Life Sciences Commons^™

Fiber Recovery From Paper Mill Primary Sludge, Christopher J. Roschek

Paper Engineering Senior Theses

Recoverable fiver is a major component of paper mill primary sludge, and it is often landfilled instead of utilized to its potential. With successful recovery of fiber from sludge, less raw materials will have to be purchased and a lesser volume will be landfilled, thus decreasing landfill disposal costs.

Primary sludge from a local paper mill was collected and stored at Western Michigan University. Solids and ash testing was done first to get background knowledge of the sludge. Fiber length was then determined using the Clark Classifier. Fiber recovery was accomplished by using a laboratory scale sidehill screen. After screening, …

The Effect Of Post Consumer Waste On Flexographic And Rotogravure Printing Operations, Kirk E. Jacobsson

Paper Engineering Senior Theses

The impact of deinked post-consumer secondary fiber (PCW) on the printability and runnability of an uncoated recycled sheet through printing operations was studied. The PCW was substituted into the base stock (50/50 HW/SW) at levels of 25%, 50%, and 100%; and printed on web fed flexographic and rotogravure printing presses. Tensile strength, brightness, and Δ gloss decreased with the addition of secondary fiber, while opacity, roughness, and bond strength increased. Stretch, tensile energy absorption, and tonal response remained relatively unchanged as the percentage of post-consumer waste increased.

Washing Between And After A Two Stage Hydrogen Peroxide Bleaching Sequence To Reduce Reversion And Increase Brightness, Craig Hellberg

Paper Engineering Senior Theses

Even though a fairly high brightness can be obtained, mechanical pulps, such as refiner mechanical pulp, contain all of the color forming groups found in the wood. This limits its use because these groups revert back to a yellow color over time. If they could be removed by washing, RMP could be used in a wider variety of grades. This project will discuss background on the subject, followed by a design and procedures to try and accomplish this goal.

It was found that excessive washing will give a temporary increase in brightness, however no statistical change in reversion is seen.

Green Liquor Pulping For Corrugating Medium, Michael Thompson

Paper Engineering Senior Theses

24 pulping runs for producing corrugating medium were conducted with various chemical concentrations of sodium carbonate and sodium sulfide (green liquor). All other pulping variables were held constant. The results showed a linear relation between the amount of total alkali (on wood) and yield decrease at constant sulfidities. The results also showed the optimum sulfidity of the liquors to be 25%. The strength properties were only affected by the pulp yield and not by the amount of chemical concentration used to produce that yield.

Correlating Bod And Cod In Paper Mill Effluent Streams, Lloyd M. Tuskan

Paper Engineering Senior Theses

Biochemical oxygen demand (BODs) is a five-day test. Chemical oxygen demand (COD) is a two-hour test. Both measure the oxygen demand exhibited by organics in a wastewater sample.

It was proposed that if a significant correlation exists between BODs and COD, the faster and simpler COD test could be substituted for the more commonly used BODs test. Three effluent streams were chosen to test: a pulp mill stream, a paper mill stream, and a combined effluent stream. The correlation that existed between BODs and COD in the combined effluent and paper mill streams were 0.90 and 0.92 respectively. A correlation …