Cotton fibers blended to give three levels of fiber maturity were mercerized in anhydrous liquid ammonia and in sodium hydroxide solution, slack and under tension. Both reagents produced similar changes in the cottons, but to differing degrees. Both ammonia and caustic treatments produced changes in morphology (swollen fibers, decrease in convolutions) and in fine structure of the cellulose (increased accessibility as measured by increased moisture regain, iodine sorption, accessibility to deuterium exchange, and decreased density). X-ray diffraction showed increased amorphous fraction and partial recrystallization into cellulose III and cellulose II lattice after treatment with ammonia and caustic, respectively; the x-ray orientation angle was decreased by treatments under tension. Both reagents produced increased fiber elongation-at-break with slack treatment and increased fiber tenacity with tension treatment; caustic mercerization produced a slight increase in fiber tenacity after slack treatment.

Fiber toughness, fabric construction, and pretreatment were found to affect abrasive wear in permanent-press trouser cuffs. Samples of Pima S-2, Hopi Acala, and Deltapine 15 cottons were processed into twelve constructions of print-cloth weight fabrics. Cross-linking with the dimethylol dihydroxyethyleneurea-type resin was applied as a continuous process to fabrics after scouring and after slack mercerizing. Nitrogen contents of treated fabrics show that type of cotton, fabric construction, and pretreatment affected the amounts of resin reacted with the fabric. Pima cotton had the lowest and Deltapine the highest level of nitrogen in almost every fabric construction. Pima cotton fabrics showed less wear during conventional abrasion test and laundering and greater crease-recovery angles than did the other cottons. Cuffs of basket-weave fabrics with 0.87% nitrogen showed less crease wear during laundering than did plain weave at 0.64% nitrogen. At comparable nitrogen content, slack-mercerized fabrics were more durable at a higher crease-recovery angle than were cuffs made from scoured fabrics. ~

Yarns spun from high- and low-maturity cottons were mercerized in liquid ammonia in a continuous process, and in liquid ammonia and sodium hydroxide in skein form under various tensions. Both swelling agents produced similar changes in mechanical properties (breaking strength, tenacity, elongation-at-break, and initial modulus) under comparable conditions. Mercerization under high tension increased breaking strength and tenacity and decreased elongation-at-break. Slack mercerization in caustic resulted in elongations-at-break substantially higher than did ammonia treatment. A major difference between reagents was noted during treatment. When skeins were swollen slack and then restretched, much greater force was required to restretch ammonia-swollen skeins, and they could not be stretched as much as those that were caustic-swollen. Measurements of length changes in yarns during swelling, tensioning, and deswelling gave quantitative data to substantiate this observation. Differences in mechanism of swelling are discussed in relation to these findings.

Heat transfer through draped windows was studied to identify and test the insulative potential of drapery materials and configurations on a window in a test wall apparatus. Free flow of room air through the window-drape cavity was found to produce dramatic losses in the insulating properties of drapes. Variations of open-bag and wind-screen draping configurations made of conventional drape materials reduced window thermal transmittance values by 50%, a reduction equal to that expected from converting heat transfer from a free convective mode to a conductive mode at the window glass/room air interface. Materials with ideal properties for control of radiative and conductive heat flow were also used as draping elements to quantify the performance levels of the drapes configured to impede natural convection. Simulated drapery materials having radiation barriers configured to minimize air flow were as effective as double pane windows.

Melt blown (MB) fabrics are composed of fine fibers which contribute to high filtration efficiency (FE) and low air flow resistance compared to high efficiency filtration media such as fiber glass paper. Furthermore, MB fabrics are mostly made of polypropylene (PP) polymer, which can be electrostatically charged to enhance the media filtration efficiency without the increase of air flow resistance. However, different charging techniques or charging at different locations on the MB line will contribute to different filtration efficiency. This paper compares the efficiencies of different charging techniques in the MB line.