Newsprint Research • This is a summary of research conducted at the Smithsonian Center for Materials Research and Education (SCMRE) during the summer of 2003. • This work was conducted by two interns, Evan Quasney and Kathy Hufford, under the supervision of David Erhardt and Charles Tumosa. • Drs. Erhardt and Tumosa may be contacted at SCMRE via these methods: Charles Tumosa [email protected] (301) 238-3700 x 118 W. David Erhardt [email protected] (301) 238-3700 x 116 Permanence and Degradation: Newsprint Over the Last 100 Years Kathy Hufford Massachusetts Institute of Technology Evan Quasney University of Michigan Charles Tumosa, Ph.D. W. David Erhardt, Ph. D. Introduction Printed material on paper dominates written communication Paper records have finite life … how finite? Mechanical concepts addressed and discussed Chemical concepts linked to mechanical properties Scope of research newsprintspecific Wood-based Newspapers Tested 06/01/2003 11/17/2001 11/27/2000 08/03/1999 12/02/1998 11/02/1997 07/10/1997 01/26/1997 05/07/1995 11/14/1993 02/08/1983 10/20/1983 07/07/1985 09/11/1985 12/14/1988 12/15/1988 10/25/1999 07/01/1975 12/11/1960 09/13/1950 12/02/1934 04/11/1915 10/07/1905 01/03/1890 05/07/1875 Washington Post Washington Post Washington Post Washington Post Washington Post Washington Post Washington Post Washington Post Washington Post Washington Post Washington Post Washington Post Washington Post Washington Post Washington Post Washington Post Washington Post Vineland Times Journal New York Times Christian Science Monitor Topeka Daily Capital Detroit Free Press Detroit Free Press The World New York Semi-Weekly Times Definitions Strain = ∆ length / length - extensibility of paper - change in length ε=∆L/L Stress = Force / Area - ‘strength’ of the paper - randomized based on sizing or technology σ=F/A Stress-Strain Curve - Graph of stress versus strain - Basis for finding plastic and elastic regions Tensile (Young’s) Modulus - Numeric value of the flexibility / stiffness of the paper E=σ/ε Definitions Isotropic: - Specimen behaves the same in all directions Breaking Strain: - Percent elongation at which a specimen fails Orthotropic: - Specimen behaves differently in mutually perpendicular directions Breaking Stress: - Pressure at the breaking strain; tensile strength of specimen Region Deformation: Elastic – Flexible Modulation of Specimen Plastic – Permanent Irreparable Damage to Specimen General Stress-Strain Curve Mancellinus Antonius, circa 1500, Vertical Dir 25 Stress (MPa) 20 Slope = E Plastic Deformation 15 10 σ = 10.25 Elastic Deformation 5 ε = 0.004 0 0 0.005 0.01 0.015 Strain (mm/mm) 0.02 0.025 Method Tests performed on screw-driven tensile tester in environmental chambers Incremental length change standard: 30-seconds, 1/200 (0.005) inches Tests performed between 42 – 52% RH and 22.5 – 24.2 deg. C 4 distinctly different sub-variations of each specimen examined Machine v. Cross Direction Directional Comparison of Century Magazine Stress (MPa) 10 circa Feb. 1925 8 6 4 2 0 0 0.003 0.006 0.009 0.012 Strain (mm/mm) Machine Dir Cross Dir 0.015 Initial Application 25 Tensile Strength of The Washington Post June 1, 2003, Average Value, Cross & Machine Dir. Stress (MPa) 20 15 10 5 0 0 0.002 0.004 0.006 0.008 Strain (mm/mm) Inked Uninked 0.01 Initial Application Individual Axial Comparison of Inked v. Uninked Paper The Washington Post, June 1, 2003 5 25 20 4 15 3 10 2 Uninked 5 Inked 0 0 0.002 0.004 0.006 Machine Direction 0.008 Uninked 1 Inked 0 0.01 0 0.005 0.01 0.015 0.02 0.025 0.03 Cross Direction Orthotropic behavior present in specimens Very little difference between inked and uninked strains Strain (mm/mm) 20 Year Study in Lab Environment 0.03 0.025 0.02 0.015 0.01 0.005 0 0 Mach. Inked 5 10 15 Age (Years) Mach. Uninked Cross Uninked 20 25 Cross Inked No great change, but a slight decreasing trend is exhibited Degradation small enough that overall damage is minimal Specimens could last 100-150 years Strain (mm/mm) 20 Year Study in Lab Environment 0.03 0.025 0.02 0.015 0.01 0.005 0 0 Mach. Inked 5 10 15 Age (Years) Mach. Uninked Cross Uninked 20 25 Cross Inked No great change, but a slight decreasing trend is exhibited Degradation small enough that overall damage is minimal Specimens could last 100-150 years 20 Year Study in Lab Environment Stress (MPa) 35 28 21 14 7 0 0 5 Mach. Inked 10 15 Age (Years) Mach. Uninked Cross Uninked 20 Cross Inked No distinguishable change in strength of specimens Specimens will last a long time under Standard Laboratory Conditions 25 20 Year Study in Lab Environment Stress (MPa) 35 28 21 14 7 0 0 5 Mach. Inked 10 15 Age (Years) Mach. Uninked Cross Uninked 20 Cross Inked No distinguishable change in strength of specimens Specimens will last a long time under Standard Laboratory Conditions 25 Stress (MPa) Inked v. Uninked Paper T.S. Comparison of The New York Times 8 7 6 5 4 3 2 1 0 Dec. 11, 1960, Cross dir. Uninked Inked 0 0.002 0.004 0.006 0.008 Strain (mm/mm) 0.01 0.012 120 Year Variable Test Strain v. Time Vert. Uninked Vert. Inked Horz. Uninked Horz. Inked