FROM SAT IVA HEMP .

The present invention relates to a method for the production of j eans products or fabrics starting from hemp, preferably sativa hemp . The method according to the present invention permits obtaining a high-quality product or fabric by exploiting particular technical solutions , from hemp cultivation and processing to yarn production and weaving into j eans fabric, resulting in a j eans product or fabric which is comfortable and characteri zed by high quality and resilience .

- PRIOR ART -

Methods for the production of j eans products or fabrics are known which utili ze cotton f ibres as well as fibres o f cotton mixed with other fibres that give elastic properties to the fabric . Such methods are now being pushed to the limit for manufacturing products based on low-cost , low-resil ience fabrics .

In order to manufacture a j eans product or fabric with a weight of 11^12 ounces , cotton yarn having a metric count comprised between Nm 10000 and 12000 is normally used . Also , for j eans fabric weaving no more than 16 warp beats and no more than 20 weft beats are normally used .

Moreover, as is known, cotton production has a strong environmental impact , particularly because of the high consumption of water for irrigation purposes .

Products or fabrics made from indica hemp are known which are seldom used for the production of garments or clothes , in particular garments or clothes intended to come in contact with the user's skin. In order to incur lower production costs, modern technologies utilize combing as a weaving technique, which causes the hemp fibres to burst and alters those very features that make hemp unique.

It has long been customary to produce yarns obtained from Liberian fibres, including hemp, by using the flax system.

The current state of the art is biased against the possibility of producing jeans products or fabric using hemp fibres. It is in fact believed to be impossible to obtain hemp yarns that allow manufacturing jeans products or fabrics which are comfortable, wearable and pleasant to the touch.

On the other hand, there is an increasing demand for raw materials for the production of products and fabrics, in particular jeans products and fabrics, which have a low environmental impact both during the manufacturing processes and during the dyeing processes.

Methods for finishing and dyeing products or fabrics are known, in fact, which are widely used at industrial level and which utilize harmful and polluting products and compounds, like sulphur. Moreover, such methods require the use of boiling water, thus consuming energy in order to bring the dye to the correct temperature.

Industrial dyeing methods are characterized by poor fastness, with colour fastness values lower than 3 over a scale of 5 according to standardized specifications. It is also known that industrial dyeing methods cannot provide acceptable colour fastness for the indigo colour, for which even the R.E.A.C.H. specification envisages a lower minimum allowable fastness value (2/3) .

- OBJECT _{0E THE} INVENTION - The present invention aims at providing a method for the production of j eans products or fabrics starting from hemp, preferably sativa hemp, with a low environmental impact both during the production and processing of the hemp and during the creation of the yarn and the fabric and the dyeing of the same , thereby obtaining a comfortable and high-quality product .

The present method can solve all the technical issues deriving from the problems discussed above in relation to the methods currently known in the art .

The present method has a substantially null environmental impact .

A substantial innovation brought about by the process for manufacturing products or fabrics according to the present invention lies in the fact that the method starts from the production of the raw material , i . e . hemp, followed by the same being processed to give a yarn, which is then processed and woven to obtain j eans products or fabrics characteri zed by high quality, wearability and comfort , wherein such method has a low environmental impact . All the phases of the method co-operate together to produce a clear synergic ef fect which cannot be obviously inferred by a person skilled in the art .

One aspect of the present invention concerns a method for the production of j eans products or fabrics from hemp having the features set out in the appended claim 1 .

A further aspect of the present invention relates to a j eans product or fabric having the features set out in claim 8 .

The features of the method and o f the product or fabric according to the present invention will now be explained in detail with reference to the following exemplary, but nonlimiting, embodiment thereof.

- DETAILED DESCRIPTION OF THE INVENTION -

The method according to the present invention essentially consists of a number of phases. The method for the production of jeans products or fabrics starts from hemp, preferably sativa hemp, as a raw material.

