Skip to main content

Temperature-adaptive Insulation Based on Multicomponent Fibers of Various Cross-sections

  • Barry S. DeCristofano (a1), Stephen A. Fossey (a1), Elizabeth A. Welsh (a1), Jeffrey Perry (a1) and Deana Archambault (a1)...

We have developed a thermal insulation based on bi-component fibers that adapts to its thermal environment, providing greater insulation at low temperatures than at warmer temperatures. The analysis of bi-metallic strips done by Timoshenko [1] for strips of rectangular cross-section concluded that “…curvature is proportional to the difference in elongation of the two metals and inversely proportional to the thickness of the strip.” We have extended Timoshenko’s formulation and applied it to bi-component fibers of circular and triangular cross-sections. In each case, the curvature resulting from the balance of the axial forces and bending moments has been brought into a standard form inversely proportional to (A+Bn+C/n) where n is the ratio of the moduli and A, B, and C are functions of the geometry of the two components. An important consequence of this result is that for any “n” there is a maximum curvature where (A+Bn+C/n) is a minimum. We have used the process of melt-spinning to produce fibers with circular and triangular cross-sections, varying the proportion of the two components. The polymers used have widely different coefficients of thermal expansion. These fibers spontaneously form mats at room temperatures. The experimentally measured thickness changes are in good agreement with the analytical results for fiber bending. The most effective samples to date change thickness by more than 1.5% per degree C (30% over a temperature range from approximately 20°C to 0°C).

Hide All
1.Timoshenko, S. Analysis of Bi-metal Thermostats. J. Opt. Soc. Am. 1925, 11 (3), pp. 233255.
2.Alici, Gursel and Huynh, Nam N. Predicting force output of trilayer polymer actuators. Sensors and Actuators A. 2006, Vol. 132, pp. 616625.
3.Slepyan, L., Ryvkin, M. and Fuchs, M.B. Temperature Insensitive Curved Bimetal Elements. Acta Astronautica.1995, Vol. 37, pp. 95103.
4.Variable Loft Thermal Insulation for Temperature Adaptive Clothing. Fossey, S.A. and du Plessis, A.J. Roseville, MN USA: Industrial Fabrics International Association. Saftey & Protective Fabrics Proceedings 2004.
5.Variable Loft Thermal Insulation. Fossey, S.A. Gilbert, D. and Hunt, V. Atlanta GA USA: s.n., 2006. AATCC 2006 International Conference.
6.Uehara, H., Yamazaki, Y. and Kanamoto, T. Tensile Properties of Highly Syndiotactic Polypropylene. 1996, Vol. 37, 1, pp. 5764.
7.Lacks, D.J. and Rutledge, G.C. Mechanisms for Axial Thermal Contraction in Polymer Crystals: Polyethylene vs Isotactic Polypropylene. Chemical Engineering Science. 1994, Vol. 49, pp. 28812888.
8.Temperature Adaptive “Smart” Thermal Insulation Based on Multicomponent Fiber Spinning. Fossey, S.A, DeCristofano, B.S., Welsh, E.A., Perry, J., Archambault, D. Orlando, FL: s.n., 2010. 2010 Army Science Conference.
Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

MRS Online Proceedings Library (OPL)
  • ISSN: -
  • EISSN: 1946-4274
  • URL: /core/journals/mrs-online-proceedings-library-archive
Please enter your name
Please enter a valid email address
Who would you like to send this to? *



Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed