Literature--APA Mar 1995

"The Standardization Process and Future Trends in NDT [Nondestructive Testing]: Comments by the E-7 Chairman," by Jack Spanner. ASTM Standardization News, Jan. 1995, p. 56-59. The author shares some philosophical views on the industrial standards-writing process and looks at future trends, saying, "First, it is generally accepted by practicing engineers that the process of standardization tends to encourage wider industrial usage of a given technology. Second, and perhaps less accepted, is the consequence that the standarization process tends to 'freeze' the technology at the level specified in the standard." He suggests that standards-writing groups should hold off until 1) the industrial need is great enough to justify the effort, 2) an adequate technology and experience base is available, and 3) a group with balanced representation can be assembled. Industrial standards should emphasize the interests of the user, he says, because the supplier intrinsically possesses a greater knowledge of the technology. It is too bad that users today are not participating as much as suppliers are in standards activities. "It seems imperative," he says, "that the user community recognize and accept its responsibilities for protecting itself and the public. And I commend the suppliers for their continued willingness to serve on such committees--even during the tough times." (1B)

"Chemical Watermarking of Paper," by Stephanie Watkins. Journal of the American Institute for Conservation, Fall 1990, p. 117-132. Chemical watermarking of paper was first patented in 1959 by Fox River Paper Corporation, which now licenses the technology to other mills. The author describes methods of identification and tells how it reacts to various conservation treatments. She found that the marks in naturally aged samples were beginning to disappear into the surrounding paper structure. Short-wave UV radiation at 180-280 nm is the easiest method of identification. All solvents used had the effect of moving or eliminating the watermarks, and washing the paper in alkaline solutions (a common practice) blurred the marks and made them indistinct under UV radiation. Bleaches and bleach neutralizers gave varying results. (1E4)

The Preservation Committee of the Canadian Council of Archives has a series of unnumbered and undated Information Bulletins,two of which were received at the Abbey office in February. One of them, entitled "What You Should know Before Deciding to Deacidify Paper Records," summarizes an article by Helen Burgess and Douglas Goltz, "Effect of Alkali on the Long-Term Stability of Paper Fibres Containing Lignin" (Archivaria, Journal of the Association of Canadian Archivists, #37, Spring 1994). The summary oversimplifies the article and previous reports in this project, saying that rag and lignin-free papers became more permanent with alkalization, while ligneous papers actually deteriorated. Actually, individual papers of all three kinds (rag, lignin-free, and ligneous) were sensitive to elevated pH levels, to some extent. In the most recent work reported in Archivaria, only one of the six older ligneous papers was adversely affected by alkalization; but the new cotton rag paper that was included as a control was quite adversely affected, as shown by the change in degree of polymerization after accelerated aging.

The best conclusions to draw from this work are not that all ligneous papers are hurt by alkalization, but that lignin may be a contributing factor to alkaline sensitivity (p. 199) and that it is very hard to predict which papers will be damaged by alkali (p. 196). The authors were able to identify three probable factors in this adverse reaction to alkali: density of the paper, type and amount of size, and degree of oxidative degradation. The first two factors affect contact between the fiber and the solution, and the third increases the reaction between the fiber and alkali. (Reprinted from the Dec. Abbey Newsletter. 2D5)

"De Bepaling van de Vouwweerstand van Zwak/Oud Papier en van Papier met een Laag m2-Gewicht" (Determining the Folding Resistance of Weak Old Paper and Paper of a Low Caliper [gsm]), by C. J. Stadig and R. Hildering. Restaurator (Rotterdam) 23, #1, 1993, p. 18-25. Dutch with English summary. The abstract (#31-396 in Art & Archaeology Technical Abstracts) says:

"Despite its inaccuracy, folding endurance is often regarded as the best indication of a paper's mechanical strength [except for weak and thin papers]. Using data from the literature, the authors developed a roll-slide folder, which they used to measure the strength after folding. The instrument is suited to test delicate papers and shows little variance between tests." (From the Nov. Abbey Newsletter. 3A9.7)

