Bast-fiber material processing method

Abstract

The invention relates to the textile industry, and specifically to methods for processing bast-fiber materials, for instance the fiber of flax, hemp, jute, nettle, kenaf, and others. The technical result which the present invention aims to achieve consists in: enhancing the quality of a cottonized fiber, when processing bast-fiber materials, by means of high-voltage electric pulse discharges following preliminary biochemical and final minimal mechanical processing; and in enhancing the physical/mechanical and spinning properties thereof, which, overall, allows for an optimized, efficient production process. Said technical result is achieved in that a bast-fiber material processing method includes a technological sequence of processes involving feeding raw material into a bale breaker, which is provided with a decompactor, and into a dosing system, processing using high-voltage electric pulse discharges, rinsing with emulsifying reagents, washing and press-drying in a drum-type installation, decompacting, final drying and light decompacting; the raw material is biochemically treated prior to being fed into high-voltage electric pulse discharge chambers.

Claims

1. A method of processing unscutched bast-fiber materials, comprising a woody part, cellulose, and encrusting substances, so as to elicit elementary fibers, comprising, in sequence, steps of: a. feeding raw materials comprising intermediate products of bast-fiber materials after biological enzyme treatment without subsequent mechanical scutching into a bale-breaker with a loosener; b. feeding the raw materials from said bale breaker with the loosener into a metering system; c. biochemically treating the raw materials; d. generating pulsed electric discharges between two electrodes disposed within a chamber containing a liquid medium and the biochemically treated raw materials so as to effectively generate enhanced hydraulic pressures and mechanical actions within the liquid medium, including shock waves and cavitation, which will tend to separate bast-fiber products from the raw materials, wherein said enhanced hydraulic pressures and mechanical actions result in generation of a discharge channel which expands at a rate of over 100 m/s and processing the biochemically treated raw materials in the chamber; e. rinsing the bast-fiber products with emulsifying reagents; and f. washing and pressing the bast-fiber products followed by loosening, final drying and fine loosening so as to obtain elementary fibers which retain the length, diameter and ordered crystalline structure of the cellulose in the bast-fiber material.

2. The method according to claim 1, wherein the step of processing the biochemically treated raw material using a pulse electric discharge in a liquid medium causes separation of woody parts and encrusting substances from the elementary fibers.

3. The method according to claim 1, wherein the liquid medium is water.

4. The method according to claim 1, which further comprises a step of removing the used liquid medium using a filtration step prior to step (e).

5. The method of claim 1, wherein the pulsed electric discharge has either (A) an energy of 2.2 kJ and is applied for 400 discharges; or (B) an energy of 3.6 kJ and is applied for between 100 and 200 discharges.

6. A method of processing unscutched bast-fiber materials, comprising a woody part, cellulose, and encrusting substances, so as to elicit elementary fibers, comprising, in sequence, steps of: a. feeding raw materials comprising intermediate products of bast-fiber materials after biological enzyme treatment without subsequent mechanical scutching into a bale-breaker with a loosener; b. feeding the raw materials from said bale breaker with the loosener into a metering system; c. biochemically treating the raw materials; d. generating either (A) 400 pulsed electric discharges each having an energy of 2.2 kJ or (B) between 100 and 200 pulsed electric discharges each having an energy of 3.6 kJ, between two electrodes disposed within a chamber containing a liquid medium and the biochemically treated raw materials so as to effectively generate enhanced hydraulic pressures and mechanical actions within the liquid medium, including shock waves and cavitation, which will tend to separate bast-fiber products from the raw materials, and processing the biochemically treated raw materials in the chamber; e. rinsing the bast-fiber products with emulsifying reagents; and f. washing and pressing the bast-fiber products followed by loosening, final drying and fine loosening so as to obtain elementary fibers which retain the length, diameter and ordered crystalline structure of the cellulose in the bast-fiber material.

7. The method according to claim 6, wherein the step of processing the biochemically treated raw material using a pulse electric discharge in a liquid medium causes separation of woody parts and encrusting substances from the elementary fibers.

8. The method according to claim 6, wherein the liquid medium is water.

9. The method according to claim 6, which further comprises a step of removing the used liquid medium using a filtration step prior to step (e).

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) The essence of the invention is explained using a drawing, where, in FIG. 1, a diagram of the process line for bast-fiber material processing is depicted.

PUTTING THE INVENTION INTO EFFECT

(2) The method of bast-fiber material processing for which the application is made is put into effect as follows.

(3) The intermediate product, fiber from bast-fiber crops which has undergone preliminary processing using biochemical methods, passes to the cottonization process line, which comprises a bale-breaker and loosener (1) installed in the sequence of the production process. The next stage is the metering system (2), which works on a batch basis, and consists of pan-type scales of the Digi-Balance type, which is filled by the fiber that arrives from the bale-breaker, and discharges it as a set weight is reached (or a Truetzschler type EBWM belt metering chamber, made by Derux GmbH of Germany). Then a liquid, for example water, is fed into the high-voltage pulse electric discharge chambers (3) which are filled with the intermediate product, and in these chambers partial cottonization of the fiber takes place. The number of discharge chambers depends on the output of the whole complex, and they are located in a sound-proofed space.

