IT202100000995A1 - METHOD OF PROCESSING SKINS FOR LONG-HAIRED FURS - Google Patents

Description

Description of the invention entitled:

?METHOD OF PROCESSING SKINS FOR LONG HAIR FURS?

Description

field of technique

The invention refers to a new industrial method for preserving and treating long-haired skins. In particular, the method described and claimed in detail below has the purpose of guaranteeing the quality, the effect required by each customer and the resistance over time of the product as treated.

Known art

Traditionally, from some hunted or specially bred animals it is possible to obtain skins which, tanned in an appropriate way, preserve the hair or fleece and are packaged to make outer garments called fur; the quality? and preciousness of a fur? given by the type of animal and the softness, shine and workability? of the hides that are used for making jackets, coats, collars and hats.

The skins coming from animals possessing fine coats, with abundant, soft, uniform, shiny and variously colored hair, are called fur skins; their basic classification? based on the animal species supplying the crude. The hides are further subdivided, according to various criteria, into:

? farmed skins - from farmed animals;

? wild skins - from animals living in the wild.

In reference to the length of the hairs we have:

? short-haired fur coats (e.g. Persians);

? medium-haired furs (e.g. mink);

? long-haired furs (e.g. fox).

With reference to the degree of processing we have:

? raw hides, simply dried;

? tanned hides, ready to be transformed into fur.

Fresh skins are preserved exclusively by drying. Dried skins, called dry skins or raw furs, are presented with hard, almost horny, thick and thick leather and with greasy and disheveled hair; they are subjected to the operations constituting the processing cycle, tanning. The tanning processing cycle includes the following phases: the operations that precede the tanning, the actual tanning and the operations that take place after the tanning. The operations that precede the tanning are the reception, the selection, the soaking and the fleshing.

? Soaking: it is carried out by immersing the hides in tanks in which clean water flows continuously in order to give them back the water they had before being dried.

? Fleshing: it is used to remove the flesh and fat from the skins and is carried out in drums containing sawdust; the removal of the cartilaginous and horny parts is generally done by hand with special tools.

The tanning of fur skins is carried out in a gentle way so as not to deteriorate the hair and so that it remains perfectly rooted and composed. The tanning processes pi? employed which vary according to the type of leather are: oil tanning, bran tanning and formaldehyde tanning. ? Tanning with oil: the skin is first spread, from the inside, with fish oil and then rolled up on itself. itself and left to rest for a few days so that the heating that takes place favors the oxidation of the fats which are so? able to exert their tanning action as already? described.

? Bran tanning: the skins are first spread with a mixture of flour or barley bran, rolled up and left to rest for the time necessary to complete the tanning action. During this time the starch contained in the flour or bran is first transformed into glucose which, by fermentation, is transformed into lactic acid responsible for the tanning action.

? Formaldehyde tanning: ? one of the processes used and is achieved by wetting the skin, on the hair side, with a formaldehyde solution; follows, after a rest of 2 or 3 hours, the drying which is carried out very slowly and at a temperature not higher than 40? C. On the other hand, tannin tanning, used for skins of little value, and chrome tanning, which requires energetic treatments, are rarely used.

The tanned leather, however?, is not? still usable to produce articles. It is a wet material which, even if it were dried, would give rise to a rather rigid product, not very flexible and with the typical color of the tanning with which it is produced. been obtained. To transform into a marketable product, useful for producing manufactured goods, it must undergo further chemical and mechanical treatments. The operations that are carried out after tanning are:

? Dyeing: has the purpose of changing, improving and uniforming the color of the fur; it is generally achieved by immersion in tanks or with a brush.

? Finishing: includes staking and sanding.

? Shaving: serves to shorten and level the hair.

? Epilation: consists in removing certain hairs (eg the bristly hair of the beaver).

After the wind, that is? the squeezing to mechanically eliminate the excess of water, the drying is carried out with various systems that aim to obtain a more? rapid and uniform and in constant times compared to drying by suspension in the air which depends on the atmospheric conditions (temperature, humidity, ventilation). The choice of drying system depends not only on economic factors and company organization but also on the type of leather and the intended use.

Finally, the finishing? the final stage and more of the tanning process and includes all the operations carried out on dry leather to modify its surface from an aesthetic and/or functional point of view.

Some industrial property rights deal with this problem. An example ? the patent RU2711399C1 which concerns the production of furs. The method for treating fur skins includes soaking, washing, pickling, tanning and stuffing steps. At this point, in the soaking phase, a modifier is added to the solution in quantity? of 2.0?2.5% of the weight of the fresh dry material and the filling phase of the semi-finished product is performed by treatment with a solution of a modifying agent in a mixture of an organic solvent and water, in which the quantity? of modifier ? 2.0-2.5% by weight of the semi-finished product. The modifier ? an amino resin modified from a low molecular weight aliphatic alcohol of formula where R = -CHCH or -CH (CH). The proposed fur skin processing method allows the processing of fur skins with weak skin texture, such as hare skins and rabbit skin from first slaughter. When using the method, weak skin tissue is strengthened, heat resistance ? improved, the properties? of the skin are leveled by the topographic sections maintaining the properties? hygiene of processed leathers.