"Effect of Carbohydrate Degradation on Zero-Span Tensile Strength," by Niraj Agarwal and Rick Gustafson. Tappi Journal v. 78, #1, p. 97-100. This study relates basic chemical changes in degradation (initial dissolution of low-DP carbohydrates, and primary and secondary peeling) with zero-span strength and degree of polymerization (DP), as a function of pulping time. Strength and DP do not always vary together. (3B1)

"The Roles of Free Radicals in Paper Permanence and Colour Reversion: Some Recent Physical and Chemical Insights," by Jeffrey K.S. Wan and M. Catherine Depew. Paper presented at the CPPA Technical Section Annual Meeting, Jan. 30-Feb. 3, 1995. Preprints, p. A219-A222. Photocopies of individual papers are available for a nominal fee from the CPPA Publications Clerk (514/866-6621, ext. 226).

The authors are studying the relationship of color reversion and permanence in a radical-containing atmosphere, and have developed a pulsed microwave-induced acoustic (MIA) sensor which monitors relative depolymerization of paper indirectly via on-line measurements of water sorption/desorption kinetics. When used together with electron spin resonance spectroscopy (which monitors free radicals directly), it provides "a potentially powerful technique to examine the effects and the relationship between color reversion and aging processes in paper." It can be of help in analyzing the effects on paper permanence of pollutant exposure.

Part of the reason for this research was to find out whether lignin served as an antioxidant in the cellulose matrix, or a source of potential radical damage. It was not possible to find a clear answer, since the lignin itself was changing as a result of exposure to free radicals. (3B1.1)

Accelerated Aging: Photochemical and Thermal Aspects, by Robert L. Feller. Getty Conservation Institute [1994]. 277 pp., soft cover.

Jim Druzik announced the appearance of this book on the Conservation DistList in January, saying:

"Ten years ago, late summer 1985, I was hired by the new Getty Conservation Institute to monitor the contract research program of the Scientific Program. I inherited three projects that had been negotiated by my supervisor Frank Preusser earlier that year. One of those projects was designed to 'capture' the wisdom and accumulated knowledge of Dr. Robert L. Feller on the subject of accelerated aging. That effort would turn out to be one of our most ambitious conservation science writing projects. Robert Feller's goal was simply to write the book he wished had been written when he was starting out in the 1950s. Now Accelerated Aging: Photochemical and Thermal Aspects is available to all. And frankly, it's the best source of information on the subject you can buy anywhere, anytime, at any cost. For ordering information call Getty Trust Publications at 800/223-3431 or (foreign) 310/453-5352."

There is little to add to Jim Druzik's evaluation. The price is $33 postpaid. The book is well laid out, well written and illustrated, and is as simple as it can be, given the technical nature of the subject. Terms and concepts are defined clearly to give the novice a foothold in a new discussion, e.g. "Such a process would be called photolysis or the photolytic breaking (scission) of a bond." (p. 47) But concepts are never oversimplified; one can dive as deeply as one desires into any aspect covered in the book, without being disappointed. (Reprinted from the Dec. Abbey Newsletter. 3B1.21)

"An Investigation of Some Environmental Factors Affecting Migration-induced Degradation in Paper," by John Slavin & Jim Hanlan. Restaurator v.13, 1992, p. 78-94. "Acid migration" is like the weather--everybody talks about it but nobody does anything about it. Slavin and Hanlan looked up previous research on migration of degradation products and did some research of their own. What they found does not always support common assumptions, although everyone has seen examples of mat burn, discoloration from newspaper clippings stuck between book pages, and so on.

Not all volatile degradation products are acidic. Both William J. Barrow and Vincent Daniels have cited cases in which products migrating from a material of higher pH affected a more acidic neighbor. This may indicate oxidative degradation, which produces peroxides and discoloration.

