FR2781652A1 - WATERPROOF BOOTS INTENDED TO FORM THE INNER LINING OF A FOOTWEAR, PROCESS FOR MANUFACTURING SUCH BOOTS AND FOOTWEAR EQUIPPED WITH SUCH BOOTS - Google Patents

Abstract

The liner (1) is intended to be fixed inside an article of footwear to act as an inner lining. It is produced by assembling an upper (2) impermeable to water but permeable to water vapor and a sole (3) made of a material permeable to liquids, and further comprises an external coating (12 ) waterproof, which covers the sole and only the lower part of the upper over its entire periphery, and which makes it possible to give the covered parts sufficient rigidity to keep them in shape while retaining a certain flexibility. Preferably, the waterproof stiffening coating (12) is produced by impregnating the liner with a liquid or semi-liquid material, which after drying solidifies in the form of a flexible and waterproof layer.

Description

WATERPROOF SLIPPERS FOR FORMING THE LINING

  INTERIOR OF A FOOTWEAR, METHOD OF

  MANUFACTURE OF SUCH A BOOT AND A FOOTWEAR

EQUIPPED WITH SUCH A CHAUSSON.

  The present invention relates to the technical field of the manufacture of waterproof footwear, and for example but not exclusively of hiking shoes, comprising an inner lining made from a material which is waterproof but vapor permeable. water. It relates to an inner lining in the form of a waterproof liner, the method of manufacturing such a liner, as well as a

  footwear fitted with this inner lining.

  It is currently known to make a footwear waterproof, such as for example a hiking shoe, by fixing inside the upper of the shoe an inner lining which is waterproof and which is permeable to water vapour. The inner lining, due to its waterproof character, has the primary function of keeping the user's foot dry with the best possible efficiency. By its permeable nature to water vapor, this inner lining has the second function of allowing the foot of the user to breathe and thereby reducing the appearance of the 2 o phenomenon of perspiration, which improves the user comfort. To date, most of the interior linings are produced in the form of a laminate comprising an breathable external membrane in a microporous or hydrophilic material impermeable to water and permeable to water vapor, and one or more internal layers, including for example a layer of polyurethane foam for the comfort of the user. The breathable membranes are for example made of expanded microporous polytetrafluoroethylene. This type of membrane is for example described in patents US-A-3,953,566 and US-A-4,187,390. There are also other known types of breathable membranes currently marketed and made based on other microporous polymers

  (polyurethane, polyester, polyamide, etc ...).

  A first solution proposed to date by certain manufacturers consists in making these interior linings in the form of a liner, which is sewn and which is made entirely of a material having the required properties of water impermeability and permeability to water vapor. The seams of the bootie are made perfectly waterproof, for example by means of waterproof strips which are glued on the seams. This slipper is then

  positioned and fixed inside the shoe.

  The first aforementioned solution has two main advantages - the slipper which envelops the foot being perfectly waterproof, any problem of water infiltration is avoided, - it is possible during the shoe manufacturing process to control during a step intermediate, the tightness of the liner, for example by immersing it in water, before it is placed inside the shoe, which

  allows the manufacturer to guarantee the waterproofness of the shoes.

  This first solution however has two main drawbacks, it generates a high manufacturing cost linked mainly to the cost of the breathable membrane which is impermeable to water but permeable to water vapor, which is used to form the entire liner. liner does not have a shape perfectly adapted to the interior volume of the shoe in which it is later fixed, and the operation of fitting and fixing this liner inside the shoe is delicate and results most of time by the formation of folds in the liner, which are completely

  detrimental to the comfort of the user.

  The use of waterproof strips to seal the seams of a liner according to the first aforementioned solution also requires making a liner whose seams are preferably made flat, which on the one hand complicates the manufacture of the liner, and on the other hand results in a shoe whose shape is even more unsuitable for the interior volume of the shoe. A second solution consists in not making an integral liner manufactured separately, but in integrating the steps of fitting and fixing the inner lining to the steps of manufacturing the shoe. In general, in this solution, during the manufacture of the shoe, the waterproof and breathable lining is fixed relative to the first fitting of the shoe, by folding the free edge of the lining along its entire periphery. , on the underside of the first shoe mount, and also folding the upper of the shoe on the underside of the first shoe, the edge of the lining being sandwiched between the upper of the shoe

and the first one.

