EP2865767B1 - Method for forming a single piece shoe upper - Google Patents

Description

In a boot made according to a conventional design, a leg width of a boot may be adjusted by providing a slit whose width is adjusted by shoelaces, such as 10 in FIG EP 0569012 B1 shown. Furthermore, it is known to subsequently subsequently slightly deform a finished shoe by means of a shoe, in order to adapt it to an individual foot shape, as for example in US Pat US 2006 / 0117501A1 is disclosed. The DE 86 412 shows a method for producing one-piece boot shafts, wherein the one-piece boot leather is tanned in a manner not described in detail and then drummed into shape.

It is an object of the present description to provide a method of making a boot with a seamless shaft.

The object of the present description is apparent from the subject matter of the independent claims. Advantageous developments emerge from the dependent claims.

The present specification discloses a method for forming an upper leather in which first a tubular integral upper leather is provided as a portion of a leg portion of a bovine skin which is specially tanned and then widened prior to processing as the upper leather. Leg area refers to the area around one of the runs. In particular, the front leg is around the front legs.

In the case of the leather tanning used here, an animal skin is given resistance to water and rot by a process that has hitherto not been synthetically reproducible. The protein fiber is converted into leather fiber.

Before the actual tanning the leather is pre-processed in a water workshop. In the first operation, the switch, the skin is placed in water so that it is cleaned and brought to the original, natural water content. It is then inserted into the liming area for a few hours to days to remove the hairy epidermis and loosen the fiber structure. The liming agent may, for example, comprise lime milk, lime and sulfides and / or enzymes. The soaked and depilated skin is called nakedness.

In a further step of the Entfleischens the sub-skin is removed mechanically, so that finally only the dermis remains. When splitting the dermis is cut horizontally over the entire surface. Due to the strong alkaline treatment of the limp, the skin swells up. During the decalcifying process, the liming chemicals are removed from the skin, the pH is largely neutralized, and the skin regains its natural state of swelling. This makes it easier for the chemicals and tannins to penetrate the skin.

The present description uses a very slow vegetable tanning with vegetable tannins (tannins in leaves, barks, woods and fruits) and / or a tanning or tanning with, for example, fish and marine oils (Trane) or fats of the brain, or a Synthetic tanning with synthetically produced tanning agents (syntans, resin tanning agents, polymer tanning agents, polyphosphates, paraffinsulfochloride), which could also be used for the tanning of transmission belts.

The nature of Vegetabilgerbstoffe requires a careful Vorgerbung for the first stabilization of the fiber structure of Skin. In particular, a pretreatment lasting up to 12 months can be carried out in dilute tanning agent, which is also referred to as "old-grape tanning".

For fat tanning, fats with a tanning effect, such as Trane or fish oils, are introduced into the leather. To introduce the water-repellent fatty substances into the wet leather, leathers are not treated with the crude fatty substances, but with mixtures containing considerable amounts of emulsifying substances. These can be soaps, sulfated or oxidized or chlorinated fats, which are called "licker". "Lickern" means, among other things, the greasing with emulsified fats and related substances (Lickerfette) in the barrel at medium temperatures.

If product specifications are mentioned in the present description, these are those of Bayer / Lanxess.

The upper leather is pre-tanned by a fat tanning using fat and Licker, in particular Tran and Baykanollicker, such as Baykanollicker T are suitable.

Thereafter, the upper leather is retanned by a vegetable tanning with increasing concentration of a tanning agent mixture, wherein the concentration of the tanning mixture is in the range of 3 - 6 Beaume degrees.

The outer range limits in the quantities given in the present description are those in which sufficient extensibility of the seamless shaft without tearing is established for a still acceptable period of tanning. More tolerance in terms of quantities leads to useless results, unless explicitly stated otherwise. In the description and in the claims this tolerance is expressed by the term "about".

The retanning tanning mixture comprises about 49 parts of a vegetable tanning agent and about 51 parts of a synthetic tannin tanning agent. The above-mentioned weight ratio of 49 to 51 parts gives a particularly intense retanning. However, even at a ratio of 40 to 60 parts or at a ratio of 55 to 45 parts of vegetable to synthetic still results in a good retanning. However, with more than 55 parts of vegetable tanning agent, the tanning effect becomes too weak.

