A Comparison of the Carding and Processing Performance of 2.25 with 1.5-Denier Cotton/Polyester Opening-Room Blends

1976 ◽  
Vol 46 (4) ◽  
pp. 284-290 ◽  
Author(s):  
Jack Simpson ◽  
Louis A. Fiori
Keyword(s):  
High Modulus ◽  
Short Term ◽  
Fiber Properties ◽  
Polyester Fibers ◽  
Shear Friction

Various levels of cotton and polyester fibers blended during opening and picking were investigated to determine their effect on carding efficiency and processing performance. A medium staple cotton of average fiber properties and a high-modulus polyester (2.25 denier) were used in the blends. Shear friction and compression recovery of the blends increased as the percent polyester increased. For the 2.25-den polyester blends, shear friction was slightly lower and compression recovery practically the same as for 1.5-den polyester/cotton blends. Higher polyester content increased friction and cylinder load, thereby reducing carding action so that the short-term sliver variability and neps of the cotton component in the card web increased. Cylinder load and neps in the card web were lower for the 2.25 than the 1.5-den polyester blends. Higher polyester contents slightly improved yarn grade, and the grades for the 2.25-den were higher than those for the 1.5-den polyester blends. Increased friction and length uniformity of the polyester improved drafting so that second-drawing sliver, roving, and yarn uniformity improved when polyester was added to the blend. Carding waste was practically the same whether using 2.25 or 1.5-den polyester; very little polyester was lost in the waste. At constant end breakage, spinning production increased up to a 50/50 blend and then decreased as the percent of 2.25-den polyester was increased. These findings indicate that for cotton and polyester blended in the opening room, one with a high percentage of cotton can be processed more efficiently than the reverse.

On a Constitutive Model for Twisted Hybrid Yarns

2000 ◽  
Author(s):  
Thomas A. Godfrey ◽  
John N. Rossettos
Keyword(s):  
Micromechanical Model ◽  
Elastic Fibers ◽  
High Modulus ◽  
Lateral Compression ◽  
Fiber Array ◽  
Fiber Properties ◽  
Hybrid Yarn ◽  
Fiber Contact ◽  
High Elongation ◽  
Frictional Forces

Abstract A simple micromechanical model is developed for the interactions in a parallel square-stacked mixed array of elastic fibers representing the microstructure of a hybrid yarn undergoing axial extension. The mixed array consists of a small fraction of relatively high-modulus, low-elongation-to-break (LE) fibers dispersed among high-elongation-to-break (HE) fibers. The LE fibers are assumed to break into fragments, and the LE fiber fragments are assumed to slip relative to neighboring fibers in regions near the fragment tips. The fiber array experiences lateral compression arising from the remote tension on the twisted yarn, and frictional forces acting at slipping fiber-to-fiber contact surfaces are assumed to obey Amontons’ Law. Solutions of a dimensionless boundary value problem for deformations in a unit cell of the fiber array are presented. Dimensionless parameters involving the constituent LE and HE fiber properties are identified and their influence on hybrid yarn tensile behavior is illustrated.

Manufacturing Techniques and Mechanical Properties of Recycle Kevlar®/PET Composite Nonwoven

2012 ◽  
Vol 627 ◽  
pp. 831-834 ◽  
Author(s):  
Ching Wen Lou ◽  
An Pang Chen ◽  
Ya Yuan Chuang ◽  
Jan Yi Lin ◽  
Mei Chen Lin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Performance ◽  
Chemical Resistance ◽  
Impact Resistance ◽  
High Modulus ◽  
Machine Direction ◽  
Nonwoven Fabrics ◽  
Polyester Fibers ◽  
Manufacturing Techniques ◽  
Composite Nonwoven

Kevlar® fiber has characteristics of thermostability, high modulus, low elongation, impact resistance, chemical resistance and high performance. Therefore, in this study Kevlar® fiber was used to reinforce the nonwoven fabrics. In this research, the content of the Kevlar® fiber was varied as 0 wt%, 5 wt%, 10 wt%, 20 wt%, and that of 15D PET fiber was changed as 70 wt%, 65 wt%, 60 wt%, 50 wt% accordingly when the Low-Tm polyester fibers was constant as 30 wt%. These fibers were used to manufacture the Kevlar®/PET composite nonwoven by nonwoven processing. Afterwards, the mechanical properties of the Kevlar®/PET composite nonwoven was measured both at cross direction and machine direction.