Buffered storage enclosures are commonly advocated for most records and artifacts, but there are some questions about how much good they do. For instance, Santucci (1973-74) found that an alkaline reserve could only be effective in slowing degradation if the RH was 70% or higher. Has anybody confirmed this? And how important is it for enclosures to have an alkaline buffer if the environment is very dry? or very cold? So the authors studied the effectiveness of buffered and unbuffered interleaving tissue in preventing migration of volatiles from old, degraded newspaper to new Whatman filter paper. They aged the papers under different conditions, apart and together, encapsulated in Mylar and "exposed." When RH in the aging oven was high (78-82%), just as Santucci said, the buffered interleaving paper did protect the Whatman paper. They concluded that decline in the pH of the filter paper was due to volatile substances given off by the newsprint, but were unable to identify any of them with certainty. Unbuffered tissue did not have a significant effect under any conditions.

This paper is hard to understand and evaluate, because it sometimes omits from the tables or does not clearly identify such information as the aging conditions and the placement and identity of the samples for which test results are reported. (From the Nov. Abbey Newsletter. 3B1.23)

"Changes in Paper Color due to Artificial Aging and the Effects of Washing on Color Removal," by Timothy Vitale and David Erhardt. In Preprints for the ICOM Committee for Conservation 10th triennial meeting, Washington, DC, 22-27 Aug. 1993, p. 507-515. Janet Bridgland, ed.

The color change of paper aged under various conditions of temperature and relative humidity is studied, and the effectiveness of washing for removing colored degradation products is assessed. The best single predictor of color change was found to be dew point. Samples with the greatest color change had the lowest percentage of color removed by washing. Samples aged under different conditions, but with similar color change, have different proportions of soluble colored material. Aging results indicate that dew point rather than relative humidity is the best predictor of chemical stability in storage--the lower the dewpoint, the better. (From the Nov. Abbey Newsletter. 3B1.4)

"The Brightness Loss in Newsprint from Natural Aging," by B. Jordan, M. O'Neill and N. Somerville. Journal of Pulp and Paper Science, v. 21 #1, Jan. 1995, p. J9-J12. As the authors say, very little effort has been devoted to understanding brightness loss of newsprint due to natural aging in the dark. Previous research indicates that different processes are at work, which may or may not depend upon atmospheric oxygen. The darkening rate is influenced by level of moisture, pH and fillers.

This study is nicely designed, with clear graphs. A large number of newsprint samples were gathered monthly from both eastern and western mills in Canada, stored in the dark for up to five years, and monitored monthly for changes in brightness. Not only did the average brightness decline, but the brightness values spread out in a distribution that was about twice as broad after five years as it was after one month. The paper from western mills lost about twice as much brightness as that from eastern mills. It was hard to explain this, but the authors noticed that the mills using deinked pulp made paper with very stable brightness, and mills using pulp from jack pine or western species darkened more quickly. The average brightness loss after two years in a filing cabinet was 2%. (3B1.4)

"Investigation of the Effect of Alkali on Paper," by Helen D. Burgess, Stephen Duffy, and Season Tse. AIC Book and Paper Group Annual, 1990, p. 29-36. This is a reprint, with minor changes, of "The Effect of Alkali on the Long-Term Stability of Cellulosic Fibres," Archivaria, #31, Winter 1990-91.

Paper and book conservators often wash paper in plain water or alkaline solutions to extend their life, but little is known about the effect of different alkaline solutions on different papers. Some of the questions addressed by this CCI research project are: Do different fibers react differently to alkalization? What role is played by lignin and the fibers' degree of oxidation in determining the effects of alkali? Is the optimum concentration of alkali dependent on the individual fiber being treated? Is there any advantage to one particular chemical or do they all work as well? and, How are different types of media affected by alkalization?

One of the procedures used as a control was washing papers in pure water, which has been reported to damage paper. This study found that about half of the thirteen papers studied were not significantly affected either way; a quarter definitely lost permanence, and a quarter gained permanence. (The test papers included papers of varying age, degree of degradation and fiber type. Their permanence was assessed by aging at 50% RH and 70°C for 8 to 12 weeks, then measuring degree of polymerization.) Pure water only partially removed calcium and magnesium from the papers.