In particular, an extract obtained from the bark or the wood of a tree and, in particular, a cold-soluble quebracho extract can be used as the herbal extract. The synthetic tannin tannin consists entirely or predominantly of a synthetically produced tannin such as Tanigan from Bayer / Lanxess.

In retanning, the use of Tanigan in the synthetic tannin tanning agent proves beneficial, with the proportion of tannin synthetic tanning agent being about 96 weight percent Tanigan and about 4 weight percent of another synthetic tanning agent.

This results in 51 parts of synthetic tannin tanning agent about 49 parts Tanigan and about 2 parts of the further synthetic tannin tanning agent. Even with a composition of 48 parts to 3 parts, corresponding to 96% by weight to 4% by weight, there is still a very useful tanning effect. Even with only 40-45 parts of Tanigan, corresponding to 78% by weight to 88% by weight of Tanigan content, the tanning can still be carried out, albeit with increasingly reduced quality. With less than 40 shares, the result is no longer satisfactory.

In particular, blending the Tanigan extra NR product to accelerate the tanning and lightening of the leather color and the Tanigan BL product for bleaching proves beneficial.

In a further step, the upper leather is licked with a Lickermischung comprising water, an anionic emulsifier and a licker. The water preferably has a temperature of about 45 ° C, but water in the temperature range of 40 - 50 ° C can be used. Experience has shown that a Lickertemperatur of up to 60 ° C is still possible. On the other hand, even a Lickertemperatur of 30 ° C still lead to useful results, but then extends the treatment time considerably.

For loosening, 200-300% water, based on the weight of leather present before licking, is required. Also, the other percentages of the mixtures for the pretanning and Lickern relate, unless otherwise stated, to a present before the respective process step leather weight. Wilted before licking so the leather weight is the Abwelkgewicht. If additionally folded, it is the fold weight.

A good lubrication results when using 2% Cutisan BS and 1% Baykanollicker T, based on the weight of leather. Even when using only 1% Cutisan BS and / or only 0.5% Baykanollicker T is still an acceptable level of grease. It is also possible to use more Cutisan BS or more Baykanollicker T than indicated, but 2% Cutisan BS and 1% Baykanollicker are quite sufficient. Instead of Baykanollicker T another Baykanollicker can be used. The product Coripol is also suitable.

In a further embodiment, about 2% Tanigan supra LH is added as aftertaste to the lickermixture of the licker and the anionic emulsifier after the upper leather is loosened, so that an improved tanning is achieved. Even with a follow-up of only 1% Tanigan supra LH the tanning effect is intensified even more.

The special tanning of the skin used for the upper of the boot allows a large width, as it is necessary for a one-piece bootleg. Without the special tanning according to the application, the upper leather would break wide.

To widen the shaft, after the above-described method steps have been performed, a boot shaft broader is inserted into a shaft of the upper. With the boot shaft further, the upper leather is widened by at least 100% relative to the circumference at the narrowest point of a shaft portion of the upper.

When passing through the Stiefelschaftweiter a propulsion is converted by means of a wedge effect in a spreading movement. The spreading movement can in particular be such that a front wedge and a rear wedge of the bootleg broader unfold like a hinge. According to a further embodiment, the shaft extension may also be such that one or more parts are moved apart by a screw mechanism and / or a wedge.

According to another embodiment, improved tanning and softening of the leather is achieved by pre-tanning a step of flexing with a mixture of 100% water, 12-15% animal fat, for example, Tran, and about 4% licker at a temperature of about 28-30 ° C. Even a temperature range of up to 26 ° C to 35 ° C is still possible. The proportion of animal fat can be as low as 10% or even 17%.

At a content of 4% Licker, based on the leather weight results in a good penetration of fat. Even when using only 2% licker and only 10% animal fat, the penetration of fat is still sufficient. Again, the use of Baykanollicker T is advantageous as a licker, but other Licker can be used. As an animal fat is preferably Tran, but also brain fat, tallow or marrow or a mixture of Tran can be used with these fats.

