TY - JOUR TI - Cavitation and hydraulic flip AU - Pourdeyhimi, B. AU - Tafreshi, H. T2 - Fluentnews: Newsletter DA - 2004/// PY - 2004/// VL - 13 IS - 1 SP - 38 ER - TY - CHAP TI - Thermal bonding in handbook of nonwovens AU - Batra, S.K. AU - Pourdeyhimi, B. T2 - Handbook of nonwovens PY - 2004/// PB - Boca Raton: Crc Press SN - 9780849317873 ER - TY - JOUR TI - Nonwovens and traditional textile know-how AU - Pourdeyhimi, B. T2 - Textile World (New York, N.Y.) DA - 2004/// PY - 2004/// VL - 154 IS - 8 ER - TY - CONF TI - In-plane liquid flow through nonwovens AU - Pourdeyhimi, B. AU - Tafreshi, H.V. AU - Maze, B. C2 - 2004/// DA - 2004/// ER - TY - JOUR TI - ITMA 2003 review: Nonwovens AU - Pourdeyhimi, B. T2 - Textile World (New York, N.Y.) DA - 2004/// PY - 2004/// VL - 154 IS - 2 ER - TY - CONF TI - Hydroentangling AU - Pourdeyhimi, B. AU - Tafreshi, H. C2 - 2004/// DA - 2004/// ER - TY - CONF TI - Wipes produced by in-line splitting of segmented pie spunbonds AU - Pourdeyhimi, B. AU - Zapletalova, T. C2 - 2004/// DA - 2004/// ER - TY - CONF TI - Sub-micron spunbonds via bicomponent fiber technology: Materials, properties and performance issues AU - Fedorova, N. AU - Pourdeyhimi, B. AU - Little, T.J. C2 - 2004/// DA - 2004/// ER - TY - CONF TI - Nonwoven simulations: A path to realistic modeling of structure property relationships AU - Maze, B. AU - Pourdeyhimi, B. C2 - 2004/// DA - 2004/// ER - TY - CONF TI - Kenaf core as a potential absorbent core for composite wipes AU - Pourdeyhimi, B. AU - Zaveri, M. C2 - 2004/// DA - 2004/// ER - TY - CONF TI - In-plane and through-plain liquid flow simulations in nonwoven glass fiber mats AU - Tafreshi, H. AU - Maze, B. AU - Pourdeyhimi, B. C2 - 2004/// DA - 2004/// ER - TY - CONF TI - Hydroentangling wet-laid fiberglass mat AU - Vaidya, N. AU - Pourdeyhimi, B. AU - Acar, M. AU - Shiffler, D. C2 - 2004/// DA - 2004/// ER - TY - CONF TI - Enzymatic treatment of cotton fibers AU - Verenich, S. AU - Shim, E. AU - Pourdeyhimi, B. C2 - 2004/// DA - 2004/// ER - TY - CONF TI - A study of hydroentangling impact force AU - Tafreshi, H. AU - Pourdeyhimi, B. C2 - 2004/// DA - 2004/// ER - TY - JOUR TI - Structure-process-property relationships in hydroentangled nonwovens - part 1: Preliminary experimental observations AU - Pourdeyhimi, B. AU - Minton, A. AU - Putnam, M. AU - Kim, H. S. T2 - International Nonwovens Journal DA - 2004/// PY - 2004/// VL - 13 IS - 4 SP - 15-22 ER - TY - JOUR TI - The mechanism of crimp removal in synthetic staple fibers - Part II: Correlating single fiber crimp and carding parameters AU - Bauer-Kurz, I AU - Oxenham, W AU - Shiffler, DA T2 - TEXTILE RESEARCH JOURNAL AB - Fiber crimp behavior is an important parameter for processing performance and product quality. In Part I, we quantified the mechanical behavior of a fiber during crimp removal based on load-extension data. A logarithmic function can be used to characterize the shape of the load-extension curve during crimp removal. Characteristic parameters for three different kinds of PET fibers are interpreted in terms of crimp processing settings and correlated with processing performance during carding. DA - 2004/5// PY - 2004/5// DO - 10.1177/004051750407400503 VL - 74 IS - 5 SP - 387-393 SN - 0040-5175 ER - TY - JOUR TI - Luminescence and mechanical properties of photoluminescent core bicomponent fibers AU - Shim, E AU - Pourdeyhimi, B AU - Little, TJ T2 - TEXTILE RESEARCH JOURNAL AB - Photoluminescent fibers with a sheath-core morphology are produced to impart good mechanical properties. Both photoluminescent and mechanical properties are examined for these fibers with respect to photoluminescent pigment concentrations in the core, draw ratios, and polymer types. The photoluminescent pigment concentration in the core of the fibers directly influences their luminance intensity and afterglow properties as well as their mechanical