Polyamide 6 and thermoplastic polyurethane recycled hybrid Fibres via twin-screw melt extrusion

  • Siti Zaharah KunchimonEmail author
  • Muhammad Tausif
  • Parikshit Goswami
  • Vien Cheung


The sorting of multi-component textile waste into individual components limit the recycling potential of textile waste. Thermo-mechanical processes can be applied to recycle mixed waste, without sorting, to extrude hybrid fibres. This research reports on the mixing of polyamide 6 (PA6) and thermoplastic polyurethane (TPU) polymers to produce hybrid fibres by melt extrusion process. Two different blending compositions; namely PA6–80 and PA6–50, were produced. SEM images show the development of interconnected multi-porous hybrid fibre structures with average PA6–80 and PA6–50 fibre diameter of 136 and 126 μm, respectively. Differential scanning calorimetry (DSC), TGA and ATR-FTIR results show the changes in the thermal and chemical properties of the blends, demonstrating the interactions that happen between PA6 and TPU. Mechanical testing shows properties of the novel hybrid fibres are in between that of the fibres spun from the constituent polymers. The multicomponent melt extrusion can be potentially applied to the mixed polymer waste.


Blends Fibres Thermoplastics Recycle Extrusion 



The authors acknowledge Ministry of Education (MoE) of Malaysia and Universiti Tun Hussein Onn Malaysia (UTHM) for providing financial support (PhD scholarship) and BASF Polyurethanes GmbH, Lemförde, Germany for providing the TPU pellets (Elastollan®1278D).

Compliance with ethical standards

Conflict of interest

The authors declare no conflict of interest.


