阅读说明：本技术 一种苎麻脱胶液及脱胶方法 (Ramie degumming liquid and degumming method ) 是由 张小祝 别晓东 杨继前 廖光辉 王惠 于 2020-04-08 设计创作，主要内容包括：本发明涉及苎麻脱胶领域,公开了一种苎麻脱胶液,包括按重量份数计的如下成分：15％～20％过碳酸钠、1％～5％冰醋酸、1％～5％表面活性剂、1％～5％乙二胺四乙酸二钠、1％～5％亚硫酸钠、1％～5％稳定剂、1％～5％助剂,其余为水,其不仅脱胶率高,而且断裂强度、断裂伸长率和柔软度性能优异；其脱胶方法为：将质量比为1:5的苎麻原麻经过氧乙酸进行前处理,然后进行水洗；以质量比为1:10与脱胶液混合,在100～150℃条件下,煮练40～60min,煮练压力为1.372×10<Sup>5</Sup>～1.96×10<Sup>5</Sup>Pa；将处理后的苎麻碱洗后,再经亚硫酸钠洗涤,然后给油干燥,即得到苎麻纤维,该方法脱胶更彻底,减少了脱胶处理工序,缩短了脱胶处理时间,提高了脱胶效率,减轻了对环境的污染,更加经济环保。(The invention relates to the field of ramie degumming, and discloses a ramie degumming liquid which comprises, by weight, 15% -20% of sodium percarbonate, 1% -5% of glacial acetic acid, 1% -5% of surfactant, 1% -5% of disodium ethylene diamine tetraacetate, 1% -5% of sodium sulfite, 1% -5% of stabilizer, 1% -5% of auxiliary agent, and the balance of water, and has high degumming rate, excellent breaking strength, breaking elongation and softness, wherein the degumming method comprises the steps of pretreating ramie raw ramie with peroxyacetic acid at a mass ratio of 1:5, washing, mixing with the degumming liquid at a mass ratio of 1:10, boiling for 40-60 min at 100-150 ℃, and boiling pressure of 1.372 × 10 5 ～1.96×10 5 Pa; the treated ramie is washed by alkali, washed by sodium sulfite and dried by oil, so that the ramie fiber is obtained.)

1. The ramie degumming liquid is characterized by comprising the following components in parts by weight: 15 to 20 percent of sodium percarbonate, 1 to 5 percent of glacial acetic acid, 1 to 5 percent of surfactant, 1 to 5 percent of disodium ethylene diamine tetraacetate, 1 to 5 percent of sodium sulfite, 1 to 5 percent of stabilizer, 1 to 5 percent of auxiliary agent and the balance of water.

2. The ramie degumming solution according to claim 1, comprising the following components in parts by weight: 17-20% of sodium percarbonate, 1-3% of glacial acetic acid, 1-3% of disodium ethylene diamine tetraacetate, 1-3% of sodium sulfite, 1-3% of stabilizer, 1-3% of auxiliary agent and the balance of water.

3. The ramie degumming solution according to claim 1, comprising the following components in parts by weight: 18% of sodium percarbonate, 2% of glacial acetic acid, 2% of disodium ethylene diamine tetraacetate, 2% of sodium sulfite, 2% of stabilizer, 2% of auxiliary agent and the balance of water.

4. The ramie degumming solution according to claim 1, wherein the surfactant is one or more of a fluorinated alkyl sulfonate surfactant, a Gemini surfactant or an APG alkyl glycoside surfactant.

5. The ramie degumming solution according to claim 1, wherein the stabilizer is one or more of sodium salicylate, sodium benzoate, resorcinol, and citric acid.

6. The ramie degumming solution according to claim 1, wherein the auxiliary agent is one or more of water glass, phosphate or an organic silicon defoaming agent.

7. The ramie degumming solution according to claim 6, wherein the phosphate auxiliary is one or more of trisodium phosphate, sodium tripolyphosphate or sodium pyrophosphate.

8. A process for degumming ramie degumming solutions according to claims 1 to 7, characterized in that it comprises the following steps:

(1) pretreating raw ramie with peracetic acid in a mass ratio of 1:5, and then washing with water;

(2) after the step (1) is finished, mixing the mixture with degumming liquid according to the mass ratio of 1:10, boiling for 40-60 min at the temperature of 100-150 ℃, wherein the boiling pressure is 1.372 × 10⁵～1.96×10⁵Pa；

(3) And (3) washing the ramie treated in the step (2) with water, washing with sodium sulfite, and then, oiling and drying to obtain the ramie fiber.

