PSI - Issue 72

Anandito Adam Pratama et al. / Procedia Structural Integrity 72 (2025) 370–376

371

1. Introduction Research and technology development regarding the engineering structure under thermal loading has been a focus for past decades until this day since the temperature is a part of the environmental effects on the designed structures (Prabowo et al., 2017;2018; Temesgen et al., 2020; Nguyen et al., 2020; Đorđević et al., 2020; Prasetyo et al., 2022; Yusvika et al., 2022; Lazuardy and Fakhruddin, 2024; Nurcholis et al., 2024; Satriatama et al., 2024; Suryanto et al., 2023). In terms of material development under thermal loading, the invention of Bakelite by Leo Baekeland marked the start of the widespread use of plastic, becoming a significant milestone in the history of polymers (Türkan and Çetin, 2023). Since then, plastic has evolved into a versatile material with numerous beneficial properties, making it essential in modern society. Polymer properties can be modified or improved for specific applications by combining them with other materials, such as composites. However, the natural flammability of polymers limits their use in many industrial sectors due to safety concerns (Yildiz et al., 2023), especially in critical areas like automotive and electronics. To address these risks, flame-retardant properties have been added to polymers. According to Levin ṭ a et al. (2019), thermoplastic polymers with fire-retardant features are widely used in automotive, electronics, defense, aviation, and railways to reduce possible fire hazards. One of the standard methods for evaluating a material’s fire resistance is the glow -wire test authorized by the International Electrotechnical Commission (IEC). The glow-wire test is a fundamental fire test widely used to evaluate how materials in electric appliances react to fire (Guillaume et al., 2011). The glow-wire technique is vital for evaluating polymers' flammability in electrical components (Bernardes et al., 2019). Thus, this paper will discuss the characteristics of polymer materials in glow-wire testing and the material-forming process used in mixing polymer materials with flame-retardant substances from pioneer research. 2. Glow-Wire Test The glow-wire test consists of two critical assessments: the Glow-Wire Flammability Index (GWFI) and the Glow Wire Ignition Temperature (GWIT). The GWFI, defined by IEC 60695-2-12 (2014), measures the highest temperature at which the material neither sustains a flame nor glows for more than 30 seconds after removing the glow-wire. It also ensures that material droplets do not ignite a tissue paper beneath the test specimen. The GWIT, according to IEC 60695-2-13 (2014), refers to a temperature of 25 °C above the highest tested temperature where the material does not ignite or burn for less than 5 seconds across three consecutive measurements. The glow-wire test setup and general procedures are outlined in IEC 60695-2-10 (2000). In this test, a 4 mm thick nickel/chromium (80/20) wire bent to a radius of 1 cm must be able to be heated to a temperature between 650 °C and 960 °C. The wire is applied to the specimen's front surface with a force of 1±0.2 N for 30 seconds. During this time, the wire's temperature is maintained without adjusting for fluctuations (increase or decrease). The wire tip is allowed to penetrate up to 7±0.5 mm into the sample. The time it takes for the material to ignite and extinguish is recorded. Additionally, tissue paper placed 200 mm below the sample is observed to see if any flaming material droplets cause ignition. 3. Additive/Blended Polymeric Material Different polymer materials have varying properties, which result in distinct flammability behaviors. Common polymers used in everyday applications include polypropylene/PP (Guillaume et al., 2011; Bernardes et al., 2019; Subasinghe et al., 2016; Kahraman et al., 2021; Tang et al., 2023), polybutylene terephthalate/PBT (Acquasanta et al., 2011a; Acquasanta et al., 2011b; Hamlaoui et al., 2021), poly(ethylene-butyl acrylate) copolymer/EBA30 (Ribeiro et al., 2017), polyethylene terephthalate/PET (Acquasanta et al., 2011a; Acquasanta et al., 2011b), polycarbonate/PC (Krämer and Blomqvist, 2007; Acquasanta et al., 2011a; Acquasanta et al., 2011b), polyamide (Krämer and Blomqvist, 2007; Acquasanta et al., 2011b; Naik et al., 2013; Jimenez et al., 2013; Casetta et al., 2018), high-density polyethylene/HDPE (Krämer and Blomqvist, 2007), low-density polyethylene/LDPE (Djakhdane et al., 2024), ethylene-propylene-diene monomer/EPDM (Zirnstein et al., 2020), nylon (Zhang et al., 2015), acrylonitrile-butadiene styrene/ABS (Krämer and Blomqvist, 2007; Ailinei et al., 2021; Petrov et al., 2023; Türkan and Çetin, 2023; Yildiz