  According to a first variant of implementation of this second solution, in order to ensure sealing at the level of the first fitting, a sealing sole, for example plastic, is bonded to the underside of the first fitting, in such a way that the edges of the upper of the shoe and of the lining are sandwiched between the sealing sole and the insole. This first variant has the drawback, however, of not effectively preventing water infiltration from the outside of the shoe towards the inside of the lining. In fact, water can infiltrate between the sealing sole of the first shoe, passing through the upper of the shoe, then infiltrate by capillarity towards the inside of the lining, penetrating into the edge.

  not waterproofed the inner lining.

  In a second known variant of implementation of the aforementioned second solution, an internal fold is provided at the peripheral edge of the inner lining and a seal is applied, for example by means of a polyurethane adhesive, between the upper of the shoe and the underside of the first shoe. The fold advantageously makes it possible, compared to the first aforementioned variant, to prevent the water which infiltrates through the upper of the shoe up to the peripheral edge of the lining from being able to

  penetrate the lining and reassemble by capillary action inside the lining.

  In a third variant of implementation of the aforementioned second solution, described in particular in international patent application WO-A-9801049, after having folded the edge of the inner lining under the underside of the original equipment, it is fixed by sew the edge of the lining on a closure piece, then apply between this closure piece and the upper of the shoe a sealing layer which extends at least until the seam between the closure piece and the edge lining device

interior.

  The main drawback of the aforementioned second solution, whatever the variant of embodiment, is linked to the impossibility of checking the tightness of the shoe without damaging it, unlike the tightness check which can advantageously be carried out at a stage intermediate on the slipper in

  as part of the first solution mentioned above.

  The present invention provides a new solution for sealing an article of footwear, while allowing the foot of the user to breathe, which has all the advantages of the first aforementioned solution, without having the drawback associated with the problem of adapting the liner inside 2 o of the shoe, and which also has the advantage of being less expensive than

the first solution.

  The solution of the invention lies in the manufacture of an inner lining, which as in the first solution is in the form of a

  bootie intended to be fixed inside an article of footwear.

  Characteristically according to the invention, the liner is produced by assembling an impermeable rod which is waterproof but permeable to water vapor and a sole made of a material which is permeable to liquids, and further comprises a coating. external waterproof, which covers the sole and only the lower part of the upper over its entire periphery, and which allows -5 to give the covered parts sufficient rigidity to keep them in

  shape while retaining some flexibility.

  In the boot of the invention, the sole can advantageously be made of any textile material at low cost, which significantly reduces the cost of the boot compared to the first aforementioned solution. The covering, by its stiffening function, advantageously makes it possible to produce a liner whose lower part can be molded into a shape adapted to the interior of the shoe, which makes it possible to facilitate the subsequent fitting of the liner to the inside of the upper of the shoe, and to avoid the formation of creases in the liner when it is fixed inside

  the upper of the shoe, especially at the sole of the liner.

  In a preferred alternative embodiment, the upper and the sole are assembled transversely to one another, in particular by a peripheral seam of the Strobel type. This variant has the advantage of simplifying the manufacture of the liner, and makes it possible to obtain a liner which intrinsically, that is to say without the tight stiffening coating, immediately has a shape that is relatively well suited to the interior volume of footwear. In particular, it is possible to choose a sole whose geometry is identical or almost identical to the geometry of the insole of the footwear. The technical characteristics of this preferred alternative embodiment are not, however, limiting of the invention. In particular, in another less advantageous variant of the invention, it is conceivable to use a sole and a rod which are assembled edge to edge in the same plane, for example by a flat seam. In the context of this other variant, two configurations may arise. In a first configuration, the sole of the chasson has a larger surface area than the insole of the footwear, and is folded so as to form a peripheral rim situated in the same substantially vertical plane as the upper of the bootie. In a second configuration, the sole of the liner has a surface which is on the contrary smaller than that of the insole of the footwear, and it is the upper of the liner which is folded so as to form a rim peripheral located in the same substantially horizontal plane as the sole of the liner; in this second configuration, the seam between the upper and the sole is in practice located under the arch of the user. Another subject of the invention is a method of manufacturing a liner intended to be fixed inside an article of footwear to act as an inner lining. Typically according to the invention, an intermediate boot is produced by assembling a rod, which is waterproof and permeable to water vapor, and a sole which is made of a material permeable to liquids. ; a rigid shape adapted to the interior volume of the footwear is introduced into the intermediate liner, and the lower part of the intermediate liner is impregnated with a liquid or semi-liquid material capable of solidifying, so as to form an impermeable external coating with water, which covers the sole and only the lower part of the upper of the intermediate liner over its entire periphery, and which makes it possible to mold the parts

  covered while retaining some flexibility.

