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Chaki, Tapan Kumar
- Acoustic Properties of Polychloroprene (Neoprene) Elastomer: Effect of Glass, Cotton and Nylon Fibers
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Authors
Affiliations
1 Naval Science & Technological Laboratory, DRDO, Visakhapatnam–530027, Andhra Pradesh, IN
2 Rubber Technology Centre, IIT Kharagpur Kharagpur–721502, West Bengal, IN
1 Naval Science & Technological Laboratory, DRDO, Visakhapatnam–530027, Andhra Pradesh, IN
2 Rubber Technology Centre, IIT Kharagpur Kharagpur–721502, West Bengal, IN
Source
International Journal of Applied Mathematical Sciences, Vol 5, No 1 (2012), Pagination: 69-79Abstract
Some of the underwater acoustical applications require a window that is both acoustically transparent and structurally rigid. A series of neoprene rubber based structurally rigid materials were developed with Cotton fiber, Nylon fiber and Glass fiber as filler in addition to SRF (N-770) carbon black filler. With each variety of fiber, three different materials of hardness 70, 80 and 90 shore-A, were made by varying the fiber loading. Acoustical and mechanical properties of these specially designed neoprene rubber materials have been investigated. Sound velocity and density of materials were measured. Acoustic impedance of the materials were evaluated and compared with the acoustic impedance of sea water. Insertion loss and echo reduction of the materials were measured in the frequency range 15kHz to 85kHz. Insertion loss was less than 2 dB and echo reduction was more than 10 dB through out the frequency range which is suitable for underwater transducer encapsulation material. Mechanical properties like tensile strength, elongation at break and hardness etc. were investigated, which are important for encapsulation materials to withstand hydrostatic or hydrodynamic pressure. Ageing resistance to hot air and sea water were also conducted in the present study.Keywords
Acoustically Transparent, Acoustic Impedance, Encapsulation, Sound Speed, Insertion Loss, Echo ReductionReferences
- Rodger N. Capps. Influence of carbon black fillers on acoustic properties of polychloroprene (neoprene) elastomers. J. Acoust. Soc. Am. 1985, 78, 406.
- C.M.Roland. Naval applications of elastomers. Rubber Chemistry & Technology, July-2004, Vol-77, No-3, pp 542-551.
- Thomas Ramotowski and Kirk Jenne. NUWC XP-I Polyurethane –Urea: A new acoustically transparent encapsulant for underwater transducers and hydrophones. Oceans 2003 proceedings, Vol-1, Page-227-230.
- Corley M. Thompson. Development of structurally rigid acoustically transparent plastic. J. Acoust. Soc. Am. 87(3), March 1990.
- J.A. Brydson, Rubbery Materials and their Compounds, Elsevier Science Publishers Ltd, 1988.
- R. N. Capps, C. N. Thompson and F. J. Weber. Handbook of sonar transducer passive materials. NRL memorandum report 4311, October 30, 1981, Naval Research Laboratory, Washington D.C.
- T.R. Natarajan, K.Trinath, V.V.S. Bhaskara Raju and A.V.N.R. Rao. “Effect of carbon black filler on the acoustical properties of rubber for underwater applications”, Conference proceedings, Materials for Marine applications, Page-83 – 89, Naval Materials Research Laboratory, DRDO, Bombay, India, 1996.
- Technical notes of Panametrics, Inc. www.panametrics.com
- Acoustic Properties of Polychloroprene (Neoprene) Elastomer: Effect of Glass, Cotton and Nylon Fibers
Abstract Views :566 |
PDF Views:0
Authors
Affiliations
1 Naval Science & Technological Laboratory, DRDO, Visakhapatnam–530027, Andhra Pradesh, IN
2 Rubber Technology Centre, IIT Kharagpur Kharagpur–721502, West Bengal, IN
1 Naval Science & Technological Laboratory, DRDO, Visakhapatnam–530027, Andhra Pradesh, IN
2 Rubber Technology Centre, IIT Kharagpur Kharagpur–721502, West Bengal, IN
Source
International Journal of Advanced Materials Science, Vol 4, No 1 (2013), Pagination: 69-79Abstract
Some of the underwater acoustical applications require a window that is both acoustically transparent and structurally rigid. A series of neoprene rubber based structurally rigid materials were developed with Cotton fiber, Nylon fiber and Glass fiber as filler in addition to SRF (N-770) carbon black filler. With each variety of fiber, three different materials of hardness 70, 80 and 90 shore-A, were made by varying the fiber loading. Acoustical and mechanical properties of these specially designed neoprene rubber materials have been investigated. Sound velocity and density of materials were measured. Acoustic impedance of the materials were evaluated and compared with the acoustic impedance of sea water. Insertion loss and echo reduction of the materials were measured in the frequency range 15 kHz to 85 kHz. Insertion loss was less than 2 dB and echo reduction was more than 10 dB through out the frequency range which is suitable for underwater transducer encapsulation material. Mechanical properties like tensile strength, elongation at break and hardness etc. were investigated, which are important for encapsulation materials to withstand hydrostatic or hydrodynamic pressure. Ageing resistance to hot air and sea water were also conducted in the present study.Keywords
Acoustically Transparent, Acoustic Impedance, Encapsulation, Sound Speed, Insertion Loss, Echo ReductionReferences
- Rodger N. Capps. Influence of carbon black fillers on acoustic properties of polychloroprene (neoprene) elastomers. J. Acoust. Soc. Am. 1985, 78, 406.
