WO2013001083A1

WO2013001083A1 - Thermoplastic sheet material provided with a support layer and use thereof

Info

Publication number: WO2013001083A1
Application number: PCT/EP2012/062779
Authority: WO
Inventors: Jean-Michel Anthony
Original assignee: Tomtec Nv
Priority date: 2011-06-30
Filing date: 2012-06-29
Publication date: 2013-01-03

Abstract

The current invention concerns a thermoplastic sheet material (1) with a support fabric and the use thereof. More in particular the invention relates to a thermoplastic sheet material (1), comprising a thermoplastic composition layer (3) having an upper surface (4) and lower surface (5) and a support layer (6) bonded on one surface of the thermoplastic composition layer (3). Such material can be used as medical braces or face masks.

Description

THERMOPLASTIC SHEET MATERIAL PROVIDED WITH A SUPPORT LAYER AND

USE THEREOF

TECHNICAL FIELD

The present invention concerns a thermoplastic sheet material comprising two superimposed layers, namely a thermoplastic layer and a support layer. More in particular, it concerns a thermoplastic sheet material suitable for molding at low temperatures on a part of the body of a person.

BACKGROUND

Thermoplastic materials are well-known in their medical use as shaped articles for the purpose of immobilizing an anatomical region of the body. These materials are also used in the medical field to manage dermal scarring from traumatic injuries such as burns, particularly of the face. The contours of the mold may be sculpted and the thermoplastic may be reshaped from time to time as to guide the patient's soft tissue into forming desired contours. Examples of thermoplastic material braces can be found in US 6,056,713 and US 5,891,071.

US 6,056,713 relates to an ankle brace constructed of a heat moldable thermoplastic material that can be formed in place around a patient's injured ankle. The moldable thermoplastic material is shaped in a manner that produces medial and lateral extensions for covering the medial and lateral malleoli of a patient's foot. A concave recess is formed between the medial and lateral extensions to improve strength and reduce cracking of the thermoplastic brace. A non-stretchable strap holds the conformable ankle brace in position against the ankle and leg. A stretchable strap secures the medial and lateral extensions or splints in place over the medial and lateral malleoli. Strategically placed pads of hook-textured material, that mate with looptype material on the fastening straps hold them in place on the ankle brace. Optionally, the moldable custom-fitted ankle brace can be held in place with athletic tape.

US 5,891,071 deals with a leg brace and method for forming thereof. The brace includes a frame formed of at least a thermoplastic material. A harness is fixed to the frame, the harness being retained adjacent a user's leg during use. The leg brace may be further formed with a tibial restricting portion running along and substantially parallel to the medial shaft of a user's tibia during use, thereby preventing any unwanted movement or rotation of the user's tibia. The brace is formed by forming a brace core of a mixture of a thermoplastic material and a blowing agent and then placing a composite material in contact with the core. Next, the core and composite material are heated in a mold to a temperature sufficient to allow the thermoplastic material to become molten, causing the blowing agent to expand and force the composite material against an interior wall of the mold cavity and to form a thermoplastic cellular core. Next, after cooling, the leg brace is reheated to a temperature sufficient to allow the thermoplastic material to become malleable, but not sufficient to destroy the structural integrity of the leg brace, and then the leg brace is reshaped for a custom fit.

These thermoplastic materials from the prior art soften a temperatures higher than 65°C. At these temperatures, the plastic thermoplastic material cannot be placed on the skin of a person. Therefore, these materials are formed on a mold of the part of the body were the thermoplastic material will be applied. This is time and material consuming and the resulting thermoplastic material will be less accurately formed compared to directly molding on said part of the person.

Another problem arises with the handling of the thermoplastic material when it is in a plastic state. Usually, the thermoplastic material is softened in warm water. When taking the material out of the water by manual handling, unwanted deformations of the thermoplastic material may occur. Correcting for these deformations is time consuming and in this time, the thermoplastic material cools down and becomes more rigid.

A third problem occurs when wearing a thermoplastic material, especially on sensitive skin such as the skin of the face. The direct contact of the thermoplastic material on the skin causes complaints or even skin irritation. Face masks for supporting the administration of medicines for example have to be worn for a long time and therefore need optimal comfort.

The present invention aims to resolve at least some of the problems mentioned above.

The invention thereto aims to provide a thermoplastic material that is moldable at low temperatures, minimizes unwanted deformations during the plastic phase and provides a comfortable material for wearing on the body. SUMMARY OF THE INVENTION

The present invention provides a thermoplastic sheet material, comprising a thermoplastic composition layer and a bonded support layer comprising an elastic fabric.

In another embodiment, the present invention provides a thermoplastic sheet material, comprising a thermoplastic composition layer and a bonded support layer comprising a hydrophilic foam.

In a second aspect, the present invention provides a thermoplastic sheet material, comprising a thermoplastic composition layer and a bonded support layer comprising a coated or impregnated elastic fabric.

