not all mlcrostructures comprising nodes and fibrils provide a material having a negative Poisson ratio and the conditions necessary to produce any particular polymer in a form having the desired microstructure may need to be determined by experiment.
- the materials comprise a microstructure comprising finite sized particles (nodes ) connected by fibrils wherein the length of the fibrils is greater than the shortest distance between the nodes which they connect and wherein the distance between adjacent nodes which are not connected by fibrils is less than maximum distance between fibrils connected to a particular node.
- This first type of microstructure is illustrated in Figure 1 which is a cross sectional sketch of such a microstructure. The nodes are represented as cross hatched spheres and the fibrils by the solid lines. Figure 1 illustrates the microstructure prior to the application of a tension in the direction of the x axis.
- Figure 2 represents the same cross section after the application of a tension along the x axis (not drawn to scale).
- the fibrils are now taut and the nodes have been displaced In the direction of the y axis. It Is this displacement which gives rise to the negative Poisson ratio.
- a second class of microstructure which can give rise to a material having a negative Poisson ratio is one in which the nodes are anisotropic.
- the useful microstructures are those in which the nodes are aligned in such a way that their longer dimension lies in the direction of the axis of the material and wherein the nodes are connected by fibrils which are longer than the distance between the nodes which they connect.
- FIG. 3 is a cross-sectional sketch of such a microstructure.
- the nodes are shown as cross-hatched discoid areas connected by fibrils which are represented by solid lines.
- Figure 3(a) shows a structure in which the nodes are close together and aligned so that their longest dimension lies along the x axis.
- Figure 3(b) shows that following the application of a tension along the x axis, the distance between the nodes measured along the x axis has Increased. At the same time there has been some expansion along the y axis by virtue of an Interaction between the nodes and fibrils of the type described in relation to Figures 1 and 2.
- Figure 3(c) shows how the continued application of the tension has caused the nodes to rotate so that their longest dimension 1s displaced toward the y axis. This rotation produces the negative Poisson ratio as each "layer" of nodes displaces the adjacent "layer” along the y axis.
- Figure 3(d) represents the limiting case 1n which the nodes have rotated so that their longest dimension Is now aligned with the y axis.
- sketches 1 to 3 are two dimensional representations which illustrate possible mechanisms whereby the polymers of this invention may exhibit a negative Poisson ratio. In practice the polymers are three dimensional and may well exhibit a microstructure which is not uniform. It 1s characteristic of the materials of this invention that they exhibit a negative Poisson ratio, i.e.
- the materials of this invention may be isotroplc or anisotropic.
- isotroplc materials the minimum Poisson ration which can be achieved is minus 1.
- anisotropic materials the minimum Poisson ratio may be much smaller (at least in one direction).
- the materials may exhibit a ratio which is close to the theoretical limit of minus the square root of the ratio of the maximum Youngs modulus of the material divided by its minimum Youngs modulus and such materials may be preferred In particular applications.
- the materials of this invention preferably exhibit a Poisson ratio of less than minus 0.25 and preferably one which 1s less then minus 0.75 although for the anisotropic materials ratios of as low as minus 10 or minus 12 are attainable and may be preferred.
- the materials of this invention may be formed from any suitable polymer which can be processed to a form having a suitable microstructure.
- a particulate thermofor able polymer as the starting material and to deform a compacted polymer material under controlled conditions.
- the polymer should be sufficiently ductile so as to enable it to be deformed under conditions which result 1n the formation of fibrils and yet retain the particulate microstructure which forms the nodes.
- suitable materials include poly- tetrafluoroethylene and copolymers thereof, polyolefins and copolymers thereof especially polyethylene and copolymers thereof and particularly high molecular weight polyethylene, polypropylene and copolymers thereof, polystyrene and poly(meth)- acrylates.
- the size of the nodes in the microstructure may vary through a wide range say a maximum dimension of from 0.1 ⁇ m to 0.1 mm.
- the ratio of the fibril length to the length of the maximum dimension of the node should preferably be greater than 1 and more usually will be within the range 1.1:1 to 2.0:1.
- the polymer from which the materials of this invention are formed will be selected so as to provide the desired properties.
