ENERGY, ENVIRONMENT, ECOSYSTEMS, DEVELOPMENT and LANDSCAPE ARCHITECTURE Engineering Sustainable Textiles: a Bamboo Textile Comparison MARILYN WAITE AND JIM PLATTS Department of Engineering, University of Cambridge, Trumpington Street, Cambridge, CB2 1PZ UNITED KINGDOM [email protected], [email protected], http://www.ifm.eng.cam.ac.uk/people/mjp/ Abstract: This paper delves into a subset of engineering for sustainable development—the engineering of sustainable textiles using bamboo. The experiments performed attempt to answer two main questions: (1) what are the differences in textile properties between chemicallymanufactured and mechanicallymanufactured bamboo textiles? and (2) what are the differences in textile properties between two different species of bamboo? The textile properties examined relate to sustainability: wear and tear (and therefore durability) and moisture wicking (and therefore the need for machine washing and drying). The following are measured for fibre, yarn, and fabric: tear force, breaking force, breaking tenacity, moisture absorption and speed of drying, and surface morphology. Key-Words: textiles, bamboo, fibre, yarn, fabric, sustainability, renewable, manufacturing, SEM 1 Introduction There are two main manufacturing methods currently One of the earliest engineering practices involved the being employed in the creation of bamboo textiles— use of scientific principles to extract and manufacture chemicallybased (hydroalkalization and multi-phase textiles for practical applications. At present, the bleaching) and mechanicallybased (stripping, boiling, industry has a poor track record for social and and enzyme-use) processes. In this paper, bamboo environmental concerns. Textiles made from bamboo textiles made from the chemical process are referred to address the aim of sustainable development by as chemical bamboo and textiles made from the utilizing a renewable resource to make clothes and mechanical process are said to be mechanical bamboo. other textile applications. The earliest record of US Both methods engender negative impacts on the Patents concerning bamboo textiles was made by environment and human health, though there is much Philipp Lichtenstadt in 1864 [9]. The advantages of debate as to which is more sustainable. bamboo textiles can be divided into two main categories: (1) those derived from the use of the plant There are also over 1500 species of bamboo globally, itself and (2) those derived from fabric properties of which only a few are being employed to create given by the plant. The advantages of using bamboo as textiles. Some companies use only one species of a raw material for textiles include its renewability, its bamboo for bamboo textile manufacturing, while other biodegradability, its efficient space consumption, its companies use many (such as 13 species) without low water use, its organic status, and its carbon distinguishing between species and textile properties. sequestering abilities given a sustainably managed The experiments performed attempt to answer two bamboo forest. Bamboo is the fastest growing plant in questions: (1) what are the differences in textile the world—it can grow a meter or more per day [5]. properties between chemical bamboo and mechanical Bamboo yields 50 times as much fibre per acre as bamboo textiles (species held constant), and (2) what cotton [3]. Bamboo textiles provide quicker harvest are the differences in textile properties between two readiness compared with 15year old trees that are different species of bamboo used to produce chemical used to make lyocell, rayon, and other regenerated bamboo (Phyllostachys edulis and Bambusa fibre [7]. The main constraints of bamboo textiles are emeiensis) (manufacturing method held constant)? those inherent in the textile industry: various energy, water, and chemical requirements that can be involved The textile properties measured here are as follows: in its manufacturing. tear force, breaking force, breaking tenacity, moisture absorption and speed of drying, and surface morphology. Tests are performed at various stages of the bamboo textile manufacturing process: fibre, yarn, 2 Problem and fabric. The properties analysed have special Bamboo textiles present a noteworthy opportunity for relevance to sustainable development. The ability to providing sustainable textiles. Nevertheless, the withstand forces is a key indicator of durability. The renewable properties of bamboo itself do not add longer a textile lasts, the more one can prolong its much to sustainable development if the textiles cannot eventual deposit in landfill, and perhaps the more one serve a practical purpose. Bamboo textiles must can refrain from replacing and wasting further exhibit properties appropriate for its applications, resources. If a textile can absorb moisture quickly and thereby providing the enduser with a useful item. dry moisture quickly, then the need for mechanical ISSN: 1790-5095 362 ISBN: 978-960-474-125-0 ENERGY, ENVIRONMENT, ECOSYSTEMS, DEVELOPMENT and LANDSCAPE ARCHITECTURE drying and perhaps washing (which can be energy and 1. A rectangular paper frame was constructed water intensive) can be lessened. with a rectangular cut out according to the dimensions in Fig. 1. 