In a further preferred embodiment, the present invention provides a thermoplastic sheet material, comprising a thermoplastic composition layer and a bonded support layer comprising a coated or impregnated hydrophilic foam.

In a third aspect, the present invention provides a method for molding anatomical shaped medical articles, in particular face masks and braces. In a further aspect, the present invention provides a method of treating burns and/or dermatologic scars.

DESCRIPTION OF FIGURES Figure 1 shows a top view of a preferred embodiment of a thermoplastic sheet material according to the invention.

Figure 2 illustrates a cross section A-A of a preferred embodiment of a thermoplastic sheet material bonded with a coated support layer according to the invention.

Figure 3 depicts a cross section A-A of a preferred embodiment of a thermoplastic sheet material bonded with an uncoated support layer according to the invention. Figure 4 depicts a preferred embodiment of the method of softening a thermoplastic sheet material according to the invention. Figure 5 shows a preferred embodiment of an ankle brace made of a thermoplastic sheet according to the invention.

Figure 6 shows a preferred embodiment of a face mask made of a thermoplastic sheet material according to the invention.

Figure 7 depicts the preferred embodiment of the production process of a thermoplastic sheet material according to the invention.

DETAILED DESCRIPTION OF THE INVENTION Unless otherwise defined, all terms used in disclosing the invention, including technical and scientific terms, have the meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. By means of further guidance, term definitions are included to better appreciate the teaching of the present invention. "A", "an", and "the" as used herein refers to both singular and plural referents unless the context clearly dictates otherwise. By way of example, "a compartment" refers to one or more than one compartment.

"About" as used herein referring to a measurable value such as a parameter, an amount, a temporal duration, and the like, is meant to encompass variations of +/- 20% or less, preferably +/-10% or less, more preferably +/-5% or less, even more preferably +/-1% or less, and still more preferably +/-0.1% or less of and from the specified value, in so far such variations are appropriate to perform in the disclosed invention. However, it is to be understood that the value to which the modifier "about" refers is itself also specifically disclosed.

"Comprise," "comprising," and "comprises" and "comprised of" as used herein are synonymous with "include", "including", "includes" or "contain", "containing", "contains" and are inclusive or open-ended terms that specifies the presence of what follows e.g. component and do not exclude or preclude the presence of additional, non-recited components, features, element, members, steps, known in the art or disclosed therein.

The recitation of numerical ranges by endpoints includes all numbers and fractions subsumed within that range, as well as the recited endpoints. The expression "% by weight" (weight percent), here and throughout the description unless otherwise defined, refers to the relative weight of the respective component based on the overall weight of the formulation. As used herein the terms "thermoplastic sheet material" and "thermoplastic sheet" are synonyms.

As used herein the terms "brace" and "splint" or "cast" are used as synonyms. In a first aspect, the present invention concerns a thermoplastic sheet material (1), comprising :

- a thermoplastic composition layer (3) having an upper surface (4) and a lower surface (5); and

- a support layer (6) bonded on one surface of the thermoplastic composition layer (3), comprising an elastic fabric.

In a preferred embodiment, the present invention concerns a thermoplastic sheet material (1), comprising :

- a support layer (6) bonded on one surface of the thermoplastic composition layer (3), comprising a hydrophilic foam.

Thermoplastic composition layer

By the term "thermoplastic composition layer" 1 as used herein, is understood a layer comprising a thermoplastic composition 3 having two surfaces: an upper surface 4 and a lower surface 5. The thermoplastic composition 3 may be chosen from the group of polycaprolactone and polyurethane or any combination thereof.

The polyurethane may be present in an amount of 0%, 10%, 20%, 30%, 40% or 50% (% by weight), preferably 20% to 40% or a value in the range between any two of the aforementioned values, most preferably 30%. The polycaprolactone may be present in an amount of 60%, 70%, 80%, or 90% (% by weight) or a value in the range between any two of the aforementioned values, preferably 60% to 80%, most preferably 70%. Typically, there will be more polycaprolactone than polyurethane which polycaprolactone lowers the temperature at which the sheet deforms. The ratio of polycaprolactone: polyurethane (weight: weight) may be 5 : 1 , 4: 1 , 3 : 2, 3 : 1 , 2.3 : 1 , 2: 1 preferably 2.3 : 1.

The molecular weight of the polyurethane may be equal to or less than 10000, 20000, 30000, 40000, 50000, 60000, 70000, 80000, 90000, 100000, 120000, 140000, 150000 or a value in the range between any two of the aforementioned values, preferably between 10000 and 100000. Polyester polyurethane is the preferred polyurethane. The molecular weight of the polycaprolactone may be 10000, 20000, 30000, 40000, 50000, 60000, 70000, 80000, 100000, 200000, 300000, 400000, 500000 or a value in the range between any two of the aforementioned values, preferably between 10000 and 60000, more preferably between 37000 and 500000. Caprolactone polyester polyurethane is particularly suitable, which polyurethane may be obtained by reacting isocyanate and polycaprolactone-based polyester. Such a caprolactone polyester polyurethane is commercially available as a granulate. The melting point of said polycaprolactone polyester polyurethane lies between 190°C and 210°C. By adding the polycaprolactone, also preferably in granulate form, a thermoplastic composition is obtained that is distortable and moldable at a temperature of about 69°C and remains distortable by cooling down about 30°C.