The walking can be carried out by hand or with the aid of tools or else in a walking barrel, which rotates at high speed.

To accelerate the tanning and to achieve a better penetration of leather with tannins, the leather can be pickled before tanning. This proves pimples with a mixture of 100% water, about 10% salt and about 3% - 5% hydrochloric acid for at least 4 hours, as effective, wherein the weights are based on the present before pickling leather weight, so for example on the pelt weight. It can also be used only 1% hydrochloric acid or 7% hydrochloric acid for pimpling. At higher hydrochloric acid content, however, the leather could be damaged. The salt content can vary from 5 to 15%. Instead of hydrochloric acid and salt also formic acid, acetic acid or lactic acid can be used for pimpling. Instead of 100% water, only 90% water or up to 110% water can be used.

Further, the present disclosure discloses a boot having a one-piece bovid-leather seamless upper with the upper of the boot pre-tanned with grease and licker, retanned with vegetable tanning agent and synthetic tannin tannin and kneaded with anionic emulsifier and licker is cut from a leg piece of bovine skin and is at least 100% expanded, based on the smallest circumference in the shaft area. The upper leather can also be widened to three times the circumference or more.

In particular, the present description discloses a boot which is treated and expanded according to one of the aforementioned methods.

Fig. 1

zeigt einen Bereich eines Rinderfelles zur Herstellung eines Oberleders,

Fig. 2

zeigt das Abziehen des Bereichs von Fig. 1,

Fig. 3

zeigt den Bereich von Fig. 1 nach dem Abziehen,

Fig. 4

zeigt eine Streckeinrichtung für ein Oberleder,

Fig. 5

zeigt eine Schablone zur Formung eines Oberleders,

Fig. 6

zeigt einen Schaftweiter,

Fig. 7

zeigt eine perspektivische Detailansicht des Schaftweiters von Fig. 7,

Fig. 8

zeigt eine Stellung des Schaftweiters nach erfolgter Schaftweitung, und

Fig. 9

zeigt eine Anordnung zur Streckung eines Oberleders.

The subject matter of the present description will now be explained in more detail with reference to the following figures.

Fig. 1

shows an area of a bovine fur for the production of an upper leather,

Fig. 2

shows the subtraction of the area of Fig. 1 .

Fig. 3

shows the range of Fig. 1 after peeling,

Fig. 4

shows a stretching device for an upper leather,

Fig. 5

shows a template for forming an upper leather,

Fig. 6

shows a sheep,

Fig. 7

shows a perspective detail view of the Schaftweiters of Fig. 7 .

Fig. 8

shows a position of the Schaftweiters after the shaft has been spread, and

Fig. 9

shows an arrangement for stretching an upper leather.

For the production of a one-piece shoe upper leather, first a funnel-shaped upper leather 10 is cut out of a bovine skin 11. This upper leather 10 may be obtained, for example, from a leg of a bovine, as in Fig. 1 to 3 illustrated. In Fig. 1 the cut-out area of the upper 10 is marked by dashed lines. The upper leather 10 is stripped from top to bottom of the bovine lobe, as in Fig. 2 shown.

Fig. 3 shows that according to Fig. 1 and Fig. 2 The upper leather 10 has a hose-like region 12 or a shaft 12 and a funnel-shaped widened area 13 which is asymmetrical with respect to the hose-like region 12.

Apart from bovine leather, pieces of leather from the lobe area of other bovids may also be used which have a sufficiently large lobe. In particular, members of the subfamily "Bovinae" such as, for example, cattle, buffalo and bison are suitable for this purpose.

In the following, the tanning process described above is further clarified by a concrete example.

The upper leather 10 is now defiled, depilated and pickled. The resulting leather is also referred to as "leatherblank" or as a nakedness. Pimpling can be done, for example, by pickling the leather with a mixture of 100% water, 10% salt and 3-5% hydrochloric acid for at least 4 hours and then de-piping it with a mixture containing 12-16% antichlorine , where the best possible Durchentpickelung is to strive for.

