Field of invention

The present invention relates to a method of dyeing denim yarns and fabrics with vegetable dyes. The present invention particularly relates to a method of dyeing denim yarns and fabrics with vegetable dyes in a continuous fashion such that the denim yarns and fabrics are obtained with natural and wider color options as well as with lower costs.

Prior Art

Nowadays, denim fabrics and denim jeans are widely used in many fields, in the garment industry in which denim fabrics and jeans are predominantly used, these are died to provide an improved appearance with different effects. The dyeing process is usually carried out using dyestuffs based on various chemicals. However, as the harmful effects of chemical dyestuffs on the health of humans and on the environment emerge day by day, alternative solutions are searched for dyeing denims.

One of the solutions produced for dyeing denim fabrics is based on dyeing the warp yarn or the fabric using vegetable dyes. As it is seen from the markets, however, this solution appears to be conducted in a quite primitive fashion. Accordingly, dyeing a denim with vegetable dyes still needs improvement both in terms of mass production and with respect to the difficulty of the retention of vegetable dyes on denim.

For thousand of years, vegetable dyes have been applied one by one by hand using extended boiling periods and involving the use of alum and similar metal salts according to conventional methods. This type of dyeing methods making use vegetable dyes went out of use in parallel with industrialization due to high costs, inadequate fastness, lack of compatibility with cotton, slow reaction times, etc.. This type of dyeing methods with vegetable dyes is now seen nostalgic and is far from the trends.

Currently-available vegetable dyeing approaches fail to provide products, which are competitive and adequate in terms of costs and physical properties (particularly fastness), as well as methods by which mass production can be performed.

Current dyeing methods using vegetable dyes are disadvantageous in terms of the dyeing costs, which are many times higher than the costs of those methods using cotton and chemical dyes, the matte and dull colors, limited color options, the lack of the indigo character as a result of wearing and washing, inadequate fastness to lemon and carbonate (the highest fastness degree is 5 and the lowest fastness degree is 1), and the resulting product. These methods are also not competitive with dyeing methods using synthetic dyes due to easy soiling or staining as a result of matte and dull colors and inadequate fastness to lemon and carbonate. Another disadvantageous feature of the currently-available vegetable dyeing methods in terms of the environment is that they involve the use of heavy metals.

In the historical process of vegetable dyes, different dark colors have been obtained using metal salts. This, however, worsens the fastness.

In spite of all these disadvantages, the demands towards vegetable dyeing methods and products obtained thereby is gradually increasing in parallel to the environmental consciousness and to the increasing demand for natural and organic products.

Object and Description of invention

The object of the present invention is to carry out a dyeing process for denim, gabardine yarns and fabrics using vegetable organic natural dyes on continuous or semi-continuous machines. In the production method according to the present invention, the binding speed and efficiency of vegetable dyes to cotton and other fibers is increased using an REM technique or process, such that organic denim and gabardine fabrics (or yarns) can be industrially manufactured in mass production. The method according to the present invention makes it possible to react vegetable dyes with cotton, vegetable or synthetic yarns under low heat, low solution concentration and reduced time parameters.

The method according to the present invention makes it possible to design novel pre-operation techniques for producing such products that can provide adequate physical and chemical fastness and standards of vegetable dyes in cotton products.

The method according to the present invention provides improvements in many features with respect to the quality, efficiency, and costs of applying vegetable dyes, such that the vegetable dyes are made competitive against synthetic dyes, and healthy fabric products with natural color and odors can be designed with brown, khaki, green colors and bright washing effects.

The problems encountered in the prior art in that the cotton fiber is a vegetable natural fiber and cannot form stable bonds by reacting with vegetable dyes are solved according to the present invention. Therefore, mass production can only be carried out as a result of developing processes based on the continuous systems according to the present invention.

The production method according to the present invention makes it possible to increase the binding rate of vegetable dyes to cotton fibers by means of the REM technique (a technique described below by which a catalyst effect is provided, increasing the binding reaction rate more than 3 times by a fiber swelling pre- operation) in continuous and semi-continuous systems. Thus, the problems encountered in the prior art are also eliminated.

The production method according to the present invention makes it possible to produce cotton yarns, dyed with vegetable organic dyes, in the form of denim and gabardine fabrics, as well as garments made thereof, in larger sizes.