Another example ? patent WO2020060928 which describes a fur trim: a semimetal or other semiconductor material that is applied to a portion of a fur. The material is applied in a liquid, aerosol or adhesive formulation, such that the material adheres molecularly to the fur, skin or feather. The material can also be applied by laser burning or branding process. The material can be applied before a chemical treatment of the fur, skin or feather.

No solution seems to have been claimed, in this area, regarding the problem of the lack of an economic and practical method, adaptable to a common tannery without the use of particularly expensive machinery.

Purpose of this patent? therefore that of defining a tanning method for the treatment and production of long-haired fur skins that can be easily used in any activity? to there? in charge.

Description of the invention

According to the present invention there is disclosed a method for treating long-haired fur skins classified according to color, which allows washing, treatment and production of long-haired skins.

The method is composed as follows:

A. Selection of hides based on color and required final article;

B. Dyeing of selected hides, preparation for barrel processing:

B.1 Retanning in charge of preparing the hides for the following phase in the barrel, to soften them and allowing color penetration through: B.2 addition of 1000% water at 40?, 1% degreaser and keeping it at rotation for 60 minutes;

B.3 addition of 8% IHL synthetic grease, 3% TIS natural grease, 2% formic acid which fixes the grease with a rotation maintenance for a period of 20 minutes;

B.4 check that the PH is within values of 3.8-4.00, in the event of a positive result, add 8% trivalent chromium to allow a uniform dyeing of the entire treated surface, and keep it at full speed for 120 minutes; in case of a negative verification of the PH of the treated hides, the method stops and resumes from the previous phase or, in case of definitive damage, the processing resumes from the second phase B;

B.5 addition of 2% sodium acetate suitable for stabilizing the PH and keeping it around for 60 minutes.

All the percentages of the products used in each phase are calculated on the minimum weights of the treated hides and measured in real time.

B.6 Draining of the water and change of the bath in the barrel with clean water, addition of ammonia to raise the PH level up to a value of 8.00, start of the hair and leather dyeing process at a temperature of 70? C; B.7 dyeing of leather and fur: through the use of special dyes for dyeing wool and of the aforementioned fatliquors used in the aforementioned phase B.3 which further soften the treated hides. Addition of dispersants which allow the uniform absorption of the color by the hides and fixing of the color through the addition of formic acid able to lower the PH of the treated wools;

B.8 unloading of the barrel and displaying the freshly dyed hides following a pressing aimed at removing the water present in the hides;

B.9 drying phase during which the treated hides are hung until completely dry;

C. preparation of the hair through the steps of trimming, combing, shaving to uniform the height of the hair and jumbatura;

In any case of non-preservation of the pre-established conditions, the method must be interrupted and resumed from the previous phase.

Advantageously, the rigorous adherence to the method described up to now guarantees the preservation of the hides as produced in the long term.

In a further version, the method in question includes further phases:

D. finishing phase during which the hides are hung up again in order to be finished: in this phase the spray finishing technique is used, carried out using large booths including nebulizers which, through circulatory movements on the treated hides which determine different characteristics :

? reduction or elimination of the braking effect to the touch;

? an anti-adherent and anti-oozing effect,

? a waterproof effect;

? fix its weight or soften it further;

? a waxed effect.

During this stage? advantageously foreseen the use of mixtures chosen from: waxes, caseins, polyurethanes, acrylic resins and pigments according to the finishing to be obtained.

Furthermore, at the end of phase D one passes to a phase D.1 of ironing.

Finally, still in a further version, the method in question comprises a further polishing step E during which parts of the skin and/or designs are created on the long-haired skins by means of a polishing machine. Possibly and advantageously the aforementioned phase B.7 is divided into two sub-phases B.7.1 for dyeing the hair and B.7.2 for dyeing the leather.

In the first, special dyes are used for dyeing wool and divided into three colours: yellow, red, blue and color fixing by means of formic acid which lowers the PH of the treated wools.

In the second, common dyes are used together with the aforementioned fatliquors used in phase B.3 which contribute to softening the treated hides. Finally, dispersants are added which allow the leathers to absorb the color evenly.

Still in a further advantageous version, in the aforementioned phase A (through a selection of semi-finished raw material), in the aforementioned phase C (thanks to the shaving of the short pile to create a boiled wool effect) and in the aforementioned phase D (through the use of thermoplastic products that wear out the leather) a vintage effect of the treated leathers is created and guaranteed.

