代写范文

留学资讯

写作技巧

论文代写专题

服务承诺

资金托管
原创保证
实力保障
24小时客服
使命必达

51Due提供Essay,Paper,Report,Assignment等学科作业的代写与辅导,同时涵盖Personal Statement,转学申请等留学文书代写。

51Due将让你达成学业目标
51Due将让你达成学业目标
51Due将让你达成学业目标
51Due将让你达成学业目标

私人订制你的未来职场 世界名企,高端行业岗位等 在新的起点上实现更高水平的发展

积累工作经验
多元化文化交流
专业实操技能
建立人际资源圈

美国作业代写:Brittleness of paper

2017-11-23 来源: 51due教员组 类别: Paper范文

下面为大家整理一篇优秀的paper代写范文- Brittleness of paper,供大家参考学习,这篇论文讨论了纸张的脆性。在纸质档案保护工作中,作为载体材料的纸张的保护极其重要,纸张保护的核心就是延缓其老化速度,延长其保存年限。而不同的纸张的脆性也不同,有的大一些,有的小一些。纸张的脆性受造纸原料、纸张老化、大气温湿度环境等因素的影响,对纸质档案的保管、保护及利用产生直接作用。

paper Brittleness,纸张脆性,essay代写,paper代写,美国作业代写

In the paper File Protection work, as the carrier material's paper protection is extremely important, the paper protection core is postpones its aging speed, lengthens its retention period. Believe that most archivists will have this experience: some paper brittle, some paper less brittle, the aging of the obvious brittleness of the paper, the air drying paper brittleness. The brittleness of paper is influenced by the factors such as papermaking raw material, paper aging, large temperature and humidity environment, and has a direct effect on the storage, protection and utilization of paper archives. Therefore, the study of paper brittleness on the production of durable paper, paper file of reasonable custody, repair and use of a guiding role, significant.

Brittleness is human sensory experience, according to some information, generally think that when the paper is bending force, easy to fold, fragile, toughness is brittle. According to experience, the composition of the paper page fiber length, the combination of good, then its toughness is large, bending compression, strength loss less, and fiber short, toughness of the raw materials made of paper, after bending compression, strength loss more. Based on this experience, the researchers gradually groped for some methods of testing brittleness. With the development of fracture mechanics, the theory and method of brittleness test are making progress continuously.

The factors that affect paper brittleness come from both the paper itself and the environment. Its own factors include: paper used raw materials, paper quantitative, pulp beating degree, paper tearing, paper resistance to energy absorption, paper modulus of elasticity, paper aging, and so on; environmental factors are mainly the temperature and humidity of the air. The results of these factors together make the paper show some brittleness.

From wheat straw, straw, reed, bagasse and other grass-like fiber raw materials made of paper brittleness is larger, and from wood pulp, cotton pulp, hemp pulp, such as paper-copying of less brittle, in the grass pulp to add wood pulp, cotton pulp, hemp pulp can reduce paper brittleness. The wheat straw pulp was treated to different beating degree after the paper was copied, and then the brittle crack was tested, and the beating degree was found in 32. 5°SR is the smallest of the brittle crack. Experiments with reed pulp show that the minimum cracking degree of embrittlement is 40°SR, and Sulfite reed pulp is 45°SR. The experiments with different quantitative bamboo pulp paper and wood pulp paper show that the higher the quantity of the same paper, the greater the brittle crack degree.

There is a certain relationship between brittle fracture degree and tearing degree, if the paper is brittle, the tearing degree is low, the corresponding brittle crack degree is improved. Anti-tensor energy absorption is an index used to evaluate the toughness of paper or paperboard. Toughness and brittleness are a pair of contradictions, paper toughness is not crisp, such as poor toughness, paper will be crisp. It can be concluded that: if the absorption value of the tensile energy is high, the brittle crack is small, whereas the brittle crack is high. The brittleness of the paper is related to the stiffness of the paper, and the stiffness depends on the modulus of elasticity. Some people think that the higher the modulus of elasticity, the greater the brittleness, the higher the corresponding brittle crack degree.

Relative humidity and brittle crack degree have a certain relationship, when the paper page in the fiber capillary water absorption, the fiber is softer, so the brittle crack with the increase in relative humidity and reduce.

The aging of the paper will also affect the brittleness of paper, especially the acid sizing paper, aging speed, paper strength decreased significantly. With the continuous development of aging, paper brittleness is increasing, the aging of the serious one touch is broken, the brittleness is great, completely lose mechanical strength.

Through the above analysis, we have a more comprehensive understanding of the factors that affect paper brittleness, so we can take measures to reduce the brittleness of paper from the following aspects:

Strictly control the beating degree, the wheat straw pulp beating degree in the 30°sr around, reed pulp is mastered in 40-45°SR; the paper adopts the method of mixing straw pulp with wood pulp, cotton pulp and hemp pulp to improve the brittle problem of straw pulp papermaking. Appropriate filling, it is reported that in bagasse pulp paper when adding filler talcum powder, calcium carbonate can reduce paper brittleness Using neutral sizing technology to fill in alkaline fillers such as calcium carbonate to increase the durability of the paper and slow down its aging.

Acid is one of the main causes of brittle paper aging, therefore, the acidity of the paper to take acid treatment, can delay the aging of the speed of the brittle, the aging of the brittle, the acidity of the paper should be first acid treatment, and then strengthened to enhance its toughness and mechanical strength, reduce its brittleness.

Paper brittleness is affected by the environmental temperature and humidity, in the paper archives custody and provide the use process, the environment should be controlled in the 14-24°c, relative humidity control in 45%-60%, in this temperature and humidity range, paper has better mechanical strength and brittleness index, in favor of paper protection.

51due留学教育原创版权郑重声明:原创paper代写范文源自编辑创作,未经官方许可,网站谢绝转载。对于侵权行为,未经同意的情况下,51Due有权追究法律责任。主要业务有essay代写、assignment代写、paper代写服务。

51due为留学生提供最好的paper代写服务,亲们可以进入主页了解和获取更多,paper代写范文 提供美国作业代写服务,详情可以咨询我们的客服QQ:800020041。

上一篇:美国作业代写:Uncle Wigley in Connect 下一篇:留学生作业代写:The pop art