- the polymer selected will result in the formation of a material having a Youngs Modulus of at least 1.0 GPa.
- the materials also preferably have a density of at least 150Kgm ⁇ 3 and more preferably at least 500 gm ⁇ 3 .
- the polymeric materials of this invention may incorporate a filler such as asbestos, carbon black, mica, silica or titanium dioxide.
- a filler 1s preferably incorporated Into the material by mixing with the polymer particles prior to the processing step which is required in order to produce the appropriate microstructure.
- Impregnating 1t with a liquid phase comprising a monomer or prepolymer for example methyl methacr late and subsequently polymerising that monomer or prepolymer. This impregnation may be carried out before or after the processing step.
- microstructure of the materials and hence their properties may also be Influenced by the form of the polymer from which they are produced.
- the materials are produced from particulate polymer granules the general shape of the particles tends to be retained by the nodes 1n the microstructure.
- the use of spherical polymer particles tends to result in a microstructure having broadly spherical nodes.
- the materials may be formed by a process which comprises compacting the polymer particles at elevated temperatures and pressures and deforming the compacted polymer.
- this invention provides a process for the production of a polymeric material having a microstructure comprising nodes interconnected by fibrils which exhibits a negative Poisson ration which comprises compacting a particulate polymeric material and de f orming the polymer so as to cause it to expand in at least one direction.
- the compaction step preferably comprises heating a mass of polymer particles to a temperature of at least 50°C and more usually at least 90 ⁇ C.
- Polymers which have a melting point above these temperatures are preferred for present use.
- the temperature shcild be within 50°C and more preferably within 20 ⁇ C of the melting point of the polymer.
- the force applied may vary through a wide range, say from 1.0 to 100 MPa.
- the polymer should preferably be subjected to these conditions for a period which Is sufficiently long to allow the entire mass to attain a thermal equilibrium.
- the polymers are deformed by expansion in at least one direction until the desired microstructure is obtained.
- the deformation may be carried out using techniques known in the polymer art such as extrusion drawing or draw assisted extrusion.
- the deformation is preferably carried out at elevated temperatures say of at least 50°C and more usually of at least 100°C.
- the polymers may conveniently be produced using conventional polymer extrusion equipment.
- the polymer powder or granules may be introduced Into the barrel of the extruder. They are then conveniently formed into a compacted rod by compression preferably at elevated temperature. Thereafter the polymer may be extruded through a die.
- the diameter of the die, the temperature at which the polymer is extruded and the speed at which the polymer is extruded may all Influence the microstructure of the polymer.
- the rate of deformation of the polymer should be sufficient to result in the production of the desired microstructure. Too low a rate may not be useful and typically for polyethylene an extrusion rate of greater than 250 or more preferably 500 mm/min may be utilised.
- the optimum conditions for each polymer may be established by experiment. In general the temperature of the polymer during the extrusion will be at least as high as that used in the compaction step and preferably the temperature may be increased before extrusion commences. Thereafter the extruded material is allowed to cool to ambient temperature.
- the microstructure of the polymer may be examined using conventional techniques such as scanning electron microscopy. If the polymer does not exhibit the desired microstructure the polymer may be subjected to a further processing step which comprises compressing the polymer in a direction which is perpendicular to the original draw direction. Such cor--resslc is preferably carried out whilst the drawn polymer is maintained at an elevated temperature generally at least 50 ⁇ C and preferably at least 90 ⁇ C. Where particular materials do not exhibit the desired microstructure the parameters of the drawing process may need to be adjusted.
- the microstructure of the drawn material may not be uniform. It may comprise regions where the Poisson ratio 1s higher or even takes a positive value. Nevertheless such materials may be useful on various applications provided that they exhibit a negative Poisson ratio in at least one direction.
- the materials produced by the process may already be fully drawn out in that direction. Such materials will not exhibit a negative Poisson ratio but may do so following a compression step as described above.
- Partially drawn materials may also be compressed 1f desired. The compression may remove all traces of the microstructure from the material but 1t is characteristic of the materials of this invention that the changes brought about by compression are at least partially reversible and the microstructure may be at least partially restored by extension in the original draw direction.
