The environmental impact of natural fiber composites through life cycle assessment analysis

The environmental impact of natural fiber composites through life cycle assessment analysis

11

M.R. Mansor 1 , M.T. Mastura 2 , S.M. Sapuan 3 , A.Z. Zainudin 4 1 Faculty of Mechanical Engineering, Universiti Teknikal Malaysia Melaka, Durian Tunggal, Malaysia; 2Faculty of Engineering Technology, Universiti Teknikal Malaysia Melaka, Durian Tunggal, Malaysia; 3Faculty of Engineering, Universiti Putra Malaysia, UPM Serdang, Selangor, Malaysia; 4Department of Real Estate, Faculty of Built Environment and Surveying, Universiti Teknologi Malaysia, Johor Bahru, Malaysia

11.1

Introduction

Growing awareness worldwide toward sustainability has spurred many initiatives to search and apply more environmentally friendly solutions in daily activities. One of the solutions highly investigated currently is for the application of natural fiber composites as substitution material especially to synthetic composites and other traditional engineering materials. Natural fiber composites offer many advantages in terms of environmental performance such as renewability, recyclability, and biodegradability, in addition to lower raw material costs and lightweight property. Due to the above reasons, the current world market on the utilization of natural fiber composites has seen remarkable growth and acceptance. A report by Marketsandmarkets.com revealed that the world natural fiber composite usage was valued at USD 3.36 billion in 2015, and was projected to be USD 6.50 billion by 2021. The global market evaluation company also projected positive natural fiber composites’ compound annual growth rate of nearly 11.68% from year 2016 until year 2021, with major demands comes from building and construction, transportation, and consumer goods industries [1]. In another report by BusinessWire.com, the automotive industry was highlighted as one of the most active players in utilizing natural fiber composites to produce vehicle components. The company’s report stated that among the reasons for the high acceptability of natural fiber composites especially for producing vehicle interior components as compared to synthetic composites are good dimensional stability, easy to be molded, and high impact resistance, as well as higher crash safety performance for passengers (eliminating the presence of sharp fractured edges during crash situation) [2]. To support higher natural fiber composite acceptance and wider application, the material’s performance is also actively investigated in term of its environmental impact especially when used in products. The sustainability performance of natural fiber composites can be assessed using life cycle assessment (LCA) analysis, a methodology

Durability and Life Prediction in Biocomposites, Fibre-Reinforced Composites and Hybrid Composites https://doi.org/10.1016/B978-0-08-102290-0.00011-8 Copyright © 2019 Elsevier Ltd. All rights reserved.

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formulated to assess the potential environmental impact of products throughout all of their life cycle stages. Governed by ISO 14040 and ISO 14044 standards, the LCA analysis quantifies the potential environmental impact of products from raw materials extraction phase, through materials processing, product manufacturing, and product use until its end-of-life phase. The cradle-to-grave analysis also provided more holistic examination on the sustainability performance for products [3]. Apart from the aforementioned meaning of LCA analysis, there are also other definitions of similar methodology in other reports. LCA analysis is also regarded as a method used to understand and evaluate the magnitude and significance of the potential environmental impacts for a product system throughout the life cycle of the product. LCA involves compiling an inventory of the environmentally relevant flows associated with all processes involved in the production, use, and end of life of a product and translating this inventory into impacts of interest [4]. LCA analysis on the other hand is also defined as an analytical method used to quantify and interpret the energy and material flows to and from the environment over the entire life cycle of a product, process, or service [5]. The LCA analysis includes the entire life cycle of the product, process or manufacturing, containing the extraction and processing of raw materials, preparation, transport and distribution, the use, reuse, maintenance, recycling, and storage on the ground (burial) or incineration of residues and waste. The principle of LCA analysis is relatively simple because for each stage of the life cycle, the quantities of materials and energy used and emissions associated with these processes are investigated [6]. LCA analysis is also defined as compilation and evaluation of the inputs, outputs and the potential environmental impacts of a product system throughout its life cycle using the cradle-to-grave concept. Cradle-to-grave concept can be addressed as the environmental aspects and potential environmental impacts throughout a product’s life cycle from raw material acquisition until the end of life. In this chapter, the implementation of LCA analysis for environmental impact assessment of natural fiber composites is discussed. Among the topics of discussion included are the LCA analysis methodology and collection of research on LCA analysis conducted for natural fiber composites. In addition, a case study on the application of LCA analysis to evaluate the potential environmental impact of automotive products made from natural fiber composites is also included. This is to showcase how the LCA methodology is able to help product designers in performing simplified LCA analysis to assess the product environmental impact holistically throughout its life cycle stages.

11.2

Review of life cycle assessment analysis for natural fiber composites

Growing concern about product impact toward the environment has resulted in various applications of sustainability studies. Sustainability analysis in product design includes development of products that can perform the desired functions successfully and gain profits for the company. Besides that, the product should be acceptable by satisfying all the customer requirements. All these elements should be performed under minimum energy and material use without producing any damage waste in order to achieve

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the sustainable target [7]. Consequently, several methods have been applied by different companies, and LCA analysis is one of the common methods that are applied to analyze the sustainability of products. Many scholars use LCA analysis to evaluate product design regarding environmental impact, including material extraction, production, operation, and retirement of the product [8]. Sustainability of products is related to application of biomaterials such as natural fiber composites. Natural fiber composites can be found in any type of product due to its environmentally friendly properties that contain less hazardous materials. Moreover, natural fiber composites known as biodegradable materials are more environmentally friendly compared to carbon and glass fiber composites [9]. Preprocessing of some natural fibers is effortless and requires minimum treatment to prepare the fibers for the composites [10]. Sugar palm fibers are one of the types of natural fibers that do not require any secondary processing such as water retting or mechanical decorticating process to extract the fiber. This type of fiber could be found originally wrapped around the plant’s trunk in woven form [11]. Natural fiber composites also have been chosen as the most suitable materials between steel and carbon fiber for automotive anti-roll bar with regard to Voice of Environment (environmental criteria such as recyclability, biodegrability, free from hazardous substances and used less material) as shown in Mastura et al. [12] study. Moreover, natural fiber is proven more advantageous in terms of ecological points compared to synthetic fibers as reinforcement in composites. As reported by a Mansor, Salit and Zainudin [13] study, proper approach of life cycle analysis of natural fiber composites would obtain higher confidence and credibility of application of natural fiber for green technology and provide positive impact to the environment. In addition, many studies had shown the positive environmental impact of natural fiber compositeebased products in material substitutions. Corbi
ere-Nicollier et al. [14] studied the substitution impact of glass fiber as reinforcement in polypropylene to China reed fiber with regard to environmental concern. Based on recycling level of glass fiber, it does not sufficiently match the lower environmental impact of China reed fiber. Regarding the positive environmental impacts of natural fiber composites, most automotive manufacturers had more interest in application of natural fiber composites. As well, other advantages of natural fiber composites, such as light weight and low cost, have attracted manufacturers to widen the application of natural fiber composites. However, the question on how “green” the natural fiber composite products are should be evaluated in terms of the products’ sustainability and life cycle assessment.

