Utilization of Bamboo Roots as Reinforcing Composite Materials for Light Vehicle Dashboards

Bamboo roots are residual material from the utilization of bamboo trees’ waste. Bamboo roots utilize in engineering by making new materials in the form of composites. Bamboo roots are easy to get, and getting bamboo root fiber is relatively easy compared to getting bamboo stem fiber. Bamboo root fibers are used as reinforcement in composites with resin binders and catalysts as hardeners. The composite made by mixing the composition consists of 10% bamboo root fiber, 89% resin, and 1% catalyst from the weight of the specimen. This composition uses three variations of fiber direction; straight, random, and woven fiber—each variation tests tensile strength, impact, and bending strength. Those three test results show that the highest values come from the woven fiber, which are 21.04 MPa from the tensile strength, 0.0693 J/mm2 from the impact value, and 34.789 MPa from the bending strength value. The test result found that applying bamboo roots composite material suits dashboard material for light vehicles (cars and motorcycles). This test result meets the standard material for dashboard vehicles based on plastic material data ABS (Acrylonitrile butadiene styrene). This research on natural fiber composite material is novel and valuable as a waste utilization solution for engineering materials.


Introduction
Bamboo is a versatile plant and is found easily in tropical countries.Almost all parts of this plant are useful to human life.Ecologically, bamboo is a barrier to erosion, filters waste, and provides water through its roots.Bamboo is a clumped living plant belonging to the grass family (Gramineae), also called giant grass.It consists of several stems that grow gradually, starting from bamboo shoots and young stems and becoming adults at 4-5 years old.Bamboo stems are cylindrical, ribbed, segmented, hollow, also hard-skinned.In each segment, there is a bud or branch.Bamboo plants grip the ground to support the growing tree trunks.It has a fibrous root system with a very strong rhizome root, also ribbed and segmented in its segment overgrown with fibers and buds that can grow into stems [1,2].
After using the bamboo stems, the bamboo roots will become waste.It is usually only used as planting media, works of art, or crafts without improvement.The utilization of bamboo root's characteristic properties in art or crafts is minimal.The specific properties of bamboo roots include being very strong, lightweight, and resistant to acids and alkalis.Table 1 shows some of the characteristics of bamboo roots.Composite is a new type of engineered material.Composite consist of two or more materials.The properties of each material are different, both chemical and physical, and remain separate in the final composite material [3].Composites have different properties and characteristics from the materials that made they formed.Composites have higher mechanical properties and specific strength (young modulus/density) than metals.Several composite laminates can be stacked with different fiber orientations, and the combination of the laminates is called a laminate.The purpose of making composites is to improve mechanical properties or certain specific properties, simplify complicated designs in manufacturing, have flexibility in shape and design that can save production costs, and make materials lighter [4].
Today, composites with synthetic fiber reinforcement are used commonly in various aspects of life, such as household needs, land, sea, and air vehicle industries, sports equipment, health and military industries such as bullet-proof vests.Using natural fibers as composite reinforcement is a wise step, considering their natural decomposed properties, and many kinds of natural fibers are available.Natural fibers have many advantages over artificial fibers.The benefits of natural fibers include easy availability of materials, lighter weights, relatively low prices, and, most importantly, being environmentally friendly since Indonesia has abundant natural resources.Natural fibers can also use as a modification of artificial fibers.
Using natural fibers in addition to functioning as a reinforcement and improving the mechanical properties of polymers can also reduce production costs [5].The advantages of using this composite are that it has good mechanical properties, is not easily corrosive, has a lower price of raw materials, has a lower density than mineral fiber, and functions as a good sound absorber [6][7][8].
The utilization of bamboo roots that are not optimal, and the volume or amount of availability in nature is extensive.Using bamboo roots as reinforcing materials in composites will increase their economic value.The benefits of using this bamboo are that bamboo roots are easy to obtain, are natural and renewable, do not endanger health, can be naturally degraded (biodegradability), and have good strength.In addition, getting bamboo root fibers is relatively easy compared to getting bamboo stem fibers.
The strength of natural fiber composite materials is influenced by the natural fibers' characteristics, the matrix characteristics, the variables of the fiber direction, and the bond between the natural fibers and the matrix.Fibers usually have greater strength and stiffness than the matrix.The research on fiber variations conducts a good strength value of the material to improve the new engineering material.
In this decade, composite materials with natural fiber reinforcement have been applied by car manufacturers [9].This study discusses composite materials with reinforcement from natural bamboo root fibers as an alternative to light vehicle dashboard materials (cars and motorcycles) made of plastic.
In this study, the bamboo root fiber composite's strength is analyzed with variations in the fiber direction.
The tests carried out were tensile, impact, and bending (flexure) to be compared with the mechanical properties of the dashboard material type ABS (Acrylonitrile butadiene styrene).

