Thermoformable liner with film for holding

Abstract

Shoe (8) for sports shoe (1), characterized in that it comprises a first layer (16) of thermoformable material, and a flexible and non-thermoformable support film (20), the support film covering at least partially said first layer at the level of overlap zones (Z1, Z2, Z3, Z4) to limit the deformation of said first layer when the shoe is subjected to a thermoforming temperature, the shoe comprising at least one deformation zone to allow local deformation of said first layer when the shoe is subjected to the thermoforming temperature.

Description

Technical field of the invention

[0001] The invention relates to a liner for a sports shoe comprising a layer of thermoformable material. The invention also relates to a sports shoe, in particular a ski or snowboard boot comprising such a liner. The invention also relates to a manufacturing method and a thermoforming method for such a liner. State of the prior art

[0002] For various sports, and in particular for skiing or snowboarding, shoes are known that are equipped with so-called thermoformable liners, comprising a layer of thermoformable material. A thermoformable material is a malleable material, or in other words, a formable material, when heated to a sufficient temperature, during a process called thermoforming. For this purpose, the liner or the shoe equipped with the liner is placed in an oven at a given temperature and for a given time. Then, the liner is removed from the oven. A user inserts their foot and keeps their foot in place in the liner for a sufficient time. The previously heated liner deforms to adapt to the precise morphology of the user's foot and lower leg. The user thus benefits, in theory, from a liner perfectly adapted to the shape of their foot and lower leg.This avoids pressure points against the foot or lower leg that can become painful when using the shoe. This improves the comfort and precision of the sports shoe. However, thermoformable slippers known from the state of the art are not satisfactory. In practice, when they are heated to thermoform them, they tend to sag and then do not properly fit the shape of the foot. Finally, the comfort and precision of use of the sports shoe are therefore not always improved.

[0003] Document EP 3183983 A describes a slipper for a sports shoe, comprising a first layer and reinforcing elements. 5 Presentation of the invention

[0004] The aim of the invention is to provide a liner for a sports shoe, a manufacturing method and a thermoforming method for such a liner which overcomes the above drawbacks and improves the liners and manufacturing and thermoforming methods known from the prior art.

[0005] More specifically, a first object of the invention is a thermoformable liner which improves comfort and precision when used in a sports shoe. Summary of the invention

[0006] The invention relates to a liner for a sports shoe, the liner comprising a first layer of thermoformable material and a flexible, non-thermoformable support film, the support film at least partially covering said first layer at overlapping zones to limit the deformation of said first layer when the liner is subjected to a thermoforming temperature, the liner comprising at least one deformation zone to allow local deformation of said first layer when the liner is subjected to the thermoforming temperature.

[0007] The support film may comprise at least one deformation zone intended to be positioned opposite a sensitive area of a foot.

[0008] The support film may include: a first opening intended to be positioned opposite an internal malleolus, and / or a second opening intended to be positioned opposite an external malleolus, and / or a third opening intended to be positioned opposite a first metatarsal, and / or a fourth opening intended to be positioned opposite a fifth metatarsal, and / or a fifth opening intended to be positioned opposite a navicular bone.

[0009] Overlap areas may include: a first zone intended to be positioned opposite the top of the foot, and / or a second zone intended to be positioned around a heel, and / or a third zone intended to be positioned under an internal malleolus, and / or a fourth zone intended to be positioned under an external malleolus.

[0010] The retaining film may comprise polyurethane and / or PVC.

[0011] The holding film can comprise from 2% to 20% polyurethane and from 80% to 98% PVC.

[0012] The retaining film may have a thickness between 0.2 mm and 1 mm.

[0013] The retaining film can be fixed by high-frequency welding to an underlying layer of the liner.

[0014] Said first layer may be thermoformable at a temperature of approximately 80°C, and the holding film may be non-thermoformable at a temperature of approximately 100°C.

[0015] The slipper may include a lower portion intended to surround a foot and an upper portion intended to surround a lower leg, and the film may extend only in the lower portion.

[0016] The slipper may comprise a first textile layer arranged inside said first layer of thermoformable material, and / or a second textile layer arranged between said first layer of thermoformable material and the support film.

[0017] The slipper may comprise a second layer more rigid than said first layer of thermoformable material, the second layer being arranged between said first layer of thermoformable material and the support film, the second layer being of thermoformable material, in particular polyethylene.