- the materials of this invention find potential use 1n a variety of applications. They can for example be used to seal a cavity since a plug formed from a material having a negative Poisson ratio will expand laterally when stretched. They also find use in applications wherein compliance of dimension under stress is desirable, e.g. as the interior filler for structural sandwich panels and for shock and vibration absorption. The materials may also find use in a variety of medical applications.
- Example 1 The barrel of a laboratory manufactured compacted powder extruder was filled with an ultra high molecular weight polyethylene powder sold under the Trademark Hostalen GUR 415 by Hoechst (UK) Ltd. of Salisbury Road, Middlesex. The extruder was fitted with a blank die and preheated to a temperature of 110 ⁇ C. The barrel, internal diameter 1 cm and length 8 cm, and contents were allowed to equilibriate for 10 minutes. The plunger was then driven into the barrel by a Schenk mechanical testing machine at a rate of 20 mm/min until a force of 7.31 kN was reached. These conditions were maintained for 20 minutes. The result was a compacted polyethylene rod.
- the extruder was then fitted with a die having a diameter of 5 mm and an entry angle of 45°. The temperature was maintained at 160°C for a further 20 minutes. The plunger was then driven into the barrel at a rate of 500 mm/min.
- the extrudate comprised a rod having the appearance shown in Figure 4.
- the Poisson ratio of the extrudate was determined by applying compressive strains in the directions indicated in Figure 4.
Abstract
Description
Claims
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB898916231A GB8916231D0 (en) | 1989-07-14 | 1989-07-14 | Polymeric materials |
GB8916231.7 | 1989-07-14 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO1991001210A1 true WO1991001210A1 (en) | 1991-02-07 |
Family
ID=10660087
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/GB1990/001081 WO1991001210A1 (en) | 1989-07-14 | 1990-07-13 | Polymeric materials |
Country Status (5)
Country | Link |
---|---|
EP (1) | EP0482058A1 (en) |
JP (1) | JPH04506638A (en) |
CA (1) | CA2063396A1 (en) |
GB (3) | GB8916231D0 (en) |
WO (1) | WO1991001210A1 (en) |
Cited By (36)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2000018564A1 (en) * | 1998-09-30 | 2000-04-06 | Toray Industries, Inc. | Highly size-stabilized polymer film and magnetic recording medium using the film |
WO2001045766A1 (en) | 1999-12-22 | 2001-06-28 | Advanced Cardiovascular Systems, Inc. | Medical device formed of ultrahigh molecular weight polyolefin |
US6428506B1 (en) | 1999-12-22 | 2002-08-06 | Advanced Cardiovascular Systems, Inc. | Medical device formed of ultrahigh molecular weight polyethylene |
WO2004012785A1 (en) | 2002-08-02 | 2004-02-12 | Auxetica Limited | Auxetic tubular liners |
US6743388B2 (en) | 2001-12-31 | 2004-06-01 | Advanced Cardiovascular Systems, Inc. | Process of making polymer articles |
US6793960B1 (en) | 2001-04-06 | 2004-09-21 | Advanced Cardiovascular Systems, Inc. | Medical device having surface modification with superoxide dismutase mimic |
US6841029B2 (en) | 2003-03-27 | 2005-01-11 | Advanced Cardiovascular Systems, Inc. | Surface modification of expanded ultra high molecular weight polyethylene (eUHMWPE) for improved bondability |
US6878320B1 (en) | 1999-03-06 | 2005-04-12 | The University Of Bolton, Higher Education Corporation A Uk Corporation | Auxetic materials |
DE102005012906B3 (en) * | 2005-03-21 | 2006-12-14 | Corovin Gmbh | Sheet-like sheeting, method and apparatus for producing the same and its use |
