International Journal of Plastics Technology

International Journal of Plastics Technology Production, characterization and prediction of mechanical properties of waste fibre reinforced composite panels for application in adjustable partition walls of buildings --Manuscript Draft-Manuscript Number: Full Title:

Production, characterization and prediction of mechanical properties of waste fibre reinforced composite panels for application in adjustable partition walls of buildings

Article Type:

Research Article

Corresponding Author:

Sohel Rana, Ph.D. University of Minho Guimaraes, Braga PORTUGAL

Corresponding Author Secondary Information: Corresponding Author's Institution:

University of Minho

Corresponding Author's Secondary Institution: First Author:

Joao Velosa, MSc.

First Author Secondary Information: Order of Authors:

Joao Velosa, MSc. Sohel Rana, Ph.D. Raul Fangueiro, PhD Paulo Mendonça

Order of Authors Secondary Information: Abstract:

In the present paper, waste fibre reinforced composite panels have been developed for application in interior partition walls of buildings. These panels were produced using waste fibres collected from the textile industries and using aminoplastic phenolformaldehyde resin. Mechanical properties such as tensile, compression and flexural properties of these composite panels were characterized and the influence of a few parameters such as fibre or matrix weight % and composite density on the mechanical properties has been analyzed. Impact properties (soft body and hard body impact), which is very important for the materials used in the partition walls, of the developed composite panels was simulated using finite element method and the influence of composite parameters (fibre or resin content, composite density) on the impact resistance and strain energy was analyzed. Although the waste fibre reinforced composites show low mechanical properties, the simulation results showed that the composite panels showed required impact properties (no collapse, no penetration or projection under both soft and hard body impact) for their successful application in the interior partition walls. It was also observed that the composite panels exhibited better impact resistance and lower deformation when produced with higher fibre % as well as higher density.

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1 Introduction 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65

A partition wall is a thin element built to divide the indoor space into rooms or other compartments. Generally, partition walls are non-load bearing. For a load-bearing wall, strength is an important factor of design; a partition wall, on the other hand, needs only to be strong enough to support itself under normal conditions of service. The main structural requirement of a partition wall is to have the necessary strength to support suitable resistance to accidental impacts caused by the occupants of the building [1, 2, 3]. In recent times, there is a growing need for the more evolutionary and adaptable housing units. However, it can be verified that a great portion of houses don’t fulfil these requirements. This happens because the technological and constructive solutions used on conventional interior partition walls, such as hollow brick or plasterboard with metallic frame systems, are static and difficult to readapt without a significant cost due to the specialized work required and material loss during the assembly process. This problem reveals to be more important in the refurbishment of existing buildings, but also when new buildings are conceived, knowing that, in future, the need of reorganizing interior space will become as difficult as today.

Growing necessity to save material and energetic resources as well as a growing concern over the environmental issues has created lots of interest on the use of more materially and energetically efficient solutions in building and construction materials [4, 5]. The development of new lightweight materials, most of which are composites with fibrous reinforcement systems, has gained tremendous interest due to these issues. Light-weight constructions present several advantages such as less material usage, fuel saving in transportation to the building sites, and possibility to design with smaller assembly fittings [6].

Composites reinforced by fibres are increasingly being considered for several uses when high performance is required [7]. Corrosion resistance, potentially high overall durability, light weight,

tailor ability and high specific performance attributes enable the use of composite materials in areas 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65

in which the use of conventional material might be constrained due to durability, weight or lack of design flexibility. Composite materials produced from waste fibres are gaining lots of interest in modern times as they are extremely low cost materials. Some industries (e.g. textile) have taken an increasing interest in developing systems for recycling waste fibers which result from the process of manufacturing products such as textile fabrics, non-woven fabrics, fishing net, lacy cloth, etc. However, due to of lack of effective recycling techniques, most of these wastes are currently destroyed by fire or buried underground [8]. These waste materials can be advantageously utilized in producing composite materials for various applications where low cost, light-weight and design flexibility are the primary requirements [9]. Therefore, several research studies have been carried out to produce and characterize waste fibre reinforced composite materials for application in various sectors [10-15].

