Rosin size, paper

The important point is that the cellulose in these alum/rosin sized papers is susceptible to acid hydrolysis, which results in a lowering of the degree of polymerisation and, eventually, to a serious reduction in the strength of fibres and to complete embrittlement of the paper. Some recent work in the writer s laboratory suggests that when alum/rosin papers are made, the hydroxonium ions which lead to the degradation are adsorbed independently of aluminium ionic species (4). 

T canvas, sewed on over rosin-sized paper or asbestos paper and, if desired, sized with glue and painted with two coats of lead and oil paint. All insulation on piping outdoors, or exposed to the weather, should be protected with a waterproof jacket, the canvas being omitted. Pipe insulation located close to the ground or where there is possibility of mechanical injury should be protected with a metal jacket. 

The pulp and paper industry and potable and wastewater treatment industry are the principal markets for aluminum sulfate. Over half of the U.S. aluminum sulfate produced is employed by the pulp and paper industry. About 37% is used to precipitate and fix rosin size on paper fibers, set dyes, and control slurry pH. Another 16% is utilized to clarify process waters. The alum sold for these purposes is usually Hquid alum. It is frequendy acidic as a result of a slight excess of H2SO4. Aluminum sulfate consumption by the pulp and paper industry is projected to remain constant or decline slightly in the near term because of more efficient use of the alum and an increased use of alkaline sizing processes (13). 

In the manufacture of colored papers, it is best to add the dyestuffs before addition of rosin size and alum. This is not always possible in continuous dyeing procedures where dyestuffs must be added to stock containing size and/or alum, and this may cause premature laking of the dyestuffs and subsequent loss of tinctorial strength and/or dullness of shade. The proper selection of dyestuffs can help to reduce these disadvantages. 

Haxz-karboUdsung, /. (Paper) solution of rosin in carbolic acid, -keraselfe, /. rosin curd soap, rosin soap, -kiefer,/. pitch pine, -kitt, m. resinous cement, -kocher, m. (Paper) rosin boiler, -kohle, /. bituminous coal, -kdrper, m. resin(ous) substance, -lack, m. resin lake resin varnish, -leim, m. (Paper) rosin size, -leimung, /. (Paper) sizing with rosin, -leimverseifung, /. rosin-size cutting. ... 

Harz-masse, /. resinous mass or composition (Paper) rosin size, -milch, /. a suspension of resin or rosin, -naphta, /. resin oil. -31, n. resin oil rosin oil. -pech, n. resinous pitch, rosin. 

Large quantities of rosin are used in sizing paper, which makes it take ink without spreading or blotting, gives it a smoother surface and makes it heavier. Rosin is also used in cheaper varnishes, in paints, and in soap making. It is furthermore used as an adulterant of the more expensive resins. Linoleum manufacturers use large amounts of rosin. 

Since the early days of machine made paper in the first half of the nineteenth century, the most widely applied method of Internal sizing has been the use of naturally occurring resinous materials ("rosins") in conjunction with an aluminium salt, usually aluminium sulphate (called "alum" by paper-makers). Various forms of rosin sizes (rosin soaps, rosin emulsions, fortified rosins) have been developed over the years to improve the process, but these variants still involve the use of alum as a means of ensuring that fibres retain a layer of size. 

One of the most industrially important characteristics of papers is their chemical stability, which enables them to withstand degradation with its consequential loss of tensile and tear strength and fold endurance under normal conditions of use. However, this stability is not absolute. Cellulose is susceptible to oxidation and the glycosidic linkage is susceptible to hydrolysis. In order to protect book papers from acid degradation, they must not be exposed to acid. Acids are generated from the alum-rosin size as well as from such... 

Materials. All paper samples were cut from a continuous length of machine-made rolls. Two different papers have been studied. One is a bleached Kraft wood pulp waterleaf (50-lb basis weight) made by Neenah Paper Mills from a stock that comprised northern softwoods (60Z) and Lake States hard woods (40J), and contained no additives. The second paper, Foldur Kraft, is a bleached Kraft paper (70-lb basis weight) made by Champion Paper Company from a stock of 90Z softwoods and 10Z hardwoods, with alum-rosin size and 8Z titanium dioxide filler. This paper was obtained 15 years ago. Since then it has been stored indoors in areas which have not enjoyed a carefully regulated environmental control. 

Paper in particular is a problem today much of it is still being made on the acid side from the use of alum rosin sizes, and this limits its life. There are 150 years of similar bad paper on the shelves. Librarians are the custodians of millions of books which are too brittle to use. Often there is nothing to be done but to cut the books apart, microfilm the information, and discard them. Textiles too have been subjected to the exigencies of rapid machine production and mishandled so that their permanence has dropped. The artifacts of our present civilization are fragile, and much of our cultural heritage is slipping silently away. 

The most commonly used sizing agent for paper has been rosin size. Rosin size requires alum and an acidic environment in the papermaking process. This results in acidity in the paper itself. 

The neutral or alkaline pH of the paper machine system necessary for a high extract pH in the paper is not compatible with the rosin size-alum sizing system. To set rosin size properly on fiber, alum is required. Since total acidity is an approximate measure of the amount of alum in solution, it is often used as a control in connection with rosin sizing. The most effective size-alum precipitate forms at a papermaking pH between 4.2 and 4.8 and a total acidity between 90 and 150 ppm. The low pH of the process water, high total acidity, excess alum, and the size-alum precipitate all place a severe limit on the permanency properties of paper. 

Calcium carbonate cannot be used in the same low pH papermaking process that contains alum and rosin size. The presence of carbonate in an acid papermaking process causes severe problems such as foam, excess alum demand, inefficient sizing conditions with rosin size, and troublesome deposits. The alkaline system, therefore, enables the paper-maker to use calcium carbonate as a primary filler as well as to use more recycled paper. 

The effect of acidity caused by alum-rosin size has been obviated by the substitution of sizing agents which are effective slightly on the alkaline side of neutrality. It has been established that papers of satisfactory permanence can be manufactured with such sizes. It is possible to use rosin as a size and to avoid the conjunction with alum by a number of processes. There are insufficient data on the aging characteristics of paper sized with the available modified rosin sizes to judge the effect on permanence. Possible reactions of the rosin, such as oxidation and formation of peroxides, must be considered. 

The paper industry is a large user of chemicals because relatively small quantities of additives can materially change the properties of paper. The use of 1-2 percent rosin size and 2-3 percent alum [A12(S04)3] will greatly increase the resistance of paper to penetration... 

The paper industry uses large amounts of the sodium salt of rosin as paper size, which accounts for the greatest single use of rosin. The synthetic rubber industry is the second most important user of rosin. In making styrene-butadiene rubber, disproportionated rosin soaps are used alone or in combination with fatty acid soaps as emulsifiers in the polymerization process. Disproportionation decreases the number of double bonds in the abietic acid of the rosin, making a more stable material. 

Sample Preparation. Two papers were selected. One was Champion Foldur Kraft, a bleached southern kraft paper, containing rosin size and fillers, from a single roll of known composition. The other paper was newsprint that had already been cut into sheets when received by the laboratory. The newsprint was analyzed as follows 80% groundwood and 20% unbleached sulfite. 

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