The production method according to the present invention makes it possible to produce denim fabric, gabardine fabric and jean, which may be of brown, red, or yellow color, can be abraded, and may have living colors.

The production method according to the present invention makes it possible to mass-produce products dyed with vegetable dyes in vivid and appealing colors. The production method according to the present invention makes it possible to make vegetable dyes competitive against industrial synthetic chemical textile dyes as a result of developing natural vegetable dyeing processes.

The production method according to the present invention makes it possible to find and define processes by which dark and vivid colors can be achieved without using metal salts (mordant) which were employed historically.

The production method according to the present invention makes it possible to increase the binding reaction rate and efficiency of vegetable dyes to cotton fibers by means of novel processes (the REM technique).

The production method according to the present invention makes it possible to produce denim and jeans having greenish, reddish, brownish and natural and fashion colors, using vegetable dyes, which are full compatible and therefore can suitably be used together with indigo dye used in jeans based on its blue color and other features.

The production method according to the present invention makes it possible to produce novel and genuine cotton fabrics, as well as garments thereof, dyed with brown and red vegetable dyes resembling the physical properties of indigo dye making standard jean products valuable.

In order to provide a better understanding of the production method and system according to the present invention, it shall be referred to the figures described below.

Description of Figures

The figures to provide a better understanding of the present invention are described below.

Figure 1 provides a table showing the steps of a vegetable pre-dyeing and dyeing process of yarns and denim fabrics made of cotton, vegetable and synthetic fibers in the form of beam and rope warp. Figure 2 provides a table showing the process and dyeing standards by which vegetable natural organic dyes are applied to denim and gabardine fabric by means of a REM technique in a continuous dyeing machinery line.

Figure 3, is an exemplary flowchart of process 1 to facilitate the understanding of the respective processes.

Reference List

R- REM technique, or simply REM

SK- Aeration passage (AirSky)

ST- Steaming (steamer)

HT- High heat treatment (high temperature)

G- Indigo dye unit

BB~ Vegetable dye nomenclature

CV- Walnut hull

MP- Acorn hull

KK~ Madder

BS~ Black cumin

BT- Black tea

CR- Cochineal

TN- Tannins

Y- Overflowing wash basin, i.e. overflowing water wash

AK- Intermediate drying

W1- First vegetable bath basin

W2- Second vegetable bath basin

W3- Third vegetable bath basin, i.e. topping vegetable dye basin F- Vegetable dye padder WCO- Vegetable dye coating

KR- Drying unit

X- Skipped process step or basin

Description of Reference Lists

REM TECHNIQUE (R):

Rem basin: A basin or bath where a REM process is carried out.

Concentration of the Rem application basin: 20-200 g/L

Application basic temperature: 30-80° C

Rem feed rate: 20-70% of the weight of the yarn fabric

Object of Rem use: Extending fiber gaps to provide swelling (volume increase).

Rem content: Wheat enzyme, honey enzyme, wetter and softener providing volume increase, tannic acid, stearic acid, citric acid and similar organic acid components. These organic and chemical substances are used singly or jointly in amounts determined according to the type and concentration of dye-plant pigments (tannins, juglone) to be added in subsequent steps.

AERATION PASSAGE (AIR SKY) (SK):

Provided to carry out aeration-oxidation for 20-100 seconds.

STEAMING (STEAMER) (ST):

Provided for steam fixation at 95-105°C for 30-180 seconds.

HIGH HEAT TREATMENT (HIGH TEMPERATURE) (HT):

Provided for steam-free heating in cabinet at 100-160°C for 30-180 seconds.

INDIGO DYE BASINS AND UNIT (G):

Number of bath or treatment basin: 1-6 (basin)

Feature: It is a bath or baths (basin or basins) of vegetable natural indigo or chemically-derived liquid or powder indigo used in denims.

OVERFLOWING WASH BASIN (Y): Provided to remove any dyes and chemicals not bond to yarns and fabrics by means of this overflowing water wash performed at 6G-80°C.