Considering the above issues, a novel design of interior partition walls has been proposed recently by the authors [16], as presented in Figure 1. This design consists of two light-weight composite panel faces and separated by a fibrous insulating material. The face panels will provide the mechanical resistance, whereas the insulating material will improve the thermal and acoustic insulation of the diving walls. The composite panels for use in the faces have been developed by the authors using non-woven textile fabrics and their properties have been already reported by them [16]. The present research, however, aims at producing waste fibre composites for application in the core of the proposed light-weight partition wall design. The main idea here was to find a core material, with advantages like light weight, low cost, high accessibility of raw material, high design flexibility, suitable mechanical properties and with other important functionalities such as thermal and acoustic insulation properties. Waste fibres, mainly natural fibres, from textile industries were used to produce these composite panels. Mechanical properties (tensile, flexural and compressive)

of these composites were characterized and the influence of matrix properties such as weight % and 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65

resin density on the mechanical properties has been analyzed. Also, the impact resistance of these composites have been simulated using finite element method (FEM) to study their application potential in the interior partition walls.

2 Experimental Work 2.1 Raw Materials The waste fibrous materials were collected from the textile industries in the outskirt of Minho area situated in the northern part of Portugal. The fibre mass consists of many unknown fibres, since it was collected from several textile industries producing a various range of textile goods and, consequently, using many different types of fibres and fibre/fabric treatments. The composition of the waste fibrous material was evaluated, presenting the following result: - 85% cellulosic fibres, mostly cotton; - 10% polyester fibres; - 2% wool fibres; - a few % of various fibres, including PP, PA, among others. An aminoplastic Urea-Formaldehyde resin in aqueous base (FM 100 from Bresfor® Industries, Portugal) has been used in the present study.

2.2 Fabrication of Composites Composite panels were produced using compression moulding machine (Figure 2). Composite samples were produced with dimensions of 530 x530 mm and thickness of 5 mm. The resin used in this study was cured at 170ºC. The samples were firstly preheated with a pressure of 18 kg/cm2 during 1 min. The pressure was then decreased up to 6 kg/cm2, during 5 min. This preheating with lower pressure was used to give an even heat distribution all over the sample surface and on both

back and reverse sides, before higher pressure was applied. Table 1 provides the details of the five 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65

types of composite panels produced. In the production of these composite panels, a number of parameters were varied in order to understand their influence on the mechanical properties. As shown in Table 1, there was a variation in the percentage of resin for a given composite density or variation of composite density for the same percentage of resin, keeping the same thickness for the whole set of samples. Composite panels with different densities were produced by compressing different amount of materials to the same thickness (5 mm).

2.3 Characterization of Mechanical Properties The composite panels produced with waste fibrous materials were tested in a Universal Tensile Machine (Hounsfield H100 KS), in order to evaluate their mechanical properties, including tensile, compression and flexural properties. The tensile tests were conducted according to ISO 527-4: 1997 standard. Samples of 25 x 200 mm dimension were used. The gauge length was 50 mm and the initial length between the clamps was 150 mm. The cross-head speed was 100 mm/min. The compression tests were conducted according ASTM D 790:1996. The cross-head speed was 100 mm/min. Finally, flexural tests were conducted according to ASTM D 695:2010, with a speed of 25 mm/min.

2.4 Modelling of Impact Resistance In practice, when these composite panels will be used in the partition walls, they will be subjected to impact loads of two kinds: (1) due to accidental falling of a person against the panel or (2) due to accidental falling of furniture or similar objects. The first case, i.e. the falling of a person can be simulated by hitting the panel by a soft body dropped from a certain height, as shown in Figure 3. On the other hand, the second case, i.e. the falling of an object can be simulated by impact of a hard

body against the panel. According to the EOTA standard [2], interior partition walls should meet 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65

the requirements presented in Table 2.