- C.M.Roland. Naval applications of elastomers. Rubber Chemistry & Technology, July-2004, Vol-77, No-3, pp 542-551.
- Thomas Ramotowski and Kirk Jenne. NUWC XP-I Polyurethane –Urea: A new acoustically transparent encapsulant for underwater transducers and hydrophones. Oceans 2003 proceedings, Vol-1, Page-227-230.
- Corley M. Thompson. Development of structurally rigid acoustically transparent plastic. J. Acoust. Soc. Am. 87(3), March 1990.
- J.A. Brydson, Rubbery Materials and their Compounds, Elsevier Science Publishers Ltd, 1988.
- R. N. Capps, C. N. Thompson and F. J. Weber. Handbook of sonar transducer passive materials. NRL memorandum report 4311, October 30, 1981, Naval Research Laboratory, Washington D.C.
- T.R. Natarajan, K.Trinath, V.V.S. Bhaskara Raju and A.V.N.R. Rao. “Effect of carbon black filler on the acoustical properties of rubber for underwater applications”, Conference proceedings, Materials for Marine applications, Page-83 – 89, Naval Materials Research Laboratory, DRDO, Bombay, India, 1996.
- Technical notes of Panametrics, Inc. www.panametrics.com
- Effect of Thickness of Epoxy Encapsulation Material on the Performance of Underwater Tonpilz Transducer
Abstract Views :221 |
PDF Views:0
Authors
Affiliations
1 Rubber Technology Division, Naval Science & Technological Laboratory, DRDO, Visakhapatnam-530027, IN
2 Rubber Technology Centre, Indian Institute of Technology, Kharagpur-721502, IN
1 Rubber Technology Division, Naval Science & Technological Laboratory, DRDO, Visakhapatnam-530027, IN
2 Rubber Technology Centre, Indian Institute of Technology, Kharagpur-721502, IN
Source
Journal of Pure and Applied Ultrasonics, Vol 37, No 2-3 (2015), Pagination: 39-43Abstract
Electro-acoustic transducers capable of converting electric energy to acoustic energy and vice versa are critical elements in Sonar systems. Among different types of electro-acoustic transducers Tonpilz transducer is widely used due to their ability to operate in both transmitting and receiving mode and generation of directional high acoustic power. Typically tonpilz transducers are encapsulated by a visco-elastic material when used in underwater applications. The primary function of encapsulation material is to protect the transducer from water ingression and physical damage without affecting significantly the acoustic transmission and reception properties, thereby influencing efficiency and reliability of transducers. In view of these, epoxy elastomers are widely used for encapsulation of tonpilz transducers. The term epoxy, epoxy resin or epoxide refers to a broad group of reactive compounds that are characterized by the presence of an oxirane or epoxy ring. For applicability and suitability of epoxy for a particular underwater application, its compositions and encapsulation thickness are the crucial parameters. In this paper the effect of the variation of encapsulation thickness of epoxy on the transmitting voltage response (TVR) and free field sensitivity (FFS) of a tonpilz transducer designed for underwater applications are presented.Keywords
Electro-Acoustic Transducer, Acoustic Impedance, Epoxy, TVR and FFS.- Acoustic & Mechanical Properties of Neoprene Rubber for Encapsulation of Underwater Transducers
Abstract Views :103 |
PDF Views:0
Mechanical properties like tensile strength, elongation at break and hardness etc. were investigated which is important for encapsulation materials to withstand hydrostatic or hydrodynamic pressure exerted on it. Materials resistance to hot air ageing and sea water were also conducted in the present study.
Authors
Affiliations
1 Naval Science & Technological Laboratory, DRDO, Visakhapatnam-530027, AP, IN
2 Rubber Technology Centre, IIT Kharagpur, Kharagpur-721502, IN
1 Naval Science & Technological Laboratory, DRDO, Visakhapatnam-530027, AP, IN
2 Rubber Technology Centre, IIT Kharagpur, Kharagpur-721502, IN
Source
International Journal of Scientific Engineering and Technology, Vol 1, No 5 (2012), Pagination: 231-237Abstract
Acoustical and mechanical properties of specially designed Neoprene rubber compounds were investigated. Three different hardness materials were developed with varied carbon black loading. Sound velocity and density of materials were measured. Acoustic impedance of the materials were evaluated and compared with the acoustic impedance of sea water. Insertion loss and echo reduction of the materials were measured in the frequency range 15 kHz to 85 kHz at room temperature. Insertion loss was less than 2 dB and echo reduction was more than 10 dB through out the frequency range which is suitable for underwater transducer encapsulation material.Mechanical properties like tensile strength, elongation at break and hardness etc. were investigated which is important for encapsulation materials to withstand hydrostatic or hydrodynamic pressure exerted on it. Materials resistance to hot air ageing and sea water were also conducted in the present study.
Keywords
Acoustically Transparent, Acoustic Impedance, Encapsulation, Sound Speed, Insertion Loss, Echo Reduction.- Epoxy Based Underwater Transducer Encapsulation Material
Abstract Views :170 |
PDF Views:0
Authors
Affiliations
1 Rubber Technology Division, Naval Science and Technological Laboratory, DRDO, Visakhapatnam-530027, IN
2 Rubber Technology Centre, Indian Institute of Technology, Kharagpur-721502, IN
1 Rubber Technology Division, Naval Science and Technological Laboratory, DRDO, Visakhapatnam-530027, IN
2 Rubber Technology Centre, Indian Institute of Technology, Kharagpur-721502, IN