[0018] The invention also relates to a sports shoe, in particular a ski or snowboard shoe, comprising an outer shell and a liner as defined previously, the liner being arranged inside the shell.

[0019] The invention also relates to a method of manufacturing a slipper as defined above, the manufacturing method comprising: the provision of a rod comprising a first layer of thermoformable material, then the three-dimensional shaping of the rod, then the placement of the retaining film around the previously shaped rod, then the fixing of the retaining film by high-frequency welding.

[0020] The invention also relates to a method of thermoforming a slipper as defined above, the thermoforming method comprising: heating the liner, in particular to a temperature between 60°C and 100°C and for a period of 8 to 10 minutes, then inserting a foot inside the previously heated liner, the liner being without any shell, then wearing the liner for a determined period to deform the first layer of thermoformable material at the level of at least one area not covered by the support film. Presentation of figures

[0021] These objects, characteristics and advantages of the present invention will be explained in detail in the following description of a particular embodiment made without limitation in relation to the attached figures among which: There figure 1 is a schematic view of an external side of a ski boot according to one embodiment of the invention. The figure 2 is a schematic view of an external side of a slipper according to one embodiment of the invention. The figure 3is a schematic view of an internal side of the slipper. The figure 4 is a schematic sectional view of part of the slipper. Detailed description

[0022] There figure 1schematically illustrates a ski boot 1 according to one embodiment of the invention. The ski boot 1 comprises a rigid outer shell, generally made of plastic, comprising in particular a shell bottom 2 and a collar 3 articulated on the shell bottom 2 around a hinge axis 4. The shell bottom 2 is intended to surround the foot of a user. It extends from a sole 5 substantially up to the level of the hinge axis 4. The sole 5 is extended towards its two front and rear ends by sidewalks 6 of a format adapted for cooperation with the jaws of a device for binding to a ski. The collar 3 is intended to surround the lower leg of the user, that is to say an area of the leg comprising approximately a lower half of the tibia and the calf of the user. The hinge axis 4 corresponds substantially to the axis of rotation of the ankle. The collar 3 can therefore pivot around the bottom of the hull 2 according to the articulation axis 4.The amplitude and / or the pivoting torque of the collar 3 relative to the bottom of the shell 2 can be fixed according to the practice for which the ski boot is intended and / or according to a level of mastery of the practice of skiing. The ski boot 1 can be for example intended for the practice of alpine skiing, ski touring, snowboarding, cross-country skiing, and more generally any snow sliding sport in which a user has his feet attached to one or two sliding boards. The ski boot further comprises tightening means 7 intended to tighten the outer shell against the foot and the lower leg. A liner 8 is inserted into the rigid outer shell.

[0023] Throughout the figures and description, the terms "top", "upper", "bottom", and "lower" refer to a vertical orientation, considering the ski boot resting by its sole on horizontal ground. The terms "inner" and "outer" refer to the lateral sides of the ski boot or the user's foot. The term "inner" refers to the left side of the right boot or the right side of the left boot. The term "outer" refers to the right side of the right boot or the left side of the left boot. Left and right are defined according to the user's point of view. The terms "inner" and "outer" are intended to specify an arrangement relative to the thickness of the ski boot or liner in question. The term "inner" designates an arrangement towards the user's foot, while the term "outer" designates an arrangement towards the outside of the boot.The terms "front" and "back" refer to the primary direction in which the foot extends. Front refers to the area toward the toes, and back refers to the area toward the heel.

[0024] The liner 8 is therefore an element of the ski boot 1 interposed between the outer shell on the one hand and the foot and lower leg of the user on the other hand. The liner 8 is an element intended in particular to improve comfort and to produce thermal insulation of the foot. The liner 8 also fulfills a function of transmitting forces and impulses between the leg and foot of the user on the one hand, and the outer shell on the other hand, to direct the sliding board(s). The liner 8 is more flexible than the outer shell. In particular, the liner 8 does not have a rigidity intended to limit the amplitude of flexion of the ankle. The liner is intended for use inside the outer shell, in particular to avoid direct contact between the foot and / or the lower leg and the harder outer shell. Preferably, the liner 8 may not be intended to be used outside the shell.However, alternatively, it could be used as such, i.e. outside of a hull.