All but one of the papers containing no lignin benefitted from alkalization. Even neutral magnesium sulphate had some benefit; it is suggested as a treatment for papers with alkaline-sensitive inks and colors. There were only two lignin-containing papers, and results for them were hard to interpret, because a) subsequent experiments with lignin-containing fibers did not show the same effect, and b) there are problems with the use of DP measurements to monitor degradation of lignin-containing fibers. (3B1.6)

"Preservation of Newspaper Records," by B.W. Scribner. National Bureau of Standards Miscellaneous Publication No. 145. USGPO, 1934. 10 pp. [At that time, the Superintendent of Documents was selling it for 5¢!]

The first half of this paper is a detailed and technical report of the research that underlies the recommendations given in the second half. (This research was summarized on p. 30 of the November APA.) Old newspapers (1830-1900) were collected from the New York Public Library, the Library of Congress, the Free Library of Oakland, California, and publishers of Pacific coast papers. The degree of discoloration of the specimens closely paralleled the degree of brittleness. Three tables present data on publication date, condition of the paper, whether it came from the east or west coast, and percentage of rag, chemical wood, straw and groundwood fibers found in each newspaper.

Pulp from straw and/or esparto grass, like groundwood, helped bridge the gap between the disappearance of rag and the availability of chemical wood pulp, between 1868 and 1890. It is interesting to see in these tables that all but one of the nine papers made mostly of straw/esparto were still in tiptop condition in 1934. Eastern papers that were made mostly of groundwood from 1869 to 1895 were all in poor condition, being rated in the bottom two of the five categories of paper condition. Comparable Pacific coast groundwood papers, on the other hand, fell mostly into the "moderate" category, perhaps because there was less air pollution on the west coast. (3B1.7)

"Effect of Alkali on the Long-Term Stability of Paper Fibres Containing Lignin," by Helen D. Burgess and Douglas M. Goltz. Archivaria, Journal of the Association of Canadian Archivists, #37, Spring 1994, p. 182-202.

Six ligneous papers, and three lignin-free control papers, of various ages, were studied. Particular attention was paid to the role of sizing and chemical additives in the effect of alkali on these papers. There were six treatment categories: untreated control, washed control, washing in weak alkaline and weak neutral magnesium solutions, and two stronger solutions (200 ppm and 2000 ppm magnesium bicarbonate). Eight different types of analytical data were collected for all samples, unaged and aged: viscometric DP, zero-span tensile, cold extraction pH, alkaline reserve, magnesium determination, thickness, density and water absorbency.

One of the ligneous papers and the cotton-fiber control paper were destabilized by alkaline treatment. Probable predisposing factors were low density, absence of size and presence of degraded, highly oxidized fibers. All of these factors would improve contact between the fiber and the magnesium solution.

The other ligneous papers benefitted more from the alkaline solutions than from the neutral magnesium sulphate, which made some of the papers less permanent than they were to start with.

Eight recommendations are given for neutralization or alkalization, covering selection of papers for treatment and choice of treatment. (3B1.7)

"What is the Effect of Residual Deinking Chemicals on the Wet-End Chemistry of the Papermaking Process and on Paper Properties?" This is a question submitted by Stephen R. Tremont to the column "Ask Your Question" in Progress in Paper Recycling, Feb. 1995, p. 107-108. It is answered by Susan A. Freeland and Jerome M. Gess, who say that the main residual chemicals are surfactants, calcium ions, sodium hydroxide, silicates and mineral fillers, as well as residual inks. They describe resulting problems, which include poor formation, sheet strength and retention, but they do not mention anything that sounds like a threat to permanence, unless you count reduced sheet strength. (3B1.8)

Which Paper? A Guide to Choosing and Using Fine Papers for Artists, Craftspeople and Designers, by Silvie Turner. Updated Edition. Published by Design Books, 1994. Available for $24.95 from Lyons & Burford, Publishers, 31 West 21st St., New York, NY 10010. 144 pp. ISBN 1-55821-312-0.