RotorRing Measurement of Fiber Cohesion and Bulk Properties of Staple Fibers

1992 ◽  
Vol 62 (10) ◽  
pp. 608-613 ◽  
Author(s):  
Subhas Ghosh ◽  
James E. Rodgers ◽  
Albert E. Ortega
Keyword(s):  
Surface Roughness ◽  
Manufacturing Processes ◽  
Staple Fiber ◽  
Critical Properties ◽  
Bulk Properties ◽  
Fiber Properties ◽  
Yarn Quality ◽  
Polyester Fibers ◽  
High Processing ◽  
Potential Tool

Fiber cohesion and bulk properties and their consistency have a significant influence on yarn manufacturing processes and yarn quality. These critical properties depend on several staple fiber properties, including staple length, finish type and level, fiber geometries, crimp type and level, fiber additives, degree of fiber entanglements, and surface roughness. In order to ensure high processing performance and good yarn quality, it is necessary to understand how various staple fiber properties affect fiber cohesion and bulk. A method has been developed using a modified RotorRing instrument to monitor changes in staple fiber cohesion and bulk. The modified RotorRing yields three measurements, fiber-to-metal and fiber-to-fiber opening energy and the bandwidth of the ribbon formed inside the rotor. The method successfully and accurately detects differences in selected nylon and polyester fibers with different crimp/bulk levels, and the correlations between the modified RotorRing and traditional crimp measurements are examined. In addition, differences in crimp/bulk properties induced during the nylon staple processing operation are detected by the modified RotorRing responses. The results indicate that different crimp variables influence the three RotorRing measurements differently, and these independent responses show that the modified RotorRing method is indeed a potential tool for understanding the total effect of crimp variables on fiber cohesion and crimp/bulk and for monitoring the resulting yarn's properties and quality.

Incremental Frictional Abrasion

1977 ◽  
Vol 47 (4) ◽  
pp. 294-302 ◽  
Author(s):  
Dorothy K. Elias ◽  
Carol L. Warfield ◽  
Ruth L. Galbraith
Keyword(s):  
Tensile Properties ◽  
Internal Structure ◽  
Cotton Fiber ◽  
Fiber Length ◽  
Cotton Fibers ◽  
Fiber Fracture ◽  
Fiber Properties ◽  
Polyester Fibers ◽  
Before And After ◽  
Abrasion Damage

Three pairs of matched fabrics, 100% cotton broadcloth, 50% polyester/50% cotton broadcloth, and 65% polyester/ 35% cotton printcloth, were abraded in an Accelerotor. One fabric of each pair had a pure finish and one had a creaseresistant finish. Eight levels of abrasion were used in the study. Fiber length distributions and fiber tensile properties were analyzed before and after abrasion to determine the effect of the abrasion on these fiber properties and to determine the mechanism by which any damage occurred. The cotton fibers tended to break into shorter lengths as a result of abrasion. This tendency was most pronounced in the resin-finished polyester/cotton printcloth, which lost virtually all of its cotton fiber content. It appeared to be least pronounced in the resin-finished cotton broadcloth, which lost many of its shortest fibers but showed no significant decrease in the number of longer fibers. The polyester fibers in the blended broadcloths showed some reductions in fiber length as a result of abrasion, while those in the printcloths did not. There were progressively greater losses in strength of the remaining fibers for both polyester and cotton fibers as a result of increasing levels of abrasion. However, much of the abrasion damage sustained by the resin-finished blended fabrics appeared to be caused by cotton fiber fracture within the internal structure of the yarn because of the unequal elongation characteristics of the cotton and polyester fibers.

Conceptual short-term memory (CSTM) supports core claims of Christiansen and Chater

2016 ◽  
Vol 39 ◽  
Author(s):  
Mary C. Potter
Keyword(s):  
Working Memory ◽  
Rapid Serial Visual Presentation ◽  
Language Comprehension ◽  
Short Term Memory ◽  
Visual Presentation ◽  
Long Term Memory ◽  
Short Term ◽  
Term Memory ◽  
Use Of Knowledge

AbstractRapid serial visual presentation (RSVP) of words or pictured scenes provides evidence for a large-capacity conceptual short-term memory (CSTM) that momentarily provides rich associated material from long-term memory, permitting rapid chunking (Potter 1993; 2009; 2012). In perception of scenes as well as language comprehension, we make use of knowledge that briefly exceeds the supposed limits of working memory.

Ultrastructural Changes of Canine Kidneys During 24-Hour Perfusion on a LI-400 Preservation System

1971 ◽  
Vol 29 ◽  
pp. 316-317
Author(s):  
M. O. Magnusson ◽  
D. G. Osborne ◽  
T. Shimoji ◽  
W. S. Kiser ◽  
W. A. Hawk
Keyword(s):  
Electron Microscopy ◽  
Electrolyte Solution ◽  
Ultrastructural Changes ◽  
Midline Incision ◽  
Short Term ◽  
Pentobarbital Anesthesia ◽  
Pulsatile Perfusion

Short term experimental and clinical preservation of kidneys is presently best accomplished by hypothermic continuous pulsatile perfusion with cryoprecipitated and millipore filtered plasma. This study was undertaken to observe ultrastructural changes occurring during 24-hour preservation using the above mentioned method.A kidney was removed through a midline incision from healthy mongrel dogs under pentobarbital anesthesia. The kidneys were flushed immediately after removal with chilled electrolyte solution and placed on a LI-400 preservation system and perfused at 8-10°C. Serial kidney biopsies were obtained at 0-½-1-2-4-8-16 and 24 hours of preservation. All biopsies were prepared for electron microscopy. At the end of the preservation period the kidneys were autografted.