The method according to the present invention comprises the following phases, preferably carried out in succession: selecting a grade of hemp seed, preferably sativa hemp, suitable for producing a dioecious plant; sowing said seed in open field by using at least 70kg of seed per hectare of sown surface, e.g. obtaining 100 plants per m ² ; harvesting the hemp plants when the plant is green, with a humid residue comprised between 20% and 35%; removing an upper part of the stalks of the hemp plants, e.g. not exceeding 1 metre from the top of the stalks ; selecting a central part of the stalks, e.g. not exceeding 3 metres in length; flaking off, e.g. peeling, by compression, the selected central part of the stalks; reducing the central part of the flaked off stalks into pieces less than 60cm long; retting the pieces of flaked off stalks, thereby obtaining a semifinished product; subjecting the semifinished product obtained by retting to ozone pressurization, thereby obtaining hemp fibres ; combing and cutting the hemp fibres to si zes comprised between 30mm and 90mm; producing, by means of a moisturi zed woollen system, a yarn with a metric count of approximately Nm 36000 , starting from said hemp fibres ; twisting the yarn with three threads ; executing a process of gassing the twisted yarn; executing a phase of dyeing the yarn part neces sary for warping, gathered into hanks ; drying the hanks of dyed yarn; heating the hanks of dyed yarn in an oven at approximately 160 ° C ; weaving the j eans fabric with at least 20 warp beats and at least 17 weft beats , using the dyed yarn for warping .

Through the above-listed phases , the method according to the present invention makes it possible to obtain high- quality j eans products or fabrics , e . g . trousers , j ackets and/or other garments , which are comfortable and pleasant to the touch, while having a low environmental impact .

Although more expensive and complex to implement compared with the methods currently known for the production of j eans products and fabrics using cotton fibres , the method of the present invention is considerably healthier and has a much lower environmental impact , resulting in signi ficantly reduced water consumption and pollution of the same , while still providing a high-quality product or fabric that is comfortable and pleasant to the touch .

A preferred, but non-limiting, embodiment of the method according to the present invention will now be described in detail . The phase of selecting a seed grade is particularly advantageous , preferably fundamental ; in fact , the sativa and dioecious variant permits obtaining plants having a large quantity of fibre . Even more preferably, the phase of selecting the grade of hemp seed envisages the selection of the variety named Reithia .

Continuing the description of the method, the phase of sowing said seed in open field preferably occurs with approximately 70kg of seed per hectare of sown surface . This sowing technique gives very close-packed plants , e . g . about 900 , 000 plants per hectare , preferably 100 plants per m ² . With this technique , the individual plants are antagonists in search of the sun, and this stimulates their growth . Such a sowing technique makes it possible to obtain plants having an average height in excess of 4 . 5 meters , up to 6 meters .

The congestion of plants on the soil results in a signi ficantly reduced growth o f infesting weeds , thus eliminating the need for using herbicidal agents to reduce the growth of such infesting weeds . This reduces pollution, making the raw material healthier .

Moreover, since the plants are very close to each other, they retain the moisture of the night , thus keeping the soil less dry and reducing the water requirements of the hemp plants . This solution results in lower consumption of water for hemp production .

Continuing the description of the phases of the method, in a preferred, but merely illustrative and non-limiting, embodiment thereof the sowing phase is followed by at least one sub-phase of irrigation with a liquid obtained by retting of nettle in water . Preferably, during the period of growth of the hemp plants , two irrigation sub-phases , preferably only two irrigation sub-phases , are carried out . In particular, the first irrigation sub-phase occurs around the month o f April ; whereas the second irrigation sub-phase occurs in the month of June , preferably in the second hal f of the month of June . As known, 250mm of rain are suf ficient for hemp to grow correctly . In particular, hemp cultivation requires only 250 litres of water per square meter of culture in the approximately 220 days that are necessary for its growth .

As aforementioned, the irrigation sub-phase is carried out by using plain water in which nettle plants have been previously retted . The water thus obtained has anti- cryptogamic and fertili zing properties , because nettle plants release nitrogen . The method according to the present invention does not envisage the use of any other anti- cryptogamic substance or product . This solution reduces pollution, making the raw material healthier .

In a preferred embodiment thereof , the method according to the present invention provides for executing the phase of harvesting the hemp plants when the plant is green, preferably when the plant has a humid residue comprised between 25% and 35% . According to the method of the present invention, therefore , the plant should not be harvested when it is fully mature , e . g . when the humid residue is lower than 10% , but when the hemp plant is still green . Such a solution facilitates the next processing phases and permits obtaining fibres of better quality for yarn production .

