Date of Award
Bachelor of Science
Pulp and Paper Technology
The rationale for this study came about from, among other things, the amount of wood waste in landfills and the decreasing amount of landfill space and increasing tipping fees. Annually, 315 pounds per capita of waste is landfilled and 20% to 30% of this is wood waste. This equals close to 9.8 million tons of wood waste per year in the United States.1
The problem with the disposal of municipal solid waste is not the amount of waste that must be disposed of but this amount in relation to available disposal capacity. The two main disposal options for municipal solid waste are landfills and incinerators. However, governmental and environmental restrictions on the siting of these establishments have resulted in a steady tightening of the demand/supply balance in the solid waste disposal market.
The experimental design for this study is as follows. Hardwood pallets (oak), representing typical wood waste found in landfills, will be chipped, screened, and then pulped using an M/K digester. The resultant pulp will be screened, refined and made into paper. This paper will then be tested for various strength properties and the results compared to some "typical values" of greenwood oak to determine if paper made from wood pallets is indeed a significant secondary fiber source.
Results from this analysis are as follows. As H-Factor increased, pulp yields and screened pulp yield decreased. Additionally, kappa numbers were calculated at each H-Factor. The kappa numbers were found to be 60.21, 52.5, 46.2, and 33.3, resulting in a decrease in kappa number as H-Factor increases.
Results from the strength tests are as follows. Values for the tear index (mN*m^2/g) were 9.74, 13.2, 16.36, and 19.39 at the appropriate H-Factors already mentioned. The breaking length (km) values for the recycled pallets were 3.06, 4.1, 4.68, and 5.22 and the burst index (kPa*m^2/g) values were 1.34, 1.96, 2.25 and 2.36 at each respective H-Factor. Lastly, the % active alkali consumed was 59%, 40%, 50%, and 42% for kappa numbers of 60.21, 52.5, 46.2, and 33.3, respectively.
This analysis proves that wood pallets provide good fiber and should be considered a viable secondary fiber source. The paper made has slightly lower strength but was deemed not to be of any significance. For what was paid for the pallets and other necessities, this seems to be a practical solution to a growing problem for the need for non-virgin fiber sources. Furthermore, there needs to be a way of diverting wood waste from landfills and this thesis is one of the possible means.
1The 1996 World Almanac and Book of Facts. Pharos Books. N.Y., N.Y.
Tironi, Marcus J., "Viability of Wood Pallets as a Significant Fiber Source" (1997). Paper Engineering Senior Theses. 542.