METHOD FOR MANUFACTURING A SHOE ITEM

Description

Technical Field

[0001] The present invention relates to a method of manufacturing an item of footwear, in particular for practicing a sport.

[0002] The present invention relates to a method for manufacturing an article of footwear, in particular the upper of said article of footwear, using one or more three-dimensional tubular knitted component(s) for producing an upper comprising an integrated sole part. Prior art

[0003] EP 3 501 316 A1 relates to a method for manufacturing footwear. 1 Footwear of the prior art generally includes two main elements, namely an upper and a sole structure. The upper is secured to the sole structure and forms a foot-receiving void or volume within the footwear to securely and comfortably accommodate the foot. The sole structure is secured to the lower region of the upper, and is thus positioned between the upper and the ground.

[0004] In footwear articles, for example, for the practice of a sport, the sole structure may include a midsole and a wear sole whose external face is intended to come into direct contact with the ground.

[0005] The midsole typically includes a polymer foam material that attenuates impact reactions with the ground to reduce the impact return forces generated on the foot and leg during walking, running, or other activities while wearing the footwear.

[0006] Additionally, the midsole may include one or more fluid-filled chambers, one or more cushioning parts or other elements that help to attenuate impact return forces and improve stability or influence foot movements and therefore proprioception.

[0007] The outsole is secured to the lower surface of the midsole and provides a ground engaging portion of the sole structure, which ground engaging portion is formed from a wear-resistant and durable material, such as, for example, a rubber-based material or a synthetic elastomer. The sole structure may also include an inner liner positioned within the foot-receiving volume of the upper and proximate the lower surface of the foot to enhance the comfort of the article of footwear.

[0008] The upper typically consists of many parts, such as a lateral quarter, a medial quarter, a toe cap, a tongue, a heel, a rear counter, a vamp, a tightening device including loops / (eyelets for a lace to pass through) and a lace, an internal lining, and possibly other parts. Some of these parts may be in several parts. The manufacture of a shoe therefore requires assembling these different parts to form a three-dimensional upper by cutting these parts and assembling them flat.

[0009] The upper generally extends over the instep and into the toe areas of the foot, along the lateral and medial sides of the foot, and around the ankle area of ​​the foot.

[0010] In some applications, such as basketball or hiking, the upper may extend up and around the ankle to provide additional support and protection to the ankle. The tightening device is often incorporated into the upper to adjust the size of the upper and thus allow entry and removal of the foot from the void formed within the upper. The upper may also include a tab that extends below the tightening device, for example the lacing system, to adjust the footwear, and the upper may include a rear reinforcement element to limit heel movement. Assembling these various components / elements / parts is time-consuming and can lead to errors in the manufacture of the footwear. The potential number of errors can thus be significant and complicate the manufacturing process and therefore also make it more expensive.

[0011] The upper, shaped, and therefore given volume, in particular by assembly at the heel, for example using a seam, is associated in a known manner with a sole element, in particular forming part of a sole structure, to delimit a footwear volume.

[0012] The upper can thus be glued to the sole element with a layer of glue; it can be glued to a relatively rigid insole.

[0013] Alternatively, the upper can be joined to the sole element by shaping the upper using various seams and then joining the upper to the insole by sewing using the so-called stroebel technique. The insole in this case is generally flexible so that it can be sewn. The insole thus forms the sole part or bottom of the upper.

[0014] The time and costs associated with transporting, storing, cutting, and assembling the various components are very significant. In addition, during the cutting and assembly of components, a lot of waste is generated. Footwear items with a large number of components made of different materials are more difficult to recycle because it is particularly complex to separate the components for recycling. Thus, by reducing the number of different components used in the composition of a shoe, it is possible to reduce the amount of waste and improve the efficiency of the manufacturing process for such footwear items and the recyclable nature of the uppers.

[0015] It has thus been proposed to produce footwear articles using an upper obtained from the manufacture of a three-dimensional knitted tube. These methods first implement the knitting of the primary upper by knitting a tubular knitted component in the shape of a substantially sock.

[0016] The method then comprises making a longitudinal cut in the sole portion of the knitted tubular component, then laying this knitted tubular component flat using the longitudinal cut so as to reveal a flat portion on which one or more functionalization components can be laid flat. These functionalization components such as a logo, reinforcing elements, lacing eyelets, a hard toe or even an upper or even a heel reinforcement, are manually applied to the flat portion of the knitted tubular component and then secured, for example by gluing and / or sewing. The longitudinal cut made in the sole portion manually is then closed, for example using a seam. A footwear assembly is then obtained comprising the primary upper secured with one or more functionalization components.This footwear assembly is placed on a foot-shaped preform, then thermoformed to the shape of the preform's foot to form the final upper. Since the dimensions of the preform correspond to a given foot size, many preforms are required. The preforms are made of plastic or composite material(s). Finally, a sole element such as a midsole is secured to the sole portion of the final upper.

[0017] Making a longitudinal cut in the sole part of the knitted tubular component in order to lay it flat and be able to carry out its functionalization requires additional steps.

[0018] There is a need for a method of manufacturing a footwear article that limits the number of steps required to manufacture an upper and does not degrade the functional component(s) used.

[0019] There is also a need for a manufacturing process that can reduce manufacturing time and improve the quality of the resulting rod. Statement of the invention

[0020] The subject of the present invention is a method for manufacturing an article of footwear, limiting the number of components and / or parts, thus making it possible to significantly reduce the manufacturing time, the number of manufacturing steps, limiting assembly errors, minimizing the quantity of waste, and improving the quality of the upper obtained in terms of appearance and mechanical properties.