For the analysis of above impact behaviours of developed composite panels, simulation has been performed using Abaqus® software. Different models have been studied in the Abaqus® software based on the data obtained from the experimental results, varying different parameters in order to propose the most representative models. The composite panel geometry used in the simulation is presented in Figure 4. This geometry has been designed considering its use in the inner layer of an adjustable partition wall. Figure 4 (a) and (b) show the front and back faces of composite panels and Figure 4(c) illustrate the positions where the panels will be fixed with the partition wall (top and bottom sides) and the position of impact (in the middle). The panel dimension was 1200 x 2600 mm and the total thickness was considered as 40 mm. The material properties used were obtained from the tensile testing results and for Poisson's ratio a value of 0.279 was used for all composite panels

According to the EOTA standard [2], the impact energy E has been considered to be 100 Nm for impactor mass of 50 kg in case of soft body impact and 10 Nm for impactor mass of 1 kg in case of hard body impact. Therefore, the speeds at which the impactor strikes the panel in case of soft body and hard body impacts have been calculated as 2 m/s and 4.47 m/s respectively, according to the following equation:

E

mv 2 2

(1)

Also, considering the time of contact of 0.1 s, the force of impact has been calculated (according to Newton's second law Fr = m x a) as 1000 N and 44.7 N, respectively. These parameters have been used to generate the numerical model using finite element method. For the finite element analysis,

tetragonal linear tetrahedron node elements were used. These elements present eight nodes, six 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65

degrees of freedom for displacements in x, y, z. As a parameter representative of the resistance of the panel, Von Mises stress was calculated representing the state of tri-axial stress which leads to breakage.

3. Results and Discussion 3.1 Experimental results Table 3 shows the summary of the results obtained in the tests undertaken to evaluate the mechanical properties of the composite panels. It can be observed that these composite panels showed lower mechanical properties as compared to the composites used in structural and high performance applications. However, these composites are proposed in this research for application the interior dividing walls of buildings, in which mechanical properties are not so important and the composite materials are mainly supposed to tolerate the accidental impacts from the occupants of the buildings. Looking at these results it can be commented that the tensile and compressive properties of these composites can be improved using higher matrix weight % and higher composite density. However, these parameters do not have significant influence on the flexural properties, which is lower as compared to the tensile and compressive properties.

3.2 Simulation Results According to the simulation, the composite panels showed no collapse or penetration or projection after impacts under the loading conditions of both hard and soft body impacts. The impactor hits the panel and rebounds back without any damage. Figure 5 shows the conditions of composite panel (P900/20) before and after impact with the hard body. It can be seen that after impact some stresses are generated mainly in the middle and at the fixing sides, but the panel shows no collapse or penetration. Similar results were also obtained in case of soft body impact and for other samples.

Figure 6 shows the stresses and strain energy obtained in hard body impact simulation of the 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65

composite panel P900/20. Other samples also showed similar stress and strain energy distribution. In can be noted that the stresses are mainly located in the middle and fixing sides of the panel and the deformation and strain energy are concentrated in the middle of the composite panel. Figure 7 shows the stress-displacement curves of various composite panels obtained from the simulation. It can be observed that impact resistance is higher in case of lower % of resin (10%). It implies that presence of higher fibre content improves the impact resistance of the panels unlike other mechanical properties. Increase in composite density, on the other hand, improved the impact resistance due to more compact structure and highest impact resistance was achieved in case of 1100 kg/m3. Similar trend was observed in case of both hard and soft body impact; however, the impact resistance and deformation were much higher in case of soft body impact.

Figure 8 shows the strain energy vs. displacement curves obtained from the simulation of impact behaviour. Similar to impact resistance, strain energy was also higher in case of lower % of resin indicating that higher fibre % was favourable to achieve higher impact energy. However, lower deformation and strain energy were achieved in case of higher composite density, due to higher compactness and less mobility of the structure. The highest value of deformation and impact energy were achieved in case of composite panel P900/10. Like impact resistance, similar trend was also observed in case of strain energy for both soft and hard body impact.