[0025] There figure 2 and the figure 3illustrate an embodiment of the liner 8. The liner 8 comprises a lower part 9 intended to surround the user's foot and an upper part 10 intended to surround the lower leg. The liner 8 optionally comprises a tongue 11, for example at the front of the upper part 10. The tongue 11 can take position in a notch formed at the front of the upper part 10 and can be fixed, for example by sewing, to the lower part 9 substantially at the height of an instep 12 of the liner 8. The tongue 11 can be pivoted forward, substantially at the level of its connection zone with the lower part, to facilitate the insertion of the foot into the liner. This makes it possible to enlarge the opening 13 through which the foot is inserted into the liner, which facilitates putting on and taking off the liner and therefore the shoe.

[0026] Alternatively, the tongue could be attached differently to the rest of the liner, in particular by means of a lateral edge of the tongue. The tongue could even be connected to the rest of the liner by means of its two lateral edges, to the left and right of the tongue. In this case, the liner would advantageously have sufficient elasticity to enlarge the opening 13 and thus allow the insertion of the foot into the liner and its extraction. According to another variant embodiment, the liner 8 could only comprise the lower part 9. Foam elements, for example attached to the collar 3, could then ensure relatively comfortable contact with the lower leg.

[0027] Finally, optionally, the slipper can have a handle 14 (shown only on the figure 1), for example in fabric, fixed at the top of the tongue, to facilitate handling of the shoe, but also to enlarge the opening 13 for inserting the foot when putting it on.

[0028] The slipper may comprise a thickness that is at least roughly constant. With reference to the figure 4 , we now describe the structure of the slipper according to its thickness, that is to say the different layers from which the slipper is formed. The figure 4 corresponds to a partial and schematic view of the shoe according to the section plane C drawn on the figure 3 . There figure 4is not to scale. Considering the liner from its inner surface to its outer surface, the liner 8 comprises a first layer or inner lining 15 generally made of textile material (intended to come into contact with the skin or a sock of the user), a padding layer 16 made of thermoformable material, a support layer 17, a second textile layer 18 and finally a support film 20 according to one embodiment of the invention. These different layers are fixed together, for example by gluing, by sewing or by high-frequency welding. Alternatively, the arrangement and / or the number of these layers could be different, in particular, the liner could not comprise the first textile layer 15 and / or the second textile layer 18 and / or the support layer 17. For example, the layer 17 could possibly be arranged above the second textile layer 18.The slipper could include a greater number of superimposed layers. Each of the different layers can also be formed by an assembly of several pieces, juxtaposed or superimposed, joined together for example by sewing, gluing or even high-frequency welding.

[0029] The thickness of the liner may be between 5mm and 3cm, for example. Advantageously, the padding layer 16 may constitute the thickest layer of the liner. The structure of the liner may not be uniform: the thickness and / or the density of each layer and / or the number of layers of the liner could be variable depending on the area of the liner considered. For example, the padding layer 16 may itself be composed of the assembly of several layers, at least one of which is thermoformable. As can be seen in the figures 2 And 3, the liner may comprise a more rigid reinforcing layer 19, intended to protect the liner from friction with the external shell. This reinforcing layer 19, sometimes referred to by the Anglicism "spoiler", extends as an outer layer of the liner and preferably only in the upper part 10 of the liner and around the tongue 11. The reinforcing layer 19 may be formed from a plastic material. The liner may also comprise means for tightening around the foot, such as a lace and / or a Velcro fastener. The person skilled in the art will be able to choose the structure of the liner according to the intended use. In particular, he will be able to adjust a compromise between comfort, lightness, precision and manufacturing cost according to the intended use for this liner.

[0030] The padding layer 16 is a layer of thermoformable material, i.e. a formable or deformable material, in particular plastically deformable, when heated to a sufficient temperature, during a so-called thermoforming process. For example, the padding layer 16 may be a thermoplastic foam based on EVA and / or polyethylene. Such a material deforms plastically (i.e. without completely returning to its original shape) when it is constrained while being heated to a deformation temperature or above the deformation temperature. The term deformation temperature is understood to mean the temperature from which the material is sufficiently softened to deform sustainably over time. Advantageously, the thickness of the padding layer 16 may be locally modified by thermoforming.The deformation temperature of the thermoformable materials that make up the padding layer 16 may be between 60°C and 100°C, for example approximately 80°C. Advantageously, this temperature is higher than the temperature of the human body so that the liner does not deform during use of the liner, in contact with the human body, or during its storage in a store or during its transport. The deformation temperature is also sufficiently low to allow a user to insert his foot into the liner heated to such a temperature without burning it. Once the foot is inserted into the liner previously heated to the thermoforming temperature, the thermoformable material is softened and becomes capable of taking the shape of the user's foot and / or lower leg in a stable and durable manner.Then the cooling of the shoe and its constituent materials to room temperature, constrained by the foot positioned inside, allows the material of the padding layer 16 to be fixed to the shape of the foot.