This is reviewed favorably by Brett Charbeneau, Journeyman Printer of Colonial Williamsburg, in the April 1994 Guild of Book Workers Newsletter. As he says, it is well printed and imaginatively laid out and lists hundreds of papers by name, under the mills that make them, with their watermarks, characteristics and uses. The book is well illustrated, and it has an index. The main sections of the book are:

Qualities of Paper (e.g., sizing, acid free, grain)
Handmade Papers (e.g., handmade paper mills--made to order, handmade papers list, handmade papers of Japan, Thai papers)
Mouldmade Papers (e.g., Arches, Whatman)
Machinemade Papers (e.g., chemical pulp or "woodfree," machinemade permanent paper)
Paper in Practice (e.g., gluing papers, framing, care of works on paper)
Uses for Paper (e.g., pastel, calligraphy, intaglio, interleaving, recycled paper)
Appendices (e.g., history, sizes, terms, address list) (From the Nov. Abbey Newsletter. 3B2.72)

"Papermaking" is a series of five videotapes by Tim Barrett, published by the University of Iowa Center for the Book. The reviewer in Paper Conservation News said that it differs from most available audiovisual materials on the subject in its distinct "how to" emphasis, covering all key steps in both Western and Japanese hand papermaking. The five tapes are:

Japanese Style Papermaking I: Simple Equipment and Techniques (80
min.) Japanese Style Papermaking II: Traditional Equipment and Techniques (50 min.)
Japanese Style Papermaking III: Professional Equipment and Techniques (70 min.)
Western Papermaking I: Classroom Equipment and Techniques (55 min.)
Western Papermaking II: Professional Equipment and Techniques (55 min.)

Price: $60/tape or $250 for the set, from UICB Papermaking Video Tapes, 364 English Philosophy Building, University of Iowa, Iowa City, IA 52242. (From the Nov. Abbey Newsletter. 3B3.2)

"Eliminating Bacterial Bloom," by Christopher A. Wener. Tappi Journal v. 78 #2, Feb. 1995, p. 269-270. Slurries of calcium carbonate in storage tanks are more vulnerable to bacterial bloom than slurries of other fillers or pigments, and can contaminate equipment down the line if not regularly sterilized and protected with biocide. Tanks should be monitored weekly or biweekly, and biocides alternated every three or four months. (3B3.44)

"Robert W. Hagemeyer Receives the 1995 Gunnar Nicholson Gold Medal Award," by Patricia M. Pauksta. Tappi Journal, March 1995, p. 36-39. (A heading above the title says "TAPPI Interview 1995.")

Hagemeyer, recipient of numerous awards in the past, received the Gold Medal Award because of his pioneering research in pigment particle packing, precipitated calcium carbonates (PCC), and the applications of his findings into new products for the paper industry. He gave impetus to the onsite manufacture of PCC and alkaline papermaking.

In the interview, recalling the earlier days of his career, he says that in the late 1960s it was apparent that the move to alkaline papermaking was under way, and there was a growing interest in affordable high-brightness fillers for paper. He developed and promoted the onsite plant concept starting in the mid-1970s. Industry was reluctant to commit to the concept, until 1985, when Pfizer and Consolidated contracted for a plant at Wisconsin Rapids, with Pfizer providing the capital investment. Hagemeyer says that special credit for this development approach goes to Walter Nazarewicz, then president of Pfizer Minerals, who convinced the corporation to finance one plant after another in the next decade, until today there are 40 of them, here and abroad. The technology wasn't new, because onsite PCC plants were built as early as the 1920s; Hagemeyer says his role was to improve the technology and promote the benefits to industry.

He predicts that by the year 2010, half of all the paper (and board) produced will be printing and writing paper. (This passage in the interview is somewhat ambiguous, however; he could have meant that half of it would be communication papers, which includes both newsprint and printing and writing papers. Still, that is a big change, because in 1960 the figure was only 38%.) He also predicts a move away from recycling of paper to burning it. (3B3.44)

"The Irony of GOP [Groundwood Office Papers]," an editorial by Mahendra R. Doshi. Progress in Paper Recycling, Feb. 1995, p. 10-11. Doshi fills in some of the background for the story on groundwood paper in federal offices that was reported in the November issue of APA. He reviews the growth of the recycling movement and industry in the last ten years, the high prices that recycled paper has been commanding, the federal government's purchase of International Paper's low-cost recycled copy paper, and the discovery that it could not be resold to office waste paper dealers because lignin is considered a contaminant by the mills that make recycled office paper. By using IP's paper, the government is unable to save the $4 to $5 million yearly in landfill fees and transportation costs that it had hoped to. The only solution seems to be to install separate collection bins for groundwood-containing and groundwood-free office papers.