US7247265B2 (en) | 2000-03-06 | 2007-07-24 | Auxetic Technologies Ltd. | Auxetic filamentary materials |
US7455567B2 (en) | 2006-08-02 | 2008-11-25 | Hanesbrands Inc. | Garments having auxetic foam layers |
WO2009142836A3 (en) * | 2008-05-23 | 2010-01-14 | Schlumberger Canada Limited | System and method for improving operational characteristics of devices used in a well |
EP2157121A1 (en) | 2006-05-24 | 2010-02-24 | Auxetic Technologies Ltd. | A composite material |
KR100990023B1 (en) * | 2008-02-29 | 2010-10-26 | 서강대학교산학협력단 | Rotational particle structure tube with negative poisson's ratio and its method |
WO2011090587A2 (en) | 2009-12-30 | 2011-07-28 | 3M Innovative Properties Company | Molded auxetic mesh |
WO2011090588A2 (en) | 2009-12-30 | 2011-07-28 | 3M Innovative Properties Company | Method of making an auxetic mesh |
US8129293B2 (en) | 2006-03-08 | 2012-03-06 | Dow Corning Corporation | Impregnated flexible sheet material |
WO2012171911A1 (en) | 2011-06-14 | 2012-12-20 | Dow Corning Corporation | Pressure material |
US8343404B2 (en) | 2008-03-07 | 2013-01-01 | Giuseppe Meli | Method for the production of cellular materials |
US8728372B2 (en) | 2005-04-13 | 2014-05-20 | Trivascular, Inc. | PTFE layers and methods of manufacturing |
US8840824B2 (en) | 2005-04-13 | 2014-09-23 | Trivascular, Inc. | PTFE layers and methods of manufacturing |
US8916262B2 (en) | 2003-03-29 | 2014-12-23 | Dow Corning Corporation | Composite materials and structures |
US8967147B2 (en) | 2009-12-30 | 2015-03-03 | 3M Innovative Properties Company | Filtering face-piece respirator having an auxetic mesh in the mask body |
WO2015038455A1 (en) * | 2013-09-10 | 2015-03-19 | The Procter & Gamble Company | Cell forming structures |
US9926416B2 (en) | 2013-01-30 | 2018-03-27 | W. L. Gore & Associates, Inc. | Method for producing porous articles from ultra high molecular weight polyethylene |
CN110524960A (en) * | 2019-08-07 | 2019-12-03 | 东华大学 | A kind of high buffering flexible function auxetic composite material and preparation method of asymmetry |
USD869889S1 (en) | 2017-12-05 | 2019-12-17 | Steelcase Inc. | Chairback |
USD869872S1 (en) | 2017-12-05 | 2019-12-17 | Steelcase Inc. | Chair |
USD869890S1 (en) | 2017-12-05 | 2019-12-17 | Steelcase Inc. | Chairback |
USD870479S1 (en) | 2017-12-05 | 2019-12-24 | Steelcase Inc. | Chair |
US10813463B2 (en) | 2017-12-05 | 2020-10-27 | Steelcase Inc. | Compliant backrest |
USD907383S1 (en) | 2019-05-31 | 2021-01-12 | Steelcase Inc. | Chair with upholstered back |
USD907935S1 (en) | 2019-05-31 | 2021-01-19 | Steelcase Inc. | Chair |
EP3673007A4 (en) * | 2017-08-25 | 2021-03-24 | Honeywell International Inc. | Impact resistant composite material |
US11291305B2 (en) | 2017-12-05 | 2022-04-05 | Steelcase Inc. | Compliant backrest |
US11864658B2 (en) * | 2016-02-05 | 2024-01-09 | Formway Furniture Limited | Chair and components |
Families Citing this family (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN100503703C (en) * | 2005-12-21 | 2009-06-24 | 中国科学院化学研究所 | Negative poisson's ratio material and its preparing method and use |
US8016549B2 (en) | 2006-07-13 | 2011-09-13 | United Technologies Corporation | Turbine engine alloys and crystalline orientations |
EP2995288A1 (en) * | 2014-09-10 | 2016-03-16 | The Procter and Gamble Company | Cell forming structures and their use in disposable consumer products |
EP2995289A1 (en) * | 2014-09-10 | 2016-03-16 | The Procter and Gamble Company | Multi-level cell forming structures and their use in disposable consumer products |
