The melting and crystallization temperature ranges are specific to particular types of PCM.During phase change, the temperature of the PCM and the surrounding substrate remain constant.
In addition to water, more than 500 natural and synthetic PCMs are known.These materials differ in their phase change temperature ranges and heat storage capacities.
Large Latent heat, good thermal and chemical stability , low vapour pressure.
PCM fabrics act as a “transient thermal barrier” against cold or hot environment
Active thermal insulation effect of PCM results in a substantial improvement in the garment’s thermo-physiological wearing comfort.In short, PCM fabrics provide “Thermo-regulation”.Thus, PCM fabrics can be referred to as an “Active Smart Textile” which is capable of sensing and reacting to the conditions or stimulus. (Onofrei, Rocha and Catarino, 2010)
PCM containment should,Meet the requirements of strength, flexibility and thermal stabilityProtect the PCM from harmful interactionProvide sufficient surface for heat transferProvide structural stability and easy handlingOtherwise, the microencapsulation system will suffer from low heat transfer rate. (A.F Regin et al, 2008)
Sportswear is one of the major areas of application of PCMs. Thermal comfort contributes to human performance.PCM fabrics interact with the microclimate between clothing and the body and respond to temperature changes caused by activitylevel and external environment.
Phase Change Materials in Sportswear
Phase Change Materials in Active Sports Wear TXA 394 Speciality Fibres Shamini Rajaganesh
Table of Contents• Introduction to PCM• Types of PCM• PCM manufacture• Working of PCM in textiles• Methods of application on textiles• PCM in sportswear• Current market scenario• Conclusion 2
Introduction to PCM• Phase Change Materials or PCMs are those that can absorb, store and release large amounts of energy, in the form of latent heat, over a narrowly defined phase change range, during which the material changes state. 4
Introduction to PCM• At melting temperature, Absorbs Heat Solid Liquid PCM PCM Breaking down of chemical structure 5
Introduction to PCM• At crystallization temperature, Releases Heat Solid Liquid PCM PCM Chemical bonds are formed again 6
Introduction to PCM Crystallization Temperature Constant Temperature• PCM of PCM and substrate Melting point 7
Introduction to PCM• The most common example of PCM is water. http://www.physicalgeography.net/fundamentals/images/latent.GIF 8
Required properties of PCMs in Textiles• Melting point between 15 and 35ºC;• Large heat of fusion• Small temperature difference between melting and crystallization point• Harmless to the environment• Low toxicity• Non-flammable• Good stability for repeated phase change• Large thermal conductivity• Ease of availability• Low Price 14
Working of PCM• Transient thermal barrier• Under hot environmental conditions, HEAT HEAT The cooling effect of PCM 15
Working of PCM• Under cold environmental conditions, HEAT HEAT The heating effect of PCM 16
Working of PCM• Active thermal insulation effect of PCM improves thermo-physiological wearing comfort.• Thermo-regulation• PCM fabrics referred as "Active Smart Textile”.• Capable of sensing and reacting to the conditions or stimulus. (Onofrei, Rocha and Catarino, 2010) 17
Microencapsulation• PCM is encapsulated in very small polymer spheres to contain the liquid during phase transition.• The polymer spheres form a continuous sealed matrix. (A.F Regin et al, 2008) 19
Microencapsulation• PCM containment requirements: – strength, flexibility and thermal stability – Protect the PCM – sufficient surface for heat transfer – structural stability and easy handling• Otherwise, the microencapsulation system will suffer from low heat transfer rate. (A.F Regin et al, 2008) 20
Microencapsulation http://tectexntu.files.wordpress.com/2010/02/2.jpg• The most successful method of microencapsulation was given by Sarier and Onder ( N.Sarier, E.Onder, 2007) , based on in-situ polymerization. Seventy-seven percentage of microcapsules were obtained in the required diameter and thickness. 21
Incorporation of PCM in textiles• Three main methods Fiber Coating Lamination Technology • PCM locked in • PCM dispersed • PCM added to a fiber structure in a polymer thin polymeric • Late injection binder film technology • Applied over • Applied on the • PCM added to fabric through fabric as a polymer dope various laminate via processes foam mix 23
Incorporation of PCM Outlast Thermo-molecules as a Outlast Thermo-molecules coating on textiles locked into the textile fiberhttp://www.sciencephoto.com/image/220752/530wm/H120 http://www.licensedelectrician.com/Store/O 0332-Phase_change_material,_SEM-SPL.jpg E/Images/Molecules.jpg 24
PCM in Sportwear• Sportswear• Thermal comfort contributes to human performance.• PCM interaction with the microclimate between clothing and the body and respond to temperature changes caused by activity level and external environment. 26