Methodology
This research is new material research by utilizing natural fibers, namely bamboo root fibers as reinforcing materials and resins as binders, and catalysts as hardeners with the following composition ratios: 10% bamboo root fibers, 89% resin, and 1% catalysts from the entire weight of the specimen.A testing process is carried out on the composite material made to find out the mechanical characteristics.
The tests performed are tensile testing, impact testing, and bending testing.The research process is carried out by first making composite materials.The treatment process on bamboo roots is intended to produce good quality bamboo roots considering that they grow in the ground.This process is designed to obtain pure bamboo roots without other materials.The following treatment process is to soak in NaOH solution to maximize bamboo roots.It is intended to be able to increase the tensile and bending strength of bamboo roots as a composite reinforcement [10].

Figure 2. Bamboo Roots that have been treated
The bamboo root soaking process is carried out with a solution of water and NaOH with a NaOH content of 5%, which is carried out for 1 hour to obtain good bending and tensile grace properties 10.After the soaking process of bamboo roots, washing thoroughly with running water is carried out, then the drying process is carried out in the sun.The specimen molding process is carried out by mixing 89% of the resin with 1% catalyst on the container, then pouring half the total resin mixture half, then laying the bamboo root fibers evenly on top of it and pressing.This method placed the fibers partially submerged, pouring back the remaining half of the volume of the mixture into the mold.
The composite manufacturing process uses molds from plywood with length x width x height for tensile test specimens 250 mm x 30 mm x 5 mm, for impact test specimens 65 mm x 10 mm x 10 mm, and for bending test specimens 120 mm x 20 mm x 5 mm.The test object is made with 3 test objects from each fiber direction variation, namely a composite of parallel, woven, and random fibers.The total number of test objects is nine specimens.The specimen manufacturing process refers to each test's standard size, i.e., ASTM D3039 for the standard size of the tensile test, ASTM D256-4 for the standard size of the impact test, and ASTM D790-02 for the standard size of the bending test.Specimen testing was carried out on three different types of tests.First is tensile testing using the Universal Testing Machine (UTM) HUNG TA HT -9501 machines with a capacity of 30,000 kgf.The second is impact testing with an impact tester machine using the Charpy impact machine with a specification of 75 cm pendulum arm length and 23 Kg pendulum weight.The last is bending testing using the AND TENSILON RTF -2350 machine.The bamboo root fiber composite specimen test results are compared with the abs-based light vehicle dashboard material data to determine the potential application of the bamboo root fiber composite.

Tensile Test
The test specimens were shown by providing different codes (A1-A3) for straight fiber direction composite specimens, (B1-B3) for random fiber direction composite specimens, and (C1-C3) for woven fiber direction composite specimens.From the tensile test using the ASTM D3039 standard with different fiber direction variations, the average values of tensile (σ) were obtained.Figure 7 shows a graph of the average tensile strength of bamboo root fiber composites with variations in the fiber direction.

Figure 7. Bamboo Root Fiber Composite Tensile Strength Value Graph
The results of the tensile test of the highest average tensile and strain strength values of bamboo root fiber composites are found in variations in the direction of woven fibers with a fiber volume fraction of 10% and fiber lengths of 250 mm.The average value of tensile strength possessed was 21.04 MPa.The directional orientation of the fibers can affect the value of mechanical properties in composite materials.The directional orientation of the woven fiber can receive the tensile discount more evenly, and the level of fiber arrangement is tighter so that the tensile that occurs in the matrix will be passed on to the fiber and cause high strength.