  Preferably, the impregnation step is carried out by soaking the lower part of the intermediate liner in at least one bath containing in its liquid or semi-liquid form the material intended to form the waterproof stiffening coating. In a preferred embodiment, it is a

  latex or synthetic elastomer bath.

  Other characteristics and advantages of the invention will appear more

  clearly on reading the description below of a preferred example of

  manufacture of a boot according to the invention and a waterproof shoe

  using this bootie, which description is given by way of example

  not limiting and with reference to the appended drawing in which: - Figures 1 and 2 are sectional views in principle illustrating the two main stages in the manufacture of a liner according to the invention, - Figure 3 is a block diagram illustrating the main operations which are implemented successively for the formation of a tight rigidification latex coating, - Figure 4 is a schematic perspective representation of the liner obtained at the end of the steps of Figures 1 and 2, - Figures 5 and 6 illustrate the two main stages in the manufacture of a shoe incorporating the boot of FIG. 4, - FIG. 7 is a view in partial section at the heel of a shoe

  obtained at the end of the steps of FIGS. 5 and 6.

  Referring to Figures 1 to 3 will now be detailed the main stages of manufacture of the particular variant of production of a liner

  of the invention illustrated in Figure 4.

  In a first step, an intermediate liner 1 ′ is made, from a rod 2 and a sole 3. In the particular example illustrated in FIGS. 1 and 4, the rod 2 consists of three textile pieces 2a, 2b and 2c sewn together. The textile pieces 2b and 2c have the same geometry and are more particularly sewn together edge to edge according to a rear seam 4a located at the heel of the bootie. The opposite edges of the pieces 2b and 2c are sewn edge to edge respectively with the textile piece 2a according to seams

  side 4b, the textile part 2a forming the front part of the liner.

  According to the example illustrated, the seams 4a and 4b are for example

zigzag seams.

  The textile pieces 2a, 2b, 2c constituting the upper 2 of the liner are designed so as to be impermeable to water while being permeable to water vapor. If we refer to FIG. 1, this double property is obtained by the use of a breathable membrane 5, which is for example a film of

  expanded microporous polytetrafluoroethylene having the properties required above

  above. More particularly, in the example illustrated, each textile piece 2a, 2b_, - 8 - 2_c constituting the rod 2 is formed by a laminate in four layers, comprising an outer layer 5 'commonly called charmeuse and consisting for example of a silicone polyethylene film, a first intermediate layer corresponding to the aforementioned breathable membrane 5, a second intermediate comfort layer 6 produced for example from a polyurethane foam, and an internal layer 7 which is chosen for example for its qualities of softness to the touch and its good capacity to absorb perspiration. This layer 7 will for example be made of a textile based on synthetic fibers, the internal face of which, intended to come into contact with the foot, has

  underwent a woolen operation giving it a softer feel.

  Once the parts 2a, 2b and 2_c constituting the rod 2 assembled together, we just seal their respective seams 4a, 4b, for example by

  applying iron-on sealing tape to these seams 8.

  Once the rod 2 is formed, it is assembled transversely to the sole 3, by means of a seam 9 extending over the entire periphery of the sole 3. Preferably, but not exclusively, it will be a seam of

Strobel type.

  According to the invention the sole 3 is made of any porous material permeable to liquids, and unlike the constituent elements of the upper, does not use a breathable membrane 5 waterproof and permeable to water vapor . This sole 3 is for example constituted

  with a simple knit made from polyester fibers.

  Once the step of making the liner 1 ′ of FIG. 1 has been carried out, a rigid shape 10 (FIG. 2) is introduced inside the liner 1 whose geometry is adapted to the interior volume of the shoe in which the liner final will be inserted. This shape 10 makes it possible to stretch the walls of the liner in it

  giving the appropriate geometry.