Therefore, analyzing the results, it can be commented that, composite panels prepared using 10 wt.% of resin and with a density of 1100 kg/m3 were suitable for the application in the inner layer of partition walls due to higher impact resistance and good impact energy with lower deformations (as compared to the panels prepared with lower composite density). However, the deformation values obtained from the simulation are still very high, especially, in case of soft body impact. However, it should be considered that these composite panels will be used only in the inner layer of the partition wall and will be protected by outer layers having

high mechanical properties. Therefore, in practical situation, their performance will be much better than 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65

obtained from these simulation results. While providing sufficient resistance to accidental impacts, these composite panels can serve other important functions such as thermal and acoustic insulation during their use in the partition walls of buildings.

4. Conclusions In this study, various waste fiber-reinforced composite sheets were produced for use in the partition walls of buildings, using compression moulding technique, varying the resin weight % and composite density. Results obtained from the mechanical tests demonstrated that the composite panels exhibited low mechanical properties, which, however, could be improved to some extent through increase in resin content and composite density. Moreover, impact behaviour of these composite panels was simulated using finite element analysis in two situations namely impact with a soft body and a rigid body. From the simulation results, it was observed that the impact resistance of these composite panels improved with fibre content and composite density and the overall impact behaviour was satisfactory according to the standard used in case of partition walls. Therefore, these extremely low cost and light-weight composite materials can find potential application in the partition wall of buildings due to their satisfactory mechanical properties and possibility to perform other important functions such as thermal and acoustic insulation.

Acknowledgments The authors wish to thank FCT (Fundaçãopara a Ciência e Tecnologia – Portugal) and COMPETE (ProgramaOperacional de Factores de Competitividade - Portugal) for supporting this research with PTDC/AUR-AQI/102321/2008 grant.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65

References 1.

ETAG_003 (1998) Guideline for European technical approval for internal partition kits for use as non-loadbearing wall.

2.

EOTA (2003) Determination of impact resistance of panels and panel assemblies, technical report TR 001.

3.

EN1991-1-1-Eurocode-1 (2001) Actions on structures - Part 1-1: general actions – densities, self-weight, imposed loads for buildings.

4.

Horden R (1995) Light tech: towards a light architecture. Birkhauser Verlag AG, Berlin.

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Slessor C, Linden J (1997) Eco-tech: sustainable architecture and high technology. Thames and Hudson, New York.

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Mendonca P (2005) Living under a second skin – Strategies for Environmental Impact Reduction for Solar Passive Constructions in Temperate Climates. PhD Thesis, Portugal.

7.

Fangueiro R (2011) Fibrous and Composite Materials for Civil Engineering Applications. Woodhead Publishing Ltd, Cambridge.

8.

Emori K, Kimura T (1999) Recyclability of Glass Cloth Waste Coated by PVC as a Fiber Reinforced Composite. Proceedings of Recycling of Fibrous Textile and Carpet Waste Conference, Georgia Institute of Technology, USA.

9.

Gomes MG, Fangueiro R, Jobim G, Pereira CG (2006) Composite Materials Reinforced by Waste Fibers. Proceedings of Mechanics & materials in design - 5 th Internacional Conference, Porto, Portugal.

10.

Jayaraman K, Bhattacharyya D (2004) Resources, Conservation and Recycling 41: 307.

11.

Savastano Jr H, Warden PG, Coutts RSP (2000) Cement & Concrete Composites 22:379.

12.

Turner TA, Pickering SJ, Warrior NA (2011) Composites: Part B 42:517.

13.

Verma D, Gope PC, Maheshwari MK, Sharma RK (2012) J Mater Environ Sci 3:1079.

14. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65

Sivaraja M, Kandasamy S (2011) Asian Journal of Civil Engineering (Building and Housing) 12: 205.

15.