Strain (mm/mm) 0.03 0.025 0.02 0.015 0.01 0.005 0 0 • • • 20 40 60 Age (Years) 80 100 120 Loss of elastic region occurs when breaking strains drops below 0.005 Acute fragility not present until samples are 80 years old Total specimen disintegration only occurs after ALL breaking strains are less than 0.003 Scientific Significance Newsprint can last 100 years if given nominal attention Archival facilities can provide up to an additional 50 – 100 years of viable storage Flexibility and elasticity data will help build an accurate model to predict degradation Chemical Composition of Wood Wood Lignin Softwood: 25% Hardwood: 21% Carbohydrates Cellulose 45% Glucose Extractives 2-8% Hemicellulose Softwood: 25% Hardwood: 35% Xylan, Xylose, Arabinose, etc. Cellulose: Glucose Glucose Glucose Glucose Glucose Trimer: Glucose Glucose Glucose Glucose Dimer: Glucose Glucose: Glucose CH2-OH O OH HO OH OH Glucose Xylan: Xylose Xylose Xylose Xylose Xylose Arabinose Arabinose Xylose: CH2-OH Arabinose: CH2-OH O O HO OH HO OH OH OH Hydrolysis of Cellulose Glucose Glucose H2O H2O Glucose Glucose Glucose Glucose H2O Monomer Glucose Glucose Glucose Glucose Dimer Glucose Trimer Method Samples prepared, extracted in water, filtered, and evaporated under vacuum Derivatized with STOX (commercial reagent containing internal standard), HMDS, and trifluoroacetic acid Supernatant analyzed by gas chromatography Sugars identified by comparison of retention times against internal standards Standard Xylose Glucose Arabinose Xylose Dimer Glucose Dimer Xylose Trimer Glucose Trimer Approximate Retention Times of Sugar Peaks Standard: 16.70 Glucose: 12.57 Xylose: 10.43 Arabinose: 10.20 Glucose Dimer: 19.45 Glucose Trimer: 24.55 Xylose Dimer: 17.45 Xylose Trimer: 22.55 Sugar Content in Wood-based Newspapers 4500 4000 Micrograms/g 3500 3000 2500 Glucose Xylose 2000 1500 1000 500 0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year Glucose and xylose levels highest in newspapers from the Industrial Revolution Of interest are the spikes around World War I and the relative stability of the past 20 years History of Papermaking Technology The Industrial Revolution (1875-1950) brought commercial use of wood-pulp paper and mass production processes Commercial use of the acid sulfite process (1880s) and Kraft process with bleaching (1930s) caused a transition from mechanical to chemical processing Glucose and xylose levels peak in the World War I era After World War I, new technology and processing techniques were invented Glucose Fraction in Wood-based Newspapers 1 Glucose/(Glucose+Xylose) 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 1860 1880 1900 1920 1940 1960 1980 2000 Year Pre-1980 glucose ratio shows a different mechanism than post-1980 Kinetics study? Changes in data from 1980 to present are particularly interesting History of Papermaking Technology •The USA Today Effect: Launching of the USA Today in 1982 and the use of color in newspapers •The environmental movement and recycling of newspapers •Advanced machinery requires thinner material •Multitude of processes for newspaper manufacturers to choose from: refiner, chemical, thermo, chemothermo, isothermo, etc. •Further research Sugar Polymers Detroit Free Press, 1905 4500 Sugar, Micrograms/gram 4000 3500 3000 2500 Glucose Polymers Xylose Polymers 2000 1500 1000 500 0 0 1 2 3 4 Polymer Xylose is more hydrolytic and more likely to hydrolyze to monomer than is glucose Arabinose and Xylose in Wood-based Newspapers 500 Arabinose, Micrograms/gram 450 400 350 300 250 250 200 200 150 150 100 50 100 0 0 50 100 0 0 1000 2000 3000 4000 5000 6000 Xylose, Micrograms/gram Initial, sharp increase in arabinose, and then nearly constant value Arabinose molecules must be located at the end of the molecule or on branches, and are hydrolyzed first Total Measured Sugar Content vs. Breaking Strain 14000 Micrograms/gram 12000 10000 8000 6000 4000 2000 0 0 0.005 0.01 0.015 0.02 Breaking Strain Similar trends appear across other sugar data Illustrates the presence of a surface phenomenon 0.025 0.03 Glucose Polymers vs. Breaking Strain Dimer Monomer 2500 Dimer, Micrograms/gram 3200 2400 1600 800 2000 1500 1000 500 0 0 0 0.005 0.01 0.015 0.02 0.025 0 0.03 0.005 0.01 0.015 Breaking Strain Breaking Strain Trimer 1600 Trimer, Micrograms/gram Glucose, Micrograms/gram 4000 1200 800 400 0 0 0.005 0.01 0.015 Breaking Strain 0.02 0.025 0.03 0.02 0.025 0.03 Hydrolysis Mechanism Conclusions Issue of dueling factors of technology and time in the process of degradation Xylan hydrolysis vs. cellulose hydrolysis Order of degradation, illustration of mechanistic details of hydrolysis Surface phenomenon Ideas for further research in kinetics and the history of papermaking technology Summary Mechanical and physical properties of specimens directly related to hydrolysis of cellulose and hemicellulose Hydrolysis of cellulose and hemicellulose affects breaking strain and plasticity of specimen Remaining life span of specimen can be estimated via sugar content analysis and/or mechanical testing
© Copyright 2026 Paperzz