[0021] The present invention also relates to a method offering more possibilities in the aesthetic design of the rod, and making it possible to improve the stabilization of the rod.

[0022] The invention is as defined in claim 1.

[0023] Advantageously, the flattening opening is formed during the knitting of the first knitted tubular part. Said flattening opening is therefore knitted. The step of cutting the flattening opening in the sole part is thus eliminated. Furthermore, since the flattening opening is formed by knitting, it is positioned and sized at least on the sole part in a reproducible manner, thus avoiding errors when producing it manually.

[0024] Preferably, said at least one flattening opening comprises edges, in particular medial and lateral, arranged between the front and rear edges of the sole part of the first knitted tubular part, still preferably at least one of the edges, in particular medial and lateral, does not comprise cut threads.

[0025] Advantageously, the flattening opening according to the invention does not include edges likely to fray since they do not include cut threads.

[0026] Preferably, the flattening opening comprises at least one longitudinal segment, extending along a longitudinal axis I, parallel or coincident with the longitudinal axis L of the footwear assembly, and in particular of the upper.

[0027] In one embodiment, the flattening opening comprises / (is formed of) a single segment or at least two segments, in particular intersecting, for example perpendicular or forming a cross.

[0028] Each segment may be substantially straight or curved, and / or extend along the longitudinal axis L or the transverse axis T or in any direction intersecting the longitudinal axes L and transverse axes T.

[0029] The segment(s) that comprise a flattening opening define(s) the shape of the latter.

[0030] In this text, the term "longitudinal" means the direction L extending along a length or major axis of the footwear article or upper or footwear assembly, or first or second tubular part. In certain cases, the longitudinal direction may extend from a forefoot region to a rearfoot region of the footwear article or upper or footwear assembly, or first or second knitted tubular part.

[0031] The longitudinal axis L is intersecting, in particular substantially perpendicular, to the transverse axis T of the upper or of the footwear assembly, or of the first or second tubular part. In this text, the term "lateral" is understood to mean the direction T extending over a minor width or axis of the footwear article or of the upper or of the footwear assembly, or of the first or second knitted tubular part. The lateral direction can thus extend between the medial side and the lateral side of the footwear article.

[0032] In this text, "vertical" means the direction extending generally perpendicular to the lateral direction and the longitudinal direction.

[0033] Preferably, the longitudinal axis L corresponds to the longitudinal axis of symmetry of the upper or footwear assembly.

[0034] During the functionalization step (iii), the functional component(s) may be held in position on the first knitted tubular part and / or the second knitted tubular part by sewing and / or gluing and / or by welding, in particular thermal welding, in particular by ultrasound, using one or more holding points; in particular by one or more sewing points and / or one or more glue points and / or one or more welding points, for example ultrasonic welding. This arrangement makes it possible to hold the functionalization component(s) in its functionalization location(s), possibly while waiting for complete joining during the thermoforming step (iv).

[0035] During step (iii) of functionalization, the functional component(s) may be secured arranged on the first knitted tubular part and / or the second knitted tubular part by sewing and / or gluing and / or by welding, in particular thermal, in particular by ultrasound.

[0036] By definition, thermoforming involves the application of heat to the footwear assembly for a time and at a temperature sufficient to thermoform the footwear assembly to the foot shape of the preform. Preferably, the temperature(s) applied during the transformation step (iv) is / are greater than or equal to the melting and / or softening temperature(s) of the thermofusible portion(s) of the first knitted tubular part and / or the second knitted tubular part.

[0037] The thermofusible portion(s) is / are distributed over the first knitted tubular part, and possibly the second knitted tubular part (defined below), so as to allow thermoforming.

[0038] The transformation step (iv) allows the heat to melt / soften the thermofusible portion(s), the footwear assembly is also compressed and pressed against the outer surface of the preform. Following cooling of the footwear assembly, in particular to room temperature, maintained under pressure against the outer surface of the preform, the footwear assembly then permanently retains the foot shape of the preform. The melting or softening, then cooling, of one or more thermofusible portions makes it possible to impart the foot shape of the preform to the footwear assembly, and possibly to secure the functional component(s) to the first tubular part.

[0039] Thermoforming can be carried out by applying one or more heat sources to the footwear assembly placed on the preform, for example using a manual iron.

[0040] Preferably, thermoforming is carried out by placing the footwear assembly in a molding volume delimited on the one hand between the outer surface of the preform, and on the other hand, with the complementary imprint of the foot shape of the preform formed by a mold, in particular in at least two parts, or formed by a flexible and deformable membrane (in particular airtight). This arrangement allows better heat distribution, and makes it possible to apply pressure to the footwear assembly via the mold or the membrane so that it perfectly matches the outer surface of the preform.

[0041] The membrane can be made of a flexible and deformable material, for example silicone or polyurethane. The membrane is by definition airtight. The flattening opening is through (and therefore in particular the segment(s) it comprises), it therefore opens onto both the internal face (and therefore the internal volume for receiving the foot) and the external face of the sole part of the first knitted tubular envelope.

[0042] Preferably, the flattening opening is formed of a longitudinal segment having a length I1 greater than or equal to 50%, more preferably greater than or equal to 70%, in particular less than or equal to 90%, of the length of the sole portion comprising said flattening opening. The length of the sole portion is calculated as being the greatest length measured between the front and rear edges of the sole portion. In one embodiment, said flattening openings are arranged in the sole portion of the first knitted tubular portion and in the sole portion of the second knitted tubular portion.

