A NiTi alloy weft knitted fabric for smart firefighting clothing

Šalej Lah, Alenka (author), Fajfar, Peter (author), Kugler, Goran (author), Rijavec, Tatjana (author)

A prototype of a new shape-memory nitinol knitted fabric intended for use as an active thermal insulating interlining in firefighting protective clothing was developed in the study presented in this paper. Weft knitted fabrics were made from commercially available cold-worked nickel titanium alloy monofils. Knits were made on a manual knitting machine from a monofil measuring 0.1 mm in diameter, while a hand-made knit was prepared from a monofil measuring 0.2 mm in diameter. Nitinol fabrics were annealed at 500 °C to achieve an austenite transition temperature of 75 °C. A special constructed mould made of a steel frame and aluminium domes measuring 30 and 20 mm in height was used to give the nitinol fabrics a new temporary shape. A two-way, shape-memory effect of the nitinol fabrics was achieved using a 15-cycle training process. The achieved shape-memory effect was tested in a heated chamber at 100 °C, where bulges measuring 12–25 mm in height occurred. NiTi knits made from finer monofil were the most successful shape-memory knits. They were machine knitted and achieved sufficiently high bulges, measuring 18 or 12 mm, that facilitated large enough air gaps for effective thermal protection. A smart textile system was prepared by inserting the trained nitinol fabric into a pocket made from two textile fabric layers sewn together. When it was exposed to environmental temperatures of 75 °C and higher, it instantly changed its form from a two-dimensional shape to a three-dimensional shape, while increasing the air gap in the pocket. A quilted fabric made from such a smart textile system could be used in firefighting protective clothing to locally improve thermal insulation and protect the human skin from overheating or burns.

• Language: English
• Keywords: interlining, personal protective garment, smart textile, shape-memory alloys (SMAs)
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: NTF - Faculty of Natural Sciences and Engineering
• Publication status: Published
• Publication version: Version of Record
• Year: 2019
• Number of pages: 10 str.
• Numbering: Vol. 28, no. 6, art. 065014
• PID: 20.500.12556/RUL-128671
• UDC: 669
• ISSN on article: 0964-1726
• DOI: 10.1088/1361-665X/ab18b9
• COBISS.SI-ID: 1805151
• Publication date in RUL: 22.07.2021

Record is a part of a journal

• Title: Smart materials and structures
• Shortened title: Smart mater. struc.
• Publisher: IOP Publishing
• ISSN: 0964-1726
• COBISS.SI-ID: 13497861

Licences

• License: CC BY 3.0, Creative Commons Attribution 3.0 Unported
• Link: https://creativecommons.org/licenses/by/3.0/deed.en
• Description: You are free to reproduce and redistribute the material in any medium or format. You are free to remix, transform, and build upon the material for any purpose, even commercially. You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use. You may not apply legal terms or technological measures that legally restrict others from doing anything the license permits.
• Licensing start date: 01.06.2019

Projects

• Funder: ARRS - Slovenian Research Agency
• Funding programme: Grant for the doctoral student