[0031] The support layer 17 is advantageously more rigid and denser than the padding layer 16. The support layer 17 is nevertheless less rigid than the outer shell. The support layer 17 covers the padding layer 16 and provides support to the liner. The support layer may also be thermoformable. In particular, the support layer may be made of polyethylene. In this case, both the padding layer 16 and the support layer 17 are thermoformable. The overall rigidity of the liner is provided by the padding layer 16 and the support layer 17.

[0032] The first textile layer or inner lining 15 may be a soft fabric layer, providing pleasant contact with the foot and / or the lower leg, while protecting the padding layer 16. The second textile layer 18 may be useful for the aesthetics of the slipper and / or to protect the support layer 17. The second textile layer 18 may be, for example, a layer of stretch fabric made from elastane and / or polyurethane fibers, such as, for example, Lycra ®<.

[0033] The retaining film 20 is a flexible membrane forming an outer layer of the liner. By "flexible", it is understood that the retaining film 20 does not prevent any possible articulation or folding of the liner and its wall, and does not contribute significantly to the overall rigidity of the liner. The retaining film 20 perfectly matches the shape of the underlying layer. The presence of the retaining film is thus imperceptible to the user. In particular, the retaining film is sufficiently flexible to allow the liner to deform when the foot is inserted into the liner. The film therefore maintains a substantially constant surface when the foot is inserted inside the liner. In addition, the retaining film is made of a material that is not thermoformable at the thermoforming temperatures envisaged for thermoforming the padding layer 16.In other words, the retaining film 20 is not formable when it is brought to the deformation temperature of the thermoformable material forming the cushioning layer 16. The retaining film 20 therefore retains its mechanical properties when it is heated to said deformation temperature. In particular, it retains its dimensions and its mechanical properties at such a temperature. Advantageously, the retaining film is not thermoformable up to a temperature of approximately 100°C, or even up to a temperature above 100°C. Advantageously, a pair of thermoformable material forming the cushioning layer 16 and non-thermoformable material forming the retaining film 20 is chosen so that there is a sufficient temperature range, for example at least 20°C, in which the thermoformable material can be formed while the non-thermoformable material retains its mechanical properties.Thus, during thermoforming of the liner, only the thermoformable materials of the padding layer 16 will reach a temperature sufficient for their deformation. In other words, the material of the support film 20 has a softening temperature higher than the softening temperature of the thermoformable material of the padding layer 16, or even of the support layer 17, when the support layer comprises a thermoformable material. Preferably, the softening temperature of the support film is at least 20°C higher than the softening temperature of the thermoformable material of the wall of the liner.

[0034] The supporting film 20 covers the padding layer 16, and, if applicable, the support layer 17. That is to say, the supporting film is arranged outside the padding layer 16 and generally conforms to its shape. The supporting film may directly cover the thermoformable padding layer, that is to say, there are no other layers of the liner arranged between the supporting film and the thermoformable padding layer. Alternatively, the supporting film may indirectly cover the thermoformable padding layer, that is to say, there may be other layers of the liner arranged between the supporting film and the thermoformable padding layer.

[0035] According to a first option, the support film 20 can extend over the entire height of the liner, in particular around the lower part 9 and the upper part 10. According to a second option, the support film can extend only over a part of the liner, for example only around the lower part 9 of the liner. In this case, the support film can extend upwards to above the malleoli area.