[0043] In one embodiment, said at least one flattening opening is disposed in the sole portion of the first knitted tubular portion and also extends into the rear portion, and optionally into the rear leg portion (e.g. in the case of a boot-type footwear article), of the first (and optionally the second) knitted tubular portion.

[0044] The functional component(s) may be secured together by means of the hot-melt portion(s) comprised in the first knitted tubular part and / or the second knitted tubular part (defined below), and / or the hot-melt portion(s) comprised in the functional component(s) themselves, and / or one or more adhesive means, in particular at least partly hot-melt. In the latter case, the adhesive means is / are considered equivalent to one or more functional component(s) according to the invention having an intermediate securing function.

[0045] The functional component(s) according to the invention has / have at least one function chosen from the following functions: cushioning, reinforcement, adhesion, continuous or discontinuous protective coating, aesthetics, or a combination of these.

[0046] The first knitted tubular part, and / or the second knitted tubular part (defined below) may be knitted on a double-bed flat-bed knitting machine, or on a circular knitting machine.

[0047] Preferably, the first knitted tubular portion and / or the second knitted tubular portion is / are each a cover comprising a sole portion (intended to come under the wearer's foot), a lateral portion (intended to come into contact with the lateral side of the wearer's foot), a medial portion (intended to come into contact with the medial side of the wearer's foot), a front portion in the extension of the medial, lateral and sole portions (intended to cover the front of the foot), and a rear portion in the extension of the medial, lateral and sole portions (intended to cover the rear of the foot, and therefore the heel, and possibly the ankle). The cover may be arranged so as to cover all or part of the ankle and possibly extend above the malleolus.

[0048] The front portion of the envelope may include a tongue and a distal pocket for receiving the toes. The tongue may be integral with the front portion only along its front edge or integral with the front portion, in addition to its front edge, along its lateral and medial edges respectively to the lateral and medial portions.

[0049] The rear portion may include a pocket configured to receive the heel.

[0050] The casing preferably defines a volume or void for accommodating the wearer's foot. In one embodiment, the first knitted tubular portion is of unitary knitted construction with the knitted casing such that the casing and the first knitted tubular portion comprise a single knitted piece.

[0051] In one embodiment, the second knitted tubular portion is of unitary knitted construction with the knitted casing such that the casing and the second knitted tubular portion are in a single knitted piece. In this case, the knitted piece forming the second knitted tubular portion and the knitted piece forming the first knitted tubular portion are secured to each other, in particular during the transformation step (iv), for example by sewing.

[0052] In another embodiment, the first knitted tubular portion and the second knitted tubular portion are each in a shell, the two shells being of unitary knitted construction with their respective first and second knitted tubular portions so as to comprise a single knitted piece.

[0053] The first knitted tubular part and / or the second knitted tubular part comprises one or more threads, in particular mechanically assembled by knitting.

[0054] The yarn(s) may be selected, independently, from: monofilament yarn(s), fiber-spun yarn(s), multifilament yarn(s), and a combination thereof.

[0055] The yarn(s) may be non-hot-melt yarn(s), at least partially hot-melt yarn(s), or fully hot-melt yarn(s), or a mixture thereof.

[0056] Thus, the first knitted tubular part and / or the second knitted tubular part comprises / comprise (each) one or more at least partly heat-fusible yarn(s), and / or one or more non-heat-fusible yarn(s).

[0057] In this text, any thermofusible material, wire, portion, first component, or equivalent is understood to mean that the latter is configured to be melted or at least sufficiently softened during the transformation step (iii) in order to allow the thermoforming of the footwear assembly, and possibly the joining of the first and second tubular part(s) together.

[0058] The footwear assembly may thus comprise one or more materials which are fusible by nature by application of heat (and therefore in the strict sense thermofusible) but which will not be activated during step (iv) because their melting temperature(s) is / are higher than the heating temperature(s) used during step (iv). This / these material(s) is / are considered in the present text as being non-thermofusible. The thermofusible threads, in particular at least partially, may be threads comprising at least two components, in particular of the two-component type, a first component having a melting temperature lower than or equal to the heating temperature(s) used during step (iv), and a second component having a given melting or degradation temperature higher than the heating temperature(s) used during step (iv).

[0059] The thermofusible wires may be single-component wires whose melting temperature is less than or equal to the heating temperature(s) used during step (iv).

[0060] Bi-component yarns may be of the core-mantle type, the core being formed of the second component and the coat being formed of the first component.

[0061] The first component may be chosen from polyurethanes, in particular thermoplastic polyurethanes; polyamides, such as polyamide 6 or 66; polyolefins, such as polypropylene (PP) or polyethylene (PE); preferably from polyurethanes.

[0062] The second component may be chosen from polyolefins, such as high density polyethylene; polyamides, such as polyamide 4-6, polyamide 6 or 6-6; polyesters, such as polyethylene terephthalate.

[0063] Bi-component yarns may be of the core-mantle type, the core being formed of the second component and the coat being formed of the first component.

[0064] The first component and / or the second component may be colored or colorless and / or opaque or transparent.

[0065] Preferably, the hot melt component(s) have a melting or softening temperature less than or equal to the heating temperature(s).

[0066] Preferably, the heating temperature(s) applied to the footwear assembly during the transformation step (iii) is / are greater than or equal to 80°C, more preferably greater than or equal to 90°C, preferably greater than or equal to 100°C.

