阅读说明：本技术 一种卷式膜过滤法制备高强度卡拉胶纤维的方法 (method for preparing high-strength carrageenan fibers by roll-type membrane filtration method ) 是由 张立峰 宁海凤 张洪奎 于 2019-09-10 设计创作，主要内容包括：本发明公开一种卷式膜过滤法制备高强度卡拉胶纤维的方法,包括以下操作步骤：(1)将麒麟菜经碱处理、清洗、蒸煮后加入珍珠岩或硅藻土过助滤剂,然后经板框压滤机去除纤维类杂质后,得到卡拉胶原液；(2)利用孔径2-20nm的卷式膜过滤设备对卡拉胶原液进行连续过滤浓缩,得到浓缩滤液；(3)使用板式换热器将浓缩滤液降温后使用乙醇或异丙醇沉淀胶液,得到絮状物；(4)将絮状物脱水、撕碎,闪蒸干燥、杀菌、粉碎、过筛后得到卡拉胶半成品；(5)将卡拉胶半成品加入至溶解液中溶解后,制得卡拉胶纺丝原液,将卡拉胶纺丝原液采用纺丝机纺丝处理后,得到细度为40μm的卡拉胶纤维。本发明方法制备卡拉胶,产率高并且制得的卡拉胶品质优异。(The invention discloses a method for preparing high-strength carrageenan fibers by a roll-type membrane filtration method, which comprises the following operation steps: (1) alkali treating Eucheuma Gelatinosum, cleaning, steaming, adding perlite or diatomaceous earth into the Eucheuma Gelatinosum, filtering with filter aid, and removing fiber impurities with plate-and-frame filter press to obtain carrageenan stock solution; (2) continuously filtering and concentrating the carrageenin stock solution by using a spiral-wound membrane filtering device with the pore diameter of 2-20nm to obtain concentrated filtrate; (3) cooling the concentrated filtrate by using a plate heat exchanger, and precipitating glue solution by using ethanol or isopropanol to obtain floccules; (4) dehydrating and shredding the floccule, flash-drying, sterilizing, crushing and sieving to obtain a carrageenan semi-finished product; (5) and adding the carrageenan semi-finished product into the dissolving solution to dissolve to obtain a carrageenan spinning stock solution, and spinning the carrageenan spinning stock solution by using a spinning machine to obtain the carrageenan fiber with the fineness of 40 mu m. The method for preparing the carrageenan has high yield and excellent quality of the prepared carrageenan.)

1. a method for preparing high-strength carrageenan fibers by a roll-type membrane filtration method is characterized by comprising the following operation steps:

(1) Alkali treating Eucheuma Gelatinosum, cleaning, steaming, adding perlite or diatomaceous earth into the Eucheuma Gelatinosum, filtering with filter aid, and removing fiber impurities with plate-and-frame filter press to obtain carrageenan stock solution with filtering pressure of 0.8-1.0 mPa;

(2) Continuously filtering and concentrating the carrageenin stock solution by using a spiral-wound membrane filtering device with the pore diameter of 2-20nm to obtain concentrated filtrate;

(3) cooling the concentrated filtrate to 40-60 deg.C with a plate heat exchanger, and precipitating with ethanol or isopropanol 1-2 times the volume of the concentrated solution to obtain floccule;

(4) Dehydrating and shredding the floccule, flash-drying, sterilizing, crushing and sieving to obtain a carrageenan semi-finished product;

(5) adding the carrageenan semi-finished product into a dissolving solution for dissolving to prepare a carrageenan spinning stock solution, and spinning the carrageenan spinning stock solution by using a spinning machine to obtain carrageenan fibers with the fineness of 40 mu m, wherein the dissolving solution is prepared from the following components in parts by weight: 10-16 parts of sodium hydroxide, 1-4 parts of 1, 2-cyclohexanediamine tetraacetic acid, 3-9 parts of triethanolamine and 150-200 parts of water.

2. The method for preparing high-strength carrageenan fibers by roll-type membrane filtration according to claim 1, wherein in the step (1), the temperature of alkali treatment is 60-80 ℃, and the mass fraction of alkali in alkali liquor is 7-10%.

3. The method for preparing high-strength carrageenan fibers by roll-type membrane filtration according to claim 1, wherein in the step (1), the base is KOH, NaOH or Na₂CO₃、NaHCO₃one or a mixture of two or more of them.

4. The method for preparing high-strength carrageenan fibers by roll-type membrane filtration according to claim 1, wherein in the step (2), the roll-type membrane filtration device is made of polyamide.

5. the method for preparing high-strength carrageenan according to claim 1, wherein in the step (4), the floccule is dewatered by: pumping the floccule into a membrane filter press, gradually pressurizing to 2.5mPa, and dehydrating for 20-30 min.

6. the method for preparing high-strength carrageenan fibers by roll-to-roll membrane filtration according to claim 1, wherein in the step (5), the mass volume ratio of the carrageenan semi-finished product to the carrageenan solution is 1kg: 2-3L.

Technical Field

The invention relates to the technical field of carrageenan preparation, in particular to a method for preparing high-strength carrageenan fibers by a roll-type membrane filtration method.

Background

carrageenan (also called carrageenan and carrageenin) is a hydrophilic colloid extracted from red algae (Rhodophyta), and is a linear high molecular polysaccharide containing sulfate groups. The carrageenan desirably has a repeating α - (1 → 4) -D-galactopyranose- β - (1 → 3) -D-galactopyranose (or 3, 6-lacto-D-galactopyranose) disaccharide unit backbone structure.