Polychlorinated biphenyl induced hepatocyte alterations

1987 ◽  
Vol 45 ◽  
pp. 716-717
Author(s):  
D.N. Collins ◽  
J.N. Turner ◽  
K.O. Brosch ◽  
R.F. Seegal
Keyword(s):  
Lipid Droplets ◽  
Wistar Rats ◽  
Homovanillic Acid ◽  
Polychlorinated Biphenyl ◽  
Corn Oil ◽  
Environmental Pollutants ◽  
Short Term ◽  
Pcb Congeners ◽  
Urinary Levels ◽  
The Brain

Polychlorinated biphenyls (PCBs) are a ubiquitous class of environmental pollutants with toxic and hepatocellular effects, including accumulation of fat, proliferated smooth endoplasmic recticulum (SER), and concentric membrane arrays (CMAs) (1-3). The CMAs appear to be a membrane storage and degeneration organelle composed of a large number of concentric membrane layers usually surrounding one or more lipid droplets often with internalized membrane fragments (3). The present study documents liver alteration after a short term single dose exposure to PCBs with high chlorine content, and correlates them with reported animal weights and central nervous system (CNS) measures. In the brain PCB congeners were concentrated in particular regions (4) while catecholamine concentrations were decreased (4-6). Urinary levels of homovanillic acid a dopamine metabolite were evaluated (7).Wistar rats were gavaged with corn oil (6 controls), or with a 1:1 mixture of Aroclor 1254 and 1260 in corn oil at 500 or 1000 mg total PCB/kg (6 at each level).

EXELFS Studies of Carbon Fibers

1990 ◽  
Vol 48 (2) ◽  
pp. 72-73
Author(s):  
V. Serin ◽  
K. Hssein ◽  
G. Zanchi ◽  
J. Sévely
Keyword(s):  
Carbon Fibers ◽  
Energy Analysis ◽  
Electron Excitation ◽  
Complex Structures ◽  
High Modulus ◽  
Promising Technique ◽  
X Ray ◽  
Fine Structures ◽  
X Ray Absorption

The present developments of electron energy analysis in the microscopes by E.E.L.S. allow an accurate recording of the spectra and of their different complex structures associated with the inner shell electron excitation by the incident electrons (1). Among these structures, the Extended Energy Loss Fine Structures (EXELFS) are of particular interest. They are equivalent to the well known EXAFS oscillations in X-ray absorption spectroscopy. Due to the EELS characteristic, the Fourier analysis of EXELFS oscillations appears as a promising technique for the characterization of composite materials, the major constituents of which are low Z elements. Using EXELFS, we have developed a microstructural study of carbon fibers. This analysis concerns the carbon K edge, which appears in the spectra at 285 eV. The purpose of the paper is to compare the local short range order, determined by this way in the case of Courtauld HTS and P100 ex-polyacrylonitrile carbon fibers, which are high tensile strength (HTS) and high modulus (HM) fibers respectively.

Acetaminophen: Macula densa hypersecretory activity by induced hepatotoxicity

1987 ◽  
Vol 45 ◽  
pp. 934-935
Author(s):  
S.S. Poolsawat ◽  
C.A. Huerta ◽  
S.TY. Lae ◽  
G.A. Miranda
Keyword(s):  
Cell Proliferation ◽  
Liver Function ◽  
Chronic Inflammation ◽  
Foam Cell ◽  
Term Effect ◽  
Short Term ◽  
Drug Induced ◽  
Experimental Induction ◽  
Tissue Alterations ◽  
Toxic Responses

Introduction. Experimental induction of altered histology by chemical toxins is of particular importance if its outcome resembles histopathological phenomena. Hepatotoxic drugs and chemicals are agents that can be converted by the liver into various metabolites which consequently evoke toxic responses. Very often, these drugs are intentionally administered to resolve an illness unrelated to liver function. Because of hepatic detoxification, the resulting metabolites are suggested to be integrated into the macromolecular processes of liver function and cause an array of cellular and tissue alterations, such as increased cytoplasmic lysis, centrilobular and localized necroses, chronic inflammation and “foam cell” proliferation of the hepatic sinusoids (1-4).Most experimentally drug-induced toxicity studies have concentrated primarily on the hepatic response, frequently overlooking other physiological phenomena which are directly related to liver function. Categorically, many studies have been short-term effect investigations which seldom have followed up the complications to other tissues and organs when the liver has failed to function normally.

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