11.2.1 Framework of life cycle assessment analysis According to the International Organization of Standardization (ISO) [15], the life cycle analysis framework includes goal and scope definition, inventory analysis, impact assessment, and interpretation as shown in Fig. 11.1.

11.2.1.1 Goal and scope definition Initially, the goal of the life cycle analysis is defined by the intention and purpose of the application within the targeted audience. The intention to perform the life cycle

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Goal and scope definition

Interpretation Inventory analysis

Impact assessment

Figure 11.1 Framework of life cycle analysis based on ISO 14040 [15].

analysis should not be a general or vague statement. Preferably, the goal statement contains useful information of the specific purpose of life cycle analysis so that adequate methodology can be proposed. Consequently, useful results from the analysis can be obtained. Moreover, the scope of the analysis also should include: (1) product system to be analyzed, (2) functions of product/system, (3) functional unit, (4) system boundary, (5) methodology, (6) data requirements, (7) assumptions, (8) limitations, (9) quality criteria, and (10) report and information that are required to be analyzed [16]. Each of the elements is determined simultaneously with the intended goal of life cycle analysis. Goal and scope that are defined adequately in the early stage of the analysis will reduce the time needed for the LCA practitioner to obtain the informative result that should be documented.

11.2.1.2 Inventory analysis Inventory analysis is required to collect all useful data for each single phase of the product life. The data includes input and output elements that may cause an impact during life cycle of a product. It includes preprocessing, where the extraction of the materials is conducted, and postprocessing of the product during the use phase until end of life. At this stage, all the data are critically viewed as they will affect accuracy of the final results [17]. The availability of data is very crucial especially for the natural fiber composite materials for which not all the desired information is available. In contrast, material like steel has the available data that can be obtained through authorized organizations such as the World Steel Association, which can provide consistent and reliable information for the steel industry [18]. In addition, the data can be obtained from literature, a company, or through experiments that are run by the researchers. However, there would be a conflict if the data that is obtained is not suitable for the particular environment. Data that is taken for a particular country may be different from another country because of the influence of environment and facility. Therefore, the database of different products that are provided by SimaPro, GABI, and Ecoinvent would assist the life cycle analysis practitioner to obtain the most useful information for the inventory analysis [19]. When all the data are gathered, the environmental impacts are identified and potential impact improvements can be constructed [20].

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11.2.1.3 Impact assessment Impact assessment is performed to evaluate impact of the physical flow of the product’s life cycle on environment. During inventory analysis, input and output data were collected and evaluated in impact assessment analysis to obtain better understanding of the impact in terms of environmental perspective. General elements that are mandatory in the impact assessment are selection of impact categories, category indicators, and characterization models [21]. Each of these elements converts the inventory analysis results to indicator results. The mandatory elements of impact assessment should be consistent with goals and scope of life cycle analysis. The referred source of impact category, category indicators, and characterization models should be justified. Detailed description of the impact categories and category indicators should be provided. In a study performed by Luz, Caldeira-Pires, and Ferr~ao [22], they considered abiotic depletion, acidification potential, eutrophication potential, global warming potential, ozone layer depletion potential, and photochemical ozone creation potential as impact categories for sugarcane bagasse fiber polypropylene composites. Similarly, Pegoretti et al. [23] performed a study on life cycle analysis of natural fiber in applications in the automotive industry. The impact categories that were included in the impact assessment are almost similar with Luz, Caldeira-Pires, and Ferr~ao [22] with the addition of freshwater aquatic eco-toxicity and terrestrial ecotoxicity. The selection of impact categories would reflect the environmental issues of the studied product system with regard to the goal and scope. Other impact categories that are used to analyze the environmental impact of natural fiber composites are summarized in Table 11.1.

11.2.1.4 Interpretation In this phase, the goal of analysis should be answered by interpretation of results in inventory analysis and impact assessment. The interpretation must completely achieve the target within the defined scope. Conclusions, recommendations, and limitations should be mentioned in the interpretation [39]. Based on this, any significant issues could be identified and consistency and sensitivity analysis could be performed. Therefore, the practitioner would be able to convey the final results completely and communicate accurately. The relevant information should be well prepared to reduce time consumption. If there is missing or incomplete information during this phase, the goal and scope should be revised and preceding phase should be revisited. Moreover, final results from the inventory analysis and impact assessment should be reliable by checking its sensitivity analysis and uncertainty analysis. Consistency check also should be performed to determine the life cycle analysis is performed within the goal and scope [40]. Finally, the report and any documentation should be prepared as a precise and unbiased decision.

11.2.2 Life cycle assessment analysis of natural fiber composites Natural fiber composites are known as environmentally friendly materials that have low impact to the environment due to the process of raw materials extraction that

Natural fiber composites

Impact categories

Bernstad Saraiva et al. [24]

High-density polyethylene reinforced with natural sponge fiber

Climate change, ozone depletion, human toxicity, cancer effects, noncancer effects, particulate matter, photochemical ozone, formation, acidification, terrestrial eutrophication, freshwater eutrophication, marine eutrophication, freshwater ecotoxicity.