In a preferred embodiment of the method according to the present invention, the phase of harvesting the plants is carried out by harvesting and binding into bundles . Such a solution makes for simpler handling and further processing of the hemp plants .

Continuing the analysis of the phases of the method according to the present invention, a phase o f removing an upper part of the stalks is subsequently carried out . In particular, the harvesting and binding steps , executed during the phase of harvesting the hemp plants , are followed by the phase of removing an upper part . During this phase , the stalk is cut to remove no more than one meter, preferably approximately 80cm, from the top of the stalk . Such removed portion of the stalk can then be used for producing animal feed with medical properties .

Without referring to any particular theory, but based on practical findings , it has been observed that an amount of such residue in excess of 15% in animal feed makes it possible to eliminate the use o f antibiotics . Furthermore , it has been observed that when such residue is used for producing chicken feed, in particular for feeding egg-laying hens , the eggs thus obtained have less or even no cholesterol .

The phase of selecting a central part of the stalks is then carried out . After the execution of the phase o f selecting the central part of the stalks , the remaining lower part of the stalk can be used for producing stabling straw, paper, additives for cement mortar, or biomass . The removed lower part of the stalk is rich in canapulo and can be hardly used for obtaining the yarn, and is therefore removed .

The method according to the present invention makes it possible to produce hemp plants that can be used in all of their parts , thus producing no waste . The part selected during the phase of selecting the central part of the stalks provides hemp stalks of 2 to 3 meters in length, preferably 2 to 2.5 meters, which are then suitably bound into bundles.

After the stalks have been selected as specified in the preceding phases, and preferably bound into bundles, the phase of flaking off, preferably peeling, by compression, the central part of the stalks is carried out. Preferably, this phase is executed by compression: for example, the stalks are fed under a compressor, e.g. a road roller, in order to flake off the stalk. The flaking off operation facilitates the next phases of the method; in particular, it permits obtaining better results from the retting phase.

Advantageously, the retting phase is preceded by a subphase of reducing the selected stalks to pieces less than 60cm long. Such phase further facilitates the next phase of retting off the pieces of flaked off stalks.

Preferably, in view of the execution of the retting off phase, the selected and flaked off part of the stalk is cut into sections approximately 50cm long.

In a preferred embodiment, the stalk pieces thus obtained are laid into vats and covered with weights to cause the stalks to remain under water, the latter being poured in afterwards. Therefore, the stalk pieces are placed into vats and completely submerged in water.

In the retting water, in order to limit the proliferation of organic substances that would make the water become, from an ecological viewpoint, wastewater with pollution values not allowed by the R.E.A.C.H. specification, fish fauna is introduced, in particular freshwater fish, e.g. catfish and dace, which feed on the organic excess produced by the hemp.

For the purposes of the present description, the R.E.A.C.H. specification is the European regulation that represents the accepted standard for recording, evaluating and authorizing the use of chemical substances, aiming at ensuring a higher level of health protection for humans and for the environment, while at the same time maintaining and enhancing the competitiveness and competitive capabilities of the European industry.

Subsequently, after about 30-40 days, the vats are emptied of the water, which, still in order to comply with the R.E.A.C.H. specification, is conveyed into a storage vat containing water in a quantity not less than 10 times the water used for retting. By way of example, when using 5, 000m ³ of retting water, said storage vat shall have a capacity of 65, 000m ³ . Preferably, said storage vat shall be provided with abundant flora capable of effecting a perfect phytopurification. For example, said flora may include spirulina, emerging microphyte and necrophyte algae, and phragmites australis, which plays an essential role as an oxygen pump.

About 20 days later, the water thus treated will be perfectly pure and can be lawfully spilled for irrigating the hemp-cultivated soil as previously specified herein.

Referring back to the retting phase, the semifinished product obtained after retting is then left to drip.

Following the retting phase, an ozone pressurization phase is carried out. During such phase, the retted hemp stalks, transformed into a semifinished product, or lint, are placed into an ozone machine. Such ozone machine can pressurize with ozone, e.g. to a pressure of 3 atmospheres, the semifinished product, or lint, obtained after retting. Preferably, such ozone is self-produced.