[0067] Preferably, the heating temperature(s) applied to the footwear assembly during the transformation step (iii) is / are less than or equal to 250°C, more preferably less than or equal to 200°C, preferably less than or equal to 180°C.

[0068] The yarn(s), in particular non-thermal, may comprise one or more material(s) chosen, independently, from synthetic, artificial (for example lyocell or viscose), natural, mineral or inorganic materials, and a combination thereof, preferably from synthetic, artificial and natural, in particular synthetic, materials.

[0069] The synthetic material(s) preferably comprise: polyesters, in particular polyethylene terephthalate (PET) and polybutylene terephthalate (PBT); polyamides (such as PA 6, PA 6-6, PA 12, PA 4-6); polyolefins (polypropylene, polyethylene, PEEK, PEUHMW); aramids, in particular meta-aramid or para-aramid or a mixture thereof; vinyl acetates (e.g. EVA), polyacrylics (e.g. polyacrylonitrile); elastomers; elastanes, or a mixture thereof, preferably polyesters and polyolefins.

[0070] The natural material(s) preferably include: cotton, viscose, linen, sisal, wool, jute, silk, hemp.

[0071] The mineral or inorganic material(s) preferably comprise: carbon, mineral fibers, such as rock fiber, glass.

[0072] The monofilament yarns preferably have a diameter greater than 0.01 mm and less than or equal to 5 mm, more preferably greater than or equal to 0.1 mm and less than or equal to 2 mm.

[0073] The multi-filament yarns and / or spun yarns of fibers preferably have a count greater than or equal to 10 dtex and less than or equal to 1,000 dtex, more preferably greater than or equal to 30 dtex and less than or equal to 500 dtex.

[0074] Multi-filament yarns can be textured yarns such as FDY (Full Drawn Yarn), DTY (Draw Textured Yarn) or POY (Partially Oriented Yarn), or a mixture of these.

[0075] The first and second knitted tubular part(s) may also comprise one or more elastic thread(s), in particular elastane.

[0076] In one embodiment, the preform comprises an interior volume and perforations opening onto its exterior surface, said interior volume and the perforations are in fluid connection, preferably the perforations open into the interior volume of the preform.

[0077] Preferably, the perforations are distributed over the entire outer surface of the preform intended to come into contact with the footwear assembly.

[0078] The preform comprises a sole part (intended to come into contact with the sole part of the envelope defined above), a lateral part (intended to come into contact with the lateral side of the envelope defined above), a medial part (intended to come into contact with the medial side of the envelope defined above), a front part in the extension of the medial, lateral and sole parts (intended to cover the front of the foot with the envelope defined above), and a rear part in the extension of the medial, lateral and sole parts (intended to cover the rear of the foot, and therefore the heel, and possibly the ankle with the envelope defined above).

[0079] In a preferred embodiment, the preform comprises perforations in at least one of the aforementioned portions, in particular in each of the aforementioned portions.

[0080] Preferably, the perforations comprise substantially circular perforations.

[0081] In a preferred embodiment, the perforations comprise (or are made up of) perforations whose largest dimension is circumscribed in a circle whose diameter is greater than 1 mm, more preferably greater than or equal to 3 mm, preferably greater than or equal to 6 mm, in particular less than or equal to 20 mm, in particular less than or equal to 10 mm.

[0082] In one embodiment, the ratio of the total sum (cm 2< ) of the surfaces of the perforations (cm 2< ) to the total surface (cm 2< ) of the external surface (cm 2< ) of the preform is less than or equal to 60%, preferably less than or equal to 40%, more preferably less than or equal to 25%, in particular greater than or equal to 10%.

[0083] The heat circulates through the entire shoe assembly but also through the perforations of the preform towards its interior volume, and conversely from its interior volume, through the perforations towards the entire shoe assembly.

[0084] This arrangement makes it possible to further improve the aesthetic and mechanical qualities of the upper by the homogeneous distribution of heat, and possibly of a flow of gas(es), in particular water vapor, combined, over the entire footwear.

[0085] In one embodiment, a flow of gas(es), in particular water vapor, is sent to the footwear assembly during the transformation step (iv), in particular through the perforations of the preform. This arrangement makes it possible to soften the upper obtained. The upper obtained has an even more regular shape, and therefore a better appearance, and its mechanical properties are improved (for example, better reproducibility of tear resistance, elongation at break, better peel resistance). The upper obtained also has an improved feel, in particular a more flexible feel. Finally, the joining, as mentioned above by the fusion of hot-melt portion(s), is further reinforced.

[0086] An explanation, not exhaustive of these technical effects, and not limiting of the present invention, would be that the water vapor would act as a plasticizer on the textile and / or polymeric elements that the footwear assembly comprises, in particular the first and / or second knitted tubular part(s).

[0087] In one variant, the outer surface of the preform comprises at least one metal.

[0088] In one variant, the outer surface of the preform comprises at least one metal alloy, in particular a ferrous or non-ferrous alloy.

[0089] The two preceding provisions make it possible to considerably reduce the duration of step (iii) because the said less a metal or the metal alloy(s), has / have a better thermal conductivity than the plastic or composite preforms of the state of the art.

[0090] Metal is understood herein to mean any metal considered to belong to the family of metals listed in Mendeleev's periodic table of elements. For example, a reduction in thermoforming time by two has been observed with the use of the preform according to the invention, from 80 seconds to less than 40 seconds.

[0091] In particular, the entire outer surface of the preform comprises at least one metal or metal alloy.