Corbiere-Nicollier et al. [14]

China reed fiber

Human toxicity, terrestrial ecotoxicity, aquatic ecotoxicity, global warming, ozone depletion, acidification, eutrophication, energy consumption

Dissanayake et al. [25]

Flax fiber-reinforced polymer matrix composites

Acidification potential, aquatic toxicity potential, eutrophication potential, global warming potential, human toxicity potential, nonrenewable/abiotic resource depletion, ozone depletion potential, photochemical oxidants creation potential, noise and vibration odor, loss of biodiversity

Zah, Hischier, Le, & Braun [26]

Curaua fiber

Depletion of abiotic resources, climate change, stratospheric ozone depletion, human toxicity, freshwater aquatic ecotoxicity, marine aquatic ecotoxicity, terrestrial ecotoxicity, acidification, eutrophication, freshwater sediment ecotoxicity, marine sediment ecotoxicity

N. P. J. Dissanayake & Summerscales [27]

Flax fiber

Abiotic depletion, acidification, eutrophication, global warming (gwp100), ozone layer depletion, human toxicity, freshwater aquatic ecotoxicity, photochemical oxidation, terrestrial ecotoxicity, nonrenewable energy consumption, land use

Alves et al. [28]

Haylock & Rosentrater [29]

Carcinogens, respiratory organics, respiratory inorganics, climate change, radiation, ozone layer, ecotoxicity, acidification/eutrophication, land use, minerals, fossil fuels Organic filler composites

Energy, global warming potential, air acidification, air eutrophication, water eutrophication, ozone layer depletion, air smog, high carcinogens, high noncarcinogens

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Author

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Table 11.1 Summary of environmental impact categories in LCA analysis for various natural fiber composites

Hybrid glass-hemp/thermoset composite

Human health, ecosystem quality, resources, global energy requirement, global warming potential, agricultural land occupation

Deng et al. [31]

Flax fiber

Climate change, ozone depletion, human toxicity, photochemical oxidant, particulate matter, ionizing radiation, terrestrial acidification, freshwater eutrophication, marine eutrophication, terrestrial ecotoxicity, freshwater ecotoxicity, marine ecotoxicity, agricultural land use, urban land use, natural land use, water depletion, metal depletion, fossil depletion

George & Bressler [32]

Hemp fibers

Climate change, ozone depletion, human toxicity, terrestrial acidification, freshwater eutrophication, marine ecotoxicity, fossil depletion

Xu, Jayaraman, Morin, & Pecqueux [33]

Natural fiber composites

Carcinogens, respiratory organics, respiratory inorganic, climate change, ecotoxicity, acidification/eutrophication, land use, minerals, fossil fuels

Bachmann, Hidalgo, & Bricout [34]

Natural fiber composites

Abiotic depletion, global warming, ozone layer depletion, cumulative energy demand

Ardente, Beccali, Cellura, & Mistretta [35]

Kenaf fiber

Global energy requirement, global warming potential, acidification, nitrification, photochemical ozone creation potential, ozone depletion potential, water consumption

Pegoretti, Mathieux, Evrard, Brissaud, & Arruda [23]

Cotton fiber

Abiotic depletion, acidification, eutrophication, global warming, ozone layer depletion, fresh water aquatic ecotoxicity, terrestrial ecotoxicity

Yuan & Guo [36]

Wooden composites

Damage to human health, damage to ecosystem quality, damage to resources

Ogawa, Ogawa, Hirogaki, & Aoyama [37]

Bamboo fibers

Global warming, ozone depletion, human toxicity (carcinogenicity), human toxicity (chronic disease), aquatic ecotoxicity, terrestrial ecotoxicity, acidification, Eutrophication, photochemical oxidant, solid waste, land use (occupation), land use (transformation), resource consumption, fossil energy

Arrigoni et al. [38]

Hemp fibers

Fossil, biogenic, land use, uptake

The environmental impact of natural fiber composites through life cycle assessment analysis

La Rosa et al. [30]

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produces low environment negative effect (such as low CO2 release, low energy usage and no soil contamination). Moreover, in automotive industry, components that are made from natural fiber composites are generally lower in weight. Consequently, the vehicle that is equipped with natural fiber composite components has less weight and therefore less fuel consumption. In this case, less carbon dioxide will be emitted and this vehicle will have less negative impact on the environment. Hence, the application of natural fiber composite would be more favorable in terms of environmental concerns. A study that was performed by Joshi et al. [41] has shown a significant environmental impact of natural fiber composites in comparison with glass fiberereinforced composites. In their study, it was found that pollutant emissions from glass fiber production are significantly higher than from natural fiber production. Moreover, application of natural fiber as reinforced material in polymer composites has reduced the volume percentage of polymer because higher volume fraction of natural fibers than glass fiber is required to achieve equivalent strength and stiffness performance of glass fiberereinforced composites. Consequently, the incineration process of natural fiber composites would produce less air emissions due to low volume of polymer materials. Xu, Jayaraman, Morin, and Pecqueux [33] also agreed that the environmental impact of natural fiber composites could lead to direct reduction due to the amount of fiber used proportionately. Luz et al. [22] also performed life cycle analysis of two different materials, in which one of them used sugarcane bagasse fibers as reinforcement material in polypropylene composites. From the cultivation process until end of life of the sugarcane bagasse fibers, superior positive impact to environment is shown in comparison with talc-filled polypropylene composites. They concluded that the sugarcane bagasse fibers have great potential in substituting talc in polypropylene composites. In another study by Akhshik, Panthapulakkal, Tjong, and Sain [42], they compared the environmental impact of glass fiberereinforced polyamide with natural fiber/carbon fiber hybridereinforced polypropylene. The natural fiber/carbon fiber hybride reinforced polypropylene demonstrated a reduction in energy demand and waste disposal cost. This would make the hybrid biocomposite more preferable compared with synthetic composite due to positive impact on environment. In addition, cost of the production of hybrid biocomposite in terms of manufacturing and transportation energy demand is less expensive even though it contains virgin synthetic fibers such as carbon fibers.

11.2.2.1 Production phase Environmental impact of processing of natural fibers has been analyzed by few researchers. Effects of the use of pesticides and other types of chemical products show negative impact on the environment during the plant fibers’ cultivation process. Due to this, typical environmental impact of natural fibers composite, that is, eutrophication, mainly occurred during cultivation stage [43]. Utilization of fertilizer during cultivation of natural fiber plants results in higher nitrate and phosphate emissions, which can lead to increased eutrophication in local water bodies [44]. In substitution of ABS to hemp fiber composites, cultivation process of hemp led to double effect of