  Then impregnates the lower part of the liner 1 'kept in shape with a liquid or semi-liquid material, which after drying solidifies -9 in the form of a flexible external layer impermeable to water, such as the coating 12 of the liner of FIG. 4. This impregnation step can be carried out by any known method of coating. Preferably, as illustrated in FIG. 2, this impregnation step is carried out by simple soaking of the lower part of the liner 1 ′ in at least one bath of a material 11 in liquid form, which after solidification forms the coating flexible 12 of the liner of Figure 4. In this figure, the height of soaking the liner in the bath is referenced h. Basically, the form 10 is not removed from the liner until the lining 12 has solidified, the lower part of the liner

  covered with this coating thus being molded into shape.

  Referring to Figure 4, the coating 12 after solidification of the material 11, covers the outer face 3a of the sole 3, the seam 9 connecting the rod 2 to the sole 3, and rises, above this seam, covering the lower part of the upper 2 over a height H, which corresponds substantially to the soaking height h of the liner in the bath of material 11. This covering 12, in addition to its function of waterproofing the sole 3 and the peripheral seam 9 , also fulfills another important function which is to give the sole 3 and the lower part of the upper 2, sufficient rigidity to keep these parts in shape, after removal of the form 10, while retaining for these parts of the liner a certain flexibility allowing the slipper to follow the movement of the foot during walking. The lower part of the upper 2 and the sole 3 are thus advantageously molded into shape, according to a geometry perfectly adapted to the interior volume of the shoe, in which the liner is later intended to be fitted, which advantageously avoids the appearance of folds in the sole 3 and in the lower part of the upper 2 during assembly of the liner inside the shoe. In addition, the better shape retention of the liner at the lower part of its upper 2 and its sole 3 facilitates the positioning operation of the liner by

compared to the upper of the shoe.

- 10 -

  It is understood that the more the tight stiffening coating 12 rises

  in height on the rod 2, and better is the maintenance in shape of the rod 2.

  However, it should be noted that this waterproof coating 12 obstructs the passage of water vapor. Consequently, the parts of the rod 2 on which the coating 12 is applied no longer allow water vapor to pass. This is the reason why the coating 12 must be applied only at the bottom of the rod 2 and must not rise too high on the rod 2. It is up to the person skilled in the art to fix the upper limit on a case-by-case basis. of this coating 12, that is to say during the aforementioned soaking step, to fix the soaking depth of the liner. In any event, the coating 12 must not

  cover the entire surface of the rod 2.

  If we refer to FIG. 4, we referenced by the letter A the front junction zone between the sole 3 and the upper 2 which is opposite to the heel T of the boot. From this front junction zone A, the upper 2 of the liner has a first front portion 2 'oriented substantially transversely to the sole 3, and which corresponds to the part of the liner commonly called the "tip" of the liner. This point 2 'is extended by a second portion 2 "which extends to the fold zone referenced B, which is substantially parallel to the sole 3, and which forms the part of the boot commonly called" above "the boot. In practice, the 2 "portion of the rod 2 corresponds to the part which covers the user's foot at the level of the toes and the instep. The fold zone B corresponds to a slope change zone, beyond which the rod 2 forms a third front portion 2 "'. In practice, this portion 2"' starts substantially at the ankle of the user and goes back above the ankle. Given the above definitions of the portions 2 ', 2 "and 2"' of the rod 2, and in the light of the example in FIG. 4, the so-called "lower" part of the rod 2, which is covered with the waterproof stiffening coating 12, corresponds to the lower part of the upper 2 which extends between the sole 3 and an upper limit situated at most at the level of the bending zone B. In addition

- 11 -

  terms, in the context of the invention, the covering 12 preferably extends as far as possible up to this folding zone B. More particularly, but not exclusively, the covering 12 is produced so as to extend beyond of the seam 9 between the sole 3 and the upper 2 over a height H at least equal to 0.1 mm, and is preferably made so as to cover at least the tip 2 'of the boot. Several types of material 11 may be suitable for producing the flexible coating 12. It may for example be a resin or a mixture of thermosetting resins, a solution based on one or more elastomers

  Synthetic O10 or latex solution.