[0092] In one embodiment, the preform, in its entirety, is made of at least one metal or metal alloy, or optionally a glass-ceramic material.

[0093] Said at least one metal or metal alloy is preferably chosen from: aluminum, iron, stainless steel, or a combination thereof.

[0094] In one variant, the outer surface of the preform comprises a glass-ceramic material, in particular the outer surface of the preform is made of a glass-ceramic material.

[0095] In one variant, the preform, in particular its outer surface, undergoes a physical and / or chemical surface treatment.

[0096] This arrangement makes it possible to give the preform one or more additional thermal and / or mechanical properties, in particular to improve corrosion, wear or impact resistance properties, optimizing the use of the preform.

[0097] In one embodiment, the sole portion of the first tubular portion includes a rear edge and a front edge, and the flattening opening extends longitudinally between the rear edge and the front edge.

[0098] The first knitted tubular part is arranged substantially flat, during step (iii), on a support, so as to present an upper flat portion to be functionalized opposite a lower flat portion comprising said flattening opening.

[0099] It is thus possible to functionalize the internal face and / or the external face of the upper flat portion by arranging and securing one or more functional component(s). In a variant, said at least one flattening opening is closed before the transformation step (iv) into a rod, in particular by sewing.

[0100] Preferably, the lateral edge and the medial edge of the flattening opening, i.e. of at least one segment, are joined edge to edge.

[0101] In one embodiment, the method comprises providing a second knitted tubular part, optionally comprising at least one heat-fusible portion, and the footwear assembly in step (iv) comprises the first and second knitted tubular parts, at least in part, superimposed, in connection with one or more functional component(s). In one embodiment, the sole portion of the second knitted tubular part comprises at least one flattening opening (similar to that provided in the first knitted tubular part), in particular of unitary knitted construction with the second knitted tubular part. This flattening opening is therefore also formed during the knitting of the second part and allows the flattening of the second part in order to functionalize it during step (iii).

[0102] Of course, if it is not necessary to functionalize the second knitted tubular part, the latter does not include a flattening opening.

[0103] In a variant, the transformation step (iv) allows the first and second knitted tubular parts to be joined together, at least partially.

[0104] The first and second knitted tubular parts are joined together following the fusion of one or more heat-fusible portion(s), which comprises at least one of the first and second tubular parts.

[0105] Preferably, at least a portion of the outer face of the second knitted tubular part is secured to at least a portion of the inner face of the first knitted tubular part, said securing portions comprising at least partly heat-fused threads. In this case, the first knitted tubular part forms an outer layer of the footwear assembly. The reverse arrangement is also possible, the second knitted tubular part forms an outer layer of the footwear assembly.

[0106] In one variant, a functional component, chosen from the functional component(s), is arranged on at least one face chosen from: the external face of the first knitted tubular part, the internal face of the first knitted tubular part, or a combination of the latter.

[0107] In one variant, a functional component, chosen from the functional component(s), is arranged on at least one face chosen from: the external face of the second knitted tubular part, the internal face of the second knitted tubular part, or a combination of the latter.

[0108] In one variant, a functional component, chosen from the functional component(s), is a film comprising at least one hot-melt material.

[0109] In a variant, after step (iv), said film forms a coating (or has dimensions determined so as to form a coating) covering at least 10%, preferably at least 25%, more preferably at least 40%, preferentially at least 50%, even more preferentially at least 70%, in particular at least 80%, or 98% to within + / - 2%, of the outer surface of the upper (or of the first or second knitted tubular part), with the exception of the outer surface of the sole part of the upper (or of the first or second knitted tubular part).

[0110] In a sub-variant, said film forms a coating covering at most 50%, preferably at most 30%, of the outer surface of the upper (or of the first or second knitted tubular part), with the exception of the outer surface of the sole part of the upper (or of the first or second knitted tubular part).

[0111] The coating may be continuous or discontinuous, and / or in the form of pattern(s) (identical or different) and / or point(s), but generally covering the aforementioned % of the exterior surface area).

[0112] In fact, since the upper flat portion is not completely accessible, it is not possible to have a film covering a large area of ​​the outer surface of the rod.

[0113] In one variant, at least one of the functional component(s) is chosen from: an at least partly heat-fusible polymeric film, a heel reinforcement element, a logo, an aesthetic element, a hard toe, a reinforcement element for a lacing zone, a cushioning element, an auxiliary knitted tubular part, a textile element, or a combination thereof.

[0114] In one embodiment, at least one of the functional component(s) is a cushioning element, in particular a foam.

[0115] In one embodiment, at least one of the functional component(s) is selected from: an at least partially heat-fusible polymeric film, a heel reinforcement element, a logo, an aesthetic element, a hard toe, a reinforcement element of a lacing zone, or a combination thereof.

[0116] The textile element may comprise a woven, knitted, nonwoven element or a combination thereof.

[0117] The auxiliary knitted tubular part may be the same as or different from the first knitted tubular part. The description relating to the first or second tubular part applies to the auxiliary tubular part.

[0118] In one embodiment, the method comprises providing a knitted tubular component, and the first knitted tubular portion and the second knitted tubular portion are of unitary knitted construction with the knitted tubular component so as to form a one-piece knitted element.

[0119] In one variant, the method comprises arranging at least one functional component between the first knitted tubular part and the second knitted tubular part, in particular during step (iii) and / or during step (iv).

[0120] In one embodiment, the first knitted tubular portion forms an outer layer of the upper and the second knitted tubular portion forms an inner layer of the upper.