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eutrophication compared to ABS production process, and it can be higher if pesticides are employed during the plant cultivation process [13]. Moreover, cultivation process of virgin cotton that needs fertilizers also has negative impact on environment through eutrophication [23]. Cotton plants require utilization of fertilizer and pesticides during the cultivation process [45]. Similarly, cultivation of the curaua plant that utilized fertilizer has impact on eutrophication about 40% greater than other environmental impacts such as acidification, climate change, and photochemical oxidation [26]. In a study conducted by Dissanayake et al. [25], during flax cultivation process, the utilization of pesticides results in contamination of water, impacts on biodiversity and humans. Bromoxynil and Trifluralin are other common herbicides used to control weeds in flax cultivation [46]. Therefore, utilization of inorganic fertilizers may result in nitrogen runoff causing environmental impacts such as acidification, aquatic toxicity, human toxicity, and eutrophication. On the other hand, kenaf has gained increased interest in recent years due to its ability to absorb nitrogen and phosphorus that are included in the soil. This would reduce the impact on the eutrophication [47,48]. This is supported by Kumar and Sekaran [49] in their study where cultivation process of kenaf plant requires almost no fertilizer or pesticides, and the plant grows to its full length in approximately 150 days. Hence, kenaf is completely biodegradable, as it does not require many chemicals for its degradation. In addition, hemp also requires almost no fertilizer or pesticides during the cultivation process [30]. Broeren et al. [50] mentioned in their study that sisal cultivation also requires no fertilizer and herbicide [51], however, some high-yield estates in Tanzania apply synthetic fertilizers such as trisodium phosphate and muriate of potash. However, some researchers have proven that the negative impact from pesticides and chemical products during cultivation process is lower than negative impact of synthetic fibers during the production process on environment. Joshi et al. [41] concluded that impact on eutrophication of natural fiber composites is lower than eutrophication effects of glass fiber composites [14]. These observations are likely to be valid across different natural fibers, since their production processes are very similar. As well, Zah et al. [26] concluded that generally, the environmental impacts of the curaua fibers are not significantly different from that of a glass fiber composite with similar stability.

11.2.2.2 Use phase Energy consumption during use phase comes from mechanical, thermomechanical, or electromechanical systems. According to Ardente et al. [35], the primary energy savings and the avoided CO2eq emissions have been estimated during the operation time in use phase. Hansen et al. [52] compared life cycle analysis for two interior side panels of an Audi A3 (flax-jute-reinforced epoxy and acryl-nitrile butadiene styrene copolymer, also known as ABS) in terms of the energy consumption during the use phase. They found that fuel consumption contributes 80% of the total energy during production phase, use, and disposal of a car. Impact on the environment is evaluated and natural fiber composite side panel is more preferable as compared to the polymer panel. The impact on the environment is studied with regard to the selected materials, energy flow, and emissions [14,33]. In order to achieve the low environmental impact in the

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life cycle analysis, it is suggested to have a low weight of the product, low percentage of thermal loss and electrical loss during the use phase [53]. By reducing the weight of the products, application of lightweight natural fiber composites seems preferable. Le Duigou and Baley [54] in their study applied light flax/polypropylene composite parts that would consume less vehicle fuel and produce less emissions during the use phase. Deng et al. [31] also studied the impact on volumetric reduction in automotive applications where the substitution of glass fiber and natural fiber takes place. During the use phase, this substitution would lead to 10%e20% impact reduction. Besides that, greenhouse gas emissions also should be evaluated as they are commonly found during the use phase. In a comparative study by Boland et al. [55], greenhouse gas emissions impact of kenaf fiberereinforced composite component is lower than glass fibere reinforced composite, which is about a 9.2% difference.

11.2.2.3 End of life Generally, polymers and composite-based products are either incinerated or landfilled. In a study performed by Duflou, Moor, Verpoest, and Dewulf [56], incineration with energy recycling was selected as the most feasible end of life (EOL) for composite cars in manufacturing industry. This is expected to exhibit less impact on environment due to no hazardous elements such as sulfur, phosphorous, halogens, or heavy metal toxic emissions during the incineration process. Poulikidou et al. [57] found that less weight of the vehicle would have less environmental impact in EOL. A steel truck roof exhibits higher environmental impact in terms of cumulative energy demand and global warming potential. The impact decreases when the lighter material is applied for the truck roof. Moreover, incineration of natural fibers would exhibit better energy recovery compared with incineration of glass fibers [26]. Glass fiber composite consists of inert materials that could hinder the incineration process. This would result in slag production, which is a residue of glass containing ashes that would be disposed through landfill. In contrast with incineration of flax fiber composite, the production could be used as an energy source without any residue and further reduce the use of conventional energy [31]. A study performed by Bensadoun, Vanderfeesten, Verpoest, Van Vuure, and Van Acker [58] has shown that the advantage of incineration process of flax fiber composite is the positive impact on environment through energy recovery. Flax fiber composites could be fully combusted and give a relatively high calorific value. Other than incineration, landfill EOL scenario also contributes an impact on environment. Cotton fibers disposal exhibits impact on eutrophication due to the significant quantity of pesticides during cultivation [23]. In comparison between incineration and landfill, landfill exhibits lower impact on respiratory inorganics, eutrophication, and fossil fuels according to a study by Alves et al. [28]. In a study by Bernstad Saraiva et al. [24], Mangobox that is made by high-density polyethylene reinforced with natural sponge fiber residue is preferable in relation to ozone depletion, mainly due to the methane emissions from landfilling the cardboard box. Moreover, the landfilling of cardboard boxes would result in net emissions of greenhouse gas emissions due their anaerobic degradation. Concerning the environmental impact of natural fiber

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composites, selection of disposal phase should be performed. Consequently, life cycle analysis should be performed in order to measure the “green” level of natural fiber composites in application of product development.

11.2.3 Summary In conclusion, LCA analysis is performed to measure the level of sustainability and “greeness” of a product. The ISO has set guidelines for life cycle analysis practitioners to evaluate the environmental impact of products during their lifetime using the given framework. Goal and scope of the analysis are set by the practitioner to ensure the required information could be obtained and available in inventory analysis. During the impact assessment, all the information with regard to the impact category is obtained to achieve the targeted goal and scope. Interpretation is performed by preparing the related documents based on the information that is obtained from inventory and impact analysis. This framework could also apply in life cycle analysis for natural fiber composites. Life cycle analysis of the natural fiber composites is performed starting from their production where the cultivation process is first considered. Generally, fertilizers and pesticides are the cause of eutrophication that is exhibited during plants’ cultivation process. However, this impact could be reduced by using some organic fertilizers. Alternatively, natural fibers that do not require any chemical fertilizers or pesticides could be applied for the product development to lessen the negative environment impact. During the use phase, the employment of natural fiber composites in product operation is evaluated in terms of their impact on environment. Most of the natural fiber composites that apply in the products such as automotive components are purposely used to reduce the weight of the vehicle. Consequently, the fuel consumption is reduced and hazardous gases such as greenhouse emissions could be reduced. At the end of life, the disposal method should be determined by evaluating the impact on the environment during each of the disposal methods. Incineration and landfill are commonly found in disposal methods of natural fiber composites. The advantage of natural fiber composites during incineration is the energy recovery. Most of the studies had compared natural fiber composites with synthetic fiber composites such as glass and carbon fiber on their environmental impact. Although natural fiber composites exhibit negative environment impact during cultivation in terms of eutrophication, this is still not as big as the impact from the carbon or glass fiber composites on environment during their whole life cycle.