[0036] The cushioning layer 16 comprises at least one covering area covered by the support film and at least one area not covered by the support film 20. With reference to the figure 2 and to the figure 3, the overlapping zones where the support film 20 covers the padding layer 16 can be identified as follows: a first overlapping zone Z1 is intended to be positioned opposite the top of the foot, substantially from the instep area to the toes. A second overlapping zone Z2 is intended to be positioned around the heel, at the back of the shoe. A third overlapping zone Z3 is intended to be positioned under the internal malleolus. A fourth overlapping zone Z4 is intended to be positioned under the external malleolus. These different zones are delimited on the figure 2 and on the figure 3by dotted lines. These different areas are shown to indicate the different places where the retaining film 20 extends but do not constitute any real discontinuity of the retaining film. The retaining film is preferably made in one piece, i.e. from a single piece. Alternatively, the retaining film could be made up of several portions of film, disjointed, positioned only in the areas where it is desired to limit the thermoforming of the underlying layers. The overlapping areas can then be joined or, on the contrary, disjointed. In this case, the areas of the liner not covered by the retaining film could deform more easily during the thermoforming process. The retaining film can also extend under the sole of the liner.Alternatively, the slipper may include a thin outer sole constituting a lower wall of the slipper and the support film may be attached to the edge of this thin sole.

[0037] Between these different overlapping zones Z1, Z2, Z3 and Z4, the retaining film 20 comprises different deformation zones. According to a preferred embodiment, these deformation zones are openings. These openings correspond to areas of the padding layer 16 not covered by the retaining film 20. These openings have roughly circular or ovoid shapes. Alternatively, the openings could have different shapes, in particular rectangular, triangular, polygonal or elongated openings. The openings may have, for example, a surface area of the order of a few square centimeters.

[0038] A first opening O1 is intended to be positioned opposite the internal malleolus. A second opening O2 is intended to be positioned opposite the external malleolus. A third opening O3 is intended to be positioned opposite the first metatarsal, i.e. the metatarsal corresponding to the largest toe. A fourth opening O4 is intended to be positioned opposite the fifth metatarsal, i.e. the metatarsal corresponding to the smallest toe. A fifth opening O5 is intended to be positioned opposite the navicular bone. Advantageously, these five openings correspond to the five areas of the foot for which thermoforming is most useful. Indeed, the morphology of each foot is particularly distinguished by a more or less marked prominence of these five areas.These are also five particularly sensitive areas of the foot, against which pressure points can appear when using ski boots that are not perfectly adapted to the morphology of the foot. These areas of the foot then become particularly painful and hinder the user in his practice. Alternatively, the support film could include a different number of openings: for example one, two, three or four openings to choose from among the five openings mentioned above. The support film could also include additional openings corresponding to other sensitive areas of the foot, for example the heel area and / or the toe area.

[0039] The openings O1 to O5 are holes formed in the retaining film. These openings may be edged with a reinforcing border 21 intended to prevent any tearing or enlargement of the film during use. Advantageously, the openings have rounded edges, which also limits the risk of tearing the retaining film.

[0040] As an alternative to a circular or ovoid shape, the openings could be simple slits, rectilinear or curvilinear, arranged opposite the different sensitive areas of the foot. These slits would thus allow the portions of film arranged on either side of the slit to move apart during the thermoforming process, no longer hindering the deformation of the underlying layers in this area. According to another embodiment, the deformation zones could be obtained by means of fragile zones of the reinforcing film opposite the different sensitive areas of the foot. These fragile zones can be, for example, slits or grooves which do not pass through the entire thickness of the support film. These fragile zones can also be zones where the support film comprises a reduced thickness which locally gives it less resistance.These fragile areas may be intended to be broken when the foot is inserted into the liner or they may make the support film locally extensible. According to yet another variant, the deformation zones could be obtained by providing a looser film or a locally extensible film opposite the different sensitive areas of the foot, in order to allow deformation of the thermoformable material at these areas.

[0041] The retaining film may be, for example, made of polyurethane, PVC (acronym for polyvinyl chloride), or a mixture of these two materials. Preferably, the retaining film 20 is formed of 2% to 20% polyurethane, and 80% to 98% PVC. It may have a thickness of between 0.2 mm and 1 mm, preferably between 0.4 mm and 0.7 mm. It may have a density of between 400 g / m2 and 600 g / m2. It may have a breaking load of between 50 N and 200 N per 5 cm, measured according to the ISO1421 standard. It may have an elongation at break of between 100% and 300% measured according to the ISO1421 standard. The retaining film is abrasion-resistant, in particular so as to withstand repeated friction with the hull with which it is in contact.

