Thermoplastic splint or cast

Abstract

Polydiene sheet material useful as a body supporting member such as a cast or splint, heat softenable at a higher than body temperature, but slowly recrystallizable or hardenable below about 40° C., treated by distributing throughout the substance small pores, perforations or surface irregularities as by foaming all or only one surface portion of the sheet material, particularly texturing, knurling, pocking or cratering the surface to be placed adjacent to the body member to be encased to allow moisture and/or air transfer away from the enclosed body surface.

What is claimed is: 
     
       1. A process of forming a body supporting member such as a cast, splint or the like, comprising warming a sheet of crystalline thermoplastic polymer having a thickness in the range of about 2 to 200 mils, to a temperature in the range of about 60° to 110° C. for a heat softening period sufficient to convert the total crystalline substance to a softened, amorphous form, said heat-softened sheet of polymer developing a hysteresis to have a setting time substantially delayed to remain soft and amorphous below the crystalline setting temperature, whereby it may be cooled to a comfortable body temperature below about 40° C., whereby the sheet may be formed and shaped for use as a body supporting cast or splint, .[.said sheet having at least its surface adjacent to the body member to be protected deformed to include surface irregularities capable of absorbing and interrupting continuous moisture films that may be developed upon the body member to be protected, said surface irregularities consisting of cup-like depressions, knurled depressions, texturing, foam and close spaced perforations which are evenly distributed throughout the surface of the said plastic and the like,.]. cutting said softened sheet to dimensional size and manually shaping, wrapping and forming said sheet .[.upon.]. .Iadd.at a comfortable body temperature in the form of .Iaddend.the body member to be supported .[.and protected at said comfortable body temperature with the surface irregularities disposed adjacent to the body member enclosed,.]. and maintaining the entire supported assembly substantially immobile until the sheet sets by crystallization to a rigid body support. 
     
     
       2. A process of forming a body supporting member such as a cast, splint or the like, comprising warming a sheet of polymer consisting of a conjugated diolefine compound having a thickness in the range of about 2 to 200 mils, setting by crystallization at temperatures below about .[.50° C..]. .Iadd.40° C..Iaddend.and being heat softened and pliable at raised temperatures in the range of 60° C. to 110° C., said sheet having a hysteresis whereby it may be cooled substantially below its normal crystallization point, to lower temperature in a comfortable contact with a body member at a temperature below about 40° C., whereby it may be heat softened, deformed and shaped for use as a body supporting medical cast or splint, said sheet having at least its surface adjacent to the body member to be protected deformed to include surface irregularities capable of absorbing and interrupting continuous moisture films that may be developed upon the body member to be protected, said surface irregularities consisting of cup-like depressions, knurled depressions, texturing, foam and .[.closed space.]. perforations which are evenly distributed throughout the surface of said plastic and the like, cutting said softened sheet to dimensional size and manually shaping, wrapping and forming said sheet upon the body member to be supported and protected at said comfortable body temperature with the surface irregularities disposed adjacent to the body member .[.enclosed.]., and maintaining the entire supported assembly substantially immobile until the sheet sets by crystallization to a rigid body support. 
     
     
       3. A process of forming a body supporting member such as a cast, splint or the like, comprising warming a sheet of crystalline thermoplastic polymer selected from the group consisting of transpolyisoprene and transpolychloroprene having a thickness in the range of about 2 to 200 mils, to a temperature in the range of about 60° C. to 110° C. for a heat softening period sufficient to convert the total crystalline substance to a softened amorphous form, said heat softened sheet of polymer developing a hysteresis to have a setting time substantially delayed to remain soft and amorphous well below the crystalline setting temperature, whereby it may be cooled to a comfortable body temperature without immediately setting, cooling said heat softened plastic sheet to a comfortable body temperature below about 40° C., whereby the sheet may be formed and shaped for use as a body supporting cast or splint, said sheet having at least its surface adjacent to the body member to be protected deformed to include surface irregularities capable of absorbing and interrupting continuous moisture films that may be developed upon the body member to be protected, said surface irregularities consisting of cup-like depressions, knurled depressions, texturing, foam and close spaced perforations which are .[.evenly.]. distributed throughout the surface of said plastic and the like, cutting said softened sheet to dimensional size and manually shaping, wrapping and forming said sheet upon the body member to be supported and protected at said comfortable body temperature with the surface irregularities disposed adjacent to the body member .[.enclosed.]., and maintaining the entire supported assembly substantially immobile until the sheet sets by crystallization to a rigid body support. 
     
     
       4. The process as defined in claim 2 wherein the sheet material has surface irregularities comprising a foamy texture formed by generation of gases in the sheet material adjacent to at least one surface prior to applying said sheet material to the body member to be supported. 
     
     
       5. The process as defined in claim 2 wherein the surface irregularities comprise foam formed by generation of gases extending throughout the body of said sheet material from surface to surface prior to applying said sheet material to the body member to be supported. 
     
     
       6. The process as defined in claim 2 wherein the sheet material includes a foaming agent activatable with heat so that upon warming said sheet material for softening sufficient to apply the said material as a body support member the foaming agent is simultaneously activated to convert at least one surface of the sheet material to a foamy mixture prior to applying said sheet material to the body member to be supported.