The leather blanks are then subjected to leather tanning as described herein. Among other things, a leather tanning according to the present description can improve the tear strength and the extensibility of the leather, so that treatment with stretching and stretching devices without tearing the boot leg is made possible in the first place.

The pickled leather blanks are rolled with a mixture of 12 - 15% Tran and 4% Baykanollicker T at a temperature of 28 - 30 ° C until they are completely tanned.

The dermis is hung for oxidation for about 1 to 2 weeks. If the oxidation has taken place, as can be seen for example from a golden yellow section of the leather, the leather is washed out with 1-3% soda at 38-42 ° C. The washing is repeated until no more leaking at double bending. The leather is then rinsed lukewarm and ventilated.

In another tanning process, the leather is retanned with increasing concentration of a tanning agent of 3 to 6 Baume degrees (° Be). It has proved to be effective, the concentration of the tanning agent during rethening from 3 degrees to 6 degrees Be instead of working immediately with the higher concentration. In particular, the retanning can be done in several operations, for example, in 3 operations, wherein the concentration of the tanning agent increases for each operation.

The concentration according to Beaume can be determined for example with a Beaume spindle or with an arometer. According to the present specification, the tanning agent contains 49 parts of cold soluble Quebracho or quebracho extract, 49 parts of Tanigan extra NR and 2 parts of Tanigan BLG, each based on the Ringer's material.

The leather is then jacked up, rinsed and ironed, the licker containing 200-300% water at 45 ° C., 2% cutisan and 1% Baykanollicker T, and 2% Tanigan supra LH as aftertaste.

Baykanol-Licker T is a fatliquoring agent manufactured by Bayer AG. Similar products which can also be used are, for example, Baykanol-Licker KM, Baykanol-Licker SCLM and Baykanol-Licker TSI as well as Baykanol PFM, Baykanol SL and OC-product 2101, which are available from Lanxess AG.

Tanigan extra NR, BLG and supra LH are synthetic tannins manufactured by Bayer AG. Tannins are polyhydroxyphenols. Similar products that can also be used include Tanigan 3LN liquid, Tanigan BN liquid, Tanigan CF liquid, Tanigan HO liquid, Tanigan MB liquid, Tanigan NH, TANIGAN UW EXP 4006, Tanigan 3LN, Tanigan AN, Tanigan BL-I Tanigan BN, Tanigan CLS 50 liquid, Tanigan F, Tanigan HO, Tanigan OS, Tanigan OS-N liquid, Tanigan PAK, Tanigan PAK-N liquid, Tanigan PR, Tanigan PV, Tanigan QF, Tanigan RFS, Tanigan S EXP 4005 and Tanigan VR available from Lanxess AG.

Cutisan BS is an anionic emulsifier which is a sulfonate of the type R-SO3Na and which is a sulfite product of unsaturated fatty oils and fatty acids, where "R" is a long chain alkyl radical of 8-24 carbon atoms.

• Fettalkoholsulfate, primäre und sekundäre, wie zum Beispiel EPPOL DL, PERAMIT ML,
• Fettalkoholether-Sulfate wie zum Beispiel TEXAPON,
• Monoglyceridsulfate wie zum Beispiel VEL,
• Sulfatierungsprodukte von ungesättigten Ölen und Fettsäuren, wie zum Beispiel LEDEROLINOR DKMS, Sulfonate R-S03Na, insbesondere
• Alkylbenzolsulfonate (ABS, TPS) wie MARLOPON oder MARLON,
• Alkylsulfonat, wie zum Beispiel MERSOLA T,
• Fettsäurekondensationsprodukte wie IGEPONA oder IGEPONT,
• Petrolsulfonate wie GRASSAN,
• Sulfitierungsprodukte von ungesättigten fetten Ölen und Fettsäuren, wie zum Beispiel CUTISAN BS,
• kurzkettige Alkylbenzolsulfonate, z. B. des Cumols, Toluols oder Xylenols.

