Multi-layered sheet

#This invention relates to multi-layered sheet materials used in making, e.g., foam products.

#In making foam automobile seat cushions, for example, a multi-layered sheet is bonded to a finish fabric. The finish fabric is then cut and sewn to form a seat cushion cover for encasing a foamed-in-place pad. Prior to forming the foam pad, the outer layer of the multi-layered sheet is peeled away, exposing an inner film layer. A foaming liquid is then injected into a mold lying adjacent the exposed inner layer. The foam fills the mold and bonds to the film layer to form the foam pad.

#One such multi-layered sheet, produced by Atochem in Germany, is manufactured by co-blown extrusion of urethane and polyethylene layers. The urethane and polyethylene layers are extruded through concentric circular dies to produce two cylindrical layers which exit the dies in an upward direction. At a point above where they exit the dies, the two layers are pressed together with nip rolls and flattened into four layers. The edges are split and the four layers are separated into two multi-layer sheets.

#FIG. 1 is a cross-sectional view of a fragment of upholstery material attached to a two-layer sheet.

#FIG. 2 is a plan view of patterns cut from the material shown in FIG. 1 for making an automobile seat.

#FIG. 3 is a perspective view of a shell of a seat cushion formed of the patterns of FIG. 2 and partially turned inside-out.

#In the invention, a two-layer sheet may be used in making, for example, foam-in-place products such as automobile seat cushions.

#Referring to FIG. 1, upholstery 10 for an automobile seat cushion is bonded by flame lamination or adhesive lamination to two-layer sheet 12 at interface 14. Upholstery 10 includes a finish fabric 16 bonded to a preformed foam layer 18. Two-layer sheet 12 has a urethane film 20 which is lightly bonded to (but separable from) a polyethylene layer 22. Urethane film 20 is substantially pin-hole free and thus provides an air-tight vacuum barrier and also a liquid foam chemical barrier during the formation of a foam pad for the finished cushion. Polyethylene layer 22 protects the urethane film during preliminary processing stages before the pad is foamed-in-place. The sheet and its layers will be discussed in more detail below.

#Referring to FIG. 2, to make the seat cushion, pattern pieces 30 are cut from a bolt of the bonded upholstery/two-layer sheet. Pattern pieces 30 include a front piece 32, side pieces 34 and 36, a top piece 38, and a rear piece (not shown). These pieces are sewn together with stitches 40 to form seat cushion shell 44, as shown in FIG. 3. Shell 44 is then turned inside out, FIG. 3, so that surface 46 is exposed on the outside of the shell and the finish fabric is hidden on the inside of the shell. Next, the polyethylene layer 22 is peeled away, leaving urethane film 20 as the exposed material. As shown in FIG. 4, modified shell 44 (not shown to scale) is then positioned over mold 50.