The advantages of groundwood recycled copy papers, Doshi says, are:

Inexpensive
Greater percentages of recycled fiber
Good smoothness and opacity.

Disadvantages are:

Lower brightness
Will discolor on exposure to sunlight
Lower recycling revenue
Performance on copy machines is less satisfactory, some say
Some people are allergic to them.

In a news item in PIMA Magazine, Jan. 1995, p. 20, it is stated that the General Services Administration, the business arm of the federal government, went from earning $50 to $70 per ton for its high grade white office waste to paying $30 to $50 per ton to recycle office waste containing the dark IP copy paper. IP says that the GSA saved that difference on the low purchase cost of the paper, and that it can be recycled into other products than office paper. (3B3.6)

"Broke Handling," by J.E. Lukins. Paper presented at the 1994 Stock Prep Short Course, Apr. 1994, p. 251-265 (TAPPI Press, 1994, 273 pp., $81). Broke is any fiber or paper that is reprocessed in the mill. Usually it is wound up on a reel but is not saleable. Broke handling systems are reviewed for slush broke, machine breaks, dry broke, winder and converting broke, and recovered saveall stock. (PBA Abstract 5043, 1994. 3B3.63)

"Rebuild Signifies Commitment to Quality," a "Mill Profile" in PIMA Magazine, March 1995, p. 36-37. Howard Paper Mills' mill in Urbana, Ohio, made Permalife paper after the first manufacturer, Standard, went out of business about 30 years ago, and has continued making it since Fox River Paper Co. bought Howard in 1991. This article tells how the Urbana mill's two paper machines, both over 60 years old, were rebuilt by Beloit Corp. Before the rebuild, it says, "the original headboxes were literally collapsing. Not only could they not keep up production, they could not produce a sheet to Fox River's quality standards." They were replaced in 1992. Both fourdriniers were replaced too, and the dry ends rebuilt. This mill converts the fine writing and printing grades it produces and packages them for immediate delivery. Its converting equipment was also upgraded.

[Permalife began its commercial career as a paper made to order for William J. Barrow in the 1960s, to show that it was possible to make permanent paper without using alum and rosin size, and to provide an alternative to the acidic printing and writing paper then on the market. It may be the brand of permanent paper most widely recognized among librarians and conservators in this country.] (3B3.7)

"Formation and Destruction of Chromophores in Kraft Pulping and Bleaching," by J.L. Minor and M.A. Smith. Presented at 1994 International Pulp Bleaching Conference, Vancouver, 13-16 June 1994. Poster Presentations p. 193-197. Preprints available for $35 from CPPA, Montreal.

This reports research by the Forest Products Lab of the USDA Forest Service. In kraft cooking, brightness first decreases, probably because of formation of chromophores in lignin; then it increases. Heat further darkens the pulp, but sodium borohydride pretreatment reduces chromophore formation. The Lab is able to identify the kinds of chromophores formed and destroyed during kraft pulping and bleaching. (PBA Abstract 184, 1995. 3B3.8)

"Are Hydroxyl Radicals Responsible for Degradation of Carbohydrates During Ozone Bleaching of Chemical Pulp?" by Y. Ni, G. Kang and A.R.P. van Heiningen. Presented at 1994 International Pulp Bleaching Conference, Vancouver, 13-16 June 1994. Poster Presentations p. 19-24. Preprints volume available from CPPA, Montreal, for $35.

This work contradicts the theory that ozone bleaching degrades cellulose mainly because of hydroxyl radicals generated in situ. Treatments that would normally decrease their formation had little effect, but other factors increased cellulose degradation during ozone bleaching. The authors conclude that it is the ozone itself which is responsible.

