Researches On Extraction Of Rice Straw Fiber Used In Non-woven Film Of Agricultural

There are abundant of agricultural waste resources in our country, especially the crops straw, According to statistics, our country has eight million tons of crops straw annually. In recent years, we rural burned crops straw in the fields, not only waste the precious resources, but also seriously polluted environment, it has become a great hazards. Furthermore, as oil and coal resources shortage,people in order to seek more available resources,Fibre plants which is the great renewable resources has become an actively exploring subject in many countries of the world. Agricultural film is an excellent agricultural production technology, Film can effectively control the soil humidity and temperature, reduce the loss of nutrition and moisture, prevent weeds. At the same time as the increase of temperature, film increased the organic decomposition and improved the soil nutrient. Therefore developed biodegradable mulch to the sustainable development of agriculture has important significance.Common straw plant fiber extraction generally adopted for straw pulping sodium hydroxide cooking,the method is very high-energy,and pollution to the environment. This based on the two kinds of different processing methods for making rice straw fibre, agricultural film has been made the rice straw fibre from different extraction methods respectively, based on the properties of fiber properties and film, I Choose the best treatment.The first kind of rice straw processing method is to use sodium hydroxide blending rice straw. Sodium sulphide was added in this experiment, that is because sodium sulphide dissociate in solutions, solution exists hydroxyl ions, sulfur hydrogen ions and sulfur ion. While sulfur hydrogen ions and sulfur ion of lignin than hydroxyl ions have stronger nucleophilic role, therefore, the ability of lignin degradation used sodium sulfide is stronger than sodium hydroxide. The experimental results : processing time is 25min, processing temperature is 90℃, mixed solution concentration is 10%, mixture ratio is 70%:30%. The experimental results are ideal: extraction of rice straw fibre average length is 13.6mm, width is 38.4um, the cellulose fibre content is 67.83%.The second method with straw is alkali - enzyme extraction rice straw fibre compound. Because of this experiment using enzymes enzyme activity for paint, the activity is very low, if rice straw is treated directly, The effect is very bad. So the first use of low concentration with rice straw, the main purpose of this treatment is made rice straw inflation and spreaded out. to prepare the next enzyme treatment. Through the processing time of alkali, processing temperature, amount of alkali and the enzyme processing time, processing temperature, enzyme concentration and PH discussion of rice straw fibre average length, width and the cellulose fibre content, comprehensive analysis of the best solution:alkali concentration is 2%,alkali processing time is 50℃,alkali processing temperature is 95℃,enzyme processing time is 60 min, enzyme processing temperature is 50℃, enzyme concentration is 1.5%,PH is 5. The experimental results are ideal: extraction of rice straw fibre average length is 18.6mm, width is 44.6um, the cellulose fibre content is68.53%.Using the above two methods of extraction fibers were making film, The technology used for senior MiaoHongChao previously get optimal process: adhesive concentration is 8%, discard silk quantity is 13.4g/m2, square metre grams is 80g/m2.Two kind of agricultural films have been tested about physical and mechanical properties. It can be informed from the result: Film performance from mixed alkali extraction method of cooking rice straw fibre is sa the same as senior MiaoHongChao's.But film performance from alkali - enzyme extraction rice straw fibre compound have been big changed in the fracture strength and moisture. This is mainly because of the experiment uses the enzyme treatment, because of alkali concentration and alkali processing time and temperature are relatively low, The damage of fiber is less, and laccase only degrade lignin but don't damage cellulose fibre, and single fiber strength improved, the membrane rupture intensity increased. From the result we can know that the method of the alkali - enzyme extraction rice straw fibre compound is good, and enzymes are protein substance, and the waste liquid don't pollute enviromente, so the method should actively promote.