INTERMEDIARY DRYING (AK):

It is a step required to provide entrance into solution from dry state (DRY IN WET). FIRST VEGETABLE DYE BASIN (W1):

Concentration factor of basin: 1/10 - 1/100 = 1 kg plant/10 L water - 1 kg p!ant 100 L water

Feed factor: 1/20 ~ 1/3

Feed rate: It is calculated so that 50-1000 g of dry color plant is used for 1 kg yarn fabric. When plant extracts are used, it is calculated so that 30-300 g of plant extract is used for 1 kg yarn/fabric.

Basin temperature: 60-95°C

Basin bath volume: 200-500 L

SECOND VEGETABLE DYE BASIN (W2):

Concentration factor of basin: 1/10 - 1/100 = 1 kg plant/10 L water - 1 kg plant 100 L water

Feed factor: 1/20 - 1/3

Feed rate: It is calculated so that 50-1000 g of dry color plant is used for 1 kg yarn/fabric. When plant extracts are used, it is calculated so that 30-300 g of plant extract is used for 1 kg yarn/fabric.

Basin temperature: 80-95°C

Basin bath volume: 200-400 L

THIRD VEGETABLE DYE BASIN, I.E. TOPPING VEGETABLE DYE BASIN (W3):

Concentration factor of basin: 1/10 - 1/100 = 1 kg plant/10 L water - 1 kg plant/100 L water

Feed factor: 1/20-1/3 Feed rate: It is calculated so that 50-1000 g of dry color plant is used for 1 kg yarn/fabric. When plant extracts are used, it is calculated so that 30-300 g of plant extract is used for 1 kg yarn/fabric.

Basin temperature: 60-95

Basin bath volume: 200-500 L

VEGETABLE DYE PADDER (WF):

Concentration factor of basin: 1/20 - 50 = 1 kg plant / 20-50 L water

Feed factor: 1/7-20

Feed rate: It is calculated so that 100-500 g of dry color plant is used for 1 kg yarn/fabric. When plant extracts are used, it is calculated so that 20-200 g of plant extract is used for 1 kg yarn/fabric.

Basin temperature: 20-85°C

Basin bath volume: 70-200 L

VEGETABLE DYE COVERING (WCO):

In vegetable dye covering (WCO), the vegetable dye has the same factors with the padder, but the process is carried out using foams and pastes.

Namely;

Concentration factor of basin: 1/20 - 50 - 1 kg plant / 20-50 L water

Feed factor: 1/7-20

Feed rate: It is calculated so that 100-500 g of dry color plant is used for 1 kg yarn/fabric. When plant extracts are used, it is calculated so that 20-200 g of plant extract is used for 1 kg yarn/fabric.

Basin temperature: 20-85X

Basin bath volume: 70-200 L

DRYING UNIT (KR):

Here, a fixation function is provided at the same time.

SKIPPED PROCESS STEP OR BASIN (X): This may be absent according to the state of the respective plant.

Detailed Description of Invention

in order to provide a better understanding of the production process according to the present invention, it will be referred to the prior art. According to the prior art, cotton fiber is a vegetable natural fiber and cannot form stable bonds by reacting with vegetable dyes. In order to eliminate this drawback, the so-called REM technique is carried out prior to vegetable dyeing process. The process step designated as REM or "R", allows to increase the distance (gap) between the fibers and to provide a catalyst effect in the binding reaction between the dye molecules and the cotton molecules so that the dyeing efficiency is increased at least three fold. The development of this technique, in turn, paved the way to use vegetable dyes in mass production with competitive costs and qualities. Here below, both the process steps, and the raw materials (or materials) used in the process will be referred to with abbreviations.

Using this REM technique (R), it is now possible to carry out industrial production in a continuous system in reduced time intervals and at lower temperatures. Thus, it is further possible to provide textile products in original natural plant colors and luster, as desired, without using any auxiliary chemicals.