The paper industry has been using non-chlorine methods of bleaching since the late 1980s, when elemental chlorine was found to produce dioxin in pulp mill effluent. Not all the new bleaching methods adopted are fully understood yet. (PBA Abstract 155, 1995. 3B3.83)

Vision Paper Newsletter, No. 1, Oct. 1994, is about kenaf, and is published by Tom Rymsza, President of KP Products Inc. Although it consists of only a single sheet, both sides, it does what other newsletters do: it gives real news, and has an events column and a letter. One news item says that kenaf has made it onto the Joint Committee on Printing's list of paper specifications with the number JCP A 150. To contact Vision Paper, write or call Vision Paper (div. KP Products Inc.), PO Box 20399, Albuquerque, NM 87154-0399, 505/294-0293. Or use e-mail: KENAFMAN@AOL.COM. (3B3.84)

"Suitability of Kenaf CTMP for Linerboard," by Gary C. Myers and Marvin O. Bagby. Tappi Journal, Dec. 1994, p. 113-118. The U.S. Department of Agriculture has done a great deal to encourage the use of kenaf (Hibiscus cannabinus, an annual) for over 30 years, and done much of the research on it. This paper continues that policy.

So does another paper in the same issue of Tappi Journal, p. 105-112, in a way, because one of the four authors is at the Forest Products Lab in Madison: "Biomechanical Pulping of Kenaf," by Harmohinder S. Sabharwal et al. They say that kenaf yields in the southern U.S. are about 6 tons/acre/year, twice that of southern pine, and the delivered price is less. "Biomechanical pulping" means letting white rot fungus work on the kenaf bast fibers for a few days to dissolve some of the lignin and separate the fibers before the refining stage. They used Ceriporiopsis subvermispora. A good quality pulp, halfway between mechanical and chemical pulp, was easily produced. (3B3.84)

"Synergisms Between Synthetic Agents and Cationic Starches in Wood-Containing Systems," by D. Glittenberg et al. Wochenbl. Papierfabr. v. 122 #14, July 1994, p. 553-560 (in German).

Now that paper mills are closing paper machine circuits (recycling process water instead of replacing it with fresh), they are experiencing an increase in contaminants ("trash materials"), especially from thermomechanical pulp and chemithermomechanical pulp. Low molecular weight polymers that are good trash catchers are described. They are highly cationic, which means that they attract the anionic trash. Some of them work synergistically with cationic starches to retain the trash in the paper sheet, reduce chemical oxygen demand and improve strength. (PBA Abstract 667, 1995. 3B3.85)

"Kappa Number Variability Problem Solving and Trouble-Shooting," by B. Fuller. Paper presented at 1994 Kraft Pulping Short Course held at Savannah, 22-25 May 1994. The 47-page preprints volume is available from TAPPI Press for $78.00.

A major cause of the variability in kappa test results that is experienced to some extent by all mills is wide variation in chip quality. To control it, the speaker recommends new chip screening systems, use of online kappa/liquor control systems, presteaming of chips, good impregnation, indirect heating and improved circulation. (PBA Abstract 1181, 1995. 3B3.86)

"A Convenient Method for the Determination of Wood Extractives in Papermaking Process Waters and Effluents," by F. Örså and B. Holmbom. Journal of Pulp and Paper Science, v. 20 #12, Dec. 1994, p. J361-J365. The method described enables quantitative determination by gas chromatography of free fatty and resin acids, sterols, steryl esters, triglycerides and lignans. The amount of dissolved lignins is then determined from the UV absorption value of the extracted water sample. Lignans are phenolic compounds consisting of two phenylpropane units. They do not interact with and tie up cationic paper-making chemicals like dissolved lignins do, but they may affect paper brightness.