Heil JP, Cuomo JJ (2011) Recycling Carbon Fibre Composites using Injection Moulding and resin Transfer Moulding. Proceedings of 16th International Conference on Composite Structures. Porto, Portugal.

16.

Velosa J, Rana S, Santos T, Fangueiro R, Ramos L (2013) Polymers and Polymer Composites, accepted.

Figure Legends: Figure1. Schematic representation of new interior dividing walls based on composite panels Figure 2. Compression moulding process for production of waste fibre composites Figure 3. Impact on vertical assembly (h - drop height, L – rope length) Figure 4. Geometry of composite panels used in the simulation: (a) front face, (b) back face and (c) position of fixing (top and bottom sides) and impact load (middle) Figure 5. Composite panel before impact (a) and after impact (b), showing generation of stresses Figure 6. Stress (a) and strain energy (b) obtained in the impact test simulation Figure 7. Stress -displacement curves obtained from the impact test simulation: (a) test with hard body and (b) test with soft body. Figure 8. Strain energy obtained in the impact test simulation: (a) hard body impact and (b) soft body impact.

*Title Page

Production, characterization and prediction of mechanical properties of waste fibre reinforced composite panels for application in adjustable partition walls of buildings J. Velosa1,3, S. Rana3*, R. Fangueiro2,3, P. Mendonça1,4 1

Territory, Environment and Construction Research Centre (C-TAC), University of Minho, Portugal 2 Department of Civil Engineering, University of Minho, Portugal 3 Fibrous Materials Research Group (FMRG), School of Engineering, University of Minho, Portugal 4 School of Architecture, University of Minho, Portugal

Abstract In the present paper, waste fibre reinforced composite panels have been developed for application in interior partition walls of buildings. These panels were produced using waste fibres collected from the textile industries and using aminoplastic phenol-formaldehyde resin. Mechanical properties such as tensile, compression and flexural properties of these composite panels were characterized and the influence of a few parameters such as fibre or matrix weight % and composite density on the mechanical properties has been analyzed. Impact properties (soft body and hard body impact), which is very important for the materials used in the partition walls, of the developed composite panels was simulated using finite element method and the influence of composite parameters (fibre or resin content, composite density) on the impact resistance and strain energy was analyzed. Although the waste fibre reinforced composites show low mechanical properties, the simulation results showed that the composite panels showed required impact properties (no collapse, no penetration or projection under both soft and hard body impact) for their successful application in the interior partition walls. It was also observed that the composite panels exhibited better impact resistance and lower deformation when produced with higher fibre % as well as higher density.

Keywords: Waste fibre composites, Mechanical properties, Impact resistance, Finite element method *Corresponding author: S. Rana. Email: [email protected]

*IJPT CTS Form

Table 1

Table 1. Details of produced composite panels Composite density Sample Codes

Thickness (mm)

Wt. % of resin (kg/m3)

P900/10

5

900

10

P1000/10

5

1000

10

P1100/10

5

1100

10

P900/15

5

900

15

P900/20

5

900

20

Table 2

Table 2. Safety criteria of internal partition walls Test

Impactor (Kg)

No. of impacts

Soft boy impact

50

1

Hard body impact

1

1

Energy (Nm) 100-200-300400 or 500 10

Criteria No collapse, no penetration and no projection

Table 3

Table 3. Mechanical properties of waste fibre composite panels Properties

Tensile Flexural Compressive

P900/10

P1000/10

P1100/10

P900/15

P900/20

Strength (MPa)

Modulus

Strength (MPa)

Modulus (MPa)

Strength (MPa)

Modulus (MPa)

Strength (MPa)

Modulus (MPa)

Strength (MPa)

Modulus (MPa)

0.87 0.24 22.33

121.47 15.70 11.47

3.39 0.28 32.40

338.18 14.00 123.16

3.11 0.24 58.74

499.01 9.51 182.00

6.50 0.31 81.65

953.45 8.00 183.30

6.66 0.46 100.18

1028.41 11.59 197.63

Figure 1 Click here to download high resolution image