properties. DA - 2004/11// PY - 2004/11// DO - 10.1177/004051750407401108 VL - 74 IS - 11 SP - 982-988 SN - 0040-5175 ER - TY - JOUR TI - The mechanism of crimp removal in synthetic staple fibers - Part 1: Crimp geometry and the load-extension curve AU - Bauer-Kurz, I AU - Oxenham, W AU - Shiffler, DA T2 - TEXTILE RESEARCH JOURNAL AB - Fiber crimp behavior is an important parameter for processing performance and product quality. This study quantifies the mechanical behavior of a fiber during crimp removal. Single fiber tensile tests are performed on various fibers using a Textechno Favimat. Simultaneously, crimp removal is optically monitored. A methodology is developed to identify the true crimp removal region of the fiber load-extension curve during a tensile test. A mechanical model accounting for the nonlinear load-deflection behavior during crimp removal is also developed. DA - 2004/4// PY - 2004/4// DO - 10.1177/004051750407400410 VL - 74 IS - 4 SP - 343-350 SN - 0040-5175 ER - TY - JOUR TI - Simulating cavitation and hydraulic flip inside hydroentangling nozzles AU - Tafreshi, H. V. AU - POURDEYHIMI, BEHNAM T2 - Textile Research Journal AB - Hydroentangling owes its success to the peculiar properties of coherent water jets. For hydroentangling to be feasible at higher pressures, it is extremely important that water jets maintain their collimation for an appreciable distance downstream of the nozzle. How ever, water-jet breakup accelerates at high pressures. Recent studies have shown that cavitation severely affects the integrity of high-pressure water jets. Investigating cavita tion experimentally is not trivial. Computational fluid dynamics simulations offer appro priate tools as a first step. This paper discusses the results of an unsteady-state simulation, which shows the inception and time-evolution of a cavitation cloud inside a hydroentan gling nozzle. Under certain conditions, the cavity cloud extends to the nozzle outlet, resulting in the so-called hydraulic flip. Once hydraulic flip occurs, cavitation suddenly vanishes because the downstream air moves upward into the nozzle and fills the cavity. This air envelops the water flow inside the nozzle, which results in the depletion of cavitation-induced instabilities from the jet surface and elongates the jet breakup length. Moreover, our simulations reveal the approximate time scales of cavity growth through the nozzle. This information is highly relevant for experimental visualization of nozzle cavitation. The discharge and velocity coefficient obtained from the simulation are in a good agreement with published experimental data. DA - 2004/// PY - 2004/// DO - 10.1177/004051750407400413 VL - 74 IS - 4 SP - 359–364 ER - TY - JOUR TI - Effect of nozzle geometry on hydroentangling water jets: Experimental observations AU - Begenir, A AU - Tafreshi, HV AU - Pourdeyhimi, B T2 - TEXTILE RESEARCH JOURNAL AB - This paper reports on the role of nozzle geometry on the characteristics of hydroen tangling water jets, specifically the behavior of three different conventional nozzle geometries under pressures below 3500 psi. Profiles of the water jets are digitized with a Nikon Dlx digital camera from which we extract the water-jet breakup lengths and spray angles under different operating conditions. Our preliminary data indicate that the cone-up nozzle produces water jets with considerably shorter intact lengths and slightly larger spray angles and a higher coefficient of discharge compared to the two other geometries considered. We attribute this distinct behavior to friction-induced and cavitation-induced turbulence inside the cone-up nozzles; a constricted water jet is formed by cone-down or cylindrical nozzles. Our results are in excellent agreement with previous experimental and computational data. DA - 2004/2// PY - 2004/2// DO - 10.1177/004051750407400215 VL - 74 IS - 2 SP - 178-184 SN - 1746-7748 ER -