  A particular example of the formation of a coating 12

  latex will now be detailed with reference to the diagram in FIG. 3.

  The process for producing a latex coating 12 in FIG. 3 mainly comprises four successive dipping operations, in four

  baths, an intermediate liner 1 ′ into which the form 10 has been introduced.

  The first bath is a bath containing latex in liquid form, for example at room temperature. The soaking operation is carried out by immersing the intermediate liner 1 ′ in the first latex bath over a given soaking height h, for a sufficient time so that the latex in liquid form deeply permeates and saturates the porous structure of the sole 3 of the intermediate liner 1 '. For example, the operation of

  soaking in the first latex bath was carried out for about 15 seconds.

  At the end of the soaking operation in the first bath, the intermediate liner 1 ′ is covered in the lower part with a first layer of latex taken from the mass of the intermediate liner and forming on the surface of the liner

  intermediate a thin film of latex.

  Then, the slipper is soaked in a second bath containing a product in liquid form capable of coagulating the latex in the usual way. It will be for example a bath containing in a known manner a vulcanizing dispersion

- 12 -

  at room temperature, in the form of an aqueous solution containing one or more oxides, including for example zinc oxides, the soaking operation lasting approximately 15 seconds. The soaking height h2 of the liner in this second bath is strictly less than the soaking height h1 in the first bath. The bootie is then soaked in a third complementary latex bath at room temperature, for example for approximately 15 seconds. The soaking height h3 is provided at an intermediate level between the soaking height h2 of the liner in the second bath and the height of

  soaking of the liner in the first bath.

  The first soaking operation in the first latex bath has the function of forming a first layer of latex which is taken in the structure of the intermediate liner and which provides a hooking surface for the second.

  latex layer formed at the end of the third bath.

  The liner is rid of any impurity by being soaked in a fourth and final hot water bath, for example at a temperature of the order of 50C 'for about 15 seconds. In the end, the intermediate liner kept in shape is dried, for example by passing through a tunnel oven at a temperature of the order of 100 ° C. After drying, the shape 10 is removed from the liner,

  which is ready to go to the next manufacturing stage.

  The particular process which has just been described with reference to the block diagram of FIG. 3, and which essentially rests on simple operations of soaking the liner in several successive baths, has the advantage of being able to be easily and completely automated, unlike for example 2 5 to the second known solution of the prior art previously described which requires at least one manual operation for the establishment of the inner lining on the first of mounts and for sealing the shoe

at the level of the original equipment.

  The boot 1 of FIG. 4 can, before being integrated into a

- 13 -

  shoe, go through an intermediate step of checking its tightness, which advantageously allows the manufacturer to subsequently guarantee the user the tightness of the shoe. This control step will be carried out for example by

  immersing the slipper in a water bath for a predetermined period.

  The operations for assembling a shoe integrating the liner 1 of FIG. 4 will now be detailed with reference to FIGS. 5 to 7. With reference to FIG. 5, the liner 1 of FIG. 4 is, in a first step manufacturing shoe, positioned relative to the rod 13 of the shoe and made integral with this rod 13, being sewn for example in the upper part with this rod. In the example illustrated, the rod 13 is formed of an internal coating 13_a, for example in Cordura, and of an external coating 13b, for example in split leather. Then, with reference to FIG. 6, the assembly thus formed is positioned on a shape 14 introduced inside the liner 1. This shape 14 has the same geometry as the shape 10 used previously during the manufacturing step shoe 1. We then glue the first shoe mounting on the underside of shoe 1, that is to say in contact with

  the part of the covering 12 covering the lower face 3a of the sole 3.

  Then the free end 13c of the rod 13 is welded over its entire periphery on the lower face 1Sa of the first assembly 15. Finally, in an ultimate step, an attached external sole 16 is bonded to the lower part of the rod 13 ( outsole), so as to obtain the shoe of which a partial sectional view in principle at the heel is shown in FIG. 7. The liner 1 acts as an inner lining which is waterproof but lets the water vapor at the parts of the liner not covered by the covering

12.