CN108367536B (en) | 2015-01-09 | 2020-11-20 | 哈佛大学校董委员会 | Negative Poisson ratio waffle structure |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4279245A (en) * | 1978-12-19 | 1981-07-21 | Olympus Optical Co., Ltd. | Flexible tube |
US4482516A (en) * | 1982-09-10 | 1984-11-13 | W. L. Gore & Associates, Inc. | Process for producing a high strength porous polytetrafluoroethylene product having a coarse microstructure |
US4668557A (en) * | 1986-07-18 | 1987-05-26 | The University Of Iowa Research Foundation | Polyhedron cell structure and method of making same |
EP0253513A2 (en) * | 1986-06-17 | 1988-01-20 | Nippon Oil Co. Ltd. | Process for the production of polyethylene materials |
EP0267719A2 (en) * | 1986-11-13 | 1988-05-18 | W.L. Gore & Associates, Inc. | Method for extruding and expanding polytetrafluoroethylene tubing and the products produced thereby |
EP0313263A2 (en) * | 1987-10-19 | 1989-04-26 | W.L. Gore & Associates, Inc. | Rapid recoverable PTFE and a process for its manufacture |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5017106B1 (en) * | 1970-12-16 | 1975-06-18 | ||
EP0161802B1 (en) * | 1984-04-13 | 1990-06-27 | National Research Development Corporation | Solid phase deformation process |
GB8628730D0 (en) * | 1986-12-02 | 1987-01-07 | Mackley M R | Polymer forming process |
GB2207436B (en) * | 1987-07-24 | 1991-07-24 | Nat Research And Dev Corp The | Solid phase deformation process |
-
1989
- 1989-07-14 GB GB898916231A patent/GB8916231D0/en active Pending
-
1990
- 1990-06-22 GB GB909014006A patent/GB9014006D0/en active Pending
- 1990-07-13 EP EP19900910845 patent/EP0482058A1/en not_active Ceased
- 1990-07-13 GB GB9015466A patent/GB2235200B/en not_active Expired - Fee Related
- 1990-07-13 JP JP51002290A patent/JPH04506638A/en active Pending
- 1990-07-13 CA CA 2063396 patent/CA2063396A1/en not_active Abandoned
- 1990-07-13 WO PCT/GB1990/001081 patent/WO1991001210A1/en not_active Application Discontinuation
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4279245A (en) * | 1978-12-19 | 1981-07-21 | Olympus Optical Co., Ltd. | Flexible tube |
US4482516A (en) * | 1982-09-10 | 1984-11-13 | W. L. Gore & Associates, Inc. | Process for producing a high strength porous polytetrafluoroethylene product having a coarse microstructure |
EP0253513A2 (en) * | 1986-06-17 | 1988-01-20 | Nippon Oil Co. Ltd. | Process for the production of polyethylene materials |
US4668557A (en) * | 1986-07-18 | 1987-05-26 | The University Of Iowa Research Foundation | Polyhedron cell structure and method of making same |
EP0267719A2 (en) * | 1986-11-13 | 1988-05-18 | W.L. Gore & Associates, Inc. | Method for extruding and expanding polytetrafluoroethylene tubing and the products produced thereby |
EP0313263A2 (en) * | 1987-10-19 | 1989-04-26 | W.L. Gore & Associates, Inc. | Rapid recoverable PTFE and a process for its manufacture |
Non-Patent Citations (1)
Title |
---|
Journal of Physics D: Applied Physics, Volume 22, No. 12, November 1989, IOP Publishing Ltd, (GB), B.D. CADDOCK et al.: "Microporous Materials with Negative Poisson's Ratios: I. Microstructure and Mechanical Properties", pages 1877-1882 see paragraphs 2.1, 2.2, 2.3 * |
Cited By (66)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6797381B1 (en) | 1998-09-30 | 2004-09-28 | Toray Industries, Inc. | Highly size-stabilized polymer film and magnetic recording medium using the film |
WO2000018564A1 (en) * | 1998-09-30 | 2000-04-06 | Toray Industries, Inc. | Highly size-stabilized polymer film and magnetic recording medium using the film |