Anionic emulsifiers are, for example, sulfates of the type R-OS03Na, in particular

• Fatty alcohol sulfates, primary and secondary, such as EPPOL DL, PERAMIT ML,
• Fatty alcohol ether sulfates such as TEXAPON,
• Monoglyceride sulfates such as VEL,
• Sulfation products of unsaturated oils and fatty acids, such as LEEDEROLINOR DKMS, sulfonates R-S03Na, in particular
• Alkylbenzenesulfonates (ABS, TPS) such as MARLOPON or MARLON,
• Alkyl sulfonate such as MERSOLA T,
• Fatty acid condensation products such as IGEPONA or IGEPONT,
• Petroleum sulfonates such as GRASSAN,
• Sulfitization products of unsaturated fatty oils and fatty acids, such as CUTISAN BS,
• short chain alkylbenzenesulfonates, e.g. As the cumene, toluene or xylenol.

"Antichlor" is another name for sodium thiosulfate that is used in tanning to remove excess chlorine or excess hydrochloric acid from a solution.

Quebracho extract is extracted from the inner red heartwood of the Quebracho tribe, which grows in South America and mainly in Argentina and Paraguay. Quebracho tanned leather gives a very firm, tough and reddish leather. The leather is sensitive to light after tanning and darkens.

The leached out of Quebrachoholz extract belongs to the catechol group and is attributed to the condensed type of tannin. The cold-soluble Quebrachoextrakt is a sulfited Quebrachoextrakt with increased tannin content of 72 to 80% increasing, in which by a special treatment of Quebrachoholzauszüge with sulfite or bisulfite the sparingly soluble components are changed so that this extract can be solved with cold water.

In contrast, in the case of warm-soluble quebracho extract, the sparingly soluble portions are only soluble in warm water and precipitate on cooling (phlobaphene). These have an average tannin content of about 66% and about 7% insoluble.

The above tanning with Tran is an example of a fat tanning. Core soap, foot oil, Turkish red oil, yak butter or egg yolk can be used instead of the trans.

Instead of Quebrachoextraktes other vegetable or vegetable tanning agents can be used. Vegetable tanning agents are obtained, inter alia, from the following parts of plants: barks woods fruit leaves root excesses oak bark Oak wood Valonea sumac Badan Gallen spruce bark quebracho Trillo Gambier canaigre Knoppern wattle chestnut Myrobalan Mangroverinde urunday Algarobilla Malettorinde Tizeraholz Dividivi willow bark Katechuholz tare Hemlockrinde Bablah

The choice of vegetable tanning agent depends on the properties to be achieved with the tanning agent. For example, oak bark is suitable for a firm, tough yellow-brown leather with a dark cut, Gambier extract for soft, elastic leather, chestnut wood extract for uniform, compact and durable leather with high light fastness, Mimosa extract for the production of soles -, belt, pocket and furniture leather, Mimosa bark for firm, light and slightly red-tinged leather, Myrabolan extract for combination with other tannins and for soft leather, sumac for soft, flexible and light leather, tare for one good dyeable leather with high light fastness, trillo for cuddly soft as well as firm and permanent leather, and valonea extract for soft leather.

After the tanning process, the upper leather 10 is widened and shaped. In 4, 5 and 6 Various devices are shown that may be used in accordance with the present description.

Since in the formulations for the leather manufacturing processes, the quantities are usually given in%, you need reference values, often taking the weight of the leather present before the respective phases of the tanning process.

If the pilling and the deliming and staining and the subsequent tanning in an uninterrupted process flow is performed, the reference is taken to the salt weight, d. H. the weight that the skin material has after preservation prior to incorporation into the tannery.

If fleshing is done after the filthy soft or fleshed out after the main turntable, it is weighed here and the resulting weight used as a reference point for the following processes including the tanning. Is fleshed and possibly split after the liming, is used for the recipes of the switch and the limer the salt weight, for deliming to incl tanning then the weight of the entrapped and possibly split skin material = pelt weight as a reference point.

A list of the references used in leather production is provided in the following table: Salt weight SG about 45% water content Green weight GG Salt weight + 10-15% = 60 - 70% water content Dry weight (preservation) about 15-20% water content Dry salt weight about 20-25% water content pelt weight about 80 - 90% water content Ausreckgewicht about 70% water content Abwelkgewicht about 50 - 60% water content shaved about 45 - 50% water content Water content final product leather about 7 - 15% water content

Fig. 4 shows four screw clamps 15, 16, 17, 18, which are clamped to a sole region 19 of the upper 10. The sole region corresponds to the edge of the funnel-shaped region 13. The tubular region 13 forms the upper 13 of the upper leather. The region further protruding from the tubular portion 12 and cut out from the front of a lobe forms the front portion 20 of the upper 10 and the portion less projecting from the tubular portion 12 and cut out from the rear portion of the lobe is, forms the heel area 21 of the upper leather.

Fig. 5 FIG. 5 shows a wood forming template 22 shaped similar to a cross-section of a foot and dimensioned to be inserted into the upper leather 10 from the sole region 19. In particular, the form template may be used in conjunction with the in Fig. 4 used screw clamps are used. This is especially good in Fig. 9 to recognize.

Fig. 6 shows a boot leg farther 23 which is inserted into the upper 12 of the upper. The Bootschaftweiter 23 is in Fig. 7 shown in more detail.

The bootleg further 32 has a front wedge 24 and a rear wedge 25. The front wedge 24 is connected to the back wedge 25 via a connecting portion 26 with each other so that the front wedge 24 and the wedge 25 can be unfolded, wherein the connecting portion 26 forms a hinge.

A linkage 27, to one end of which a handwheel 28 is mounted, is inserted into a space 30 between the front wedge 24 and the wedge 25 from the side of the connecting portion 26. The linkage 27 has an external thread 27, which engages in an internal thread that is located in the interior of the Stiefelschaftweiters 32, and in Fig. 7 not shown.

This internal thread is stationary in the direction of the linkage 27 connected to the front wedge 24 and the wedge 25. A pressure body 30 is connected to the threaded rod 27 so that it moves with a movement of the threaded rod 27 along the longitudinal direction of the threaded rod 27 with the threaded rod 27. The pressure body 30 is dimensioned so that it bears against the inner sides of the front wedge 24 and the wedge 25, or that it bears against the inner sides of another body, which is in contact with the inner sides of the front wedge 24 and the wedge 25.

For widening of the shank 12, the front wedge 24 and the back wedge 25 of the boot shank extension 23 are inserted into the shank 12, so that the outer surfaces of the front wedge 24 and the rear wedge 25 bear against the shank 12 from the inside. Here, an initial angular position between the front wedge 24 and the wedge 25 can be adjusted in the manner described below.

The hand wheel 28 is rotated in a forward direction 31, so that the threaded rod 27 along its longitudinal axis and in a forward direction 32 in the space between the Front wedge 24 and the wedge 25 moves. The Vortriebrichtung 31 is shown here for a right-hand thread and would be entered the other way around for a left-hand thread. The use of a left or right-hand thread depends, among other things, on whether the boot shaft further 23 is to be operated by a right-handed or a left-handed person.

By the movement of the threaded rod 27, the pressure body 30 is driven along the forward direction 32 in the space between the front wedge 24 and the wedge 25, so that a wedge effect is created, which hingedly fold the front wedge 24 and the wedge 25 against each other, wherein a fulcrum the unfolding movement in the region of the fastening region 26 is located. Thus, the attachment portion 26 acts as a kind of hinge.

The expansion of the shaft 12 can in particular be such that the boot shaft further 23 is repeatedly held in its last position to let the leather work. If for this purpose the self-locking of the thread is not sufficient, a separate locking device can be provided for this purpose. When widening the boot shaft, a doubling or tripling of the diameter of the shaft can be achieved, or even an even greater widening. This is done so that the boots can be tightened comfortably later, without the need for an additional seam, such as a zipper. In addition, this creates a particularly waterproof and durable leather boots in the "the real one piece" design.

To remove the Stiefelschaftweiters 23, the handwheel 28 is rotated counter to the advancing direction 31 until the Stiefelschaftweiter 23 dissolves from the inside of the shaft 12.

Fig. 8 shows a position of the Stiefelschaftweiters 23 after bootleg widening in which the gap 33 between the front wedge 24 and wedge 25 has widened wedge-shaped and in which the shaft 12 has expanded so far that he has assumed the diameter of a human ankle.