These substances are dissolved or dispersed during the pulping process and most of them carry over to the paper machine, where they cause a variety of problems, and to the effluent. Rapid determination like that made possible by this method is useful in dealing with those problems. (3B3.86)

"Behavior of Residual Lignin in Kraft Pulp During Bleaching," by D. Lachenal, J.C. Fernandes and P. Froment. Paper presen-ted at 1994 International Pulp Bleaching Conferencre, Vancouver, 13-16 June 1994. Paper Presentations vol., p. 41-45 ($35 from CPPA). A sample of unbleached softwood kraft pulp was bleached by five different methods to see which was best at removing residual lignin: chlorine, chlorine dioxide, oxygen, hydrogen peroxide and ozone. A kind of NMR spectroscopy was used for determination of hydroxyl, phenolic and carbonyl groups. The abstract (PBA #194 , 1995) says "Chlorine is shown to have unique properties as a bleaching chemical with respect to the depolymerization of residual lignin and the formation of new free phenolic groups." (3B3.86)

"Technical and Economic Implications of Converting Bleached-Kraft Mills to Low-Effluent Operation," by Heikki Mannisto, Eva Mannisto, and Pertti Winter. Tappi Journal v.78 #1. Liquid effluent can be eliminated, but it is expensive. Even converting a mill to low-effluent production will, on the basis of estimates resulting from this study, increase the cost of pulp manufacture by $50-$150 per air-dried ton. Major issues to be addressed are product quality, increase in solid-waste generation, and air emissions. (3B3.9)

Risk Analysis: A Guide to Principles and Methods for Analyzing Health and Environmental Risks. Prepared by The Council on Environmental Quality, in cooperation with the National Science Foundation. 407 pp. $17.50 from the National Technical Information Service (NTIS, 703/487-4650); order # PB89-137772CAU. The publisher's blurb says this guide is both an introduction to risk analysis and a readily accessible reference manual. Designed for users of risk analysis information, it offers a balance between the technical and nontechnical literature. Some of the topics covered in the guidebook include methodology and techniques, an overview of risk analysis, hazard identification, and risk communication. The report includes a glossary, numerous case studies, examples, and reference materials. (3B3.9)

"Significance of AOX vs. Unchlorinated Organics: AOX is Not a Suitable Parameter for Regulating Effluent," by N. McCubbin and J. Folke. Pulp & Paper Canada 96:2, 1995, p. 43-48. Both authors have been involved in writing regulations limiting discharge of organochlorines, as measured since about 1990 by AOX (adsorbable organic halogen) and dioxin/furan concentrations. Here they object to conclusions drawn by some regulators and environmentalists from their own research, which goes back to 1984-85 in Sweden. At the low levels of AOX now achieved or soon to be achieved by mills, the correlation with organochlorines is very weak. No one has investigated the other toxic substances found in the same rivers with dioxin-poisoned fish; perhaps these substances account for some of the effects attributed to dioxin. Very little information is available concerning the environmental effects of effluents from TCF (totally chlorine free) bleaching. And so on. (3B3.91)

"Forestry Proof-of-Performance Initiative Renews Industry Commitment," by Scott Wallinger. Tappi Journal, 78/1, Jan. 1995, p. 10-11 (the "AF&PA Corner"). Last October, the American Forestry and Paper Association approved a set of guidelines for sustainable forestry, titled the AF&PA Sustainable Forestry Initiative (SFI), written with widespread participation of 60 of its member companies. It contains objectives and performance measures (not spelled out in this article) by which the public can evaluate whether member companies are meeting their commitments. Adherence to the guidelines becomes a condition of continuing membership in AF&PA on Jan. 1, 1996. A sidebar lists 12 objectives and performance measures, with their various aspects, e.g., "2. Prompt reforestation: * Time certain, * Report success." (3B3.95)

Energy from Biomass and Municipal Waste, a monthly bulletin prepared by the U.S. Department of Energy and distributed by NTIS at a price of $110 per year (subscription # is 006CAU; call 703/487-4630). Abstracts of worldwide information on all aspects of biomass production, conversion, and utilization for energy. Coverage includes selection, growth, and harvesting of terrestrial and aquatic plants; availability and collection of agricultural and forest residues; information on thermochemical and biochemical conversions; pretreatments; physical processes (sorting, drying, handling, compacting); fuels use, combustion properties; and economic and environmental aspects. (3B3.96)

Volume 1, Number 1 Mar 1995

Literature

Volume 1, Number 1
Mar 1995