11.3

Case study on simplified life cycle assessment analysis for hybrid natural fiber composite automotive components

To demonstrate the application of LCA analysis for design of natural fiber composite products, a simplified LCA analysis on automotive anti-roll bar (ARB) component was conducted. The purpose of the assessment is to evaluate the potential environmental

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impact throughout all product life cycle stages when the component is proposed to be designed and manufactured using hybrid natural fiber composites, as replacement to its current spring steelebased material. The materials substitution project is aimed to take advantage of the lightweight property of composite materials as opposed to metallic materials, in conjunction with current automotive drive toward developing lighter vehicles for lower fuel consumption and greenhouse gas emissions. Through the LCA analysis evaluation, the actual environmental impact between the current spring steele based ARB and the proposed hybrid natural fiber compositeebased ARB can be determined. The environmental impact information can later be used by the designer to compare the advantages between both materials, in addition to other material properties such as functionality and cost.

11.3.1

Anti-roll bar

Stability during cornering plays an important role in vehicle movement. So, car a manufacturer has to design a system in a vehicle to make sure movement of car during cornering is safe and comfortable from rolling, which is the suspension system. In order to make a car more stable during cornering at high speed, the ARB was added in the vehicle suspension system. The ARB is a rod or tube that connects the right and left suspension members. It can be used in front suspension, rear suspension, or in both suspensions, no matter whether the suspensions are rigid axle type or independent type [59]. ARB at both the front and the rear wheels can reduce more body roll compared to ARB at front or rear wheel only. This will make handling better and increase driver confidence. A spring rate increase in the front ARB will produce understeering effect while a spring rate increase in the rear bar will produce oversteering effect. Thus, ARB is also used to improve directional control and stability especially during cornering. Besides, ARB also improves traction by limiting the camber angle change caused by body roll. This will improve handling of a vehicle because of increasing stability and tires are kept in contact with the road surface that causes traction force increase. This is because when traction forces higher, stability of a vehicle will increase. So, the percentage of car to roll during cornering will be low compared to a vehicle that does not have ARB [60]. Besides this, another function of the ARB is to relieve the main suspension springs of some of their load every time the body rolls. In certain situations, ARB that is tuned can take as much as 30%e40% of the total vertical load imposed on the suspension when subjected to severe body roll [61]. ARB also has a cross section that is usually divided into three types, including solid circular, hollow circular, and solid tapered. Most ARBs commonly use the solid circular type, which is also the oldest type of ARB. ARB commonly is produced from steel such as the Society of Automotive Engineers (SAE) Class 550, Class 700 steels and includes SAE codes from G5160 to G6150 and G1065 to G1090. This is because this steel can operate in strength above 700 MPa that is the minimum requirement for material strength to produce ARB. The SAE has stated information about torsion bar in the “Spring Design Manual” about the process to manufacture ARB that is heated, formed (die forged or upset), quenched, and tempered. For assembly of ARB, it is connected at four places in the suspension

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system, two places at the main frame using rubber bushings and two place at fixtures between the suspension members and the ARB ends, either through the use of short links or directly [59]. Table 11.2 summarizes the properties of ARB made from spring steel material.

11.3.2 Hybrid sugar palm/glass fiberereinforced polyurethane composites Nowadays, sources for manufacturing products have decreased drastically because of continuous use without thinking about the future. Manufacturers mostly depend on sources that are nonrenewable and that have taken billions of years to produce. So, research has come out with solutions to use renewable sources that can give the same functions or performance as current sources. One of them is by using hybrid natural fiber composites as an alternative. Hybrid composite is a combination of multiple natural-based reinforcing phases and multiple matrix phases compared to single composites that are comprised of single natural fiber reinforcement with a single matrix type. In general, the use of hybrid natural fiber composites for product development offers the advantage of gaining balance between cost and performance, especially between the two combined reinforcement materials. For example, formulation of hybrid composites made from the combination of synthetic fiber and natural fiber resulted in improved initial natural fiber composites’ mechanical properties, while at the same time reducing the cost of producing synthetic fiber composites. Many researchers have reported successful hybridization efforts between synthetic fiber and natural fiber for product development, such as kenaf/glass fiberereinforced epoxy composites [62], oil palm/juteereinforced epoxy composites [63], kenaf/aramidereinforced epoxy composites [64], kenaf/glass fiberereinforced polyester composites [65], and kenaf/ glassefiber reinforced polypropylene composites [66]. In this case study, the ARB component is planned to be produced using hybrid sugar palm/glass fiberereinforced polyurethane composites, to substitute for current spring steelebased component. One of the natural fibers is sugar palm. Sugar palm is a species of plant in the Arecaceae family that comes from Southeast Asia, Australia, and North America. Its scientific name is Arenga pinnata Merrill, having a variety of Table 11.2 Properties of ARB spring steel material [59] Properties

Value

Modulus of elasticity

206 GPa

Poisson’s ratio

0.27

Yield strength

1200 MPa

Ultimate tensile strength

1400 MPa

Endurance limit

706 MPa

Density

7800 kg/m3

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names such as kabung, gomuti palm, and aren [67]. Sugar palm is a fast growing palm that can reach maturity in 10 years after planting, hence it is a highly potential source of natural fiber in terms of availability similar to other commodity natural fibers such as kenaf, hemp, sisal, and jute. Sugar palm is useful because of its multipurpose characteristics, used not only use as food and beverages, but every part in the sugar palm can be a source to produce material such as biofibers, biopolymers, and biocomposites. There are three main products that sugar palm produces, which are palm sugar, fruit, and fibers. Sugar palm tree is one of the most natural fibers used in industry. Among the reasons why sugar palm was chosen are high durability and resistance to seawater, inherent natural availability in the form of woven fiber, and easy to be processed. Sugar palm can be categorized as four types, including ijuk fiber, sugar palm trunk (SPT), sugar palm bunch (SPB), and sugar palm frond (SPF). Among them, ijuk fiber has the highest density (1.20151 g/cm3), followed by SPT (1.1180 g/cm3), SPB (0.5101 g/cm3), and lastly SPF (0.4920 g/cm3). This is due to the ijuk fiber structure being more compact than other fibers especially for cellulose and hemicellulose. Besides, there are big pores present in the SPF and SPB structure that make their densities lower than ijuk [68]. The fiber was obtained from the sugar palm tree and combined with unsaturated polyester (PE). The composites of fiber are labeled as SPF/PE for sugar palm frond composite, SPB/PE for sugar palm bunch composites, SPT/PE for sugar palm trunk composites, and ijuk/PE for sugar palm fiber composites [69]. It should also be noted that sugar palm fiber properties vary according to the height and age of the ijuk tree. This is because of differences in chemical composition at varying tree height and age. It was reported that the fiber’s cellulose, hemicelluloses, and lignin contents increased with an increase of the tree height up to 5 m height, and beyond this height (5 m), the compositions remained unchanged. Similar reports also indicated that the optimum fiber strength is obtained from sugar palm tree height of 11 m [11]. Besides sugar palm, the other material to produce hybrid natural fiber composites is glass fiber and polyurethane as matrix. Glass fiber is used widely in most industries such as aerospace, leisure, automotive, construction, and sporting industries. Glass fiber, especially E-glass, is usually used as composite reinforcement material due to its relatively low cost and good mechanical properties compared to other synthetic fibers such as carbon fiber and aramid fiber. Table 11.3 shows the properties of E-glass fiber used in this case study. Table 11.3 Properties of glass fiber [70] Glass fiber properties 3