US6878320B1 (en) | 1999-03-06 | 2005-04-12 | The University Of Bolton, Higher Education Corporation A Uk Corporation | Auxetic materials |
WO2001045766A1 (en) | 1999-12-22 | 2001-06-28 | Advanced Cardiovascular Systems, Inc. | Medical device formed of ultrahigh molecular weight polyolefin |
US6428506B1 (en) | 1999-12-22 | 2002-08-06 | Advanced Cardiovascular Systems, Inc. | Medical device formed of ultrahigh molecular weight polyethylene |
US6602224B1 (en) | 1999-12-22 | 2003-08-05 | Advanced Cardiovascular Systems, Inc. | Medical device formed of ultrahigh molecular weight polyolefin |
US6890395B2 (en) | 1999-12-22 | 2005-05-10 | Advanced Cardiovascular Systems, Inc. | Medical device formed of ultrahigh molecular weight polyolefin |
US6761786B2 (en) * | 1999-12-22 | 2004-07-13 | Advanced Cardiovascular Systems, Inc. | Process of making a balloon for an intraluminal catheter |
US7247265B2 (en) | 2000-03-06 | 2007-07-24 | Auxetic Technologies Ltd. | Auxetic filamentary materials |
US7396582B2 (en) | 2001-04-06 | 2008-07-08 | Advanced Cardiovascular Systems, Inc. | Medical device chemically modified by plasma polymerization |
US6793960B1 (en) | 2001-04-06 | 2004-09-21 | Advanced Cardiovascular Systems, Inc. | Medical device having surface modification with superoxide dismutase mimic |
US7311970B2 (en) | 2001-04-06 | 2007-12-25 | Abbott Cardiovascular Systems Inc. | Medical device having surface modification with superoxide dismutase mimic |
US7470469B1 (en) | 2001-04-06 | 2008-12-30 | Advanced Cardiovascular Systems Inc. | Medical device having surface modification with superoxide dismutase mimic |
US6780361B1 (en) | 2001-12-31 | 2004-08-24 | Advanced Cardiovascular Systems, Inc. | Process of making polymer articles |
US6743388B2 (en) | 2001-12-31 | 2004-06-01 | Advanced Cardiovascular Systems, Inc. | Process of making polymer articles |
WO2004012785A1 (en) | 2002-08-02 | 2004-02-12 | Auxetica Limited | Auxetic tubular liners |
GB2393657A (en) * | 2002-08-02 | 2004-04-07 | Rudy Hengelmolen | Auxetic tubular liners |
US6841029B2 (en) | 2003-03-27 | 2005-01-11 | Advanced Cardiovascular Systems, Inc. | Surface modification of expanded ultra high molecular weight polyethylene (eUHMWPE) for improved bondability |
US7425357B2 (en) | 2003-03-27 | 2008-09-16 | Advanced Cardiovascular Systems, Inc. | Surface modification of expanded ultra high molecular weight polyethylene(eUHMWPE) for improved bondability |
US8916262B2 (en) | 2003-03-29 | 2014-12-23 | Dow Corning Corporation | Composite materials and structures |
DE102005012906B3 (en) * | 2005-03-21 | 2006-12-14 | Corovin Gmbh | Sheet-like sheeting, method and apparatus for producing the same and its use |
US9446553B2 (en) | 2005-04-13 | 2016-09-20 | Trivascular, Inc. | PTFE layers and methods of manufacturing |
US10864070B2 (en) | 2005-04-13 | 2020-12-15 | Trivascular, Inc. | PTFE layers and methods of manufacturing |
US9549829B2 (en) | 2005-04-13 | 2017-01-24 | Trivascular, Inc. | PTFE layers and methods of manufacturing |
US11510774B2 (en) | 2005-04-13 | 2022-11-29 | Trivascular, Inc. | PTFE layers and methods of manufacturing |
US8840824B2 (en) | 2005-04-13 | 2014-09-23 | Trivascular, Inc. | PTFE layers and methods of manufacturing |
US8728372B2 (en) | 2005-04-13 | 2014-05-20 | Trivascular, Inc. | PTFE layers and methods of manufacturing |
US8129293B2 (en) | 2006-03-08 | 2012-03-06 | Dow Corning Corporation | Impregnated flexible sheet material |
EP2157121A1 (en) | 2006-05-24 | 2010-02-24 | Auxetic Technologies Ltd. | A composite material |
US7455567B2 (en) | 2006-08-02 | 2008-11-25 | Hanesbrands Inc. | Garments having auxetic foam layers |
