Effects of Steaming and Steam Explosion on Mechanical Properties of Snake Fruit (Salacca) Fiber

Abstract

Abstract-Application of natural fiber needs treatments, such as chemical, physical and mechanical treatments. The aim of these treatments is for getting purer, cleaner and smaller size cellulose fiber. This paper describes the treatment of Snake Fruit frond fiber using alkali, steaming and steam explosion and investigates the effects on mechanical properties. The single fiber was firstly subjected to alkali treatments with 2%-8% NaOH for 2 -8 hours to room temperature and steaming in 1 -2 bar. The tensile test of single fiber was done according to standard ASTM D3379. The tensile tests show that the alkali and steaming treatment resulted in the different tensile strength of Snake Fruit frond fiber compared those without soaking. The highest tensile strength was found at Snake Fruit front fiber immersed in 2% NaOH for 6 hours and steaming 2 bars. The strength also increases with combination treatment both alkali-steaming and alkali-steam explosion with starting from 160 MPa before treated, increases as high as 275 MPa and 225 MPa with alkali-steaming and alkali-steam explosion, respectively. These results show that the combination of alkali treatment, steaming and steam explosion can significantly increase mechanical properties of Snake Fruit frond fiber.

The effect of alkali treatment on the surface and mechanical properties of fibrovascular bundles of Salacca sumatrana Becc. fronds

“…Hemicellulose is one of the easiest lignocellulose materials to degrade via alkali treatment, because the structure contains more amorphous regions compared to crystalline regions (Cai et al 2015). This study was comparable with the report by Darmanto et al (2017), where a 74.9% hemicellulose content was reported after a 3% alkali treatment. Other studies showed a 5% NaOH treatment on Borassus fiber yielded a 3.02% hemicellulose content (Boopathi et al 2012), while a 5% NaOH treatment on banyan roots led to a 10.7% reduction in the hemicellulose content (Ganapathy et al 2019).…”

“…In this study, the percentage increase in the αcellulose content after the NaOH + Na2SO3 treatment was higher compared to previous studies. Furthermore, the NaOH + Na2SO3 treatment was more effective in maintaining the α-cellulose, hemicellulose, and lignin contents, compared to previous studies using S. zalacca as a raw material with a higher concentration and high energy steam treatment (Darmanto et al 2017).…”

“…This decrease was due to the NaOH + Na2SO3 concentration, which has the ability to degrade amorphous cellulose at high concentrations (Wang et al 2003). According to previous studies, subjecting FVB from S. zalacca fronds to a 3% NaOH and steaming treatment, led to an increase in the αcellulose content of approximately 54.5% (Darmanto et al 2017), while a 5% NaOH treatment led to a 54.5% increase in oil palm empty fruit bunch (Medina et al 2015). In addition, a 15% NaOH treatment led to a 63.4% increase in the α-cellulose content of areca palm (Dypsis lutescens) (Shanmugasundaram et al 2018), while a 5% NaOH treatment led to a 45% increase in Tridax procumbens (Vijay et al 2019).…”

“…Meanwhile, Kurniawan et al (2017) successfully increased the tensile strength of FVB fronds (S. zalacca) to 554.8 MPa, using a 6 h immersion treatment, at a pressure of 2 bar and a varying degree of steaming. Darmanto et al (2017) also continued the experiment with the steaming and steam explosion treatments of FVB and obtained a 225.7 MPa increase in tensile strength. However, these studies utilized a lot of energy, i.e., pressure, steaming, explosion, and high concentration, and were therefore considered expensive and ineffective in increasing the strength of FVB fronds.…”

“…The fibrovascular bundles of salacca have been investigated by several researchers, including studies using alkaline chemical modification. Darmanto et al (2017) used alkaline modification and steaming to increase the tensile strength by 275 MPa in a single FVB frond of Salacca zalacca. Meanwhile, Kurniawan et al (2017) successfully increased the tensile strength of FVB fronds (S. zalacca) to 554.8 MPa, using a 6 h immersion treatment, at a pressure of 2 bar and a varying degree of steaming.…”