PSI - Issue 72

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

373

and formed by injection molding. Then, in 2019, Zirnstein et al. (2019) studied the effect of adding phosphorus flame retardant to EPDM material. Piperazine-pyrophosphate (FP), Polyaniline (PANI), and Ammonium polyphosphate (APP) were mixed in an internal EPDM rubber mixer and then mixed on a two-roll mill machine. Specifically for material characterization, the composite rubber was cured in a compression mold. In addition, tools such as press molding are also used in forming specimens, for example, in a study conducted by Tang et al. (2023). In this study, Tang et al. (2023) added flame-retardant APP substances plus Nitrogen/silicon-based macromolecules (MNSi) with a ratio of 3:1 and APP with Melamine cyanurate (MCA) also with a ratio of 3:1 to the polypropylene base material. First, these raw materials are mixed in specific proportions and stirred evenly. Then, the mixture is plasticized using The following is documentation of the glow-wire testing process carried out by Acquasanta et al. (2011b) and Casetta et al. (2018) shown in Fig. 1. Fig. 1(a) is the result of GWIT testing by Acquasanta et al. (2011b) on PBT material mixed with 30% glass fiber and 14% flame-retardant substance Melamine polyphosphate (MPP). The flame retardant substance used as a flame-retardant did not help the PBT material in GWIT performance. It can be seen in Fig. 1(a) that the flame was powerful and difficult to extinguish. The MPP mixture hurt the GWIT performance of the PBT material, along with the decrease in the thickness of the specimen used. Fig. 1(b) is the result of glow-wire testing conducted by Casetta et al. (2018) on PA6 material mixed with glass fiber (PA6-GF) at a test temperature of 700 °C. Initially, glow-wire testing was performed at 550 °C to 650 °C and did not indicate any ignition of PA6-GF; the polymer only melted to form a hole but did not drip. However, at 700 °C, PA6-GF dripped, and a small amount of charred residue formed around the wire; after the wire was removed, PA6-GF burned for more than 30 seconds, as shown in Fig. 1(b). Thus, the test failed at this temperature, which led to the GWFI being set at 650 °C. To determine the GWIT, testing was performed at 675 °C where no ignition of the PA6-GF sample occurred, which led to the GWIT being set at 700 °C. a screw extruder and formed with a press molding machine. 4. Characteristic Polymer Material on Glow-Wire Test

Fig. 1. Documentation of glow-wire testing (a) during glowing wire penetration from Acquasanta et al. (2011b) and (b) after glowing wire penetration from Casetta et al. (2018).

Fig. 2 shows documentation of the outcomes of the glow-wire test on various polymer materials. Specifically, Fig. 2(a) shows a composite with a synergistic flame-retardant combination of PP/Ke/APP/Wool charred due to glow-wire penetration at 800 °C in a study by Subasinghe et al. (2016). Fig. 2(b) comes from the study of Riberio et al. (2017), who evaluated the effect of adding montmorillonite as a flame-retardant to the EBA-30 polymer material. It can be seen in Fig. 2(b) that the EBA-30 and Cloisite composite material only melts slightly and does not form droplets when the glowing wire penetrates at a temperature of 800 °C. Next, Fig. 2(c) presents the 960 °C glow-wire test resultsconducted on 3 mm thick PC specimens, as performed by Krämer and Blomqvist (2007). PC material can