Carrageenan can be classified according to the number and position of sulfate groups contained in the repeating units of carrageenan, and commercially used are three types of kappa, iota and lamda at most, and particularly kappa type has been widely used. Kappa carrageenan contains only one sulfate group at the C (4) of D-galactose, iota carrageenan is similar to Kappa carrageenan, and is characterized in that iota carrageenan contains one sulfate group at each of the C (4) of D-galactose and the C (2) of 3, 6-anhydrogalactose.

The Kappa carrageenan has high gel strength, is crisp, has obvious gel bleeding phenomenon, and has good elasticity and toughness and no bleeding phenomenon. The price of the Iota carrageenan raw material E.spinosum is about 1/2 of that of the kappa carrageenan raw material E.Cottonii, and the cost advantage is obvious.

the prior iota carrageenan production process comprises the following steps: weighing → water washing → alkali treatment → water washing → cooking → filtering → cooling → alcohol precipitation → extrusion → drying → crushing. The large consumption of precipitated colloidal alcohols in the production process is a major cause of the high production costs.

Chinese patent CN102174118A discloses a method for preparing iota carrageenan, which adopts the conventional technology to obtain carrageenan liquid, then foams the carrageenan liquid through a liquid crusher or a colloid mill, simultaneously adds KCl, CaCl2 and dodecyl trimethyl ammonium bromide through a spray generating device to carry out two-step salting out, and then the iota carrageenan is prepared through separation, dehydration and alcohol washing. The process is complicated and inconvenient for industrial production, and the introduction of the chemical component dodecyl trimethyl ammonium bromide is not beneficial to product safety.

Chinese patent CN1721448A discloses a method for extracting iota carrageenan, which is prepared by using inorganic acid to soak, wash, steam and boil, gel, dehydrate, dry and crush. The method consumes a large amount of CaCl2 in the process of precipitation due to low concentration of the filtrate, a homogenizer needs to be added, and the pH of the final finished product cannot meet the national standard. And the use of inorganic acid can cause the breakage of glycosidic bonds in the carrageenan to a certain extent, and the functional properties of the final product are influenced.

Disclosure of Invention

the invention aims to reduce the consumption of alcohols during precipitation, reduce the production cost, improve the productivity and simultaneously improve the strength of carrageenan fibers on the basis of the prior art.

The invention is realized by the following technical scheme.

A method for preparing high-strength carrageenan fibers by a roll-type membrane filtration method comprises the following operation steps:

(1) alkali treating Eucheuma Gelatinosum, cleaning, steaming, adding perlite or diatomaceous earth into the Eucheuma Gelatinosum, filtering with filter aid, and removing fiber impurities with plate-and-frame filter press to obtain carrageenan stock solution with filtering pressure of 0.8-1.0 mPa;

(2) continuously filtering and concentrating the carrageenin stock solution by using a spiral-wound membrane filtering device with the pore diameter of 2-20nm to obtain concentrated filtrate;

(3) Cooling the concentrated filtrate to 40-60 deg.C with a plate heat exchanger, and precipitating with ethanol or isopropanol 1-2 times the volume of the concentrated solution to obtain floccule;

(4) dehydrating and shredding the floccule, flash-drying, sterilizing, crushing and sieving to obtain a carrageenan semi-finished product;

(5) Adding the carrageenan semi-finished product into a dissolving solution for dissolving to prepare a carrageenan spinning stock solution, and spinning the carrageenan spinning stock solution by using a spinning machine to obtain carrageenan fibers with the fineness of 40 mu m, wherein the dissolving solution is prepared from the following components in parts by weight: 10-16 parts of sodium hydroxide, 1-4 parts of 1, 2-cyclohexanediamine tetraacetic acid, 3-9 parts of triethanolamine and 150-200 parts of water.

specifically, in the step (1), the temperature during alkali treatment is 60-80 ℃, and the mass fraction of alkali in the alkali liquor is 7-10%.

Specifically, in the step (1), the alkali is KOH, NaOH or Na₂CO₃、NaHCO₃One or a mixture of two or more of them; .

specifically, in the step (2), the spiral membrane filtration device is made of polyamide.

Specifically, in the step (4), the operation of dewatering the flocs is as follows: pumping the floccule into a membrane filter press, gradually pressurizing to 2.5mPa, and dehydrating for 20-30 min.

Specifically, in the step (5), the mass volume ratio of the carrageenan semi-finished product to the carrageenan is 1kg: 2-3L.

According to the technical scheme, the beneficial effects of the invention are as follows:

(1) After the carrageenin stock solution is filtered by a plate-frame filter, the carrageenin stock solution is filtered and concentrated by a polyamide nanofiltration membrane, the concentration of the filtrate is improved by more than 2 times, and the subsequent use amount of ethanol/isopropanol is greatly reduced;

(2) After the nanofiltration membrane is used for filtering and concentrating, the total amount of the carrageenan filtrate is reduced, so that the requirements of subsequent equipment such as a condenser, a membrane filter press and the like are reduced, and the equipment investment cost is reduced;

(3) the carrageenan filtrate after nanofiltration concentration removes partial pigment and small molecular impurities, the carrageenan is further purified, and the quality of the final product is improved;

(4) The carrageenan semi-finished product is subjected to spinning after being dissolved by the dissolving solution provided by the invention, and the obtained carrageenan fiber has excellent strength and quality.

Detailed Description

embodiments of the present invention will be described in detail below with reference to examples, but it will be understood by those skilled in the art that the following examples are only illustrative of the present invention and should not be construed as limiting the scope of the present invention. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products commercially available.