KR100990023B1 (en) * | 2008-02-29 | 2010-10-26 | 서강대학교산학협력단 | Rotational particle structure tube with negative poisson's ratio and its method |
US8343404B2 (en) | 2008-03-07 | 2013-01-01 | Giuseppe Meli | Method for the production of cellular materials |
US20130171409A1 (en) * | 2008-03-07 | 2013-07-04 | Giuseppe Meli | Device for the production of cellular materials |
US8453730B2 (en) | 2008-05-23 | 2013-06-04 | Schlumberger Technology Corporation | System and method for improving operational characteristics |
US8783346B2 (en) | 2008-05-23 | 2014-07-22 | Schlumberger Technology Corporation | System and method for improving operational characteristics |
WO2009142836A3 (en) * | 2008-05-23 | 2010-01-14 | Schlumberger Canada Limited | System and method for improving operational characteristics of devices used in a well |
US8728369B2 (en) | 2009-12-30 | 2014-05-20 | 3M Innovative Properties Company | Method of making an auxetic mesh |
AU2010343220B2 (en) * | 2009-12-30 | 2013-05-09 | 3M Innovative Properties Company | Method of making an auxetic mesh |
EP2519397A4 (en) * | 2009-12-30 | 2014-07-02 | 3M Innovative Properties Co | Method of making an auxetic mesh |
EP2519397A2 (en) * | 2009-12-30 | 2012-11-07 | 3M Innovative Properties Company | Method of making an auxetic mesh |
US8967147B2 (en) | 2009-12-30 | 2015-03-03 | 3M Innovative Properties Company | Filtering face-piece respirator having an auxetic mesh in the mask body |
WO2011090588A3 (en) * | 2009-12-30 | 2011-10-20 | 3M Innovative Properties Company | Method of making an auxetic mesh |
WO2011090588A2 (en) | 2009-12-30 | 2011-07-28 | 3M Innovative Properties Company | Method of making an auxetic mesh |
WO2011090587A2 (en) | 2009-12-30 | 2011-07-28 | 3M Innovative Properties Company | Molded auxetic mesh |
WO2012171911A1 (en) | 2011-06-14 | 2012-12-20 | Dow Corning Corporation | Pressure material |
US10577468B2 (en) | 2013-01-30 | 2020-03-03 | W L. Gore & Associates, Inc. | Method for producing porous articles from ultra high molecular weight polyethylene |
US9926416B2 (en) | 2013-01-30 | 2018-03-27 | W. L. Gore & Associates, Inc. | Method for producing porous articles from ultra high molecular weight polyethylene |
WO2015038455A1 (en) * | 2013-09-10 | 2015-03-19 | The Procter & Gamble Company | Cell forming structures |
US11864658B2 (en) * | 2016-02-05 | 2024-01-09 | Formway Furniture Limited | Chair and components |
EP3673007A4 (en) * | 2017-08-25 | 2021-03-24 | Honeywell International Inc. | Impact resistant composite material |
USD921409S1 (en) | 2017-12-05 | 2021-06-08 | Steelcase Inc. | Chair |
US11291305B2 (en) | 2017-12-05 | 2022-04-05 | Steelcase Inc. | Compliant backrest |
USD869872S1 (en) | 2017-12-05 | 2019-12-17 | Steelcase Inc. | Chair |
US11819139B2 (en) | 2017-12-05 | 2023-11-21 | Steelcase Inc. | Compliant backrest |
US10813463B2 (en) | 2017-12-05 | 2020-10-27 | Steelcase Inc. | Compliant backrest |
USD870479S1 (en) | 2017-12-05 | 2019-12-24 | Steelcase Inc. | Chair |
USD869889S1 (en) | 2017-12-05 | 2019-12-17 | Steelcase Inc. | Chairback |
USD921410S1 (en) | 2017-12-05 | 2021-06-08 | Steelcase Inc. | Chair |
US11583092B2 (en) | 2017-12-05 | 2023-02-21 | Steelcase Inc. | Compliant backrest |
USD869890S1 (en) | 2017-12-05 | 2019-12-17 | Steelcase Inc. | Chairback |
USD907935S1 (en) | 2019-05-31 | 2021-01-19 | Steelcase Inc. | Chair |
USD947560S1 (en) | 2019-05-31 | 2022-04-05 | Steelcase Inc. | Chair |
USD947559S1 (en) | 2019-05-31 | 2022-04-05 | Steelcase Inc. | Chair with upholstered back |
USD907383S1 (en) | 2019-05-31 | 2021-01-12 | Steelcase Inc. | Chair with upholstered back |
