How To Elimination or Protected Cellulose From Alkalinity of the Cement ?

Key words :

Cellulose is not permanently resistant to the alkalinity of the cement.
Sizing to the Cellulose Fiber.

Background :
In the Papermaking Process ( in the first started from china as early as AD 768 ) , why to sized the cellulose fiber ?
- To improve the water resistance of the paper surface
- To improve the Surface Strength
- To Improve printability of paper

Basic Fundamental:
Cellulose a complex carbohydrate, (C6H10O5)n, that is composed of glucose units, forms the main constituent of the cell wall in most plants, and is important in the manufacture of numerous products, such as paper, textiles, etc.

Cellulose is Hydrophilic (water-loving)
Hydrophilic literally translates as "water loving" or "water friend." Hydrophilic substances are attracted to, and dissolve well within, water.Hydrophilic is typically used to describe a property of a molecule, and refers to the likelihood of its bonding with the hydrogen molecule in water. A hydrophilic molecule is not just soluble in water but also in other polar solvents; it will dissolve less readily in oils and other hydrophobic solvents. Hydrophilic molecules are charge-polarized so that one end is positive and the other negative.A hydrophilic molecule or portion of a molecule is one that is typically charge-polarized and capable of hydrogen bonding, enabling it to dissolve more readily in water than in oil or other hydrophobic solvents. Hydrophilic and hydrophobic molecules are also known as polar molecules and nonpolar molecules, respectively. Some hydrophilic substances do not dissolve. This type of mixture is called a colloid. Soap, which is amphipathic, has a hydrophilic head and a hydrophobic tail, allowing it to dissolve in both waters and oils.
An approximate rule of thumb for hydrophilicity of organic compounds is that solubility of a molecule in water is more than 1 mass % if there is at least one neutral hydrophile group per 5 carbons, or at least one electrically charged hydrophile group per 7 carbons
History
As the process of sizing had and has the intent of making the paper suitable for printing, it would seem slightly ironic that some processes of sizing would make printing paper a problem for the continued existence of that paper and those who would preserve them. Sizing processes started early on in the papermaking processes, with historians citing that items, such as starch, were early sizing agents used on paper. Dade Hunter in papermaking through Eighteen Centuries corroborates this by writing, “The Chinese used starch as a size for paper as early as A.D. 768 and its use continued until the fourteenth century when animal glue was substituted.” The early modern paper mills Europe, which produced paper for printing and other uses, the sizing agent of choice was gelatin, as Susan Swartzburg writes in Preserving Library Materials, “Various substances have been used for sizing through the ages, from gypsum to animal gelatin.” Hunter describes the process of sizing in these paper mills in the following:The drying completed, the old papermakers dipped their paper into an animal size that had been made from the parings of hides, which they procured from the parchment-makers. It was necessary to size that paper so that it would be impervious to ink, but sizing was more needed in writing than in printing papers. Many books of the fifteenth century were printed upon paper that had not been sized, this extra treatment not being essential for a type impression. The sizing was accomplished by a worker holding a number of sheets by the aid of two wooden sticks, and dipping the paper into the warm gelatinous liquid. The sheets were then pressed to extract the superfluous gelatine. This crude method of sizing the paper was extremely wasteful as many sheets were torn and bruised beyond use. The sizing room of the early paper mills, was, for this reason, known as the ‘slaughter-house.’With the advent of the mass production of paper, the type of size used for paper production also changed. As Swartzburg writes, “By 1850 rosin size had come into use. Unfortunately, it produces a chemical action that hastens the decomposition of even the finest papers.” In the field of library preservation it is known “that acid hydrolysis of cellulose and related carbo-hydrates is one of the key factors responsible for the degradation of paper during ageing.” Some recent professional work has focused on the specific in the degradation involved in the deterioration of paper that has had a rosin sizing process, and what amount of rosin affects the deterioration process, in addition to work on developing permanent paper and sizing agents that will not eventually destroy the paper. An issue on the periphery to the preservation of paper and sizing, is washing, which is described by V. Daniels and J. Kosek as, “The removal of discolouration in water is principally effected by the dissolution of water-soluble material; this is usually done by immersing paper in water. In such a process, surface level items applied to the paper, such as size in early paper making processes as seen above, have the possibility of being removed from the paper, which might have some item specific interest in a special collections library. With later processes in paper making being more akin to “engine sizing,” as H. Hardman and E. J. Cole describe it, “Engine sizing, with is part of the manufacturing process, has the ingredients added to the furnish or stock prior to sheet formation, the concern for the removal of size is less, and as such, most literature focuses on the more pressing issue of preserving acidic papers and similar issues.

Implementation on Fiber Cement making

Cellulose Fiber Sized in Fiber Cement Process :
Chemically treating cellulose fibers to impart the fibers with hydrophobicity and/or durability, and making cellulose fiber reinforced cement composite materials using the Chemical / Additive treated cellulose fibers which the cellulose fibers are treated or sized with specialty chemicals that impart the fibers with higher hydrophobicity by partially or completely blocking the hydrophilic groups of the fibers.
This technology advantageously provides fiber cement building materials with the desirable characteristics of reduced water absorption have advantage reduced rate of water absorption, lower water migration, lower water permeability so the final products made from these materials have improved freeze-thaw resistance, reduced efflorescence, reduced dissolution and re-deposition of water-soluble matrix components in natural weathering.
Using fiber sizing almost to improve other product properties to the physical and mechanical of final product.

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