The REM technique (R) is characterized in that natural and synthetic fibers are treated with wetting agents, natural soaps, textile softening agents and natural enzymes (comprising wheat and honey-glucose enzyme) individually or jointly, so that the binding efficiency of the dyes to the fibers is increased at least three fold (geometric or multiplier effect). Thus, using the REM technique (R), the binding rate of vegetable dyes to cotton fibers are increased so that continuous systems or semi-continuous systems can be used. What is meant here with the terms continuous or semi-continuous is a system flow composed of integrated machines. Here, the REM technique is the foremost among all processes and process steps. Here, wetting and softening are achieved using enzyme catalysts together with natural soap agents which are applied singly and/or in mixture in the form of steeping, along with air passage, preferably in a concentration of 50-350 g/L at 0- 100°C for 20-120 seconds, so that relatively larger vegetable dye pigment molecules are penetrated into the fiber gaps more easily and rapidly. Here, the use of 50-350 g mixture per liter is a preference in the implemented process. In this technique, the target effect is enhanced with an increase in the amount of added mixture. The effect is linear. Therefore, this interval may be 1-1000 g/L. The REM technique (R), which is a totally new approach implemented prior to dyeing using hot and concentrated softening, soap and wetter, organic enzymes (wheat enzyme and glucose enzyme) provides at least a three fold increase in the affinity (dye binding, binding rate) of vegetable dyes to cotton and other fibrous products so that stable and strong chemical bonds are formed between them. Wheat enzyme and honey glucose enzyme are produced by means of fermenting wholly organic and natural dough and honey which are left standing for a long period of time (10 to 100 days). Thus, the main agent is reproduced in wheat products. In addition, single or joint treatment with organic acids such as citric acid, tannin acid, stearic acid will increase the dyeing efficiency.

The vegetable dyeing method according to the present invention comprises different versions according to the vegetable dyes used, the products to be treated, and to the target results. These versions are divided into eight main groups, ft is required to implement the REM technique (R) before each process. However in process 4, it is implemented not at the beginning, but within the process (between the steps of the process). In order to carry out the present invention on industrial continuous machines, seven basic separate processes are designed and developed upon standardization.

Processes:

Process 1 : it is a process (mono deep) in which denim warp yarn and rope- shaped cotton yarn are dyed in single colors and fight color tones with an organic vegetable dye.

Process 2: It is a process (double deep) in which denim warp yarn and rope- shaped cotton yarn are dyed in double colors and dark color tones (intermediate color) with vegetable dyes, wherein 2-3 basins (passages) or 2 vegetable dyes are used to give dark and intermediate colors. Here, the term intermediary color means a color which is obtained by mixing two colors. For instance, an intermediate orange color is obtained as a result of applying red and yellow colors one after the other.

Process 3: It is a process in which vegetable dyes are applied to the bottom as a base color on a warp yarn under an indigo dye. Here, the dye is applied to the bottom of a material to be dyed. Here, e.g. natural indigo dye or blue indigo bye may be used. Namely, it is used under the natural dye or synthetic indigo dye to obtain different color hues of a normal blue denim jean dye, thereby giving 3 colors and the tones thereof. These three colors are grayish blue (grey cast), greenish blue (green cast, turquoise), and reddish blue (red cast). It is used with natural vegetable dyes (walnut, tannin, etc.) for natural indigo dye or blue indigo dye.

Process 4: it is a process in which vegetable dyes are used as a topping hue dye on indigo dye in dyeing denim fabric and yarns. Here, the dye is applied to the top of a material to be dyed.

Processes 5-6-7: These are processes in which raw denim, desized, flat cotton and mixed fiber denim and gabardine fabrics are dyed in a single color with a top dye (over-dyed by covering, foaming covering methods) in continuous fabric dyeing machines.

Process 8: It is a processes in which raw denim, desized, flat cotton and mixed fiber denim and gabardine fabrics are dyed with vegetable dyes by means of foaming, knife-, press- and other covering techniques in continuous fabric dyeing machines. These covering methods are foaming covering, knife covering, press covering etc..

The aforesaid processes are briefly described in the tables in figures 1 and 2. In order to understand these tables, however, it will also be referred to an exemplary flowchart of process 1 given in figure 3. Accordingly, the tables in figure 1 and figure 2 show the process types and the flow type of the process. The process tables may define the flow of the process from left to the right. Each ceil resembles a process step. For instance, in describing a process, the beginning of the table (in figure 1 and figure 2) (i.e. the processes column) shows the type of the process, the next column shows the codes of the vegetable dyes used, and the following columns show the following steps. In order to understand these tables, however, it will also be referred to an exemplary flowchart of process 1 given in figure 3.