[0042] The retaining film may be the outermost layer of the liner. It is attached to the underlying layer of the liner, i.e., the layer of the liner directly covered by the retaining film 20. In particular, the retaining film may be glued and / or welded to the underlying layer, i.e., to the second textile layer 18 according to the embodiment presented. Advantageously, the retaining film is pressed against the layer of the liner against which it is affixed. There is therefore no volume of air trapped between the retaining film and the layer of the liner against which it is affixed. Thus, the retaining film 20 may be slightly constrained when the user's foot is inserted inside the liner. The retaining film then provides a reaction force tending to press the liner against the user's foot. For this purpose, a certain elasticity of the retaining film may be provided. This allows the foot to be held without play in the liner.The use of the shoe thus allows for more precise sporting practice without the risk of friction at the interface between the shoe and the user's foot.

[0043] The retaining film may be provided to be non-removable from the rest of the liner. Alternatively, the retaining film could be provided to be removed from the rest of the liner after a thermoforming operation of the liner. The retaining film could also be in the form of an accessory separate from the liner, and which is slipped like a sock around a liner solely for the purposes of a thermoforming process. Following the thermoforming process, the retaining film could then either be kept in place or removed from the liner.

[0044] For the manufacture of the liner 8, a flat upper may first be provided comprising at least the padding layer 16 made of thermoformable material. Then, the upper is shaped three-dimensionally, to the shape of the foot. Then, the retaining film is placed around the previously shaped upper and is fixed to the upper by high-frequency welding. Fixing by high-frequency welding consists of fixing the retaining film 20 by subjecting it to a high-frequency electromagnetic field and possibly applying pressure to the retaining film. The electromagnetic energy sets the molecules of the material constituting the retaining film 20 and / or the underlying layer of the liner in motion, which generates heat and causes the materials to melt. This process does not generate heat outside of the layers fixed together. Consequently, the thermoformable material of the padding layer is not modified by this process.This process is particularly suitable for welding PVC (polyvinyl chloride) and / or polyurethane-based materials. The frequency of the electromagnetic waves can be in the order of several megahertz, for example between 10 MHz and 50 MHz. Such a process makes it possible to obtain a fixation of the retaining film without excess thickness and without altering the padding layer made of thermoformable material. Alternatively, the retaining film could also be fixed by another means, for example by gluing and / or sewing. If glue is used, it will be chosen so as to remain flexible and to retain its adhesive properties during a thermoforming process.

[0045] Subsequently, to adapt the liner to the morphology of a particular user, the following thermoforming process can be applied: first, the liner is heated, in particular to a temperature between 60°C and 100°C and for a period of between 8 and 10 minutes. For this, the liner can be placed in a suitable heating means such as an oven, a drying oven or a hot air blower. The liner is placed in the heating means preferably without the outer shell of the shoe, which may not be designed to be heated to such a temperature. When the temperature of the liner is sufficient, the padding layer 16 (and if applicable, also the support layer 17) is softened and becomes malleable and can be thermoformed. The liner is removed from the heating means and the user inserts his foot. The liner is then always preferably outside the outer shell.Since the support film 20 is not thermoformable at the heating temperature of the thermoforming process, it maintains the general shape of the liner even though the liner is softened by the effect of the temperature. This prevents the liner from sagging or deforming in an undesired manner. In particular, the liner does not descend downwards under the effect of its own weight. The liner is held at least as well as if it had been inserted into the outer shell. The liner thus remains firmly pressed against the foot and the lower leg and can perfectly fit the morphology of the user. Thanks to the different openings O1 to O5 formed in the support film, the liner deforms more easily at these openings which correspond to the different sensitive areas of the foot. At the different openings, a local displacement of the walls of the liner can be observed.Outside the openings, the walls of the liner are held in place by the support film. In the overlapping areas, however, a thermoforming effect is maintained, linked to the possible compression of the layer of thermoformable material from the inside of the liner, without changing the shape of the outer wall of the liner. The liner must then, while cooling to room temperature, be worn for a specific period of time to obtain permanent deformation of the layer of thermoformable material.

[0046] The result is a liner that retains its overall shape but is locally deformed in various sensitive areas of the foot. During the thermoforming process, the liner does not sag. The formation of gaps or free spaces between the foot and the liner is avoided, which improves foot support and reduces friction. The liner can then be inserted into the outer shell to form a ski boot. This allows for precise and comfortable skiing. In addition, the support film reinforces the liner's waterproofness while allowing moisture to escape through its various openings. The openings also provide a visual indication of the areas with increased thermoformability, for which deformation is preferred.In the event that several slippers are offered with different configurations for the openings, a user who knows where the most sensitive areas of his feet are located can thus easily identify slippers that can be effectively thermoformed to his feet. The second textile layer 18 can be made visible through the openings which gives the slipper an original aesthetic appearance.