Fig. 9 Figure 4 shows another upper leather forming apparatus 10 having a template 22 inserted into the upper leather 10 from the side of the sole. In the example of Fig. 9 are three screw clamps 15, 16, 17 respectively supported on support plates 34 down against a lower edge of the template 22 and another screw clamp 18 is supported via a support plate, not shown here forward against a front edge of the template.

A first region of the sole region 19 is fastened in each case with a first fastening screw 35 and a first retaining plate 36 to the respective screw clamp 15, 16, 17, 18, and a second region of the sole region 19 opposite the first region is each provided with a second fastening screw 37 and a second fastening screw 37 second holding plate 38 to the respective screw clamp 15, 16, 17, 18 attached.

Furthermore, the screw clamps each have a threaded rod 39 and a rotary knob 40, which are in a manner known in principle with an internal thread, not shown here, of a housing 41 and with the support plate 34 in conjunction.

For example, if the knob 40 of the screw clamp 15 is rotated in a propulsion direction 42, then that moves Housing 41 in a stretching direction 43 from the lower edge of the template 22 away, so that the leather is stretched in a stretched direction 44.

Similar to the Stiefelschaftweiter 23 can also be provided here a left or a right-hand thread. In the device of Fig. 9 The stretching direction 43 corresponds to the opposite direction of the forward direction 32 of FIG Fig. 7 , the propulsion direction 42 corresponds to the propulsion direction 31 of FIG Fig. 7 , the rotary knob 40 corresponds to the hand wheel 28 of Fig. 7 and the threaded rod 39 corresponds to the threaded rod 27 of Fig. 7 ,

Unlike the Stiefelschaftweiter 23 of Fig. 7 is through the device of Fig. 9 but causes stretching by a tensile force and no widening of the upper 10 by a wedge effect.

In further processing steps, for example, an inner shank and an intermediate shank or intermediate lining can be fastened inside the upper shoe 10, for example by sewing and an insole or insole and an outsole connected thereto can be fastened to the sole area, for example by nailing or by sewing.

Claims (6)

1. A method for forming an upper leather, comprising:

   - Providing a tube shaped integrally formed upper leather as a section of a leg portion of a bovine skin,

   - Pretanning the upper leather using fat and fatliquor,

   - Retanning the upper leather at an increasing concentration of a tanning agent mixture, wherein the concentration is in the range of 3 - 6 degree Beaume, and wherein the tanning agent mixture comprises about 49 parts of a vegetable tanning agent and about 51 parts of a synthetic tanning agent,

   - fatliquoring of the upper leather with a fatliquor mixture that comprises water, an anionic emulsifier and a fatliquor, wherein the water has a temperature of about 45 °C,

   - Introducing a bootleg widener into a leg of the upper leather,

   - Widening of the leg with the bootleg widener by at least 100%.
2. The method according to claim 1, wherein the vegetable tanning agent comprises a cold-soluble quebracho extract.
3. The method according to one of the preceding claims, wherein the pre-tanning comprises a step of milling with a mixture of 100% water, about 12 - 15 % animal fat and about 4% fatliquor at a temperature of about 28 - 30 °C, wherein the percentage values are weight percent with respect to the leather weight that is present before the step of milling.
4. The method according to one of the preceding claims, which comprises furthermore a step of pickling for at least 4 hours with a mixture of 100% water, about 10% salt and about 3 - 5% hydrochloric acid, respect to the leather weight that is present before the step of pickling.
5. Boot with an integral seamless bootleg of bovine leather, pre-treated with the following substances:

   - fat and fatliquor for pretanning,

   - a tanning agent mixture of vegetable tanning agent and synthetic tanning agent for retanning, wherein the tanning agent mixture comprises about 49 parts of the vegetable tanning agent and about 51 parts of the synthetic tanning agent,

   - an anionic emulsifier and fatliquor for fatliquoring, wherein the bootleg is cut from a leg area of the bovine skin and is widened by at least 100%.
6. Boot according to claim 5, which is treated and widened according to a method according to one of the claims 1 to 4.

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