In process 1 , the REM technique (R) is applied to denim yarns with at least one vegetable dye selected from madder (KK), acorn hull (MP), black tea (BT), black cumin (BS), cochineal (Carmen, CR), walnut hull (CV) and tannins (TN). Then, it is passed through an aeration passage (SK) for 20-100 seconds. Thereafter, it is subjected to overflow washing in a overflowing wash basin (Y) at 30-60°C. This step (Y) is repeated twice. Then, it is put into a first vegetable dye basin (W1 ) with a basin concentration factor from 1/10 to 1/100 and a bath volume of 200-500 L at 60-95°C. The feed rate here is 1/8 to 1/15, such that 300-1.000 g of dry plant extract is used for 1 kg of yarn. Then, it is passed again through the aeration passage (SK) for 20-100 seconds, after which one process step is skipped, and it is then subjected again to overflowing water wash (Y) at 30-60°C at least three times.

Describing process 1 as above will facilitate the understanding of other processes. A person skilled in the art or a person generally familiar with vegetable dyes and textile dyeing will understand the invention better from this standard description of process 1. Accordingly, the type of material to be treated (e.g. denim, gabardine fabrics, yams and similar materials), the conditions under which the treatment is carried out, the amount and type of the natural vegetable dyestuffs to be used, and the duration of the treatment in process 2, process 3, process 4, process 5, process 6, process 7, and process 8 are indicated in the tables in figure 1 and figure 2. The general characteristics of these tables will be as follows:

Accordingly, the present invention provides a production method for dyeing denim yarns and denim fabrics with vegetable dyes, the method having the following characterizing features.

- Natural or synthetic fibers are subjected to the REM technique (R) in a continuous manner so that they are dyed with at feast one vegetable dye selected from madder (KK), acorn hull (MP), black cumin (BS), walnut hull (CV) black tea (BT), cochineal (Carmen, CR), and tannins (TN) in process

1 , process 2, process 3, process 4, process 5, process 6, process 7 or process 8. ~ The REM technique or process (R) is carried out in the beginning of process 1 , process 2, process 3, process 5, process 6, process 7 and process 8, and during process 4, so that natural or synthetic fibers are dyed with vegetable dyes in these steps; the REM process (R) is conducted using natural soap agents, textile softening agents and natural enzymes (wheat enzyme and honey glucose enzyme etc.) such that wetting and softening are achieved, wherein said natural soap agents, textile softening agents and natural enzymes are used singly or in mixtures in a concentration of 1-1000 g L, preferably 50-350 g/L at 0-100°C in the form of steeping, along with an air passage application for 20-120 second.

- The process 1 is a process in which denim warp yarn and rope-shaped cotton yam are dyed in a single color and light color tones with organic vegetable dyes, wherein denim warp yarn and rope-shaped cotton yarn are first subjected to the REM process (R), after which at least one vegetable dye selected from madder (KK), acorn hull (MP), black tea (BT), black cumin (BS), walnut hull (CV), cochineal (CR), and tannin (TN) is supplied to the respective process step(s) comprised by process 1 as follows: aeration passage (SK), overflowing wash basin (Y), overflowing wash basin (Y), first vegetable dye basin (W1), skipped (X), aeration passage (SK), skipped (X), overflowing wash basin (Y), overflowing wash basin (Y), skipped (X), skipped (X), skipped (X), skipped (X), skipped (X), skipped (X), skipped (X), skipped (X), skipped (X), overflowing wash basin (Y), overflowing wash basin (Y), overflowing wash basin (Y), and overflowing wash basin (Y), in this given order.

- The process 2 is a process (double deep) in which denim warp yarn and rope-shaped cotton yarn are dyed in double colors or dark color tones (intermediate color) with vegetable dyes, wherein 2-3 basins (passages) or 2 vegetable dyes are used to give dark and intermediate colors, wherein denim warp yarn and rope-shaped cotton yarn are first subjected to the REM process (R), after which at least one vegetable dye selected from madder (KK), acorn hull (MP), black tea (BT), walnut hull (CV), cochineal (CR), and tannin (TN) is supplied to the respective process step(s) comprised by process 2 as follows: aeration passage (SK), overflowing wash basin (Y), overflowing wash basin (Y), first vegetable dye basin (W1), second vegetable dye basin (W2), aeration passage (SK), steaming (ST) and/or high heat treatment (HT), overflowing wash basin (Y), overflowing wash basin (Y), skipped (X), skipped (X), skipped (X), skipped (X), skipped (X), skipped (X), skipped (X), skipped (X), skipped (X), overflowing wash basin (Y), overflowing wash basin (Y), overflowing wash basin (Y), and overflowing wash basin (Y), in this given order.