(4) The dimensions and geometry of the discharge chamber, the electrical parameters of the high-voltage pulse generator, the frequency of the pulses, the length (gap) and geometry of the inter-electrode space, the number of electrodes and their distribution in space, the ratio of the mass of liquid to the mass of raw material and other parameters are selected in such a way as to create the optimum conditions for development of sparkover and a shock wave configuration for effective modification of the initial materials and the best output of the installation as a whole. The discharges occur alternately (haphazardly) and are automatically regulated.

(5) The discharge chambers are linked by the liquid feed pipes, and the used liquid passes with the aid of pumps to a filtration and recirculation system (4). After the end of the discharge cycle the chambers tip up and the processed fiber passes via a transporter to an industrial drum-type washing and drying installation (5), where rinsing, pressing and drying of the fiber takes place. To increase the elasticity and flexibility of the fiber, a plasticizing agent based on surfactants and surfactant-based emulsions is added to the washing and drying installation.

(6) The washing and drying installation is also connected to the filtration and recirculation system (4).

(7) The wet loosener unit, the dryer and a type EFO-IV or EMZH fine loosener made by Derux GmbH (Germany) for thorough and careful loosening of the natural fibers are located in section 6.

(8) The line ends with a fiber press 7.

(9) It has been established that Agata grade short fiber flax (Great Britain) processed using 400 discharges at an energy level for each discharge of 2.2 kJ is the most suitable for future spinning, since the fiber obtained was compatible in its mean diameter, mean length and short fiber content with American mountain cotton. Independent tests were carried out on the properties of both the fiber and the spinning capacity at the company Filartex SpA (Italy), which is one of the leading cotton processing companies in Europe.

(10) It was also proven that increasing the discharge energy to 3.6 kJ gives the same results in terms of the quality of processed short flax fiber yield, and this quality may be achieved with a number of discharges of between just 100 and 200.

(11) Breaking load tests on the yarn in a mixture with cotton 40% flax, Electra grade\60% cotton.

(12) Yarn 74.2 tex, 100 repeats.