9. The degumming method according to claim 8, wherein the parameters of the peroxyacetic acid pretreatment process in step (1) are as follows: the temperature is 50-70 ℃, the pH value is 5.0, the time is 1-2 h, and the concentration of the peroxyacetic acid is 1.5-2.5%.

10. The degumming method according to claim 8, wherein the sodium sulfite washing in step (3) is to rinse the ramie bundles in a sulfurous acid washing solution with a concentration of 1-2 g/L for about 15min, and then to take out and repeatedly rinse with water until the pH is neutral.

Technical Field

The invention relates to the field of ramie degumming, in particular to a ramie degumming liquid and a degumming method.

Background

As the biggest China Ramie producing country in the world, China has abundant resources. The ramie contains cellulose as main component, lignin, pectin, hemicellulose and other non-cellulose components, which are collectively called as pectin. The non-cellulosic component is an amorphous crusting substance that binds the cellulose together to make the fiber stiff and therefore the raw ramie fiber cannot be directly used for spinning, and the gum must be removed before spinning to separate the ramie filaments from each other, a process known as "degumming". The degumming method commonly used in the current factory production is a double-boiling one-scouring or double-boiling one-bleaching method, and the specific process of the method mainly comprises unpacking, bundling, pickling, first scouring, second scouring, beating ramie, bleaching and pickling, washing, dehydrating, bleaching, feeding oil and drying of raw ramie; the treatment process is complicated, long in time consumption and high in energy consumption, the strength of the hemp is greatly damaged due to long-time alkali boiling, and the flexibility of the hemp fiber is reduced.

Disclosure of Invention

In view of the above-mentioned disadvantages of the prior art, the first object of the present invention is to provide a ramie degumming solution which not only has high degumming rate, but also has excellent properties of breaking strength, elongation at break and softness.

The second purpose of the invention is to provide a degumming method, which has more thorough degumming, reduces degumming treatment procedures, shortens degumming treatment time, improves degumming efficiency, reduces environmental pollution, and is more economic and environment-friendly.

In order to achieve the above purpose, the solution adopted by the invention is as follows:

the ramie degumming liquid comprises the following components in parts by weight: 15 to 20 percent of sodium percarbonate, 1 to 5 percent of glacial acetic acid, 1 to 5 percent of surfactant, 1 to 5 percent of disodium ethylene diamine tetraacetate, 1 to 5 percent of sodium sulfite, 1 to 5 percent of stabilizer, 1 to 5 percent of auxiliary agent and the balance of water.

A degumming method comprising the steps of:

(1) pretreating raw ramie with peracetic acid in a mass ratio of 1:5, and then washing with water;

(2) after the step (1) is finished, mixing the mixture with degumming liquid according to the mass ratio of 1:10, boiling for 40-60 min at the temperature of 100-150 ℃, wherein the boiling pressure is 1.372 × 10⁵～1.96×10⁵Pa；

(3) And (3) alkali-washing the ramie treated in the step (2), washing with sodium sulfite, and then oiling and drying to obtain the ramie fiber.

The invention has the beneficial effects that:

1. the degumming solution provided by the invention not only utilizes sodium percarbonate with strong degumming effect as a main degumming component, but also creatively adds glacial acetic acid and a surfactant into the degumming solution, utilizes the strong permeation effect of the glacial acetic acid to ensure that non-cellulose positioned on the surface of cellulose is easy to wet and permeate, is helpful for assisting the sodium percarbonate to permeate into non-cellulose substances such as hemicellulose, lignin and the like, weakens the connection between the non-cellulose and the fiber, and removes the non-cellulose substances such as the hemicellulose, the lignin and the like; simultaneously, under the carrying of strong permeability of glacial acetic acid, the surfactant can quickly enter the non-cellulose on the surface, so that the oleophilic end of the surfactant can better permeate into the colloidal layer, the colloid can be directly dissolved after the oleophilic end is combined with the colloid, the colloid can be removed more favorably, the degumming rate is greatly improved, the cellulose cannot be easily damaged during quick degumming, and the ramie fiber obtained after degumming has excellent breaking strength, breaking elongation and softness.

2. The degumming method provided by the invention has the advantages of more thorough degumming, reduction of degumming treatment processes, shortening of degumming treatment time, improvement of degumming efficiency, reduction of environmental pollution, and more economy and environmental protection.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. 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 available commercially.

