Shaped article with thermoformed composite sheet

• US 5,635,271 A
• Filed: 09/02/1994
• Issued: 06/03/1997
• Est. Priority Date: 02/20/1990
• Status: Expired due to Fees

• Current Assignee: Xymid LLC
• Original Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Inventors: Zafiroglu, Dimitri P.
• Primary Examiner(s): Ahmad, Nasser
• Application Number:
  US08/193,007
• Time in Patent Office: 1,005 Days
• Field of Search: 428/309.9, 428/314.4, 428/319.7, 428/102, 428/230, 264/46.4, 264/45.3
• US Class Current: 428/102
• CPC Class Codes: B29C 51/145 having at least one layer of textile or fibrous material combined with at least one plastics layer
• CPC Class Codes: B29K 2033/12 Polymers of methacrylic acid esters, e.g. PMMA, i.e. polymethylmethacrylate
• CPC Class Codes: B29K 2995/0097 Thickness
• CPC Class Codes: B32B 2333/12 Polymers of methacrylic acid esters, e.g. PMMA, i.e. polymethylmethacrylate
• CPC Class Codes: B32B 27/12 next to a fibrous or filamentary layer
• CPC Class Codes: B32B 27/308 comprising acrylic (co)polymers
• CPC Class Codes: B32B 5/06 characterised by a fibrous or filamentary layer mechanically connected, e.g. by needling to another layer, e.g. of fibres, of paper
• CPC Class Codes: B32B 7/12 using interposed adhesives or interposed materials with bonding properties
• CPC Class Codes: D06N 3/0031 Retractable fibres; Shrinking of fibres during manufacture
• CPC Class Codes: D06N 7/00 Flexible sheet materials not otherwise provided for, e.g. textile threads, filaments, yarns or tow, glued on macromolecular material paper-based or board-based structures for surface covering D21H27/20
• CPC Class Codes: Y10T 428/1362 Textile, fabric, cloth, or pile containing [e.g., web, net, woven, knitted, mesh, nonwoven, matted, etc.]
• CPC Class Codes: Y10T 428/1366 Textile, fabric, cloth, or pile is sandwiched between two distinct layers of material unlike the textile, fabric, cloth, or pile layer
• CPC Class Codes: Y10T 428/24033 including stitching and discrete fastener[s], coating or bond
• CPC Class Codes: Y10T 428/24996 With internal element bridging layers, nonplanar interface between layers, or intermediate layer of commingled adjacent foam layers
• CPC Class Codes: Y10T 428/249976 Voids specified as closed
• CPC Class Codes: Y10T 428/249992 Linear or thermoplastic
• CPC Class Codes: Y10T 442/469 Including a foamed layer or component
• CPC Class Codes: Y10T 442/59 At least three layers
• CPC Class Codes: Y10T 442/601 Nonwoven fabric has an elastic quality
• CPC Class Codes: Y10T 442/647 Including a foamed layer or component
• CPC Class Codes: Y10T 442/667 : Needled

Abstract

An improved shaped article comprising a thermoformed composite sheet, which is a layer of thermoplastic polymer attached to a surface of a lightweight conformable fabric, the other surface of the fabric being attached to a layer of rigid foam, provides the article with improved wall thickness uniformity and impact resistance.

Claims

1. A shaped article which comprises a thermoformed composite sheet that has an outer layer of thermoplastic polymer attached to a first surface of a relatively lightweight conformable fabric layer, characterized by the composite sheet having a thermoformed area expansion factor of at least 1.5, the conformable fabric amounting to no more than 20% of the weight of the thermoplastic layer, the surface of the fabric opposite the first surface being attached to a layer of rigid foam having a specific volume in the range of 3 to 30 cm³ /gram and a thickness of at least 2.5 cm and the fabric layer being a nonwoven fabric stitchbonded with elastic threads, or a needled felt or a knitted fabric.

2. A shaped article in accordance with claim 1 wherein the composite sheet is made with a fabric layer having a specific volume of at least 5 cm³ /gram, a weight in the range of 100 to 500 g/m² and a conformability at 180°

C. in the range of 2 to 9, the composite sheet is thermoformed with an expansion factor of at least 2.0, the fabric layer is a nonwoven fabric stitchbonded with elastic threads and the foam is generated in-situ.

3. A shaped article in accordance with claim 2 wherein, the thermoplastic polymer is of a methylmethacrylate homopolymer or copolymer and the foam is of polyurethane polymer.

4. A shaped article in accordance with claim 3 wherein the expansion factor is in the range of 3 to 6, the conformability is in the range of 4 to 7 and the fabric weight is in the range of 5 to 15% of the total weight of the composite sheet.