The lint is pressurized with an ozone system capable of removing pectin from the hemp fibres, so that the fluff can then be processed for producing a tape, which is the last operation that is necessary prior to spinning, in order to be able to obtain a high-quality, soft yarn offering high performance in terms of breathability and UV protection.

This ozone pressurization phase facilitates the separation of the individual filaments of the hemp stalks. This phase is particularly advantageous because it permits obtaining an easily spinnable fibre.

Preferably, prior to the execution of the phase of producing a yarn, the method according to the present invention envisages the execution of a phase of combing and cutting the fibres. During such phase, prior to starting the spinning phase, the fibre is combed and cut to different sizes, preferably in the range of 40mm to 80 mm. Any fibres that are shorter than 30 mm, preferably shorter than 40mm, will be rejected and will not undergo the next phase of the method, but may be used as stabling straw.

The next phase of the method according to the present invention is the yarn production phase.

As previously specified herein, in the current state of the art the yarn of all Liberian fibres, including hemp, is produced by means of the so-called flax system.

In contrast, the method according to the present invention uses a moisturized woollen system.

The woollen system for spinning is already per se known to those skilled in the art. Such operation takes place, in the method according to the present invention, in a high- humidity environment to permit spinning the semifinished product so far obtained. As an example, carding is carried out in an environment into which water is constantly nebulized.

In order to improve the quality of the fabric, the moisturized woollen system is used for producing a yarn with a metric count Nm 36000, equivalent to 36 km of yarn per 1kg of the same yarn. As previously specified herein, in order to produce a jeans product or fabric with a weight of 11-12 ounces, cotton yarn with a metric count of Nm 10000 to 12000 is normally employed.

Once the yarn has been obtained at the end of the yarn production phase, a twisting phase is carried out. In the method according to the present invention, the yarn is twisted with at least three threads, preferably three times. Thread twisting improves the quality and softness of the yarn and provides it with an elastic effect; in particular, the yarn and the fabric are given mechanical elasticity thanks to the double "S" and "Z" twists.

After obtaining the twisted yarn, a gassing phase is carried out. During such phase, the twisted yarn undergoes an open-flame gassing process or treatment. Such gassing process permits removing, or reducing as much as possible, any lumps, imperfections and hairiness.

After the gassing process, the thickness of the yarn is reduced by an amount comprised between 10% and 15%. Such gassing process causes the twisted yarn to become de facto a yarn with a metric count of Nm 12000 to 14000.

The yarn thus obtained is advantageously wound into hanks for warping and on cones for weft. The method according to the present invention includes a phase of dyeing at least a part of the yarn gathered into hanks .

The dyeing phase advantageously comprises the following sub-phases :

• at least one cleaning sub-phase , wherein the hanks to be dyed are cleaned;

• at least one dyeing sub-phase , wherein the hanks are dyed .

Said at least one dyeing sub-phase comprises a step of preparing a dyeing bath . Advantageously, said dyeing bath comprises : at least one dye for obtaining the blue colour , in particular indigo or isatis tinctoria, which is typical of j eans fabric ; water at a temperature of 12 ° C to 20 ° C ; at least one natural resin, preferably of tree origin, suitably dispersed in the aqueous solution; hemp pectin, suitable for keeping the dye in suspension, and sodium bicarbonate .

As can be understood, the rej ects of the retting and distillation process become a component which is useful for preparing the dyeing bath .

In particular, hemp pectin improves the fixation of the colour to the hemp yarn .

Preferably, a part of the obtained yarn, e . g . 60% o f the total yarn that will be needed for manufacturing the fabric, is wound into hanks , and such hanks are subj ected to the dyeing phase .

Preferably, the dye i s a natural one obtained from indigo , isatis tinctoria and/or vegetable carbon powder, or a mixture thereof .

In a preferred embodiment of the method, the dyeing bath used in the dyeing phase comprises : blue dye 1 to 40 parts lemon juice concentrate 150 parts hemp pectin 30 parts rosemary essential oil 5 parts damar resin 50 parts linseed oil 20 parts conifer resin 50 parts sodium bicarbonate 5 to 25 parts.