[0121] The reverse is also possible. The first knitted tubular part forms an inner layer of the upper, and the second knitted tubular part forms an outer layer of the upper.

[0122] In a variant, the first knitted tubular part comprises one or more at least partly heat-meltable yarn(s), the ratio of the mass of the at least partly heat-meltable yarn(s) to the total mass of the first knitted tubular part is greater than or equal to 20%, preferably greater than or equal to 40%, more preferably greater than or equal to 60%, in particular greater than or equal to 80%.

[0123] In a variant, the second knitted tubular part comprises one or more thermofusible thread(s), the ratio of the mass of the at least partly thermofusible thread(s) to the total mass of the second knitted tubular part is less than or equal to 80%, preferably less than or equal to 60%, more preferably less than or equal to 40%, in particular less than or equal to 20%.

[0124] In one variant, the first knitted tubular portion comprises a foot insertion opening area and the second knitted tubular portion comprises a foot insertion opening area, said foot opening insertion areas are superimposed. In one variant, the at least partially heat-meltable yarn(s) form(s) said at least one heat-meltable portion, preferably having a melting or softening temperature less than or equal to T1, which is preferably less than or equal to the heating temperature(s).

[0125] In a variant, step (iv) comprises heating the preform to a heating temperature greater than or equal to Tp, with Tp≥T1.

[0126] In a variant, step (iv) comprises heating the molding volume to a heating temperature greater than or equal to Tvm, with Tvm≥T1.

[0127] The temperatures Tp and Tvm can be the same or different.

[0128] In one variant, the upper obtained in step (iv) comprises a sole part, and the method comprises securing at least one sole element chosen from an intermediate sole and a wear sole to said sole part. Brief description of the drawings

[0129] The invention will be better understood on reading the following description of an embodiment of the invention given by way of non-limiting example, with reference to the appended drawings, in which: [ Fig. 1 ] there figure 1 illustrates a first example of a tubular knitted component comprising first and second knitted tubular portions; [ Fig. 2 ] there figure 2 illustrates the first knitted tubular part of the component shown in figure 1 , bottom view; [ Fig. 3 ] there figure 3 represents a second example of a knitted tubular component; [ Fig. 4 ] there figure 4 represents the first knitted tubular part of the component shown in figure 1 partially flattened on a support seen from above; [ Fig. 5 ] there Figure 5 illustrates the first knitted tubular part of the component shown in figure 1 partially flattened on a support seen from below; and [ Fig. 6 ] there figure 6 illustrates the closed longitudinal flattening opening of the sole part of the first knitted tubular part of the component of the figure 1 ; [ Fig. 7 ] there figure 7 illustrates an example of a shoe assembly arranged on the outer surface of a preform, in longitudinal section; [ Fig. 8 ] there figure 8 illustrates the footwear assembly disposed on the outer surface of a preform disposed in a molding volume for step (iv); [ Fig. 9 ] there figure 9illustrates an example of an article of footwear according to the invention comprising an upper obtained at the end of the transformation step (iv). Description of the embodiments

[0130] There figure 1shows a first example of a knitted tubular component 10 in a single piece 15, comprising a first knitted tubular part 20 and a second knitted tubular part 30, each being bent. The knitted tubular component 10 thus has a substantially U-shape. The first and second knitted tubular parts 20, 30 are of unitary knitted construction with the knitted tubular component 10. The first knitted tubular part 20 comprises an open distal end 22, which will preferably be closed by a seam before arrangement on the preform 50, an open proximal end 24 delimiting a foot insertion zone 26, as well as a foot reception volume 28. The second knitted tubular part 30 comprises a distal end 32 closed during knitting of the tubular component 10, and an open proximal end 34 delimiting a foot insertion zone 36 as well as a foot reception volume 38.Preferably, the first and second knitted tubular parts 20, 30 comprise respective heel zones 25, 35 intended to receive the heel of the user's foot. When programming the knitting machine to knit the knitted tubular component 10, the zoning of the first and second knitted tubular parts 20, 30 is determined according to different stitch patterns (reverse jersey, right jersey, ribbed stitches, etc.) and different types of yarns (by their nature and / or their color and / or their transparency and / or their count (dtex)). It is thus possible to vary the relief, the thickness, the aesthetics, and the functionality of the determined zone(s), and this for the first knitted tubular part 20 and the second knitted tubular part 30, independently of each other.

[0131] Alternatively, only one of the first and second tubular portions 20 and 30 may comprise a bent portion such that the tubular component 10 has a generally L-shape.

[0132] The first knitted tubular portion 20 comprises at least partly heat-meltable yarns arranged in one or more portions. The second knitted tubular portion 30 may also comprise one or more heat-meltable portions formed of at least partly heat-meltable yarns. The at least partly heat-meltable yarns represent, for example, at least 30% by mass, and at most 60% by mass, of the total mass of the first knitted tubular portion, and are distributed over the entirety of the latter. Alternatively, the first knitted envelope 20 consists essentially of heat-meltable yarns.

[0133] The at least partly thermofusible yarns represent, for example, at least 50% by mass, and at most 80% by mass, of the total mass of the second knitted tubular part, and are distributed over the entirety of the latter. This arrangement can of course vary depending on the stability and flexibility sought.