2. Double-sided tape was then used to apply an 3 Materials adhesive surface to one side of the paper Bamboo fibre, yarn, and fabric samples were collected frame. The rectangular cut out was preserved using two different species of bamboo—Phyllostachys by cutting through the double-sided tape. edulis and Bambusa emeiensis (formerly known as 3. Five individual fibres were carefully picked Neosinocalamus affinis). To perform the scanning using fine tweezers and placed along the electron microscope (SEM) observations, the rectangular cut as seen in Fig. 1. CamScan MX2600 was used. The mechanical tests 4. Masking tape was cut and placed along both were performed with a Hounsfield Low Load Electric ends of the fibres to hold them in place. Screw Machine. In order to conduct the moisture 5. The paper frame and the attached fibres were absorption and drying experiments, the following then clamped using the Hounsfield tensile materials were used in addition to fabric: 17cm testing machine. diameter embroidery hoop, deionised water, balance, 6. Slits were cut through two ends of the paper pipettes and pipette tips, and a beaker. frame so that the only materials pulled during the test were the fibres. 7. A standard breaking force program was used 4 Methods with a load range of 5N, a speed of 100 mm/min, and an extension range of 10 mm. 4.1 SEM Images Standard test procedures for live specimens were used Fig. 1: Sample Preparation for Bamboo Fibre to observe the differences in surface morphology among various bamboo fibres. The fibres were cut and gold-plated as preparation. 4.2 Moisture Wicking Tests AATCC Test Method 792007 was employed to measure textile absorbency [1]. To measure the speed of drying of the different fabrics, 50 L of deionised water was placed on a piece of fabric cut 4 cm wide and 5 cm long. The weight of the fabric was taken before and after the 50 L of water was introduced, as well as at set time intervals until the weight of the fabric reached its initial recording. 4.3.2 Yarns To measure the tensile properties of yarns, ASTM 4.3 Mechanical Tests standard D 225602, Standard Test Method for Tensile Mechanical tests were completed according to various Properties of Yarns by the Single-Strand Method, was internationally-recognised standards, including those employed [2]. A total of ten trials were performed for from the American Society for Testing and Materials each yarn type. (ASTM), the International Organization for Standardization (ISO), the British Standards Institution 4.3.3 Fabric (BSI), and the American Association of Textile To measure the tear properties of fabric, EN ISO Chemists and Colorists (AATCC). 139372:2000, Tear properties of fabrics Part 2: Determination of tear force of trouser-shaped test 4.3.1 Fibres specimens (Single tear method), was employed [6]. A To measure the breaking force of the bamboo fibres, total of six trials were performed for each fabric type, standard test methods had to be modified to conduct a three to calculate the tear force across warp and three comparison adequate for the short and fine chemical to calculate the tear force across weft. bamboo fibres. Bamboo fibres were measured at the following stages: thick pulp (earliest stage) chemical bamboo fibre, fine pulp chemical bamboo fibre, and mechanical bamboo fibre. Ten trials were completed 5 Results for each sample type. The following method was employed: 5.1 SEM Analysis - Fibres ISSN: 1790-5095 363 ISBN: 978-960-474-125-0 ENERGY, ENVIRONMENT, ECOSYSTEMS, DEVELOPMENT and LANDSCAPE ARCHITECTURE The SEM images show various similarities and Fig. 4: B. emeiensis Chemical Bamboo Fibre (Thick differences among the four bamboo fibre types Pulp) analysed. Both species of chemical bamboo fibre Left: cross-sectional direction (SEM Mag1406X) displayed a tubular and ribbed (celery-like) Right: longitudinal direction (SEM Mag3152X), longitudinal surface; the cross sections of both species Diameter is ≈ 31.5 m were filled with voids (Fig. 2 and Fig. 3). The thick pulp of chemical bamboo fibre has a rough and very porous surface (Fig. 4); this is to be expected as it is the closest to the actual bamboo plant among all of the fibre types. Mechanical bamboo fibre displayed a bamboo-like longitudinal section, tubular with nodes (Fig. 5); the cross section displayed some voids, though much fewer than the chemical bamboo fibres. Fig. 5: P. edulis Mechanical Bamboo Fibre The mechanical bamboo fibre also has a higher linear Left: cross-sectional direction (SEM Mag4476X) density (5.88 dtex) than the chemical bamboo fibres Right: longitudinal direction (SEM Mag1708X), (1.56 dtex). Diameter is ≈ 16 m Fig. 2: P. edulis Chemical Bamboo Fibre Left: cross-sectional direction (SEM Mag7900X) Right: longitudinal direction, Diameter is 13.4 m - 15.6 m (SEM Mag3346X) 5.2. Mechanical Tests 5.2.1 Mechanical Tests - Fibres The results for fibre breaking force and breaking tenacity illustrate that mechanically-manufactured B. emeiensis Fig.