Value

Density (cm )

2.55

Tensile strength (MPa)

2400

Elastic Modulus

73

Elongation at failure (%)

3

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271

In contrast, polyurethane resin is selected as the composite’s matrix because of its structural versatility that can be in many forms such as elastomer, thermoplastic, thermosetting, rigid, and flexible forms. Polyurethane resin also can be derived from petroleum or vegetable oils but is particularly more compatible to vegetable fibers in relation to other resins. Previous studies revealed that polyurethane can be extracted from plants such as soybean oil [71] and castor oil [72]. This is because of possible reaction of hydroxyl groups of fiber and the isocyanate groups of the polyurethane [73]. Besides that, other advantages of using polyurethane are having low viscosity, excellent bonding with the matrix material without special sizing of the fibers, relatively low price, and fast reaction time. Polyurethane also has versatile properties such as high abrasion resistance, tear strength, excellent shock absorption, flexibility, and elasticity [71]. Fiber loading in hybrid natural fiber composites is an important factor to ensure that the composite material is able to safely meet the structural requirements to produce ARB component. Most of hybrid natural fiber composite contains between 30 and 40 vol% of fiber loadings to produce the composite that exhibits the optimized tensile properties. In a previous study, hybrid kenaf fiberereinforced thermoplastic polyurethane composites that encompassed 30 vol% of fiber loading were shown able to produce the highest tensile properties [74]. Apart from that, the combination aloe vera fiber and sugarcane bagasse fiber at 35 vol% of fiber loading has been reported able to produce the maximum tensile strength for the hybrid natural fiber composites when reinforced with epoxy matrix [75].

11.3.3 Simplified life cycle assessment analysis of hybrid sugar palm and glass fiberereinforced polyurethane composite anti-roll bar LCA is method implemented to assess the potential environmental impact of anti-roll bar made from hybrid sugar palm and glass fiberereinforced polyurethane composites. This assessment process is divided into four phases, defined as the goal and scope of study, inventory analysis, impact assessment analysis, and interpretation of results. Details for each phase are described following.

11.3.3.1 Define the goal and scope of study The first step in LCA is to define the goal of study. The definition for goal of study must be clear and reflect the purpose of the project. Besides that, the scope of study must also be defined in order to ensure that the analysis performed is in line with the system boundaries. Hence, the goal and scope of this study is to perform LCA analysis to the current material (spring steel) and hybrid sugar palm/glass fiberereinforced polyurethane composite for manufacturing of ARB. Subsequently, the LCA results shall be used to compare the environmental impact between the current material and the new materials candidate, which is hybrid sugar palm/glass fiberereinforced polyurethane composites.

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The boundary system is a flow that includes the input, process for producing ARB until end life of ARB. At this phase, the functional unit for analysis is also defined. Functional unit is a measure of the function of the analysis system and function as reference for relating the input and outputs. This enables comparison of two different materials for production of ARB. In this case study, the functional unit selected is the ARB structural strength, which should be at least 700 MPa to function safely as per design requirements. Thus, it can be concluded that the minimum structural requirement for ARB functionality is 700 MPa. Another functional unit is width of ARB that is 1394 mm. Width of ARB is defined as width of a predefined Malaysian car model. The structural strength and width of ARB is defined as a functional unit to use in overall LCA analysis. Figs. 11.2 and 11.3 showed the system boundaries defined for the overall LCA analysis of spring steel bar and the system boundaries for overall LCA analysis for hybrid natural fiber composites, respectively.

11.3.3.2 Inventory analysis of LCA Life cycle inventory (LCI) analysis involved collecting of data to create according to the flow of life cycle phases in the overall analysis. LCI is the straight-forward accounting of everything involved in the LCA analysis. It consists of the details for all the resources and activities that flowed in and out of the product system boundary, including raw materials, energy by type, water, and emissions to air, water, and land by parameter in LCI analysis. The data for input and output are collected in this phase for the whole system analysis as stated in system boundary for ARB LCA analysis. The data required for the analysis must be related to the functional unit that was defined in the initial goal and scope phase. At this stage, all information for input and output is provided in the form of elementary flow that is related to all unit processes involved in the analysis.

Transport

Raw material

Electricity

Steel production

Material processing

Manufacturing

Figure 11.2 System boundary of LCA for spring steel bar.

End of life

Use

The environmental impact of natural fiber composites through life cycle assessment analysis

Transport

Electricity

Glass fiber production Glass fiber composites component production

273

Polymer production

Hybrid composites component production

Natural fiber production Component use

Component use

Component end of life

Component end of life

- Incineration

- Incineration

Figure 11.3 System boundary of LCA for hybrid natural fiber composites.