At this temperature, the thermoplastic composition layer 3 may be stretched at least up to twenty times the original length thereof. In the hardened condition, the thermoplastic material is rigid and has a memory effect that, after heating, returns to the shape formed on cooling. It is non-elastic in the hardened condition. The thermoplastic composition layer of the present invention is used to be directly molded on a human body part thereby obtaining anatomical shaped medical articles (corresponding to the thermoplastic composition layer at the hardened condition). The anatomical shaped medical articles obtained from thermoplastic compositions of the prior art and/or available on the market deform and return to the layer status when they are subject to heat treatment. This is not the case of the thermoplastic material of the present invention which is characterized by a memory effect. Said memory effect is very advantageous as it avoids deformation and/or a return to the layer status of the hardened thermoplastic material and hence of the anatomical shaped medical articles after certain treatments, such as sterilization and/or washing at high temperatures (from 85 to 100°C). The thermoplastic composition layer 3 may have a thickness of 0.8 mm, 1.0 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2.0 mm, 2.1 mm, 2.2 mm, 2.3 mm, 2.4 mm, 2.5 mm, 2.6 mm, 2.7 mm, 2.8 mm, 2.9 mm, 3.0 mm, 3.1 mm, 3.2 mm, 3.3 mm, 3.4 mm, 3.5 mm, 3.6mm, 3.7 mm, 3.8 mm, 3.9 mm, 4.0 mm, 4.1 mm, 4.2 mm, 4.3 mm, 4.4 mm, 4.5 mm, 4.6mm, 4.7 mm, 4.8 mm, 4.9 mm, 5.0 mm, 5.1 mm, 5.2 mm, 5.3 mm, 5.4 mm, 5.5 mm, 5.6 mm, 5.7 mm, 5.8 mm, 5.9 mm or 6.0 mm or a value in the range between any two of the aforementioned values.

In one embodiment, the thermoplastic composition layer 3 comprises between 1% to 40% (weight %) of microspheres of non-metallic, heat-accumulating material which is especially suited for heating in a micro-wave oven. Preferred are glass microspheres with a diameter between 20μηη and 800μηη. A coloring agent may be added to the composition. The thermoplastic composition layer 3 is preferably perforated to increase breathability. The perforations 2 may have a diameter of 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2.0 mm or a value in the range between any two of the aforementioned values.

A non-limiting example of a thermoplastic composition that can be used in the current invention is Turbocast^® (T Tape Company BV).

Support layer

By the term "support layer" 6 is meant a layer that comprises a different composition as the thermoplastic composition layer 3 and supports the thermoplastic composition layer 3. In a preferred embodiment of the invention, the thermoplastic composition layer 3 comprises a support layer 6 only on one of its surfaces 4 or 5. In another embodiment of the invention, the thermoplastic composition layer 3 comprises support layers 6 on both of its surfaces 4 and 5.

In a preferred embodiment of the invention, the support layer 6 comprises an elastic fabric. More by preference, the support layer 6 comprises an elastic fabric comprising yarns that are suitable for continuously bonding by heat to a thermoplastic material.

In another preferred embodiment of the invention, the support layer 6 comprises a breathable foam, preferably a hydrophilic foam, more preferably a breathable hydrophilic foam, most preferably a breathable hydrophilic open cell foam. More by preference, the support layer 6 comprises polyurethane open cell foam suitable for continuously bonding by heat to a thermoplastic material. In another preferred embodiment of the invention, the support layer 6 comprises foam, preferably a closed cell foam, more preferably a hydrophilic foam closed cell foam, most preferably a flexible hydrophilic foam closed cell foam.

By the term "continuously bonding" is meant that 100% of the surface area of one side of the support layer 6 is bonding on 100% of the surface area of one side of the thermoplastic composition layer 3.

By the term "bonding by heat" is meant that the bonding reaction is caused by heat only, no additional adhesive or glue is required.

By the term "breathable" it is meant that air can pass through the fabric and/or the material.

As used herein, the term "breathable" also refers to a material which is permeable to water vapor. Breathable fabrics of the present invention have a water vapor transmission rate WVTRs comprised between 1 and 2000 g/m²/24 hours, preferably between 2 and 1800 g/m²/24 hours, more preferably between 3 and 1600 g/m²/24 hours, most preferably between 3 and 1400 g/m²/24 hours. By the term "breathable foam" it is meant a foam through which air passage is possible.

