If a synthetic fiber has an average specific gravity

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If a synthetic fiber has an average specific gravity of 1.32 and a filament of this material has a denier of 5.0, what is the mass per unit length in pounds- mass per yard? What is the cross sectional area of this fiber in square inches? The specific gravity is defined as density specific gravity = density of water 2-10. To begin this problem, we note that there is a conversion factor hidden in the problem statement, i.e., 1 denier 1 g 9000 m (1) or 4 1 denier 1.11 10 g m (2) The answer to the first question is given by 4 mass per 5 denier 5.55 10 g m unit length (3) and in order to obtain the desired units we make use of the proper conversion factors to express Eq. 3 in the form 4 2 m 6 m mass per 5.55 10 g lb 2.54 10 m 36 in × × unit length m 453.6 g in yard 1.12 10 lb yard (4) To determine the cross-sectional area we first note that the mass is given by mass density volume = AL (5) The density of the yarn can be expressed as 2 H O  (6) where is the specific gravity . Substitution of Eq. 6 into Eq. 5, and solving for the area, leads to Solution: 2 H O mass L A  (7) This represents the solution to the problem, and we can obtain the answer by making use of the values for the various parameters to obtain
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Chapter 2 2-6 Answer: 2 4 -2 3 6 2 denier 1.11 10 g 10 m in denier - m cm 2.54 cm (1.32) 1 g cm 0.652 10 in A (8) 2-11. (Adopted from Safety Health and Loss Prevention in Chemical Processes by AIChE). The level of exposure to hazardous materials for personnel of chemical plants is a very important safety concern. The Occupational Safety and Health Act (OSHA) defines as a hazardous material any substance or mixture of substances capable of producing adverse effects on the health and safety of a human being. OSHA also requires the Permissible Exposure Limit, or PEL, to be listed on the Material Safety Data Sheet (MSDS) for the particular component. The PEL is defined by the OSHA authority and is usually expressed in volume parts per million and abbreviated as ppm. Vinyl chloride is believed to be a human carcinogen, that is an agent which causes or promotes the initiation of cancer. The PEL for vinyl chloride in air is 1 ppm, i.e., one liter of vinyl chloride per one million liters of mixture. For a dilute mixture of a gas in air at ambient pressure and temperature, one can show that that volume fractions are equivalent to molar fractions. Compute the PEL of VC in the following units: (a) moles of VC/m 3 (b) g of VC/m 3 (c) moles VC/mole of air 2-11. We begin the formulation of this problem with the definition of PEL in the form of an equation 3 3 PEL Permissible Exposure 1 cm of VC in 1 m of of 1 ppm Limit of vinyl chloride a mixture of air and VC VC (1)
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  • Summer '13
  • LeThuy
  • Mole, Mass, TCE, International System of Units

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