Forest Sciences Commons^™

Effect Of Calendaring On Flexographic Print Ability Of Linerboard, William P. Woods

Masters Theses

Today's corrugated board end user demands a higher quality than ever. Retailing techniques are moving toward so-called ''value-added packaging," which consists of high quality printed packaging that works to sell the product from the shelf. To preserve'its dominance in the corrugated market, the flexographic printing industry must find new ways to cost effectively satisfy the new demands.

One possibility is the use of an additional calendering step to give the linerboard better printability. This study evaluated two different types of calenders: the shoe (extended nip) calender and the hot/soft nip calender (Appendix A). The test material was commercially produced linerboard, …

Fundamental Study Of The Coating And Basesheet Influences On Gloss In Relationship To Coated Inkjet Papers, Raja Ramakrishnan

Masters Theses

The use of fumed metallic oxides for glossy ink jet media offers alternatives to expensive cast coated and extruded film methods. Fumed metallic oxide pigments provide a high internal porosity and packing porosity that enable the rapid diffusion of liquid inks into the coating layer. Their small particle size (0.1-0.3μm), enable the development of gloss. However, calendering is needed to develop gloss values in the range of cast coated and extruded film grades.

Calendering of coated sheet reduces production speed, adds additional handling and rewinding cost (if performed off-line) and reduces the bulk and porosity of the coating layer, consequently …

Effect Of Various Starch Sources On The Silicone Holdout Of Release Paper, Chandrasekaran Duraiswamy

Masters Theses

Siliconized papers are widely being used from food and packaging industry to pressure sensitive label industry and their use has increased considerably over the last decade. Surface and structural properties of the sheet influence the silicone hold out and release properties.

Surface sizing of the sheet is done prior to silicone coating. The objective of this research is to find their film forming capabilities, fluid hold out of various starches, and the effect of the various calendering process on the release properties was also studied.

No significant difference between the starch sources were observed, except for the modified com starch …

Use Of Boron Compounds To Reduce Phototyellowing Of Mechanical Pulps, Qilin Zhou

Masters Theses

Bleached chemithermomechanical pulps (BCTMP) are replacing chemical pulps such as bleached kraft pulp (BKP) in many paper grades. However, the loss of brightness that arises from exposure to light remains a significant impediment to the wider use of these pulps. Efforts have been made in reducing photoyellowing, but so far no universal, economical method has been found which converts high-yield pulp into a product with brightness stability comparable to that of a bleached chemical pulp.

This study evaluates the ability of sodium borate and/or boric acid to inhibit the yellowing process of paper that was made from BCTMP, with an …

Borax As A Strength Additive In Recycling, Siva Krishnagopal Devisetti

Masters Theses

The effect of multiple recycling on strength properties and fiber properties like strength of fiber, weighted average fiber length, fines percentage and water retention values were investigated in this study. Borax was used as a strength aid and swelling agent to improve the flexibility of fiber and strength of recycled paper. Bleached softwood kraft pulp was used to make the hand sheets and recycled repeatedly for up to four cycles. The main objectives were to evaluate the chemically treated pulp and untreated pulp at each stage of recycling, to study the effect of multiple recycling on strength properties of paper …

The Influence Of Fumed Metallic Oxides On Coating Structure And Their Relationships To Print Quality, Hyun-Kook Lee

Masters Theses

Aqueous-based coating for paper or paperboard applications use traditional coating pigments such as clay, calcium carbonate, and titanium dioxide. But, for matte coated ink jet papers, amorphous and gelled silicas are used due to their unique morphological properties, which are sponge-like in nature. The unique structure of these pigments provides an internal porosity and packing porosity which enables the rapid diffusion of liquid inks into the coating layer. The rapid uptake of the ink immobilizes the anionic dyes at the surface of the coating, allowing high optical print densities to be achieved.

The particle size of precipitated and gelled silicas …

Dimethyldioxirane In Tcf Bleaching Sequences, Nayereh Mahdavi

Masters Theses

The use of chlorine containing bleaching process creates various organic compounds such as chlorinated furan, dioxin, and AOX (adsorbable organic halogen). The human and aquatic life has been affected with the formation of these chlorinated organic compounds. EPA is proposing new regulations to impose discharge limits on the conventional pollutant materials of the bleaching effluents.

The objective of this research was to evaluate two TCF (Total Chlorine Free) bleaching sequences that use hydrogen peroxide and DMD on oxygen delignified hardwood kraft pulp. In one of the sequences, the DMD stage (A) was used prior to the hydrogen peroxide stage (P), …

Effects Of Temperature Control On Gravure Packaging Inks, Rodrigo Sosa

Masters Theses

It is well known that variations in ink temperature cause a variation in color density and viscosity. The viscosity of almost all liquids decreases with increasing temperature. In this research project, three different ink temperatures were selected to measure the effects of temperature control on solvent and ink consumption and on printability. Two colors were selected (magenta and cyan) and two heat exchangers were constructed to cool and/or heat the ink.

It was found that variations in ink temperature cause variation in solvent and ink consumption. As the temperature of the ink increases, solvent consumption and ink consumption increase, but …

The Effect Of Using Hemicellulase And Oxidase Successively As Pre-Bleaching Agents For Hardwood Kraft Pulp, Bryan R. Moore

Honors Theses

Environmental concerns have applied pressure on the paper industry to change many erstwhile processes that have traditionally remained unchallenged. One process in particular is pulp bleaching. Elemental chlorine, while effective in bleaching pulp and low in capital cost, is a major environmental threat because of the toxic chlorinated compounds and other dioxins that are generated in mill effluents. With increasing technology and demand, there has been much research devoted to the development of alternate bleaching sequences, whether Elemental Chlorine Free (ECF), which can use Chlorine Dioxide (ClO₂), or Totally Chlorine Free (TC). THe wide acceptance of these bleaching …