In another embodiment of the invention, the elastic fabric has an elasticity comprised between 0.5% and 100% in the x and/or y direction. More by preference, the elastic fabric has an elasticity comprised between 1% and 15% in the x and/or y direction. Most by preference, the elastic fabric has an elasticity comprised between 2% and 5% in the x and/or y direction.

The support layer 6 is a flat sheet-like product which has very small height compared to the dimensions of length and width. The x and y direction are defined to be respectively the length and the width of the support layer, whereas the z direction is defined as the height. An elasticity of 100% in the x direction means that the support layer will elongate to twice its original length upon applying an external force on said support layer and after said external force is removed, the support layer will return to its original length without loss of material properties. The term "elasticity in x direction" can be expressed as the ratio of the elongation upon application of an external force to the initial length of the material in which said force is applied. This definition holds mutatis mutandis for "elasticity in the y direction".

In one embodiment of the invention, the elasticity of the elastic fabric is equal in x and y direction. In another embodiment of the invention, the elasticity in x and y direction is different, more in particular is the elasticity in y direction comprises between 10%- 90% of the elasticity of the x direction. By preference is the elasticity in y direction comprised between 20%-70% of the elasticity of the x direction. Such material will be suitable for molding a face mask in which the deformation in x direction will be more detailed than the deformation in y direction. This is because the longest dimension, being the length x, of the sheet 1 will be used to cover the width of a face.

By the term "elastic fabric" is meant a fabric comprising an elastic yarn or a combination of different elastic yarns. In a preferred embodiment of the invention, the support layer 6 comprises a woven fabric whereby the warp and/or weft yarn are elastic thread. In another embodiment of the invention, the elastic fabric is a knitted fabric. The elastic fabric can be made according to the knowledge available in the prior art. When the support layer 6 is a knitted material, it comprises by preference a polyamide-based knitted fabric material with a thickness of between 0.05 and 1.5 mm. In one embodiment of the invention, the knitted fabric material is formed from a yarn comprising between 80 % to 95 % polyamide, and between 5 % and 15 % elastane, preferably comprising 90 % polyamide and 10 % elastane.

Suitable yarns for the elastic fabric of the support layer 6 comprise but are not limited to: polyamide, elastane, polyester, elasticated neoprene and styrene rubber or any other elasticated material suitable for weaving or knitting. In a preferred embodiment of the invention, the support layer is suitable for freely following the deformations of the thermoplastic composition layer 3, during and after molding of the thermoplastic sheet material. The support layer will give support to the thermoplastic sheet material 1 when it is in moldable phase but during hardening and molding of the thermoplastic composition, the support layer freely follows the expansions and contractions of the thermoplastic composition. When the thermoplastic composition is rigid, the support layer is fully adapted to the form of the thermoplastic sheet material 1.

In yet another preferred embodiment of the invention, the support layer 6 comprises hydrophiiic foam, preferably a hydrophiiic open cell foam. More by preference, the support layer 6 comprises hydrophiiic open cell foam suitable for continuously bonding to a thermoplastic material. The bonding may be heat-bonding or performed using an adequate adhesive. The hydrophiiic open cell foam is selected from the group of cellular polyvinyl chloride, polyolefins, polystyrene, styrene-acrylonitrile copolymer, styrene-methylmethacrylate copolymer. Preferably, said hydrophiiic open cell foam is polyurethane open-cell foam. In a preferred embodiment of the invention, the thermoplastic composition layer 3 comprises hydrophiiic open cell foam only on one of its surfaces 4 or 5. In another embodiment of the invention, the thermoplastic composition layer 3 comprises hydrophiiic open cell foam on both of its surfaces 4 and 5. The density of said hydrophiiic open cell foam is comprised between 1 kg/m³ and 500, preferably between 10 and 450 kg/m³, more preferably between 20 and 400 kg/m³. The hardness of said hydrophiiic open cell foam is comprised between 0.5 and 30 kPa, preferably between 1 and 25 kPa, more preferably between 1.3 and 20 kPa. The cell size of said hydrophiiic open cell foam, measured by scanning electron microscopy, is comprised between 0.05 and 5 mm, preferably between 0.08 and 4 mm, more preferably between 0.1 and 3 mm. Density, hardness and cell size of the hydrophiiic open cell foam can be measured by techniques known to a person skilled in the art. The hydrophiiic open cell foam can be of any color, preferably the hydrophiiic open cell foam have white color.

In one embodiment of the invention, the support layer 6 is uncoated. Such embodiment is depicted in Figure 3.

In a second aspect, the invention relates to a thermoplastic sheet material 1, comprising a thermoplastic composition layer 3 bonded with a support layer 6, comprising a coated or impregnated elastic fabric. In another aspect, the invention relates to a thermoplastic sheet material 1, comprising a thermoplastic composition layer 3 bonded with a support layer 6, comprising a coated or impregnated hydrophilic cell foam, preferably a coated or impregnated polyurethane open-cell foam.

In an embodiment of the invention, the support layer 6 is coated with a polymer as in Figure 2. By preference, the polymer is chosen from the group comprising but not limited to elastomers such as ethylene-vinyl acetate, ethylene propylene rubber, silicone rubber; polyester, breathable polyurethane; and synthetic silicone. The support layer 6 may be coated on one side or on both sides. The advantage of using polymer coating 7 is that when it is applied to an elastic fabric, the coating 7 will not alter the elastic properties of said elastic fabric. The coating 7 will follow the expansion and contraction of the fabric freely. In another preferred embodiment of the invention, the elastic fabric is coated with silicone-foam, which can be made of synthetic silicone or natural silicone. Such foam has the advantage that it provides high flexibility and permeability.

In another preferred embodiment of the invention, the hydrophilic cell foam is coated with silicone-foam, which can be made of synthetic silicone or natural silicone. The silicone-foam is breathable and has the advantage that it provides high flexibility and permeability. Moreover, when a silicone-foam is applied to a hydrophilic cell foam, the coating 7 will not alter the breathability of said hydrophilic cell foam and thereby the breathability of the thermoplastic sheet material. In one embodiment of the invention, the coating 7 optionally comprises a backing layer which is removed before application to the subject. The backing layer reversibly adheres to the silicone layer intended for contact with the skin of the subject. The backing layer may be made of any suitable material such as, for example, polyethylene, polythene or other polymeric substance. According to an aspect of the invention, the backing layer is smooth, or is regularly patterned with pits or grooves.

In another preferred embodiment of the invention, the coating 7 optionally comprises a backing layer or liner which is removed before application to the subject. The backing layer reversibly adheres to the silicone layer intended for contact with the skin of the subject. Said silicone layer is sticking to the skin of the subject. The silicone layer can be a silicone pressure sensitive adhesive. The backing layer may be made of any suitable material such as, for example, polyethylene, polythene or other polymeric substance. According to an aspect of the invention, the backing layer is smooth, or is regularly patterned with pits or grooves.

In another embodiment of the invention, the elastic fabric can be impregnated. By preference, the elastic fabric is impregnated with a polymer. More by preference, the polymer is chosen from the group comprising but not limited to elastomers such as ethylene-vinyl acetate, ethylene propylene rubber, silicone rubber; polyester; synthetic silicone.

In another embodiment of the invention, the hydrophilic foam can be impregnated. By preference, the hydrophilic foam is impregnated with a polymer. More by preference, the polymer is chosen from the group comprising but not limited to elastomers such as ethylene-vinyl acetate, ethylene propylene rubber, silicone rubber; polyester; synthetic silicone.

In a preferred embodiment of the invention, the support layer 6 is a silicone-coated elastic fabric whereby the silicone-coating is applied on the surface which is not bonded to the thermoplastic composition layer 3.

In a preferred embodiment of the invention, the support layer 6 is a silicone-coated hydrophilic foam whereby the silicone-coating is applied on the surface which is not bonded to the thermoplastic composition layer 3.

The silicone coating can form ridges on the support layer 6 or it can be smooth. The silicone can be coated in such a way as to form a continuous layer or, in contrast, to produce a network of textile fibers on which it is deposited following the natural holes formed by the network of the weave. The silicone coating can be applied in an amount of 5g/m² to 25g/m², preferably from 7g/m² to 20g/m². In another embodiment of the invention, the elastic fabric is covered with a silicone coating in an amount between 25g/m² to 1000g/m².

A silicone-coated elastic fabric and silicone-coated hydrophilic foam have the advantage that the silicone will act as a friction restraining material. Silicone-coated fabrics, such as textile, are known in the prior art and provide comfort to the wearer when the silicone coated side is the skin facing side of the fabric. Silicone reduces the friction between a textile and the skin. Another advantage of silicone is its heat resistance capacity; this will buffer the heat of the thermoplastic sheet material 1 when it is directly molded on the skin. Another advantage of silicone is that it is vapor- permeable. An embodiment of the invention in which the elastic fabric is silicone- coated is suitable to create a micro-climate where it is applied. Such micro-climate will allow for an accelerated healing of burns and or dermatologic scars and it will lessen permanent scars on the skin.

In a preferred embodiment, the present invention provides a breathable thermoplastic sheet comprising a thermoplastic composition layer 3, a support layer 6 bonded on one surface of the thermoplastic composition layer 3. The thermoplastic composition layer 3 is preferably provided with perforations. Said support layer 6 is preferably polyurethane open cell foam which is coated and/or impregnated with a breathable silicone elastomer. Thus, the thermoplastic sheet exhibit good breathability and improved wear comfort which is advantageous for the user.