The degumming liquid and the degumming method for ramie provided by the embodiment of the invention are specifically explained below.

The ramie degumming liquid comprises the following components in parts by weight: 15 to 20 percent of sodium percarbonate, 1 to 5 percent of glacial acetic acid, 1 to 5 percent of ethylene diamine tetraacetic acid disodium, 1 to 5 percent of sodium sulfite, 1 to 5 percent of stabilizer, 1 to 5 percent of auxiliary agent and the balance of water.

The degumming liquid is added with sodium percarbonate which is used as a main bleaching agent and an oxidant, and the sodium percarbonate has the dual properties of hydrogen peroxide and sodium carbonate, has higher active oxygen content and can be decomposed in an aqueous solution to generate hydrogen peroxide and sodium carbonate, so that the property of the aqueous solution is the same as that of the aqueous solution of the hydrogen peroxide and the sodium carbonate. The perhydroxyl ions generated by the sodium percarbonate in an alkaline solution have a bleaching effect; therefore, sodium percarbonate has similar bleaching properties to hydrogen peroxide, and sodium percarbonate degumming utilizes perhydroxyl ions and sodium carbonate generated by hydrolysis to remove non-cellulosic substances such as hemicellulose, pectin and lignin in ramie. Meanwhile, the bleaching property of sodium percarbonate is utilized to carry out bleaching treatment on the ramie fibers.

On one hand, the glacial acetic acid can adjust the pH value of the solution, on the other hand, the glacial acetic acid can be used as a penetrating agent to reduce the surface tension of the solution, so that non-cellulose on the surface of cellulose is easy to wet and penetrate, the permeation of sodium percarbonate into non-cellulose substances such as hemicellulose and lignin is facilitated, the connection between the non-cellulose substances and the fiber is weakened, and the non-cellulose substances such as the hemicellulose and the lignin are removed. For ramie fiber, as long as good wetting occurs, the degumming liquid can automatically generate good permeation action through the mutually communicated capillary tubes, thereby being beneficial to the whole degumming process.

The surfactant is one or more of a fluorine-containing alkyl sulfonate surfactant, a Gemini surfactant or an APG alkyl glycoside surfactant. The fluorine-containing alkyl sulfonate surfactant has good thermal stability, the lowest surface tension of the surfactant is far lower than that of sodium perfluoroheptyl sulfonate, and the surfactant shows high surface activity and better water solubility; the Gemini surfactant has better surface activity and wetting property; the APG alkyl glycoside is a novel nonionic surfactant, has the advantages of high surface activity, fineness, stability, good decontamination and compatibility performance and the like, can be quickly biodegraded, belongs to a nontoxic surfactant and is more environment-friendly; the APG alkyl glycoside surfactant is an environment-friendly degradable surfactant, and reduces pollution to the environment in the subsequent degumming process.

The raw ramie contains more dust and metal substances which can promote the decomposition of sodium percarbonate, and the disodium ethylene diamine tetraacetate is used as a complexing agent for complexing metal ions and separating metals, so that the ineffective decomposition of the sodium percarbonate in the degumming process can be reduced, the degumming effect of the sodium percarbonate can be fully exerted, and the degumming effect of the sodium percarbonate can be improved. Meanwhile, in the degumming process of the sodium percarbonate, the ethylene diamine tetraacetic acid disodium can also be used as an antioxidant synergist, a stabilizer, a softener and the like so as to fully play the oxidability and the bleaching property of the sodium percarbonate in the degumming process and improve the degumming effect.

Sodium sulfite is a reducing agent and can deprive oxygen in other substances to prevent the sodium sulfite from reacting with cellulose to produce oxidized cellulose. Especially in the boiling-off process, sodium sulfite can cooperate with sodium percarbonate to improve the degumming effect, lignin can be changed into lignosulfonate to be easily dissolved in degumming liquid, the damage to fibers is reduced, the breaking strength of the fibers is improved, and simultaneously, the sodium sulfite has a bleaching function and can improve the boiling-off effect by cooperating with sodium tripolyphosphate.

Preferably, the composition comprises the following components in parts by weight: 17-20% of sodium percarbonate, 1-3% of glacial acetic acid, 1-3% of disodium ethylene diamine tetraacetate, 1-3% of sodium sulfite, 1-3% of stabilizer, 1-3% of auxiliary agent and the balance of water.