Impact Test
Impact test using shock loads on the specimen.The rapid provision of a load absorbs large energy absorption from the kinetic energy of a load that mashes onto the specimen.The highest average value of impact strength and absorbed energy is found in the variation in the direction of the woven fiber with a fiber volume fraction of 10% and a fiber length of 55 mm.The average impact strength value is 0.0693 J/mm2, and the absorbed energy is 5.532 Joules.This is because the directional orientation of the fibers can affect the value of mechanical properties in composite materials.The directional orientation of the woven fiber can receive the absorption energy value of the shock load higher, and the level of arrangement on the fiber is tighter so that the energy from the shock load that occurs on the matrix will be passed on to the fiber and cause high strength.

Bending Test
A bending test is carried out by applying a specific load at a point in the middle of the specimen to determine the magnitude of the bending strength value of bamboo root fiber composites with different fiber direction variations.Figure 9 shows the average value of the bending strength of the bamboo root fiber composite with variations in the fiber direction.

The Potential of Composite Materials
The manufacture of composite materials aims to determine the value of mechanical properties and to see the potential of the composite material of bamboo root fiber that is applied as a substitute for basic materials on car and motorcycle dashboards.The following is the dashboard data of cars and motorcycles with the type of ABS (Acrylonitrile butadiene styrene) material which is a comparison.From the results of tensile testing data, impact testing, and curve testing after being compared with the dashboard data in the table above, the research results of the bamboo root fiber composite have met the traditional values of the car dashboard and motor type abs plastic material (Acrylonitrile butadiene styrene) and from the test results carried out, the bamboo root fiber composite material has the potential as a primary material to replace the car and motor dashboard.

Conclusion
The highest mechanical properties of bamboo root fiber composites were obtained from variations of the woven fibers direction that comes from the value of the tensile test, impact test, and bending tests.
The comparison using the standard data for the type of ABS plastic material (Acrylonitrile butadiene styrene) shows that the bamboo root fiber composite has met the standard value, which can be used as a light vehicle dashboard.This result means that the composite material of bamboo root fiber has the potential as a primary material for light vehicle dashboards.

Figure
Figure 3. Molds for Bending Test

Figure 6 .
Figure 6.Specimen Results with Fiber Direction Variations

Figure 9 .
Figure 9. Average Value of Bending Strength

Figure 10 .Figure 11 .Figure 12 .
Figure 10.Comparison of the Tensile Strength of ABS and bamboo root fiber composites [1] Lewis D, Miles CA 2007 Farming bamboo Lulu.com.[2] Reed M R, Sari D 2020 Indonesia's Contribution to Macro Sustainability Available at SSRN 3526758 [3] Yang Y, Boom R, Irion B, Van Heerden D J, Kuiper P, De Wit H 2012 Recycling of composite materials Chemical Engineering and Processing: Process Intensification 51 53-68 [4] Harris B 1999 Engineering composite materials [5] Faruk O, Bledzki A K, Fink H P, Sain M 2014 Progress report on natural fiber reinforced composites Macromolecular Materials and Engineering 299 9-26 [6] Kamarudin S H, Mohd Basri M S, Rayung M, Abu F, Ahmad S, Norizan M N, Osman S, Sarifuddin N, Desa M S Z M, Abdullah U H 2022 A Review on Natural Fiber Reinforced Polymer Composites (NFRPC) for Sustainable Industrial Applications Polymers 14 [7] Ngo T D 2020 Introduction to composite materials.Composite and Nanocomposite Materials-From Knowledge to Industrial Applications [8] Drzal LT 2007 Sustainable Bio-Based Structural Material: opportunities and challenges Michigan State University [9] Holbery J, Houston D 2006 Natural-fiber-reinforced polymer composites in automotive applications.Jom 58 80-6 [10] Ramesh M, RajeshKumar L, Bhuvaneshwari V 2021 Bamboo fiber reinforced composites.Bamboo Fiber Composites: Processing, Properties and Applications 1

Table 2 .
Data on the Calculation of Tensile Strength and Strain Values

Table 3 .
Average Value Of Absorbed Energy And Impact Value

Table 4 .
Bending Strength Average Value Data

Table 6 .
Comparison data on the mechanical properties of ABS material dashboard with Bamboo Root Fiber Composite