As far as the blue dye is concerned, the number of parts may vary within the above-mentioned range according to the desired colour shade to be given to the yarn; in particular, the higher the number of parts, the darker the colour shade.

As concerns sodium bicarbonate, such value will depend on the type of fibre to be used. Preferably, 5 parts should be used for Liberian fibres. For other fibre types, e.g. animal fibres like wool, cashmere or baby camel, the bicarbonate amount should be increased to 25 parts.

The method according to the present invention preferably envisages that, during the dyeing sub-phase, the dyeing bath must be kept at a temperature of 10 to 20 °C. In addition, the dyeing sub-phase includes a step of immersing the hank into the dyeing bath. Such immersion step lasts 0.1 seconds to one minute, preferably about one second.

In the dyeing sub-phase, the immersion step is followed by a hydro-extraction step, during which as much dyeing bath as possible is removed from the yarn hanks.

The cleaning sub-phase comprises the following steps: placing the yarn hanks into a container; preparing at least one washing liquid with said ionizing substances and/or a natural detergent; executing the washing. Preferably, said washing l iquid is a combination or mixture of the following elements : lemon concentrate 200 parts orange essential oil 100 parts chestnut flour 20 parts sodium carbonate 10 parts olive oil 16 parts laurel oil 20 parts

This embodiment of the washing liquid is particularly suitable for Liberian fibres , including hemp .

At the end of the dyeing phase , the method according to the present invention envisages a phase of drying the dyed yarn hanks . During such phase , the hanks are preferably laid on wooden sticks and frequently stirred . I f necessary, drying may be promoted by forced ventilation . The drying phase i s similar to the technique used for drying egg dough .

When the dyed hanks are dry, a phase of heating in an oven is carried out . During such phase , the dyed hanks stay in an oven at approximately 160 ° C for at least 120 seconds . This phase is useful to fix the dye on the yarn through a polymeri zing ef fect .

Preferably, said oven is a curing oven capable o f operating at a temperature of 160 degrees .

This oven heating phase is a phase necessary for finishing the dyed hanks .

The ( dyed) yarn obtained after the above process is ready for the j eans fabric weaving phase .

The method according to the present invention envisages a phase of weaving the j eans fabric, wherein weaving occurs with 21 warp beats of dyed yarn; although the yarn has been prepared with three twisted threads , the yarn is woven by means of shuttle looms, preferably of old design, in order to attain the same results as those ensured by the technique that was formerly employed for making the first jeans.

More in general, the weaving techniques may vary, but in any case, the yarn so far produced by implementing the method of the present invention will make it possible to obtain a high-quality jeans product or fabric having the aforementioned properties.

Preferably, when the fabric has been obtained at the end of the jeans fabric weaving phase, in order to obtain a weight loss such product or fabric is placed in the ozone machine again, executing an additional ozone pressurization phase. At the end of this additional ozone pressurization phase, the product or fabric will be ready for use, and the colour will have reached a fastness of 4/5 over a scale of 5. The colour thus conceived is also fast to hyperchlorite, hydrogen peroxide and sodium permanganate. The present invention ensures environmental-friendly dyeing, because the fabric will suffer no colour loss.

The method according to the present invention makes it possible to manufacture a jeans product or fabric starting from hemp. Such jeans product or fabric preferably has one or more pockets. Each pocket preferably comprises an inner lining, also made from hemp.

Said jeans product or fabric is, for example, a pair of trousers, a jacket and/or another garment.

Thanks to the method according to the present invention, which makes and uses a yarn with a metric count Nm 36000, in turn twisted three times, a fabric is obtained which is of higher quality, pleasant to the touch and comfortable, although it has been obtained starting from hemp. Moreover, due to the triple twisting of the yarn, the product or fabric has higher quality, softness and mechanical elasticity .

In addition, thanks to the gassing of the twisted yarn, a further improvement of the properties of the yarn according to the present invention is attained in view o f manufacturing products or fabrics , because any imperfections and/or lumps are eliminated .

Lastly, due to the larger number of beats and to the stronger beating force obtained through the use of shuttle looms , preferably of old design, for both warp and weft , in comparison with the classical methods , the product or fabric will have a better qual ity .