PCM in Sportwear• Quantity of PCM ≡ Level and duration of activity for garment use Thermal Balance• Heat generated by body Heat released into environment 27
Research findings so far• Several authors have experimentally verified that PCM fabrics provide increased thermal comfort.• Shu-Xiao Wang et al (2008) experimentally showed that PCM treated clothing had thermo-regulating effect and improved temperatures and humidity of inner layers during exercise in an cold environment.• According to Fan and Cheng (2005), thermal performance of PCM is also influenced by the structure of the textile.• Ghali et al (2004) showed that PCMs introduced into garments can temporarily improve the thermal comfort. This effect increases as PCM concentration increases, but the thermal properties can decrease after laundering. 28
Characterization of Thermal Properties of PCM• Differential Scanning Calorimeter (DSC) – Analyzes and quantifies material’s energy absorption and release.• Fourier Transform Infrared Spectroscopy (FTIR) – Identifying types of chemical bonds in molecule through IR absorption spectrum• Thermal Gravimetric Analysis (TGA) – Measures weight loss or weight gain as a function of temperature• Infrared Thermography – Produces ‘thermograms’ by detecting radiation in IR range• Fabric Intelligent Hand Tester (FIHT) – Measures, records and analyzes the thermal and mechanical properties exhibited during hand evaluation process. 29
Research findings so far• Bendkowska and Wrzosek (2008) studied the thermo- regulating properties of nonwovens treated with PCM and found that – TRF (Temperature Regulating Factor) depends on amount of latent heat per unit area of fabric – Method of microPCM distribution – Position of microPCM layer.• Bo-an Ying et al (2004) proposed three indices to characterize the thermal performance of PCM fabrics. 30
Current Market Scenario• Outlast Technologies, Inc. manufactures exclusive sportswear apparel using PCM fabrics. http://www.outlast.com• Comfortemp products with Thermasorb® microcapsules are being manufactured by J&C Microchem Inc. http://www.microcapsule.com/come.htm• Schoeller TextilAG http://www.schoeller- textiles.com/ 31
Challenges and Opportunities• Lack of standards and testing methods• Durability, functionality under various conditions will take a long time• Practicality in everyday life• Expanding the duration of thermal insulation property 32
References• S. Mondal, Phase change materials for smart textiles – An overview, Applied Thermal Engineering, Volume 28, Issues 11-12, August 2008, Pages 1536-1550, ISSN 1359-4311, 10.1016/j.applthermaleng.2007.08.009. (http://www.sciencedirect.com/science/article/pii/S1359431107002876) Keywords: Phase change materials; Clothing comfort; Microencapsulation; Smart temperature adaptable fabrics• Textiles integrating pcms – a review by elena onofrei, ana maria rocha and andré catarinobuletinul institutului politehnic din iasi publicat de universitatea tehnică „gheorghe asachi” din iasi tomul LVI (LX), fasc. 2, 2010• Bendkowska W., Kłonowska M., Kopias K., Bogdan A.; Thermal Manikin Evaluation of PCM Cooling Vests. FIBRES & TEXTILES in Eastern Europe 2010, Vol. 18, No. 1 (78) pp. 70-74• S.X. Wang, Y. Li, J.Y. Hu, Hiromi Tokura, Q.W. Song, Effect of phase-change material on energy consumption of intelligent thermal-protective clothing, Polymer Testing, Volume 25, Issue 5, August 2006, Pages 580-587, ISSN 0142- 9418, 10.1016/j.polymertesting.2006.01.018. (http://www.sciencedirect.com/science/article/pii/S0142941806000894) Keywords: PCM; Energy consumption; Thermal-protective clothing• Nihal Sarier, Emel Onder, The manufacture of microencapsulated phase change materials suitable for the design of thermally enhanced fabrics, Thermochimica Acta, Volume 452, Issue 2, 15 January 2007, Pages 149-160, ISSN 0040- 6031, 10.1016/j.tca.2006.08.002. (http://www.sciencedirect.com/science/article/pii/S0040603106004357) Keywords: Microencapsulation; Phase change materials; Functional textiles; Thermal; Comfort; DSC• Gordon Nelson, Application of microencapsulation in textiles, International Journal of Pharmaceutics, Volume 242, Issues 1-2, 21 August 2002, Pages 55-62, ISSN 0378-5173, 10.1016/S0378-5173(02)00141-2. (http://www.sciencedirect.com/science/article/pii/S0378517302001412) Keywords: Microencapsulation; Yeast; Textiles; Fragrance; Phase-change materials• A. Felix Regin, S.C. Solanki, J.S. Saini, Heat transfer characteristics of thermal energy storage system using PCM capsules: A review, Renewable and Sustainable Energy Reviews, Volume 12, Issue 9, December 2008, Pages 2438- 2458, ISSN 1364-0321, 10.1016/j.rser.2007.06.009. (http://www.sciencedirect.com/science/article/pii/S1364032107001001) Keywords: PCM capsules; Packed bed; Thermal energy storage 33