The advantages offered by the present invention are evident in the light of the description set forth up to now and will be even more clear thanks to the annexed figure and its detailed description.

Description of the figures

The invention will come described hereinafter in a preferred embodiment by way of explanation and without limitation with the aid of the annexed figure, in which: - FIGURE 1 shows the three main phases of the method in question starting from the choice of materials of phase A, passing through the long dyeing process included in phase B and in all its developments up to B.9 to arrive at the final preparation C.

- FIGURE 2 shows further phases of the method including each variant: see how, in this case, phase B.7 is further divided into B.7.1 and B.7.2 and how the method consists of two further phases D and E .

Detailed description of the invention

This invention will come now illustrated purely by way of example but not in a limiting or binding way, making use of the figures which illustrate some embodiments with respect to the present inventive concept.

The method for treating long-haired fur skins allows for the washing, treatment and production of high-quality, durable long-haired skins. It ? easily adaptable to any type of tannery plant and is characterized by the following three fundamental phases:

A. Selection of hides based on color and required final article,

B. Dyeing of selected hides,

C. preparation of the hair through the steps of trimming and combing, shaving to make the height of the hair uniform and jumbatura.

Furthermore, the method in question is developed in two further optional phases:

D. finishing,

E. of sanding.

As shown in Fig.1, the dyeing phase B is divided into a plurality? of steps: starting from the preparation of the processing in the barrel, we move on to phase B.1 of retanning for the preparation of the hides for the following phase in the barrel, to soften them and allowing a subsequent penetration of the color through the steps:

- B.2 of addition of 1000% of water at 40?C, 1% of degreaser and maintenance at rotation for 60 minutes,

- B.3 addition of 8% IHL synthetic grease, 3% TIS natural grease, 2% formic acid to fix the grease and keep rotating for 20 minutes,

- B.4 check of the PH, in case of positive result addition of 8% of trivalent chromium suitable to allow a uniform dyeing of the entire treated surface, and maintenance at full speed for 120 minutes; in case of a negative verification of the PH of the treated hides, the method is interrupted and resumed from the previous phase or, in case of definitive damage, from the beginning of the second phase B.

- B.5 addition of 2% sodium acetate suitable for stabilizing the PH and maintaining revolutions for 60 minutes.

Subsequently we move on to phase B.6 during which the water is drained, the bath in the barrel is changed with clean water and ammonia is added to raise the PH level: these steps are preparatory to the beginning of the hair dyeing process and leather at a temperature of 70?C.

The subsequent phase B.7, in a preferred version, is divided into:

- B.7.1 dyeing of the hair using special dyes for dyeing wool and divided into three colours: yellow, red, blue and fixing of the color by means of formic acid to allow the PH of the treated wool to be lowered;

- B.7.2 dyeing of the leather through the use of common dyes combined with the aforementioned fatliquors used in the aforementioned retanning phase B.3 which further soften the treated hides and addition of dispersants suitable for allowing the uniform absorption of the color by the hides .

At the end of the dyeing we move on to phase B.8 of unloading the barrel and placing the freshly dyed hides on display for the ?setting out? a pressing that allows the removal of the water present in the hides and which in turn allows the passage to a drying phase B.9 during which the treated hides are hung until they are completely dry.

Fig. 2 shows the possible phases of the method in question, including the aforementioned finishing phase D, during which the hides are hung up again in order to be finished: in this phase the spray finishing technique is used, carried out through the use of large cabins including nebulizers which through circulatory movements on the treated leathers are able to determine different characteristics: reduce or eliminate the braking effect to the touch, determine an anti-adherent and anti-sweating effect, make an effect waterproof; fix its weight or soften it further; add a waxed effect. The aforementioned finishing phase comprises D.1 of ironing.

During the finishing, at the request of each customer, blends of choice between waxes, caseins, polyurethanes, acrylic resins and pigments are used according to the finishing to be obtained.

Furthermore, during the further polishing step E, parts of the skin and/or patterns are created on said long-haired hairs by means of a polishing machine. Furthermore, three variants used in the method described above are programmed which allow the creation of a vintage effect of the long-haired hides processed in the aforementioned phases:

- A. through a selection of semi-finished raw materials;

- C. preparation of the hair, this is shaved short to create a boiled wool effect;

- D. of finishing, thermoplastic products are used to wear out the leather, creating a vintage effect.

The percentages of the products used in each phase are calculated on the minimum weights of the treated hides and detected in real time and the method in question, in any case of failure to preserve the pre-established conditions, resumes from the previous phase guaranteeing the conservation of the tanned hides and wools treated making them resistant over time.

? finally, it is clear that modifications, additions or variations that are obvious to a person skilled in the art can be made to the invention described up to now, without thereby departing from the scope of protection which ? provided by the appended claims.

Claims (10)

Claims 1. Method of treating long-haired fur skins, classified by color, suitable for washing, treating and producing long-haired skins; said method being applicable in any plant suitable for tanning and treating hides and being characterized in that it comprises the following steps: (A) selection of hides based on color and required final article; (B) dyeing of selected hides, preparation for barrel processing: (B.1) retanning phase suitable for preparing the hides for the next phase in a special barrel, softening them and allowing the color to penetrate through: (B.2) adding 1000% water at 40?, 1% degreaser and stirring for 60 minutes in said barrel; (B.3) adding 8% IHL synthetic fat, 3% TIS natural fat, 2% formic acid suitable for fixing the fat to the barrel and keeping it in rotation for a period of 20 minutes; (B.4) check of PH, in case of result within the maximum value of 4.00 and minimum of 3.00, addition of 8% of trivalent chromium able to allow a uniform dyeing of the entire treated surface, and maintenance at full speed for 120 minutes ; (B.5) addition of 2% sodium acetate suitable for stabilizing the PH and maintaining the revolutions for 60 minutes; (B.6) draining of the water and change of the bath in the barrel with clean water, addition of ammonia to raise the PH level, start of the hair and leather dyeing process at a temperature of 70? C; (B.7) dyeing of leather and fur: through the use of special dyes for dyeing wool and of the aforementioned fatliquors used in the aforementioned phase (B.3) suitable for further softening the treated hides; addition of dispersants able to allow the uniform absorption of the color by the hides and fixing of the color by means of formic acid able to lower the PH of the treated wools; (B.8) unloading of the barrel and placing the freshly dyed hides on display and pressing to remove the water present in the hides; (B.9) drying during which the treated hides are hung until completely dry; (C) preparation of the coat through the steps of trimming and combing, shaving to uniform the height of the coat and jumbatura; said method, in any case of non-preservation of the pre-established conditions, being capable of restarting from the previous phase; said method ensuring the conservation of the tanned leathers and treated wools making them resistant over time. 2. Method of treating long-haired fur skins, classified according to colour, according to the preceding claim 1, characterized in that it comprises a finishing step (D) during which the skins are hung up again in order to be finished: in this phase the spray finishing technique is used, carried out through the use of large booths including nebulizers which, through circulating movements on the treated hides, are able to determine at least one of the following characteristics: ? reduce or eliminate the braking effect to the touch; ? determine an anti-adherent and anti-sweating effect; ? make a waterproof effect; ? fix its weight or soften it further; ? add a waxed effect. 3. Method of treating long-haired fur skins, classified on the basis of colour, according to the preceding claim 2, characterized in that it comprises a drawing step (D.1) following said finishing step (D). 4. Method of treating long-haired fur skins, classified on the basis of colour, according to the preceding claims 2 or 3, characterized in that during said finishing step (D) mixtures with choice between waxes, caseins, polyurethanes, acrylic resins and pigments. 5. Method of treating long-haired fur skins, classified on the basis of colour, according to any one of the preceding claims, characterized in that in said step (B.4), following a negative check of the PH of the treated skins, the method ? capable of interrupting and resuming from the previous phase or, in the event of definitive damage to the treated leather, resuming processing from the second phase (B). 6. Method of treating long-haired fur skins, classified on the basis of colour, according to any one of the preceding claims, characterized in that said phase (B.7) is divided into two further sub-phases: - (B.7.1) dyeing of the hair using special dyes for dyeing wool and divided into three colours: yellow, red, blue and fixing of the color by means of formic acid suitable for lowering the PH of the treated wool; - (B.7.2) dyeing of the leather through the use of common dyes combined with the aforementioned fatliquors used in said retanning phase (B.3) suitable for further softening the treated hides, addition of dispersants suitable for allowing uniform absorption of the color on the skins. 7. Method of treating skins, for furs, with long hair, classified according to the color, according to any one of the preceding claims, characterized in that it comprises a further polishing step (E) during which parts of the skin and /or designs created on said long-haired hides by means of a polishing machine. 8. Method of treating long-haired fur skins, classified on the basis of colour, according to any one of the preceding claims, characterized in that it allows a vintage effect of the long-haired skins processed by means of variations: in said step (A ) through a selection of semi-finished raw material; in said phase (C) of preparation of the hair, this is shaved short to create a boiled wool effect. 9. Method of treating long-haired fur skins, classified on the basis of colour, according to any one of the preceding claims from 2 onwards, characterized in that in said finishing phase (D) thermoplastic products are used which are suitable for wearing the leather building a vintage effect. 10. Method of treating long-haired fur skins, classified on the basis of colour, according to any one of the preceding claims, characterized in that the percentages of the products used in each phase are calculated on the minimum weights of the treated skins and detected in time real.