The process 3 is a process in which vegetable dyes are applied to the bottom as a base color on a warp yarn under an indigo dye, wherein the warp yarn is first subjected to the REM process (R), after which at least one vegetable dye selected from acorn hull (MP), black tea (BT), cochineal (CR), and tannin (TN) is supplied to the respective process step(s) comprised by process 3 as follows: aeration passage (SK) and/or high heat treatment (HT), overflowing wash basin (Y), overflowing wash basin (Y), first vegetable dye basin (W1), skipped (X), aeration passage (SK), steaming (ST), overflowing wash basin (Y), overflowing wash basin (Y), indigo dye unit (G), skipped (X), skipped (X), skipped (X), skipped (X), skipped (X), skipped (X), skipped (X), skipped (X), overflowing wash basin (Y), overflowing wash basin (Y), overflowing wash basin (Y), overflowing wash basin (Y), in this given order.

The process 4 is a process in which vegetable dyes are used as a topping hue dye on an indigo dye in dyeing denim fabric and yarns, wherein at least one vegetable dye selected from walnut hull (CV), black tea (BT), acorn hull (MP), (CR), and tannin (TN) is supplied to the process step(s) comprised by process 4 as follows: skipped (X), skipped (X), overflowing wash basin (Y), overflowing wash basin (Y), skipped (X), skipped (X), skipped (X), skipped (X), skipped (X), skipped (X), indigo dye unit (G), overflowing wash basin (Y), overflowing wash basin (Y), Rem process (R), overflowing wash basin (Y), overflowing wash basin (Y), third vegetable dye basin (W3), aeration passage (SK), steaming (ST), overflowing wash basin (Y), overflowing wash basin (Y), overflowing wash basin (Y) and overflowing wash basin (Y), in this given order.

- The processes 5, 6, and 7 are processes in which raw denim, desized, flat cotton and mixed fiber denim and gabardine fabrics are dyed in a single color with a top dye (overdyed by covering, foaming covering methods) in continuous fabric dyeing machines, wherein raw denim, desized, flat cotton and mixed fiber denim and gabardine fabrics are first subjected to the REM process (R), after which at least one vegetable dye selected from walnut hull (CV), black tea (BT), acorn hull (MP), madder (KK), (CR), and tannin (TN) is supplied to the respective processes step(s) comprised by processes 5, 6, and 7 as follows: overflowing wash basin (Y), overflowing wash basin (Y), overflowing wash basin (Y), intermediary drying (AK), vegetable dye padder (WF), steaming (ST), overflowing wash basin (Y), overflowing wash basin (Y), overflowing wash basin (Y) and drying unit (KR), in this given order.

- The process 8 is a process in which raw denim, desized, flat cotton and mixed fiber denim and gabardine fabrics are dyed with vegetable dyes by means of foaming, knife-, press- and other covering techniques in continuous fabric dyeing machines, wherein raw denim, desized, flat cotton and mixed fiber denim and gabardine fabrics are first subjected to the REM process (R), after which at least one vegetable dye selected from walnut hull (CV), black tea (BT), acorn hull (MP), madder (KK), (CR), and tannin (TN) is supplied to the respective process step(s) comprised by process 8 as follows: overflowing wash basin (Y), overflowing wash basin (Y), overflowing wash basin (Y), intermediary drying (AK), vegetable dye covering (WCO), steaming (ST), overflowing wash basin (Y), overflowing wash basin (Y), overflowing wash basin (Y), and drying unit (KR), in this given order. Denim yarns and fabrics dyed with vegetable dyes based on the methods described above provides the achievement of the aforesaid results which cannot be provided according to the prior art. These methods can be applied both to al! denim yarns and fabrics and other textile materials used together with denim, as well as to composite, nonwoven, knitting and similar weaving techniques.