  1. 1.
    United Nations (2018) The sustainable development goals report 2018Google Scholar
  2. 2.
    Bartl A (2011) Textile waste. In: Letcher TM, Vallero DA (eds) Waste: a handbook of management (pp 167–179). Elsevier BVGoogle Scholar
  3. 3.
    Global Fashion Agenda, The Boston Consulting Group I (2017) Pulse of the fashion industryGoogle Scholar
  4. 4.
    Zainab ZI, Ali RT (2016) Recycled medical cotton industry waste as a source of biogas recovery. J Clean Prod 112:4413–4418. CrossRefGoogle Scholar
  5. 5.
    De FF, Gullo MP, Gentile G et al (2018) Evaluation of microplastic release caused by textile washing processes of synthetic fabrics. Environ Pollut 236:916–925. CrossRefGoogle Scholar
  6. 6.
    Ellen MacArthur Foundation (2017) A new textiles economy: redesigning Fashion’s future. Accessed 20 Aug 2018
  7. 7.
    Sandin G, Peters GM (2018) Environmental impact of textile reuse and recycling – a review. J Clean Prod 184:353–365. CrossRefGoogle Scholar
  8. 8.
    Econyl some see trash. Others see treasure. Accessed 31 Aug 2018
  9. 9.
    Repreve grow your brand with REPREVE. Accessed 31 Aug 2018
  10. 10.
    Toray (2011) Toray Draws Up Strategy to Expand Fibers and Textiles Recycling Business. Accessed 31 Aug 2018
  11. 11.
    Teijin The Outstanding Potential of Teijin’s ECO CIRCLE™ SystemGoogle Scholar
  12. 12.
    Evrnu (2016) Evrnu™ and Levi Strauss & Co. Create first jeans made from post-consumer cotton garment waste. Accessed 4 Jul 2016
  13. 13.
    Re:newcell we make fashion sustainable. Accessed 31 Aug 2018
  14. 14.
    Östlund Å, Wedin H, Bolin L, et al (2015) Textilåtervinning Tekniska möjligheter och utmaningar [Tetxile recycling-technical opportunities and challanges]. In: Naturvårdsverket. Accessed 20 Aug 2018
  15. 15.
    Wang L, Guo Z-X, Yu J (2012) Cocontinuous phase morphology for an asymmetric composition of polypropylene/polyamide 6 blend by melt mixing of polypropylene with Premelted polyamide 6/Organoclay Masterbatch. J Appl Polym Sci 123:1218–1226. CrossRefGoogle Scholar
  16. 16.
    Tran NHA, Brünig H, Auf der Landwehr M, Vogel R, Pionteck J, Heinrich G (2016) Controlling micro- and nanofibrillar morphology of polymer blends in low-speed melt spinning process. Part II: influences of extrusion rate on morphological changes of a PLA/PVA blend through a capillary die. J Appl Polym Sci 133:1–10. CrossRefGoogle Scholar
  17. 17.
    Tran NHA, Brünig H, Heinrich G (2016) Controlling micro- and nanofibrillar morphology of polymer blends in low-speed melt spinning process . Part I . Profiles of PLA / PVA-filament parameters along the spinline. J Appl Polym Sci 133:1–14. CrossRefGoogle Scholar
  18. 18.
    Pötschke P, Paul DR (2003) Formation of co-continuous structures in melt-mixed immiscible polymer blends. J Macromol Sci C Polym Rev 43:87–141. CrossRefGoogle Scholar
  19. 19.
    Willemse RC, Posthuma De Boer A, Van Dam J, Gotsis AD (1999) Co-continuous morphologies in polymer blends: the influence of the interfacial tension. Polymer (Guildf) 40:827–834. CrossRefGoogle Scholar
  20. 20.
    Erez (2018) 2018 technology report for marine safety textilesGoogle Scholar
  21. 21.
    Wesołowski J, Płachta K (2016) The polyamide market. Fibres Text East Eur 24:12–18. CrossRefGoogle Scholar
  22. 22.
    Huntsman (2010) A guide to thermoplastic polyurethanes (TPU)Google Scholar
  23. 23.
    Pan Z, Chen Y, Zhu M, Jiang C, Xu Z, Lu W, Pionteck J (2010) The non-uniform phase structure in blend fiber. II. The migration phenomenon in melt spinning. Fibers Polym 11:625–631. CrossRefGoogle Scholar
  24. 24.
    Zhang P, Xu D, Xiao R (2015) Morphology development and size control of PA6 nanofibers from PA6/CAB polymer blends. J Appl Polym Sci 132:1–8. CrossRefGoogle Scholar
  25. 25.
    Afshari M, Kotek R, Gupta BS, Haghighat Kish M, Nazock Dast H (2005) Mechanical and structural properties of melt spun polypropylene/nylon 6 alloy filaments. J Appl Polym Sci 97:532–544. CrossRefGoogle Scholar
  26. 26.
    Dotto G, Santos JMN, Tanabe EH et al (2017) Chitosan/polyamide nanofibers prepared by Forcespinning®technology: a new adsorbent to remove anionic dyes from aqueous solutions. J Clean Prod 144:120–129. CrossRefGoogle Scholar
  27. 27.
    Aslan S, Laurienzo P, Malinconico M, Martuscelli E, Pota F, Bianchi R, di Dino G, Giannotta G (1995) Influence of spinning velocity on mechanical and structural behavior of PET/nylon 6 fibers. J Appl Polym Sci 55:57–67. CrossRefGoogle Scholar
  28. 28.
    Li W, Liu J, Hao C, Jiang K, Xu D, Wang D (2008) Interaction of thermoplastic polyurethane with polyamide 1212 and its influence on the thermal and mechanical properties of TPU/PA1212 blends. J Polym Eng Sci 48:249–256. CrossRefGoogle Scholar
  29. 29.
    Zhang SL, Bin WG, Jiang ZH et al (2005) Impact properties, phase structure, compatibility, and fracture morphology of polyamide-1010/thermoplastic poly(ester urethane) elastomer blends. J Polym Sci B Polym Phys 43:1177–1185. CrossRefGoogle Scholar
  30. 30.
    Chiu H-T, Chuang C-Y (2009) The mechanical and rheological behavior of the PA/TPU blend with POE-g-MA modifier. J Appl Polym Sci 115:1278–1282. CrossRefGoogle Scholar