Furthermore , in the product or fabric obtained from the present invention, the inner lining, e . g . of the pockets of the product or fabric, is made from hemp yarn with a metric count of Nm 36000 . Also the inner lining is preferably woven with 26 to 28 warp and weft beats .

In addition, in the product or fabric obtained from the present invention the sewing thread is also made starting from hemp . Preferably, such sewing thread is made by us ing the CORESPAN method, with a s ilver filament core . By us ing the CORESPAN production technique it is possible to insert a silver filament into the sewing thread, the metric characteristics of which envisage the use of 1 kg of product per 280km of filament . Such s ilver filament is coated with hemp f i 1 aments .

The use of the silver filament has several purposes . I t allows , in fact , increasing the sewing speed, compared with using a sewing thread made from hemp only, because the hemp filament is composed of hollow fibres that might break under the heating occurring during the sewing operation . In addition, although to a l imited extent because of the very small quantity employed, the silver filament provides an antibacterial ef fect .

The present invention also improves the yarn dyeing process , since industrial dyeing is not suitable for providing an increased fastness index . In the dyeing phase , in fact , the method according to the present invention makes use of healthy and ecological products while ensuring a high level of colour fastness in excess of level 4 over a scale of 5 for all colours . Moreover, the dyeing phase according to the present invention allows defining beforehand the exact final shade of colour .

In addition, the j eans product or fabric obtained from the present invention can be washed multiple times without its shade of colour changing between one washing and the next , which will remain the same over time . Even potassium permanganate , hydrogen peroxide and hyperchlorite will not modi fy the tone of the product or fabric manufactured by means of the method according to the present invention .

In the method according to the present invention, the dyeing phase is executed at room temperature , thus not requiring any energy consumption . Furthermore , the residual dyeing bath is not drained; on the contrary, the remaining dyeing bath solution is stored and reused for other dyeing phases and/or for further processing .

In addition, in the process according to the present invention, when the dye colour needs to be changed, the wastewater used for washing the dyeing devices is supplied to an evaporator to obtain distilled water that can then be reused in the method of the present invention; while the dry waste, amounting to approximately 2% to 3%, is stored and disposed of.

Preferably, said evaporator operates on photovoltaic energy, preferably only on photovoltaic energy, thus considerably reducing the environmental impact of the method according to the present invention.

More generally, the evaporator will give two products or compounds, in particular distilled water, which can then be supplied again to the initial production cycle or used for irrigation purposes during the retting phase, and a solid residue. Such solid residue will mainly comprise pectin and other compounds, e.g. substantially imperceptible parts of C.D.B. active principle, etc.

Such solid residue, normally in powder form, can be used in the process, particularly in the dyeing phase.

All the products used for dyeing, of course other than the dye itself when indigo or isatis tinctoria are used, comply with the Italian food legislation, and are therefore healthy to the point that no certification is necessary.

Lastly, one very important feature of the method according to the present invention is that the little energy used therein is exclusively produced, preferably selfproduced, from renewable sources.

Moreover, without particular reference to any principles or theories, the jeans product or fabric obtained from the method according to the present invention, as originally conceived, has a substantially negative carbon footprint, because more than 36kg of CO ₂ are eliminated per pair of jeans thus manufactured.

The present invention makes it possible to obtain a jeans fabric made exclusively from hemp which sticks to the history of j eans products and technically increases the j eans resilience by at least 10 times , while of fering the user the benefit of wearing a garment whose hollow fibre allows for thermal exchange , thereby protecting from the heat in the summer and from the cold in the winter, in addition to protecting against UV rays .

The j eans fabric according to the present invention is also non-allergenic and anti-mite . The yarn thus produced i s much more irregular than the one produced by using the flax system, but this increases its resilience .

The method according to the present invention can be subdivided into a number of sub-processes , each one dedicated to a particular set of phases o f the present method, e . g . the hemp cultivation sub-process , the hemp processing subprocess , the spinning sub-process and the weaving subprocess , each one being separately provided with inventive activity .

Any alternative embodiments which have not been speci fically described in the present patent application, but which can be easily inferred by a person skilled in the art in the light of the contents of the present patent application, should be considered to fall within the protection scope of the present invention .

Barzand & Zanardo Milano S . p .A.