The LCA analysis performed is based on the mass of component, according to the specified type of material. The theoretical mass for the ARB component is calculated based on its geometry. In this case study, a standardized ARB component used in one of the Malaysian national cars was selected. The cross-sectional geometry of the ARB was in circular form, with a measured diameter of 1.6 cm. Later, the cross-sectional area and the volume of the ARB component were calculated to be 2.0106 and 280.28 cm3, respectively. Using the material properties of spring steel bar, the theoretical ARB weight was later calculated. Table 11.4 summarizes the ARB-based spring steel bar material properties. Table 11.4 Summary of ARB-based spring steel bar material properties Material properties

Spring steel bar

Composition

97% low alloy steel, 3% chromium

Density

7.85 g/cm3

Tensile strength

724 MPa

Total component weight

2200.198 g

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Durability and Life Prediction in Bio-, Fibre-Reinforced, and Hybrid Composites

As mentioned before, the hybrid natural fiber composites applied for the ARB in this case study are produced from the combination of sugar palm (SP) fiber and glass fiber (GF), and reinforced with polyurethane (PUR) matrix. Successful materials substitution is possible only when the hybrid natural fiber composites can withstand similar structural strength as depicted for the functional unit of the component, which is 700 MPa. Due to the lack of information from literature review on the hybrid SP/GF/ PUR composites structural properties, the composite micromechanical models, namely, rules of mixture (ROM) and rules of hybrid mixture (ROHM), were applied to predict the final hybrid composite properties. Fig. 11.4 summarizes the overall procedure applied in predicting the hybrid SP/GF/PUR composites structural properties and Table 11.5 summarizes the final hybrid SP/GF/PUR composite properties obtained from the analysis. Based on the above prediction results, since sℎ (710.08 MPa) calculated is greater than the minimum required ARB structural strength (700 MPa), hence the information in Table 11.5 was used in the next life cycle assessment stage. The calculation process uses similar information as the existing ARB geometrical volume, which is 280.28 cm3. In addition, the fiber-to-matrix ratio used in Table 11.5 was also applied to calculate the theoretical SP/GF/PUR composites’ individual component weights as summarized in Table 11.6.

11.3.3.3 Impact assessment analysis Impact assessment analysis is the phase of evaluating the significant potential environmental impacts using the results from life cycle inventory flow. Impact assessment is selection of impact categories, indicator categories, and characterization model. At this phase, inventory parameters are sorted and separated according to specific impact categories. After parameters are divided into impact categories, parameters will measure according to impact measurement in impact assessment. In this phase, the Ecoindicator 99 method is used for impact assessment analysis. The Eco-indicator 99 method was selected for the simplified LCA analysis due to its simplicity and straightforward procedure, which is adequate for preliminary product design assessment. According to the Eco-indicator 99 manual, 1 unit score (Pt) in eco-indicator represents 1000 of the yearly environmental load of one average European inhabitant [76]. Table 11.7 summarizes the eco-indicator rating applied for ARB-based spring steel bar. Due to lack of data from literature review, several calculated values shown in Table 11.5 are obtained based on the author’s assumptions. In the product life cycle, the bending steel and forging process were selected for the spring steel ARB component production. Apart from that, the incineration process was selected for the disposal of the spring steel ARB material. Furthermore, the total power requirement for operation to produce one unit of component is 1.026 kWh. In addition, the electricity input values for the system boundary were based on Malaysian electric system transmission voltage networks, which are 500, 275, and 132 kV, whilst the distribution voltages are 33 kV, 11 kV 400/230 V, and the supply frequency is 50 Hz
1%. Other assumptions

The environmental impact of natural fiber composites through life cycle assessment analysis

275

START

Determine the selected fiber and matrix material properties (density, strength, stiffness)

Determine hybrid composite fiber loading (vol%)

Determine fiber loading for GF and SP from total fiber loading

Calculate single system modulus for GF/PUR system using ROM

Calculate single system modulus for SP /PUR system using ROM

σc1 = σf1 Vf1 + σm 1 + Vf1

σc2 = σf2 Vf2 + σm 1 + Vf2

Calculate overall hybrid composite modulus using RoHM

If σ

hybrid

<700 MPa

σhybrid = σc1Vc1 + σc2Vf2

END

Figure 11.4 Flowchart for overall methodology to determine hybrid natural fiber composite tensile modulus. (Note: rf, fiber density; rm, matrix density; Vf, fiber volume fraction; Vm, matrix volume fraction; sm, matrix tensile strength; sc1 and sc2, relative hybrid tensile strength of the first and second system, respectively; Vc1 and Vc2, relative hybrid volume fraction of the first and second system, respectively.)

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Table 11.5 Estimation results for fiber loading in SP/GF/PUR composites (assumed hybrid formulation made from 38% total fiber loading to achieve ARB functional unit requirement) Glass fiber/polyurethane (GF/PUR)

Sugar palm/polyurethane (SP/PUR)

86% from total fiber loading

14% from total fiber loading

32.68% for Vf1

5.32% for Vf2

sc1 ¼ 816.6336 MPa

sc2 ¼ 55.5698 MPa

Vc1 ¼ 0.86

Vc2 ¼ 0.14

Hybrid strength, sℎ ¼ 710.08 MPa

made for the life cycle inventory were the transportation distances from the steel production facility to the component production plant. The determination of the eco-indicator score for SP/GF/PUR hybrid composite ARB component was also performed in similar manner as the spring steel ARB component. Due to lack of data from literature review, similar assumptions to spring steel material were also made in terms of electricity input value and transportation distance from the natural fiber composites production facility to the component production plant. However, the total power requirement calculated to produce one unit of SP/ GF/PUR hybrid composite ARB component is 0.00046 kWh. Another assumption made is that the reaction injection molding process is selected for the SP/GF/PUR

Table 11.6 Summary of SP/GF/PUR composites’ individual components properties SP/GF/PUR composite properties

Value

Fiber loading (vol%)

32.68 (Glass fiber) 5.32 (Sugar palm fiber) 62.00 (Polyurethane)

3

Density (g/cm )

2.55 (Glass fiber) 1.20151 (Sugar palm) 1.40 (Polyurethane)

Total hybrid composites weight (g)

460.01

Individual constituent weight (g)

233.58 (Glass fiber) 17.91 (Sugar palm fiber) 208.52 (Polyurethane)

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Table 11.7 Eco-indicator rating for ARB made from spring steel bar Material or process

Indicator, millipoint (mPt)

Stage: Production (Materials, processing, transport and extra energy) Steel spring (50CrV4)

75.3

Stage: Use (Transport, energy and auxiliary materials) Electricity HV Europe (UCPTE) > 24 V

22.0

Manufacturing process: Bending steel

0.00008

Forming (forging)

16.8

Transport: Truck 16 t (ton  km ¼ t$km); 305 km total distance travelled

34.0

Stage: End of Life (Disposal processes per type of material) Disposal: Incineration steel

32.0

hybrid composite component production because this process is commonly used in polyurethane-based composites manufacturing process. In addition, the production and disposal stage of the component is divided into three categories, according to the type of hybrid composite individual constituents, which are polyurethane matrix, glass fiber, and sugar palm fiber. The overall eco-indicator rating selected for the SP/GF/PUR hybrid composites are summarized in Table 11.8. The final impact assessment process conducted is determination of the overall ecoindicator score for the spring steelebased ARB and SP/GF/PUR hybrid composite ARB component based on the eco-indicator score as listed in Tables 11.7 and 11.8, respectively. Table 11.9 summarizes the overall eco-indicator score for both ARB materials.