(13) Appendix 3 Yarn tensile testing results

(14) 40/60 Flax (Electra variety)/Cotton yarn, 74.2 tex, 100 repeats

(15) TABLE-US-00001 Force at Elongation Force at Elongation Strain at Strain at Test Break at Break Peak at Peak Break Peak No (N) (mm) (N) (mm) (%) (%) 1 7.68 28.17 7.96 27.27 5.63 5.46 2 8.51 30.81 8.51 30.81 6.16 6.16 3 6.87 32.60 8.96 31.70 6.52 6.34 4 4.15 33.49 10.26 32.58 6.70 6.52 5 10.33 34.38 10.33 34.38 6.88 6.88 6 9.76 33.45 9.76 33.45 6.69 6.69 7 6.29 33.44 9.52 32.55 6.69 6.51 8 3.22 29.88 8.02 28.96 5.98 5.79 9 10.11 34.38 10.11 34.38 6.88 6.88 10 10.88 37.06 10.88 37.06 7.41 7.41 11 5.32 32.45 9.82 31.56 6.49 6.31 12 8.28 29.91 8.28 29.91 5.98 5.98 13 5.60 30.67 8.22 29.77 6.14 5.95 14 8.95 33.51 9.32 32.61 6.70 6.52 15 3.49 34.36 9.15 33.44 6.87 6.69 16 10.21 31.66 10.21 31.66 6.33 6.33 17 7.67 27.14 7.67 27.14 5.43 5.43 18 4.55 32.43 9.67 31.52 6.49 6.30 19 4.72 30.70 8.65 29.79 6.14 5.96 20 4.93 36.17 11.24 35.26 7.24 7.05 21 5.48 33.47 9.24 32.55 6.69 6.51 22 3.35 34.35 9.79 33.44 6.87 6.69 23 9.04 31.67 9.04 31.67 6.33 6.33 24 7.91 28.97 7.91 28.97 5.79 5.79 25 4.34 32.44 8.94 31.53 6.49 6.31 26 7.97 29.78 7.97 29.78 5.96 5.96 27 6.38 29.77 7.52 28.89 5.95 5.78 28 8.96 30.75 8.96 30.75 6.15 6.15 29 4.82 34.37 9.59 33.44 6.87 6.69 30 9.28 31.62 9.28 31.62 6.32 6.32 31 3.94 30.73 8.56 29.81 6.15 5.96 32 8.23 28.84 8.23 28.84 5.77 5.77 33 6.93 29.78 7.51 28.89 5.96 5.78 34 9.12 30.66 9.12 30.66 6.13 6.13 35 7.48 30.72 7.48 30.72 6.15 6.15 36 6.44 26.10 6.91 25.21 5.22 5.04 37 6.46 28.88 7.10 28.00 5.78 5.60 38 5.55 33.35 8.97 32.45 6.67 6.49 39 3.53 34.33 9.34 33.40 6.87 6.68 40 6.80 30.69 7.73 29.80 6.14 5.96 41 6.70 33.45 9.62 32.55 6.69 6.51 42 3.84 30.76 8.08 29.84 6.15 5.97 43 8.22 28.98 8.22 28.98 5.80 5.80 44 6.28 32.65 9.59 31.75 6.53 6.35 45 7.64 28.16 7.64 28.16 5.63 5.63 46 9.11 31.69 9.11 31.69 6.34 6.34 47 7.24 29.91 8.16 29.01 5.98 5.80 48 8.90 32.62 8.90 32.62 6.52 6.52 49 4.75 30.82 8.84 29.90 6.16 5.98 50 8.04 29.01 8.04 29.01 5.80 5.80 51 8.53 32.61 10.10 31.70 6.52 6.34 52 10.21 33.47 10.21 33.47 6.69 6.69 53 9.48 31.80 9.48 31.80 6.36 6.36 54 7.33 31.70 10.03 30.81 6.34 6.16 55 10.16 33.49 10.16 33.49 6.70 6.70 56 6.45 31.68 8.82 30.79 6.34 6.16 57 4.49 30.83 9.11 29.91 6.17 5.98 58 2.92 31.64 7.58 30.74 6.33 6.15 59 3.46 33.49 9.23 32.57 6.70 6.52 60 10.25 33.60 10.25 33.60 6.72 6.72 61 9.67 35.28 9.67 35.28 7.06 7.06 62 7.96 28.10 7.96 28.10 5.62 5.62 63 4.76 30.78 8.24 29.87 6.16 5.97 64 5.81 30.78 8.29 29.90 6.16 5.98 65 5.98 28.94 7.06 28.05 5.79 5.61 66 4.01 31.70 9.00 30.79 6.34 6.16 67 8.69 30.74 8.69 30.74 6.15 6.15 68 7.68 29.03 7.73 28.14 5.81 5.63 69 4.05 31.76 8.46 30.84 6.35 6.17 70 8.72 34.44 9.76 33.55 6.89 6.71 71 2.87 28.98 8.18 28.06 5.80 5.61 72 7.97 27.21 7.97 27.21 5.44 5.44 73 3.11 29.86 7.52 28.96 5.97 5.79 74 7.93 28.94 7.93 28.94 5.79 5.79 75 3.75 36.19 10.05 35.28 7.24 7.06 76 3.24 32.63 9.05 31.71 6.53 6.34 77 9.33 33.50 9.33 33.50 6.70 6.70 78 7.54 28.03 7.54 28.03 5.61 5.61 79 8.65 30.81 8.65 30.81 6.16 6.16 80 7.02 27.23 7.02 27.23 5.45 5.45 81 8.56 31.73 9.18 30.80 6.35 6.16 82 8.00 34.42 9.26 33.51 6.88 6.70 83 7.15 31.77 9.19 30.88 6.35 6.18 84 9.18 32.67 9.18 32.67 6.53 6.53 85 4.45 32.59 8.87 31.67 6.52 6.33 86 2.63 28.12 7.37 27.21 5.62 5.44 87 7.88 29.02 7.88 29.02 5.81 5.81 88 3.73 29.82 8.01 28.91 5.96 5.78 89 9.72 34.37 9.72 34.37 6.87 6.87 90 6.18 31.65 8.60 30.76 6.33 6.15 91 9.40 32.70 9.40 32.70 6.54 6.54 92 7.33 27.18 7.33 27.18 5.44 5.44 93 7.32 26.25 7.32 26.25 5.25 5.25 94 3.50 29.04 7.08 28.13 5.81 5.63 95 8.19 30.82 8.88 29.92 6.16 5.98 96 4.35 29.88 8.51 28.97 5.98 5.79 97 8.09 29.92 8.09 29.92 5.98 5.98 98 9.54 31.76 9.54 31.76 6.35 6.35 99 3.32 29.87 7.87 28.96 5.97 5.79 100 9.72 35.36 10.73 34.46 7.07 6.89 Min 2.63 26.10 6.91 25.21 5.22 5.04 Mean 6.85 31.34 8.77 30.82 6.27 6.16 Max 10.88 37.06 11.24 37.06 7.41 7.41 S.D. 2.26 2.32 0.98 2.29 0.47 0.46 C. of V. 33.02 7.41 11.12 7.44 7.41 7.44 L.C.L. 6.40 30.88 8.58 30.36 6.18 6.07 U.C.L. 7.29 31.80 8.96 31.27 6.36 6.25

INDUSTRIAL APPLICABILITY

(16) The fiber obtained in the method for which the application is made has a quality that enables it to be used in the production of a wide range of yarn on existing spinning equipment, non-woven materials and various items used for technical, mechanical and everyday purposes.