CN110524960B (en) * | 2019-08-07 | 2021-10-01 | 东华大学 | Asymmetric high-buffering flexible functional auxetic composite material and preparation method thereof |
CN110524960A (en) * | 2019-08-07 | 2019-12-03 | 东华大学 | A kind of high buffering flexible function auxetic composite material and preparation method of asymmetry |
Also Published As
Publication number | Publication date |
---|---|
GB9015466D0 (en) | 1990-08-29 |
GB2235200A (en) | 1991-02-27 |
JPH04506638A (en) | 1992-11-19 |
GB9014006D0 (en) | 1990-08-15 |
GB2235200B (en) | 1993-02-10 |
EP0482058A1 (en) | 1992-04-29 |
CA2063396A1 (en) | 1991-01-15 |
GB8916231D0 (en) | 1989-08-31 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
WO1991001210A1 (en) | Polymeric materials | |
US4973609A (en) | Porous fluoropolymer alloy and process of manufacture | |
Alderson et al. | The fabrication of microporous polyethylene having a negative Poisson's ratio | |
CA2956703C (en) | Articles produced from vdf-co-(tfe or trfe) polymers | |
US4596837A (en) | Semisintered polytetrafluoroethylene article and production thereof | |
CA1057014A (en) | Porous products and process therefor | |
DE69723280T2 (en) | AQUEOUS POLYOLEFIN COMPOSITION, PRE-EXPANDED PARTICLES MADE THEREOF, METHOD FOR THEIR PRODUCTION AND EXPANDED MOLDED PARTS | |
US5026513A (en) | Process for making rapidly recoverable PTFE | |
DE69432771T2 (en) | Thermoplastic foam articles and their manufacturing processes | |
JP6792448B2 (en) | Manufacture of porous material by expansion of polymer gel | |
Halldin et al. | Powder processing of ultra‐high molecular weight polyethylene I. Powder characterization and compaction | |
JP2001526129A (en) | Manufacture of cellular honeycomb structure | |
JPS61501695A (en) | Improved polyethylene molding composition and method for making the same | |
JPS62279920A (en) | Porous heat-shrinkable tetrafluoroethylene polymer pipe and its manufacture | |
IE60288B1 (en) | "Porous ptfe" | |
US3642976A (en) | Solid phase hydrostatic extrusion of a filled thermoplastic billet to produce orientation | |
KR102652700B1 (en) | Unsintered expanded polytetrafluoroethylene composite membranes having dimensional stability | |
DE2414396A1 (en) | FOAM | |
Webber et al. | Novel variations in the microstructure of the auxetic microporous ultra‐high molecular weight polyethylene. Part 1: Processing and microstructure | |
DE2209608C2 (en) | Process for the production of moldings from thermoplastic material | |
WO2004054709A1 (en) | Sorbents with standard pore sizes | |
Beloshenko et al. | Shape-memory effect in polymer composites with a compactible filler | |
Song et al. | Energy of compressed aluminum foam | |
JPS63160816A (en) | Method of forming polymer | |
CA1092316A (en) | Fiber-orientated composites |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AK | Designated states |
Kind code of ref document: A1 Designated state(s): CA JP US |
|
AL | Designated countries for regional patents |
Kind code of ref document: A1 Designated state(s): AT BE CH DE DK ES FR GB IT LU NL SE |
|
WWE | Wipo information: entry into national phase |
Ref document number: 1990910845 Country of ref document: EP |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2063396 Country of ref document: CA |
|
WWP | Wipo information: published in national office |
Ref document number: 1990910845 Country of ref document: EP |
|
WWR | Wipo information: refused in national office |
Ref document number: 1990910845 Country of ref document: EP |
|
WWW | Wipo information: withdrawn in national office |
Ref document number: 1990910845 Country of ref document: EP |