The thickness of the support layer 6 is equal to or less than 0.025 mm, 0.05 mm, 0.06 mm, 0.08 mm, 0.1 mm, 0.5 mm, 0.8 mm, 1 mm, 1.2 mm, 1.5 mm, 2.0 mm, 2.5 mm, 3.0 mm, 3.5 mm, 4.0 mm, 4.5 mm, 5.0 mm or a value in the range between two of the aforementioned values. The thickness will depend on the thickness of the elastic fabric or the hydrophilic foam, and the coating. A silicone-foam coated elastic fabric will have higher thickness than a non-foam polymer coating. Similarly, a silicone-foam coated hydrophilic foam will have higher thickness than a non-foam polymer coating.

The support layer 6 may be disposed with a plurality of perforations to increase breathability. The perforations may have a diameter of 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm or 1mm or a value in the range between two of the aforementioned values. Such perforations also enhance the elasticity properties of the support layer 6, thereby assuring that the support layer 6 freely follows the expansions and contractions of thermoplastic composition layer 3.

Bonding of support layer on thermoplastic composition layer

The support layer 6 is disposed on the thermoplastic composition layer 3 and bonded to it during the production process of the thermoplastic sheet material 1. The process is similar for uncoated fabrics and coated fabrics. In a preferred embodiment, the support layer 6 is heat-bonded to the thermoplastic composition layer 3. In a preferred embodiment of the production process as shown in Figure 7, a preformed plate of thermoplastic composition 19 is put on a conveyor belt 15. In the preferred case that the support layer is a fabric, the fabric 17 is provided on a roll 16 positioned above the conveyor belt 15. The fabric 17 is unwind from the roll 16 at a speed so that it follows the movement of said thermoplastic composition plate 19 and covers one surface of said plate 19. A guiding element 18 aligns the fabric 17 with the thermoplastic plate 19 and cuts the fabric 17 when the plate 19 is covered over its total length. The covered thermoplastic composition plate 21 is then transported further on the conveyor belt 15 and passes under a set of heating elements 20 which blow air of a temperature of 70°C-120°C depending on the thermoplastic composition. At this temperature, the thermoplastic plate 21 is melted and bonds to the support layer by virtue of the adhesive property of the thermoplastic plate in its melted condition and the yarns of the elastic fabric or the hydrophilic foam of the support layer 6. Additional adhesives or glue can be added but are not required.

In a preferred embodiment of the invention, the support layer 6 is heat-bonded on the thermoplastic composition layer 3. By the term "heat-bonded" is meant that the bonding reaction is caused by heat only, no additional adhesive or glue is required. The use of polyurethane open cell foam as a support layer 6 is advantageous as an improved thermo-fusion or heat-bonding to the thermoplastic composition layer 3 is achieved. Another advantage is a high level of comfort provided to the user as the pressure originating from the thermoplastic composition layer 3 will be better divided and thus lowered by the polyurethane open cell foam. Moreover, the obtained thermoplastic sheet material easily adheres to the forms and shapes of the body part on which it will be applied.

In a preferred embodiment of the invention, the support layer 6 is continuously bonded to the thermoplastic composition layer 3. By the term "continuously bonded" is meant that 100% of the surface area of one side of the support layer 6 is bonded on 100% of the surface area of one side of the thermoplastic composition layer 3. In another embodiment of the invention, the support layer 6 is not continuously bonded, leaving some of the surface area of the thermoplastic composition layer 3 not bonded to the support layer 6.

As the covered plate 21 moves further on the conveyor belt 15, the next step comprises quenching of the material with a cooled press 22. Said cooled press 22 has a temperature of 0°C-10°C, and by preference between 1°C-6°C. This pressurized quenching will firstly consolidate the bonding between the support layer 6 and the thermoplastic composition layer 3 and secondly will it cause the quick hardening of the thermoplastic composition and the polymer coating of the support layer if such coating was applied.

The resulting product is an embodiment of a thermoplastic sheet material 1 according to the invention. Thermoplastic sheet material

By the term "thermoplastic sheet material" 1 as used herein, is understood a sheet material that is deformable under the application of heat and after cooling down retains the deformed shape and becomes rigid. The overall thickness of the sheet material 1 may be 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2.0 mm, 2.2 mm, 2.4 mm, 2.5 mm, 2.6 mm, 2.7 mm, 2.8 mm, 2.9 mm, 3.0 mm, 3.2 mm, 3.4 mm, 3.5 mm, 3.6 mm, 3.7 mm, 3.8 mm, 3.9 mm, or 4.0 mm or a value in the range between any two of the aforementioned values. In one embodiment of the invention, the thickness of the thermoplastic sheet material 1 is higher than 4.0 mm, for example, 4.1 mm, 4.5 mm, 5.0 mm, 5.5 mm, 6.0 mm, 7.0 mm, 8.0mm or a value in the range between any two of the aforementioned values.

