RU2196850C1 - Modified bast fiber for cellulose manufacture - Google Patents

Abstract

FIELD: flax processing industry. SUBSTANCE: bast fiber is made from split filaments of up to 15 mm length with woody fiber content not in the excess of 3%, with weight part of 5-8 mm length filaments being at least 50%; using short flax fiber, bast or hemp as bast fiber. Method is used for production of raw material for cellulose and esters thereof. EFFECT: wider operational capabilities of fiber by using it in existing cellulose production processes, namely, in production of general-purpose modified bast fiber for cellulose manufacture and wider range of bast fibers. 2 tbl

Description

 The invention relates to the flax processing industry and relates to bast fiber for special purposes, obtained by machining.

 The problem of rational, more active use of domestic low-grade bast fiber and flaxseed waste from the point of view of national economic income, as well as the provision of technological processes with natural cellulose-containing raw materials, is relevant for the country.

 At present, short bast fiber, the total mass of which reaches 60% of the total amount of fiber produced, is not sold, since the yarn made from it has been displaced from the market by synthetic threads. This reduces the profitability of the flax complex as a whole and is one of the causes of the crisis in the bast industry. At the same time, bast fibers can serve as a valuable source of cellulose instead of cotton fiber that has become imported.

 Known modified flax fiber made of shortened split fibers with a length of 15-45 mm in an amount of not less than 50%, or a length of 15-70 mm in an amount of not less than 50%, or a length of 20-90 mm in an amount of not less than 50%, the mass fraction of fibers up to 15 mm long is not more than 10%.

 However, the known fiber is processed on high-performance cotton, wool and cotton combing equipment and cannot be used for the production of pulp (RU 2170778, D 01 C 1/00, publ. 07.20.2001).

 Coniferous and deciduous wood is mainly a traditional raw material for pulp production.

 It is known that wood chips with a length of 30 mm and a thickness of up to 5 mm, containing 10-15% hardwood and 85-90% conifers, are used to produce cellulose. (RU 2010067, D 21 C 1/00).

 It is known that cellulose is produced from wood with a thickness of 2-4 mm, a length along the fibers of 40-60 mm (RU 2082845, D 21 С 1/10).

 However, the widespread use of wood is becoming a problem and there is already a shortage of wood raw materials, which requires a transition to the use of non-wood cellulose-containing raw materials.

 The main source of non-wood pulp-containing raw materials is cotton.

 It is known to obtain cotton cellulose from cotton lint, the length of which is less than 20 mm (T.F. Korotkov, V.I. Shonina, etc. Tashkent. FAN, 1969, p.21-27).

 However, cotton is an imported raw material and its final product becomes uncompetitive due to the high price.

 It is known to use cereal plants (wheat, oats, corn, etc.) for the production of cellulose.

 However, the yield and quality of cellulose is rather low (A.S. USSR 437310, D 21 C 3/02, 70 g).

 It is known to use flax bonfire to produce cellulose.

 However, the presence of an increased lignin content reduces the yield of cellulose, and the presence of a large amount of fiber in it complicates the process (A.S. 931872, D 21 C 3/02, 82 g).

 The objective of the invention is to obtain a modified bast fiber, ensuring the achievement of a technical result consisting in expanding the technological capabilities of the fiber by using it for existing processes for the production of cellulose, i.e. in obtaining universal modified bast fiber for the production of pulp and in expanding the range of bast fibers.

 This technical result is achieved in that the modified bast fiber for the production of cellulose is made of shortened split fibers up to 15 mm long with a degree of taperedness of not more than 3%, and the mass fraction of fibers from 5 to 8 mm in length is not less than 50%. The modified bast fiber is made of short flax fiber, or from bast, or from hemp.

 Flax, hemp are cellulose-containing annually renewable raw materials for the production of cellulose and its products.

 The proposed modified bast fiber can be obtained from wastes from flaxseed production, from urine, shale flax fiber or bast in the form of tow, short fiber, as well as from scuffing, scratching (more than 60% of which) and other flax production, tearing or spinning mixtures thereof .

 Modified bast fiber is made according to the following technology.

 Bast fiber (mainly waste) is modified, split and shortened into thinner and shorter fibers by mechanical methods, cleaning and cutting.

 Short flax fiber 3 (up to 10 cm long), the main characteristics of which are shown in table. 1, was cleaned on machines CHG-115-P and Ch-600, and the moisture content of the processed fiber was 14-18%, at which the windings were eliminated.

 The wiring installed on the ChG-115-P machine is given in table. 2.

 After cleaning, a fiber with a taperedness of not more than 3% is obtained, the yield of which is ~ 73%, then the purified fiber is subjected to special cutting and a fiber with a length of up to 15 mm is obtained, while the number of fibers of longer and shorter fractions should be minimal.

 Upon modification (cleaning and cutting), a split, shortened fiber with a length of up to 15 mm with a degree of taperedness of not more than 3% is obtained with a mass fraction of fiber with a length of 5 to 8 mm equal to at least 50%.

 To obtain a modified bast fiber, short flax fiber, flax production waste, bast or hemp are used as bast fiber.

 The obtained modified bast fiber is a new type of fiber for the production of cellulose, when changing the parameters of the modified fiber, a violation of the technological process of production of cellulose and a change in its properties are observed.

 Modified bast fiber is a cost-effective raw material, as it is renewed annually and more environmentally friendly due to the conservation of forest reserves and the reduction of the harmfulness of pulp and paper production.

 Tests of experimental processing products obtained from flax pulp (varnishes, paints, glues, gunpowder) showed their high quality.

 The resulting modified bast fiber is universal, it is suitable for all existing technologies for the production of cellulose.

Claims (2)

 1. Modified bast fiber for cellulose production, made of shortened split fibers up to 15 mm long with a degree of taperedness of not more than 3%, and the mass fraction of fibers from 5 to 8 mm in length is not less than 50%.  2. The modified bast fiber for the production of cellulose according to claim 1, made of short flax fiber, or from bast, or from hemp.

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