Fibers writing materials

The word paper is taken from the ancient material called papyrus, a paper-Uke writing material developed and used approximately five thousand years ago in ancient Egypt. Papyrus was a constructed material, made by weaving together the fine fibers of the papyrus bush and compressing the resulting weave into a hardened, paper-like sheet. 

True paper was invented in China by a court official, Gai Lun, in the year 105. Cai Lun found that by treating cotton rags in a certain way, the material would break down into a mushy mass of fibers. When more water was added, the mixture could be pressed and dried into a thin, hard sheet that could be used for writing. This true paper became popular because it was much lighter than bamboo mats and less expensive than silk, both of which were used as writing materials at the time. Gai s method of making paper eventually made its way to Europe, where it became the material of choice for use with the printing press in the fifteenth century. Industrialization and mechanization since that time have led to the modern paper industry and to the thousands of types and forms of paper that are a basic commodity of modern society. 

The precursors of paper were papyrus and parchment, which were used for writing as early as 3000 BC in Egypt. In China, strips of bamboo or wood were used for writing and drawing before the discovery of paper. The invention of paper has been attributed to Ts ai Lun in AD 105, who produced a uniform writing-material paper from felted plant fibers [3]. The original paper was made in China from rags, bark... 

Nonwood fibers are used in relatively small volumes. Examples of nonwood pulps and products include cotton Enters for writing paper and filters, bagasse for cormgated media, esparto for filter paper, or Manila hemp for tea bags. Synthetic pulps which are based on such materials as glass (qv) and polyolefins also are used (see Olefin polymers). These pulps are relatively expensive and usually are used in blends with wood pulps where they contribute a property such as tear resistance, stiffness, or wet strength which is needed to meet a specific product requirement. 

Secondary Fiber. Increasing costs of taw fiber, legislative mandates for recycling (qv), and avadabdity of inexpensive waste papers have contfibuted to the increased use of recycled fibers. The use of secondary fiber in the United States has grown from 22% of pulp from all sources in 1978 to close to 31% (24 x 10 metric tons) in 1993 (3). Recycled fibers ate sometimes used in special writing papers, but the principal use is for the manufacture of linetboatd, newsprint, tissue, cereal boxes, towels, and molded paper products such as paper plates and egg cartons (see Packaging materials, containers AND INDUSTRIAL materials). 

The paper and allied products industry comprises three types of facilities pulp mills that process raw wood fiber or processed fiber to make pulp paper and board mills that manufacture paper or board and converting facilities that use these primary materials to manufacture more specialized products such as writing paper, napkins, and other tissue products. The process of converting paper is not a source of water or air pollution, as is the case for the first two facilities. This chapter focuses primarily on the greatest areas of environmental concern within the pulp and paper industry those from pulping processes. 

We can, however, write a list of parameters for cure optimization. To limit the possible combinations, we assume that the composite composition is known (i.e., resin, fibers, geometry, etc., are given, and the mold design and mold material is known). This reduces the number of buttons for control of cure to the following ... 

A given material in a fibrous form can have a very large surface area. Consider a fiber of length and diameter d. Then, for the fiber volume, we can write... 

Viscoelasticity is the phenomenon of time-dependent strain. Often, it is also referied to as anelasticity. Glassy materials, above the glass transition temperature show Newtonian viscosity, i.e. the stress is proportional to the strain rate. This property is exploited in the drawing of fiber and sheet forms. We can write, in terms of normal stresses and strains. 

Crime detection primarily identification of poisons, of bloodstains, writing and typewriter inks, and a host of miscible materials such as textile fibers from clothing, hair, skin, etc. A variety of analytical methods are used in police laboratories, including microscopes, spottests, color reactions, and spectrophotometry. 

Paper specimens were obtained from Mead Paper, Printing and Writing Paper Division (Chillicothe, Ohio 45601). Samples were identified as being free from other materials, i.e., no preservatives, slimicides, defoamers, etc. Internally-sized samples were sized by conventional alum/rosin sizing surface-sized materials were prepared by an application of starch at the size press and all the other samples were unsized. Whatman filter paper was extracted with a 68/32 mixture of chloroform/acetone to remove any organic binder from the fiber surface. The fiber composition of the Whatman filter paper was identified by optical microscopy as cotton. The sample identified as "No Sizing" was... 

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