The thermoplastic sheet material 1 according to the invention is by preference moldable at temperatures of between 40°C and 90°C, more by preference between 50°C and 70°C. This temperature is depending on the polycaprolactone content of the sheet material. The sheet material will remain in a plastic condition until it is cooled below 30°C. Typically the sheet is brought into the moldable state by heating in a water bath 8 set around 5°C above the melting temperature, most preferable at 65°C. Such method is depicted in Figure 4. Alternatively, the sheet material 1 can be heated using a convection or fan oven, a microwave oven or a hair dryer or by any other heat producing apparatus or method.

Perforations 2 with a diameter of at least 0.5 mm and preferably between 1.0 to 2.0 mm, or a value in the range between any two of the aforementioned values may be provided in the thermoplastic sheet material, so as not to hamper the skin breathing after applying the sheet. When handling an unsupported thermoplastic sheet while it is in a moldable state, initial deformations occur in the thermoplastic composition 3, such as impression of fingers or gloves which make contact with the sheet. An unsupported thermoplastic sheet also deforms under its own weight when it is reheated prior to molding. A preferred embodiment of the support layer according to the invention will counteract to these deformations due to the elastic properties and/or due to the additional strength provided by a coating or impregnation. As a result, a thermoplastic sheet according to the invention will keep its original form until it is molded during its plastic phase.

The characteristics of the support layer will allow for wanted deformation of the thermoplastic material upon application of external forces, such as during molding.

The thermoplastic sheet 1 remains by preference in the moldable state for 1-10 minutes, more by preference between 2-5 minutes. The elastic fabric or the hydrophilic foam of a preferred embodiment of the support layer 6 are capable of freely following the expansion and the contraction of the thermoplastic composition 3 while the thermoplastic composition hardens during and after molding. Such sheet 1 can directly be molded on a person and is suitable for use as a brace, splint or cast material for immobilizing a part of a person. Figure 5 depicts a brace made of thermoplastic sheet material 1 of the invention. The support layer, preferably coated, is by preference the skin-facing side 9 while the outer side 10 comprises by preference the thermoplastic sheet material. In an embodiment of the invention, the thermoplastic sheet material 1 comprises a Turbocast® thermoplastic composition on which a silicone-coated hydrophilic foam, preferably silicone-coated polyurethane open cell foam, is disposed.

In another embodiment of the invention, the thermoplastic sheet material 1 comprises a Turbocast® thermoplastic composition on which a silicone-coated elastic fabric is disposed. The fabric has elasticity in the y direction comprised between 20% and 70% of the elasticity in the x direction.

The sheet, according to the present invention, can directly be molded on a person and is suitable for the use as a face mask whereby the silicone coated fabric will be the skin-facing layer. The resulting face mask will provide a comfortable wearing and the support layer 6 prevents adhesion to the skin and/or hair by the thermoplastic composition 3. The sheet 1 exhibits excellent deformability properties, conforming to the shape of the face without the need to apply excessive pressure. The silicone- coated support layer provides a comfortable wearing against the skin. Figure 6 shows an embodiment of a face mask made of a thermoplastic sheet material 1 according to the invention. Side 11 is the skin-facing side and comprises by preference the support layer. The face mask comprises further an aperture 13 for the nose, fixture 12 for attachment to a strap and coupling 14 for coupling for attachment of one or more tubes for delivery of the fluid to the nose. The coupling is comprised in a hollow tubular fitting 14 in connection with the aperture 13 adapted to receive a coupling from an air supply. Because of the support provided by the support layer, the preformed mask does not deform during its plastic phase prior to molding.

A brace or face mask according to the invention is further easily removed by warming it to a temperature at which it becomes soft enough to deform and then the heated brace or face mask is manually deformed to permit removal from the body.

A thermoplastic sheet material 1 according to the invention is suitable to be used in the treatment of burns and/or dermatological scars. By preference, the thermoplastic sheet material 1 comprises a coated or impregnated support layer. Said support layer is an elastic fabric or a hydrophilic foam, preferably polyurethane open cell foam. More by preference, said coating or impregnation comprises silicone. Additionally, the support layer may contain anti-bacterial products.

In another embodiment of the invention, a thermoplastic sheet material 1 according to the invention is suitable to be used for cosmetic skincare. Additionally, the elastic fabric or the hydrophilic foam of the support layer 6 may be treated with cosmetic products, suitable to be used in cosmetic therapy.

In another embodiment of the invention, a thermoplastic sheet material 1 according to the invention is suitable to be used for treatment of dermatological scars after breast operations. A thermoplastic sheet material 1 can be included in a bra whereby the silicone-coated/impregnated side is the skin-facing side. The inclusion of a thermoplastic sheet material according to the invention in a bra will fasten the healing process of the skin after such operation and will lessen the amount and grade of the scars.