[0134] There figure 2represents the first knitted tubular part 20 seen from below, the sole part 27 of which comprises a longitudinal opening 29 for laying flat arranged between the front 27a and rear 27b edges. The longitudinal opening 29 is through, that is to say that it opens onto both the external face 21 and the internal face 23 of the first knitted tubular part 20. The opening 29 is formed of a single, substantially rectilinear segment. The longitudinal opening 29 is delimited by a medial edge 29a and a lateral edge 29b, and has a length I1 of between 50% and 90% of the length p of the sole part 27, preferably between 60% and 80% of the length p.

[0135] There figure 3shows a second example of a knitted tubular component 100 also in a single piece 150, comprising first and second knitted tubular portions 200 and 300. The knitted tubular component 100 is substantially straight, the first and second tubular portions 200 and 300 not comprising bent portions. The sole portion 270 comprises a longitudinal opening 290 similar to the longitudinal opening 29.

[0136] The longitudinal opening 29 of the knitted tubular component 10 makes it possible to lay the first tubular part 20 flat on a support S as shown in figure 4 top view for its functionalization, here of the external face 21 of the forefoot, medial and lateral parts of the first knitted tubular part 20. The figure 4 thus represents an upper flat portion 42 of the first knitted tubular part 20, opposite a lower flat portion 44 shown in Figure 5. The open distal end 22 may be closed before or after the functionalization step (iii) to form the toe-receiving tip of the first knitted tubular portion 20. Advantageously, the longitudinal flattening opening 29 is formed during the knitting of the first knitted tubular portion 20, and therefore during the knitting of the knitted tubular component 10. The medial and lateral edges 29a and 29b preferably do not comprise cut yarns; they may, for example, be formed by stitch transfer, so that they are not likely to fray. Fraying of the edges could indeed alter the structure of the sole portion 27 and propagate to the other parts of the first knitted tubular portion 20.The longitudinal opening 29 formed by knitting makes it possible to eliminate a cutting step, to form an opening whose positioning and size are reproducible but also to improve the stability of the structure during flat functionalization.

[0137] Four functional components 75 are secured to the external face 21, for example by a seam, or a weld (in particular thermal, for example by ultrasound) or using an adhesive agent. The functional components 75 are cited as a non-limiting example for the purposes of illustration, other functional components could be implemented and according to different regions on the external face 21 and / or the internal face 23 of the first knitted tubular part 20. The size and location chosen for the functional components are however limited to the available flat surface shown in the figure. figure 4. The second knitted tubular part 30 is not shown for reasons of simplification on the Figures 4 and 5 . Here the external face 23 is available for its functionalization but the first knitted tubular part 20 could be turned over and laid flat to functionalize its internal face 21. As can be seen on the figure 7 , the footwear assembly 40 also comprises a functional component 60 which is a heel reinforcement and a functional component 70 which is an instep cushioning element. The functional components 60 and 70 are arranged between the first and second knitted tubular parts 20 and 30, respectively between the forefoot parts and the rearfoot parts at the heel. The functional component 60 extends vertically from the longitudinal axis L. These components 70 and 60 are not shown in the Figures 4 and 5for reasons of simplification, but are preferably secured to the internal face 23 of the upper flat portion 42 of the first knitted tubular part 20.

[0138] The longitudinal opening 29 is then closed, in particular using a seam 35 in order to restore the volume of the footwear assembly 40, then the footwear assembly 40 is placed on a preform 50 as shown in figure 7in order to undergo a transformation step (iv) during which the preform 50 coated with the footwear assembly 40 is placed in a molding volume 80. The molding volume 80 is delimited between, on the one hand, the preform 50 coated with the footwear assembly 40, and on the other hand, the volume formed by a mold 90 in two parts 95 and 96. The interior volume of the mold 90 corresponds substantially to the footprint of the foot-shaped preform 50. Alternatively, the molding volume can also be delimited between the exterior surface of the preform 50 and a waterproof flexible membrane, comprising a hollow shape substantially of a foot coming to fit the footwear assembly arranged on the preform 50.

[0139] Heat is then applied to the footwear assembly 40, in particular combined with water vapor, in order to thermoform the footwear assembly 40 to the foot shape of the preform 50. The thermofusible portion(s) that comprises the first knitted tubular part 20, and possibly that comprises the second knitted tubular part 30, is / are melted / softened during the transformation step (iv), the footwear assembly 40 is also compressed against the outer surface of the preform 50. The footwear assembly 40, still on the preform 50, is then cooled, in particular to room temperature, and then retains the shape of the outer surface of the preform 50. This transformation step (iv) allows, in addition to thermoforming, to join together the first and second knitted tubular parts 20 and 30, in particular at least in part along their inner 23 and outer faces 31 respective.

[0140] The knitted tubular component 10 may alternatively comprise only the first knitted tubular part 20. In this case, the transformation step only allows the thermoforming of the first knitted tubular part, without joining. Alternatively, the first knitted tubular part 20 may be arranged in the interior volume 38 of the second knitted tubular part 30. The second knitted tubular part then forms the outer layer of the footwear assembly and the first knitted tubular part forms the inner layer.

[0141] The preform may also include perforations, in particular having a diameter of approximately 5 mm to 10 mm, opening onto an interior volume of the preform such that the perforations and the interior volume of the preform are in fluid connection. The performances allow water value to be injected onto the footwear assembly from the interior volume. This arrangement makes it possible to soften the upper obtained.

[0142] The transformation step (iv) allows the formation of an upper 400 whose sole part 450 is then secured to a sole element 500 to obtain the footwear article 1 shown in figure 9. The upper 400 may thus comprise different knitted zones 401 to 406 for the first knitted tubular part 20. The zones 401 to 406 differ in their mesh patterns, their colors, their elasticities, or their rigidities. The zones 406 thus correspond to knitted unidirectional reinforcement elements reinforcing the medial and lateral parts of the upper 400.