Preferably, the composition comprises the following components in parts by weight: 18% of sodium percarbonate, 2% of glacial acetic acid, 2% of disodium ethylene diamine tetraacetate, 2% of sodium sulfite, 2% of stabilizer, 2% of auxiliary agent and the balance of water.

Preferably, the surfactant is one or more of a fluorine-containing alkyl sulfonate surfactant (such as perfluoroalkyl sulfonyl fluoride), a Gemini surfactant or an APG alkyl glycoside surfactant.

Preferably, the stabilizer is one or more of sodium salicylate, sodium benzoate, resorcinol and citric acid, and free radicals generated by catalytic decomposition are inhibited by adding the stabilizer, so that the damage to the fiber is kept to the minimum.

During boiling, in order to promote uniform permeation of alkali liquor, shorten boiling time and improve boiling quality, a part of auxiliary agent is often added during boiling, and preferably, the auxiliary agent is water glass or phosphate; preferably, the phosphate auxiliary agent is one or more of trisodium phosphate, sodium tripolyphosphate or sodium pyrophosphate, and under the coordination of the sodium tripolyphosphate and the sodium sulfite, the bleaching performance is better, and the scouring effect can be improved.

A degumming method comprising the steps of:

(1) pretreating ramie raw ramie with a mass ratio of 1:5 by peroxyacetic acid, wherein the parameters of the peroxyacetic acid pretreatment process are as follows: the temperature is 50-70 ℃, the pH value is 5.0, the time is 1-2 h, the concentration of the peroxyacetic acid is 1.5-2.5%, and then water washing is carried out; the peroxyacetic acid degumming pretreatment process utilizes the high selectivity of peroxyacetic acid and the low reactivity of the peroxyacetic acid with cellulose and alcoholic hydroxyl groups in the hemicellulose to remove non-cellulose substances such as hemicellulose, pectin, lignin and the like in ramie, so that the residual gum rate is greatly reduced, degumming is more thorough due to the oxidizing property of the peroxyacetic acid in the pretreatment process, and the pectin, the lignin and the peroxyacetic acid have the effect on the peroxyacetic acid, so that part of pectin and lignin in the fiber are removed, and the oxidizing property of the peroxyacetic acid has specificity on the oxidation of the lignin, and aromatic hydrocarbons of the lignin can be oxidized to generate dicarboxylic acid and lactone, so that part of the lignin is degraded; with the removal of impurities such as pectin, lignin and the like, the concentration of the impurities in the system is increased, and part of the colloid is adhered to the surface of the fiber again along with the increase of the temperature, so that the breaking strength of the fiber is greatly improved;

in addition, the bleaching property of the peroxyacetic acid is utilized to carry out bleaching treatment on the ramie fibers, so that the pretreatment time for degumming is shortened, and the degumming efficiency is improved; because of the degumming and bleaching functions in the pretreatment of the peroxyacetic acid, the consumption of sodium percarbonate in the subsequent degumming process is greatly reduced, the damage to cellulose in the degumming process is reduced, and the product quality is improved.

(2) After the step (1) is finished, mixing the mixture with degumming liquid according to the mass ratio of 1:10, boiling for 40-60 min at the temperature of 100-150 ℃, wherein the boiling pressure is 1.372 × 10⁵～1.96×10⁵Pa; the invention utilizes the characteristics of the degumming liquid, reasonably combines the two most time-consuming and energy-consuming processes of boiling and bleaching in the traditional process together for one-step completion, namely, the bleaching process is completed while degumming, the flow is simple, the time is shortened, the energy consumption is greatly reduced, the using amount of the used medicines is less than that of the two steps of degumming and bleaching, the discharge capacity is reduced, and the environment protection is facilitated.

(3) Washing the ramie treated in the step (2) with water, and then washing with sodium sulfite, wherein the sodium sulfite washing is to rinse the ramie bundles in a sulfurous acid washing solution with the concentration of 1-2 g/L for about 15min, and then taking out and washing with water repeatedly until the pH value is neutral; then, oil is supplied for drying, and the ramie fiber is obtained; the post-treatment is carried out by washing with sodium sulfite to neutrality, and the anhydrous sodium sulfite can dissolve the cross-linked protein in the washing process to reduce the protein level, thereby improving the flexibility of the fiber and reducing the pollution of the waste liquid to the environment.