- 14 -

Claims (15)

  1. Slipper (1) which is intended to be fixed inside an article of footwear to act as an inner lining, characterized in that it is produced by assembling a rod (2) waterproof but permeable to water vapor and a sole (3) made of a material permeable to liquids, and in that it further comprises an external coating (12) waterproof, which covers the sole and only the lower part of the rod over its entire periphery, and which gives the covered parts sufficient rigidity for the   keep in shape while retaining some flexibility.   2. The boot according to claim 1, characterized in that the upper (2) and the sole (3) are assembled transversely with respect to one another, in particular by   a peripheral seam (9) of the Strobel type.   3. The boot according to claim 1 or 2, the upper (2) of which comprises a front portion (2 ′) which is oriented substantially transversely to the sole (3), which is commonly called the “tip” of the boot, and which is extended by a portion (2 ") substantially parallel to the sole (3) and extending to a bend zone (B) of the rod (2), characterized in that the waterproof stiffening coating (12)   extends as far as possible to this fold zone (B).   4. Slipper according to claim 3 characterized in that the coating of   waterproof stiffening (12) covers at least the tip (2 ') of the liner.   5. Slipper according to one of claims 1 to 4 characterized in that the   waterproof stiffening coating (12) is made so as to extend beyond the peripheral junction zone between the sole (3) and the upper (2) over a height H at least equal to 10mm.   6. Slipper according to one of claims 1 to 5 characterized in that the   waterproof stiffening coating (12) is made by impregnating the liner with a liquid or semi-liquid material (11), which after drying solidifies under   the shape of a flexible and waterproof layer.   7. Slipper according to claim 6 characterized in that the coating of - 15 -   tight stiffening (12) is based on latex or a synthetic elastomer.   8. A method of manufacturing a liner (1) which is intended to be fixed inside an article of footwear to act as an inner lining, characterized in that an intermediate liner (1 ') is produced by assembly a rod (2), which is impermeable to water and permeable to water vapor, and a sole (3), which is permeable to liquids, in that it is introduced into the intermediate liner ( 1 ') a rigid shape (10) adapted to the interior volume of the footwear, and in that the lower part of the intermediate liner (1') is impregnated with a liquid or semi-liquid material (11), capable of solidify so as to form an outer waterproof coating (12) which covers the sole (3) and only the lower part of the upper (2) of the intermediate liner (1 ') over its entire periphery, and which allows molded covered parts while   retaining some flexibility.   9. The manufacturing method according to claim 8 characterized in that the intermediate liner (1 ') is made by assembling a rod (2) and a sole (3) transversely to one another, in particular by a   peripheral seam (9) of Strobel type.   10. Method according to claim 8 or 9 characterized in that the impregnation step is carried out by soaking the lower part of the liner   2 0 intermediate (1 ') in at least one bath containing in its liquid or semi-form   liquid the material (11) intended to form the waterproof stiffening coating.   11. Method according to one of claims 8 to 10 characterized in that the rod (2)   of the intermediate liner (1 ') comprising a front portion (2') which is oriented substantially transversely to the sole (3), which is commonly called "tip" of the liner, and which is extended by a portion (2 "), substantially parallel to the sole (3) and extending to a bend zone (B) of the upper (2), the impregnation step is carried out so that the coating of   tight stiffening (12) extends as far as possible to this fold zone (B).   12. Method according to claim 11 characterized in that the impregnation step - 16 -   is made in such a way that the tight stiffening coating (12) covers   at least the tip (2 ') of the liner.   13. Method according to one of claims 8 to 12 characterized in that the impregnation step is carried out so that the waterproof stiffening coating (12) extends beyond the peripheral junction zone between the sole ( 3) and the rod   (2) over a height H at least equal to 10 mm.   14. Method according to one of claims 8 to 13 characterized in that the   material (11) used to form the waterproof stiffening coating (12) is   based on latex or a synthetic elastomer.   o 15 A method according to claim 14 characterized the waterproof stiffening coating (12) is produced by successively dipping the intermediate liner (1 ') in a first latex-based bath, in a second bath containing a coagulating product of latex, and in a third latex-based bath, and in that the soaking height (hl) in the first bath is greater than the soaking height (h3) in the third bath, which is itself greater than the height of   soaking (h2) in the second bath.   16. Footwear characterized in that it has an inner lining   formed of a liner (1) according to one of claims 1 to 7, or made   according to the process referred to in one of claims 8 to 15.