[0143] The flattening opening shown in the figures is a longitudinal opening, of course, the opening can have a cross shape or other shape as long as the shape of this opening allows the flattening of the knitted tubular part comprising it.

Claims

1. A method for manufacturing a footwear article (1) comprising the steps of: (i)- providing a first knitted tubular part (20;200) comprising at least one fusible portion, at least one sole part (27;270), and at least one flattening opening (29;290) of unitary knitted construction with the first knitted tubular part (20;200) and extending at least in the sole part (27;270), and providing one or more functionalization component(s) (60;70;75); (ii)- disposing, at least partly, the first tubular part (20;200) substantially flat using the flattening opening (29;290); (iii)- functionalizing the first knitted tubular part (20;200), at least partly, substantially flat, with one or more functionalization component(s) (60;70;75) to form a footwear assembly (40); (iv)- transforming the footwear assembly (40) previously disposed on a preform (50) having a foot shape in an upper (400), said transforming step comprising thermoforming the footwear assembly (40) to follow the foot shape of the preform (50), and in that the first knitted tubular part (20;200) is disposed substantially flat during step (iii), on a support (S), such as to present an upper planar portion (42) to be functionalized opposite to a lower planar portion (44) comprising, at least in part, said at least one flattening opening (29;290).

2. The method as claimed in claim 1, characterized in that the sole part (27;270) of the first tubular part (20;200) comprises a rear edge (27b) and a front edge (27a), and in that the flattening opening (29;290) extends, particularly at least longitudinally, between the rear edge (27b) and the front edge (27a).

3. The method as claimed in any of claims 1 to 2, characterized in that the flattening opening (29;290) is closed before the step (iv) of transforming into an upper (400), particularly by sewing.

4. The method as claimed in any of claims 1 to 3, characterized in that it comprises the providing of a second knitted tubular part (30;300), optionally comprising at least one fusible portion, and in that the footwear assembly (40) in step (iv) comprises the first and second knitted tubular parts (20;200;30;300), at least in part, superimposed, linked to one or more functional component(s) (60;70;75).

5. The method as claimed in claim 4, characterized in that the transforming step (iv) allows the at least partial securing of the first and second knitted tubular parts to one another (20;200;30;300).

6. The manufacturing method as claimed in one or the other of claims 4 and 5, characterized in that it comprises the layout of at least one functional component (60;70) between the first knitted tubular part (20;200) and the second knitted tubular part (30;300), particularly in step (iii) and / or in step (iv).

7. The manufacturing method as claimed in any of claims 4 to 6, characterized in that the first knitted tubular part (20;200) forms an outer layer of the upper (400) and the second knitted tubular part (30;300) forms an inner layer of the upper (400).

8. The manufacturing method as claimed in any of claims 4 to 7, characterized in that it comprises the providing of a knitted tubular component (10;100), and in that the first knitted tubular part (20;200) and the second knitted tubular part (30;300) are of unitary knitted construction with the knitted tubular component (10;100) such as to form an element made of a knitted piece (15;150).

9. The manufacturing method as claimed in any of claims 4 to 8, characterized in that the first knitted tubular part (20;200) comprises an opening area for insertion of the foot (26) and the second knitted tubular part (30;300) comprises an opening area for insertion of the foot (36), said foot insertion opening areas (26;36) are superimposed.

10. The manufacturing method as claimed in any of claims 4 to 9, characterized in that the second knitted tubular part (30;300) comprises one or more fusible yarn(s), the ratio of the weight of the at least partly fusible yarn(s) to the total weight of the second knitted tubular part (30;300), is less than or equal to 80%, preferably less than or equal to 60%, still preferably less than or equal to 40%, particularly less than or equal to 20%.

11. The manufacturing method as claimed in any of claims 1 to 10, characterized in that at least one of the functional component(s) is chosen from: a polymer film, at least partly fusible, a heel reinforcement element, a logo, an esthetic element, a hard cap, a textile element, a reinforcement element of a lacing area, a shock-absorbing element, an auxiliary knitted tubular part, or a combination thereof.

12. The manufacturing method as claimed in any of claims 1 to 11, characterized in that the first knitted tubular part (20;200) comprises one or more at least partly fusible yarn(s), the ratio of the weight of the at least partly fusible yarn(s) to the total weight of the first knitted tubular part, is greater than or equal to 20%, preferably greater than or equal to 40%, still preferably greater than or equal to 60%, particularly greater than or equal to 80%.

13. The manufacturing method as claimed in any of claims 1 to 12, characterized in that a functional component, chosen from the functional component(s), is disposed on at least one face chosen from: the outer face (21) of the first knitted tubular part (20;200), the inner face (23) of the first knitted tubular part (20;200), or a combination thereof.

14. The manufacturing method as claimed in any of claims 1 to 13, characterized in that a functional component, chosen from the functional component(s), is a film comprising at least one fusible material.

15. The manufacturing method as claimed in claim 14, characterized in that after step (iv), said film forms a coating covering at least 10%, preferably at the most 50%, of an outer surface of the upper (400).

16. The manufacturing method as claimed in any of claims 1 to 15, characterized in that the upper (400) obtained in step (iv) comprises a sole part (450), and in that the method comprises the securing of at least one sole element (500) chosen from a midsole and an outsole to said sole part.