In an embodiment of the invention, the thermoplastic material may be pre-formed prior to molding. In another embodiment of the invention, the thermoplastic sheet material 1 is available in sheets with standard dimensions. In an embodiment of the invention, the thermoplastic material may be sealed prior to use. This sealing is preferably sterile, vacuum and water-repellent. Such embodiment is suitable to use for treatment of burns and dermatological scars. Such embodiment of a thermoplastic sheet material 1 is by preference heated while hermetically sealed and opened in a sterile environment just before application to the skin that needs to be treated. The sealing is by preference watertight.

The invention is further described by the following non-limiting examples which further illustrate the invention, and are not intended to, nor should they be interpreted to, limit the scope of the invention.

It is supposed that the present invention is not restricted to any form of realization described previously and that some modifications can be added to the presented example of fabrication without reappraisal of the appended claims.

EXAMPLES Example 1 : Thermoplastic sheet material

A preferred embodiment of the invention is depicted in Figure 1 and has a thermoplastic composition layer 3 with following properties: - material : 30% polyester polyurethane, 70% polycaprolactone

- melting point: 200°C

- thickness: 2mm

perforations: 0.7mm diameter During the production process, this composition is covered on the lower surface 5 with an elastic fabric having following characteristics

- type: knitted fabric

- yarn : 90% polyamide, 10% elastane in warp and weft

- thickness: 0.8mm

elasticity: 3% in x-direction and y-direction

perforations: 0.7mm diameter this elastic fabric is prior to application in the production process coated with following coating : material : synthetic silicone

- coating weight: 12 g/m²

application : continuous layer-forming coating on one side of the elastic fabric

During the production process, the single-surface covered thermoplastic composition layer is heated to a temperature of about 110°C, thereby bonding to the support layer.

After quenching with a cooled press of 2°C, a thermoplastic sheet material is obtained according to the invention. Example 2: Thermoplastic sheet material

A preferred embodiment of the invention is a thermoplastic composition layer 3 with following properties: - material : 30% polyester polyurethane, 70% polycaprolactone

- melting point: 200°C

- thickness: 2mm

perforations: 0.7mm diameter During the production process, this composition is covered on the lower surface 5 with a polyurethane open cell foam having the following characteristics

- thickness: 1.5 mm

Colour: white this polyurethane open cell foam is prior to application in the production process coated with following coating : material : synthetic silicone

- coating weight: 12g/m²

application : continuous layer-forming coating on one side of the polyurethane open cell foam During the production process, the single-surface covered thermoplastic composition layer is heated to a temperature of about 110°C, thereby bonding to the support layer. After quenching with a cooled press of 2°C, a thermoplastic sheet material is obtained according to the invention.

Claims

1. A thermoplastic sheet material (1), comprising :

- a support layer (6) bonded on one surface of the thermoplastic composition layer (3).

2. A thermoplastic sheet material (1) according to claim 1, whereby said support layer is continuously heat-bonded on the thermoplastic composition layer (3).

3. A thermoplastic sheet material (1) according to claims 1-2, wherein said support layer comprises an elastic fabric.

4. A thermoplastic sheet material (1) according to claims 1-2, wherein said support layer comprises a hydrophilic foam.

5. A thermoplastic sheet material (1) according to any of the previous claims 1-4, whereby said elastic fabric has similar elasticity in x direction and y direction.

6. A thermoplastic sheet material (1) according to any of the previous claims 1-5, whereby said elastic fabric has elasticity comprised between 1%-15% in x and y direction, and more by preference between 2% and 5%.

7. A thermoplastic sheet material (1) according to any of the previous claims 1-6, whereby said support layer (6) further comprises a coating (7) on the surface which is not bonded to the thermoplastic composition layer (3).

8. A thermoplastic sheet material (1) according to any of the previous claims 1-7, whereby said support layer (6) is impregnated, said impregnation or coating (7) comprises a synthetic polymer.

9. A thermoplastic sheet material (1) according to any of the previous claims 1-7, whereby said support layer (6) is impregnated, said impregnation or coating (7) comprises silicone.

10. A thermoplastic sheet material (1) according to any of the previous claims 1-9 whereby the sheet material (1) is moldable at a temperature comprised between 40°C and 90°C, preferably between 50°C and 70°C and remains in plastic condition until cooled below 30°C.

11. A thermoplastic sheet material (1) according to any of the previous claims 1-10, whereby the sheet material (1) is rigid and has a memory effect at hardened condition.

12. Use of a thermoplastic sheet material (1) according to any of the previous claims 1-11 for molding directly on a person.

13. Use of a thermoplastic sheet material (1) according to any of claims 1-11 for molding a face mask or a medical brace whereby the support layer (6) is the skin- facing layer.

14. Use of a thermoplastic sheet material (1) according to any of claims 1-11 for treatment of burns or dermatologic scars.

15. A method for the production of a thermoplastic sheet material (1) as described in any of claims 1-11, comprising the step of heat-bonding a support layer (6) to the thermoplastic composition layer (3).