  31. 31.
    Rashmi BJ, Loux C, Prashantha K (2017) Bio-based thermoplastic polyurethane and polyamide 11 bioalloys with excellent shape memory behavior. J Appl Polym Sci 134:1–10. CrossRefGoogle Scholar
  32. 32.
    Zhou S, Huang J, Zhang Q (2012) Mechanical and tribological properties of polyamide-based composites modified by thermoplastic polyurethane. J Thermoplast Compos Mater 27:18–34. CrossRefGoogle Scholar
  33. 33.
    John B, Furukawa M (2012) Structure and mechanical behaviors of thermoplastic polyurethane thin film coated polyamide 6 fibers part II. A solution coating method. J Polym Res 19:1–12. CrossRefGoogle Scholar
  34. 34.
    Genovese A, Shanks R (2001) Simulation of the specific interactions between polyamide-6 and a thermoplastic polyurethane. Comput Theor Polym Sci 11:57–62. CrossRefGoogle Scholar
  35. 35.
    Zo HJ, Joo SH, Kim T, Seo PS, Kim JH, Park JS (2014) Enhanced mechanical and thermal properties of carbon fiber composites with polyamide and thermoplastic polyurethane blends. Fibers Polym 15:1071–1077. CrossRefGoogle Scholar
  36. 36.
    Sichina WJ (2000) DSC as problem solving tool: measurement of percent crystallinity of thermoplastics. Perkin Elmer InstrumentsGoogle Scholar
  37. 37.
    Schick C (2009) Differential scanning calorimetry (DSC) of semicrystalline polymers. Anal Bioanal Chem 395:1589–1611. CrossRefPubMedGoogle Scholar
  38. 38.
    Millot C, Fillot L, Lame O et al (2015) Assessment of polyamide-6 crystallinity by DSC: temperature dependence of the melting enthalpy. J Therm Anal Calorim 122:307–314. CrossRefGoogle Scholar
  39. 39.
    Stankowski M, Kropidłowska A, Gazda M, Haponiuk JT (2008) Properties of polyamide 6 and thermoplastic polyurethane blends containing modified montmorillonites. J Therm Anal Calorim 94:817–823. CrossRefGoogle Scholar
  40. 40.
    Frick A, Rochman A (2004) Characterization of TPU-elastomers by thermal analysis (DSC). Polym Test 23:413–417. CrossRefGoogle Scholar
  41. 41.
    John B, Furukawa M (2009) Enhanced mechanical properties of polyamide 6 fibers coated with a polyurethane thin film. Polym Eng Sci 47:1970–1978. CrossRefGoogle Scholar
  42. 42.
    Murase S, Kashima M, Kudo K, Hirami M (1997) Structure and properties of high-speed spun fibers of nylon 6. Macromol Chem Phys 198:561–572. CrossRefGoogle Scholar
  43. 43.
    Liu L, Wu Y, Zhu Z (2017) Internal structure and crystallinity investigation of segmented thermoplastic polyurethane elastomer degradation in supercritical methanol. Polym Degrad Stab 140:17–24. CrossRefGoogle Scholar
  44. 44.
    Hepperle J (2008) Rheological properties of polymer melts. In: Kohlgrüber K (ed) Co-rotating twin-screw extruders: fundamentals, technology and applications. Hanser Publishers, Munich, pp 35–45Google Scholar
  45. 45.
    Tavanaie MA, Shoushtari AM, Goharpey F, Mojtahedi MR (2013) Matrix-fibril morphology development of polypropylene / poly ( butylenes terephthalate ) blend fibers at different zones of melt spinning process and its relation to mechanical properties. Fibers Polym 14:396–404. CrossRefGoogle Scholar
  46. 46.
    He H, Chen L, Sun S, Wang T, Zhang Y, Zhu M (2014) Study on the matrix-fibril morphologies of polypropylene/polystyrene blends under non-isothermal uniaxial elongational flow. Fibers Polym 15:744–752. CrossRefGoogle Scholar
  47. 47.
    Tang H, Wrobel LC, Fan Z (2003) Fluid flow aspects of twin-screw extruder process: numerical simulations of TSE rheomixing. Model Simul Mater Sci Eng 11:771–790. CrossRefGoogle Scholar
  48. 48.
    Martin C (2013) Twin Screw Extrusion for Pharmaceutical Processes. In: Repka M., Langley N, DiNunzio J (eds) Melt extrusion; materials, technology and drug product design (pp 47–79). SpringerGoogle Scholar
  49. 49.
    Kirchhoff J (2007) Mixing and dispersing: principles. In: Kohlgrüber K (ed) Co-rotating twin-screw extruders: fundamentals, technology and applications (pp 159–179). Carl Hanser PublisherGoogle Scholar
  50. 50.
    Lu G, Kalyon DM, Yilgör I, Yilgör E (2003) Rheology and extrusion of medical-grade thermoplastic polyurethane. Polym Eng Sci 43:1863–1877. CrossRefGoogle Scholar
  51. 51.
    Todros S, Venturato C, Natali AN, Pace G, di Noto V (2014) Effect of steam on structure and mechanical properties of biomedical block copolymers. J Polym Sci B Polym Phys 52:1337–1346. CrossRefGoogle Scholar
  52. 52.
    John B, Kojio K, Furukawa M (2009) High performance polyamide 6 fibers using polycarbonate based thermoplastic polyurethane thin film coatings- a novel method. Polym J 41:319–326. CrossRefGoogle Scholar
  53. 53.
    Eltahir YA, Saeed HAM, Xia Y et al (2016) Mechanical properties, moisture absorption, and dyeability of polyamide 5,6 fibers. J Text Inst 107:208–214. CrossRefGoogle Scholar

Copyright information

© The Polymer Society, Taipei 2019

Authors and Affiliations

  1. 1.School of DesignUniversity of LeedsLeedsUK
  2. 2.School of Applied ScienceUniversity of HuddersfieldHuddersfieldUK
  3. 3.Department of Mechanical Engineering, Faculty of Engineering TechnologyUniversiti Tun Hussein Onn MalaysiaBatu PahatMalaysia

Personalised recommendations