Fibrous materials, paper production

Containers made flxm fibrous materials such as paper, cardboard and sacking, are generally heavily contaminated (especially with moulds and bacterial spores) and should not be taken into clean or aseptic areas where fibres or microorganisms shed flxm them could contaminate the product. Ingredients which must be brought into clean areas must first be transferred to suitable metal or plastic containers. 

The mill has also been used to grind industrial minerals and technical ceramics including limestone, lead zirconates, metal powders, fibrous materials, such as paper, wood chips and peat, and chemicals and agricultural products, such as grains and oilseeds. 

Industrial plants for pulp from timber or other fibrous materials and paper or hoard production (>20 t/d) 67 X 103 2.7... 

Source Agriculture, industrial processes. Specifically, industrial plants for the production of pulp from timber or other fibrous materials, and paper or board production are responsible of 70% of the total organic carbon released directly into water from industry per year. 

The quality tests are of greater value in evaluation of fibrous raw materials for manufacture of cellulose derivatives. The tests do, in a general way, serve to show the presence of grossly hydrolyzed, over oxidized, or otherwise seriously degraded materials. Products of such poor quality, however, are not normally to be expected from modem manufacturing practices the resulting deficiency in the necessary strength properties would preclude use in most paper products. 

Bagasse and beet pulp. Bagasse is a fibrous residue of the cane stalk that is obtained after crushing and extraction of juice. It consists of water, fiber, and relatively small quantities of soluble solids. Bagasse is usually used as fuel in the furnaces to produce steam in sugar factories. It is also used as a raw material for production of paper and as feedstock for cattle. 

Use Floor polishes, paints, adhesives, paper coatings, catalyst supports, latex products, textile cleaning treatments, photosensitized paper, binder for inorganic fibrous materials, reactant for synthetic silicates. 

A growing volume of waste materials, especially vulcanized rubbers and crosslinked polymers are proving difficult to recycle. As an alternative to their disposal in landfills, there have been many attempts to grind these materials and use the products as a substitute for fillers in composite materials. Other non-plastic materials such as glass, paper, natural fibrous materials, and fly ash are also used for filler replacement. There is extensive literature on the use of ground tires as filler replacements. This is a specialized topic with only a minor relationship to fillers. 

Products and Uses The fibrous material in the cell walls of trees and plants. It is used to make rayon, natural cellulose sponges, and building insulation. Basis for wood, paper, linen, and cotton. 

In principle, all pulps are intermediates in paper production obtained by different treatments of wood or other non-wood fibrous raw materials such as different grasses, bagasse (sugar cane, stalks after sugar removal) or cotton fibres and secondary or recovered fibres from used paper. 

Honeycomb ho-ne- kom (before 12c) n. Manufactured product consisting of sheet metal or resin-impregnated sheet material (paper, fibrous glass, etc.) that has been formed into a network of open-ended, hexagonal cells, each cell s walls being shared with its immediate neighbors. Honeycombs are used as cores for sandwich constructions. 

Briefly, paper is made from a very dilute aqueous suspension of anionically charged cellulosic fibres which, after water removal, fam a fibrous network, i.e., a paper sheet. In many cases, filler particles such as ground or precipitated calcium carbonate or clay are added to the fibre suspension to enhance the optical performance or printability of the paper. Also, a variety of other components are added to improve specific properties of the paper sheet (e.g., wet and dry strength agents) or to facilitate the paper production process (e.g., retention aids to minimize the loss of fines and filler material to the process water, dewatering aids or defoaming chemicals). The majority of these chemical additives are polymers. 

Paper production is mainly based on fibrous raw material which may consist of primary or secondary fibers. Primary fibers are obtained directly from plant raw materials, mainly from wood and annual non-wood plants. Industrially, mostly thinnings and sawmill wastes are used. Secondary fibers are produced from recovered paper. Rags are used only in very small amounts. Synthetic and mineral fibers do not play an important role. 

Surface evaporation can be a limiting factor in the manufacture of many types of products. In the drying of paper, chrome leather, certain types of synthetic rubbers and similar materials, the sheets possess a finely fibrous structure which distributes the moisture through them by capillary action, thus securing very rapid diffusion of moisture from one point of the sheet to another. This means that it is almost impossible to remove moisture from the surface of the sheet without having it immediately replaced by capillary diffusion from the interior. The drying of sheetlike materials is essentially a process of surface evaporation. Note that with porous materials, evaporation may occur within the solid. In a porous material that is characterized by pores of diverse sizes, the movement of water may be controlled by capillarity, and not by concentration gradients. 

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