[0047] In general, the invention makes it possible to obtain a thermoformable slipper, not over its entire surface but only in selected areas, by applying a specific support film, covering a thermoformable material, in these selected areas. This allows the best adaptation of the slipper to all types of users' feet.

Claims

1. Liner (8) for a sports shoe (1), comprising a first layer (16) made of thermoformable material and a flexible, non-thermoformable support film (20), the support film at least partially covering said first layer in covering zones (Z1, Z2, Z3, Z4) to limit the deformation of said first layer when the liner is subjected to a thermoforming temperature, the liner comprising at least one deformation zone to allow local deformation of said first layer when the liner is subjected to the thermoforming temperature.

2. Liner (8) according to the preceding claim, characterized in that the support film (20) comprises at least one deformation zone (O1, O2, O3, O4, O5) intended to be positioned opposite a sensitive zone of a foot.

3. Liner (8) according to any one of the preceding claims, characterized in that the support film (20) comprises: - a first opening (O1) intended to be positioned opposite a medial malleolus, and / or - a second opening (O2) intended to be positioned opposite a lateral malleolus, and / or - a third opening (O3) intended to be positioned opposite a first metatarsal, and / or - a fourth opening (O4) intended to be positioned opposite a fifth metatarsal, and / or - a fifth opening (O5) intended to be positioned opposite a navicular bone.

4. Liner (8) according to any one of the preceding claims, characterized in that the covering zones comprise: - a first zone (Z1) intended to be positioned opposite an instep, and / or - a second zone (Z2) intended to be positioned around a heel, and / or - a third zone (Z3) intended to be positioned below a medial malleolus, and / or - a fourth zone (Z4) intended to be positioned below a lateral malleolus.

5. Liner (8) according to any one of the preceding claims, characterized in that the support film (20) comprises polyurethane and / or PVC.

6. Liner (8) according to the preceding claim, characterized in that the support film (20) comprises from 2% to 20% polyurethane and from 80% to 98% PVC.

7. Liner (8) according to any one of the preceding claims, characterized in that the support film (20) has a thickness between 0.2 mm and 1 mm.

8. Liner (8) according to any one of the preceding claims, characterized in that the support film (20) is fixed by high-frequency welding to an underlying layer of the liner.

9. Liner (8) according to any one of the preceding claims, characterized in that said first layer (16) is thermoformable at a temperature of approximately 80°C, and in that the support film (20) is non-thermoformable at a temperature of approximately 100°C.

10. Liner (8) according to any one of the preceding claims, characterized in that it comprises a lower portion (9) intended to surround a foot and an upper portion (10) intended to surround a lower leg, and in that the film extends only within the lower portion (9).

11. Liner (8) according to any one of the preceding claims, characterized in that it comprises a first textile layer (15) arranged inside said first layer (16) of thermoformable material, and / or a second textile layer (18) arranged between said first layer (16) of thermoformable material and the support film (20).

12. Liner (8) according to any one of the preceding claims, characterized in that it comprises a second layer (17) that is more rigid than said first layer (16) of thermoformable material, the second layer being arranged between said first layer (16) of thermoformable material and the support film (20), the second layer being made of thermoformable material, in particular polyethylene.

13. Sports shoe (1), in particular ski or snowboard shoe (1), characterized in that it comprises an outer shell and a liner (8) according to any one of claims 1 to 12, the liner being arranged inside the shell.

14. Method for manufacturing a liner (8) according to any one of claims 1 to 12, characterized in that it comprises: - providing an upper comprising a first layer (16) made of thermoformable material, then - three-dimensional shaping of the upper, then - placing the support film (20) around the previously shaped upper, then - fixing the support film (20) by high-frequency welding.

15. Method for thermoforming a liner (8) according to any one of claims 1 to 12, characterized in that it comprises: - heating the liner (8), in particular to a temperature between 60°C and 100°C for a duration of 8 to 10 minutes, then - inserting a foot inside the previously heated liner, the liner being outside any shell, then - wearing the liner for a defined duration to deform the first layer (16) of thermoformable material in at least one zone not covered by the support film (20).

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