11.3.3.4 Interpretation of results The final phase in the LCA analysis is the interpretation of the impact assessment results. In this phase, conclusions and recommendations for overall analysis of LCA were also performed. In general, the materials that scored the lowest eco-indicator points will result in the lowest environmental impact performance. Hence, based on the overall eco-indicator performance shown in Table 11.9, it was revealed that ARB made from spring steel bar generated an eco-indicator score of 174.785 mPt, while ARB made from SP/GF/PUR hybrid composites generated eco-indicator score of 115.595 mPt. Therefore, results from the impact assessment analysis indicated that ARB made from SP/GF/PUR hybrid composites generated up to 33.4% lower overall environmental impact performance compared to ARB made from spring steel bar.

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Table 11.8 Eco-indicator rating for ARB made from SP/GF/PUR hybrid composites Indicator, millipoint (mPt)

Material or process

Stage: Production (Materials, processing, transport and extra energy) Polyurethane (PUR)

490.0

Glass fiber (for reinforcement)

2.1

Sugar palm fiber (for reinforcement)

3.4

Stage: Use (Transport, energy, and auxiliary materials) Electricity HV Europe (UCPTE) > 24 V

22.0

Manufacturing process: Reaction injection molding (for PUR)

12.0

Transport: Truck 16 t (ton  km ¼ t$km); 305 km total distance traveled

34.0

Stage: End of Life (Disposal processes per type of material) Incineration - Polyurethane

2.8

Incineration - Glass fiber (assume nearest to glass)

5.1

Incineration - Sugar palm fiber

0.0

Similar results from Table 11.9 were later tabulated to compare the performance between both ARB materials at individual life cycle stages as shown in Fig. 11.5. The comparative analysis further showed that the production stage for ARB-based spring steel bar obtained higher eco-indicator score of 160.705 mPt compared to ARB-based SP/GF/PUR hybrid composites that scored 102.73 mPt. In addition, the ARB-based spring steel bar also obtained the higher eco-indicator score (82.368 mPt) compared to ARB-based SP/GF/PUR hybrid composites (11.11 mPt) during the product use stage. However, it is also observed that ARB-based spring steel bar showed lower Table 11.9 Overall impact assessment result for ARB made from spring steel bar and SP/GF/PUR hybrid composites Eco-indicator score (millipoint, mPt) Product life cycle stage

Spring steel bar

SP/GF/PUR hybrid composites

Production

160.705

102.73

Use

82.368

11.11

Disposal

68.288

1.755

Total

174.785

115.595

The environmental impact of natural fiber composites through life cycle assessment analysis

279

200 160.705

Eco indicator score (mPt)

150 102.73 100

82.368

50 11.11

1.755

0 Production

Use

Disposal

–50 –68.288 –100 Spring steel bar

SP/GF/PUR hybrid composites

Figure 11.5 Comparison of environment impacts at individual life cycle stages between ARB made from spring steel bar and ARB made from SP/GF/PUR hybrid composites.

environmental impact score compared to ARB-based SP/GF/PUR hybrid composites during the disposal stage of the product life cycle. This is contributed to by the ability of the spring steel to be recycled during the disposal stage as compared to SP/GF/PUR hybrid composites (assumed to be disposed using incineration process), which significantly reduced the impact to the environment. Results from Fig. 11.5 also highlighted several important findings toward better product environmental performance. One of the findings indicated that selection of the type of materials greatly affects the environmental performance for all life cycle stages (production, use, and disposal). The selection outcome can be analyzed by screening the eco-indicator impact score for each material as their subsequent processing, use and disposal activities. In addition to that, the weight of the product also plays an important role to achieve lower environmental impact performance. This is because the weight of the product proportionally affects the final eco-indicator score for each activity throughout the product life cycle stages during the impact assessment analysis. Therefore, it is evident that ARB made from SP/GF/PUR hybrid composites was able to produce lower eco-indicator impact scores compared to ARB made from spring steel bar, due to its better lightweight property as similar structural strength requirement. Both findings can be very beneficial for product designers to assess their product design outcome in terms of environmental impact, in addition to conventional functional and cost criteria. The overall exercise highlighted that SP/GF/PUR hybrid composites are more environmentally friendly compared to spring steel bar for producing ARB throughout all of the product life cycle stages. It can also be concluded from this case study that ARB made from SP/GF/PUR hybrid composites is theoretically viable in terms of functionality and environmental performance to be used as substitution material for spring steel bar in producing similar components in the future.

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11.4

Conclusion

The overview of the environmental impact of natural fiber composites through LCA analysis has been discussed in this chapter. Several highlights on the topic are listed herein: • •

•

•

LCA is a holistic approach in assessing the potential environmental impact of products, where all of the product life cycle phases from raw material extraction until disposal are taken into account. Assessment on the environmental impact of natural fiber composites using LCA analysis is becoming a necessity, to determine the overall material contribution to the environment. The assessment results can be very beneficial especially to decision makers to assess in detail their product design performance in terms of environmental impact, in addition to conventional functional and cost criteria. Case study on the application of LCA analysis for automotive ARB component made from hybrid natural fiber composites quantitatively showed the potential environmental impact of the component throughout the product life cycle, and further indicated in theory the viability of using hybrid natural fiber composites as substitution material for more environmentally friendly components in the future. LCA analysis can also be applied for design and planning purposes prior to the actual introduction of the product into the market. To gain higher sustainability performance, designers and planners may assess individual stages within the product life cycle to determine the stages that contributed undesirable environmental impact based on the eco-indicator score. Later, improvement actions can be made either by selecting other options available that have lower impact score for processing, use and disposal activities of the intended product, or by taking action to reduce the existing weight of the product without jeopardizing its functionality and safety. As shown through the case study, efforts to reduce the product weight proportionally affect the final eco-indicator score for each activity throughout the product life cycle stages, hence reducing the potential environmental impact.

Acknowledgments The authors wish to thank Universiti Teknikal Malaysia Melaka, Universiti Putra Malaysia, and Universiti Teknologi Malaysia for providing valuable support and continuous encouragement throughout the completion of this chapter. The authors also wish to thank Mr. Wan Kaznil Hisham Wan Hashim and Mr. Muhammad Taufiq Jumadi for the ideas and comments shared for this chapter.

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