M. M. Ratnam

Recycle Polypropylene (RPP) - Wood Saw Dust (WSD) Composites - Part 1: The Effect of Different Filler Size and Filler Loading on Mechanical and Water Absorption Properties

The compounding of recycled polypropylene (RPP) and wood saw dust (WSD) are carried out using five different filler loadings (0, 10, 20, 30, 40, and 50%) with three WSD filler sizes (100, 212, and 300 mm). The composites are mixed and extruded using Haake Rheodrive 500 twin screw extruder. The mechanical and water absorption properties of composites are characterized accordingly. The results show that composites with a smaller particle size (100 mm) have remarkably higher properties compared to others (212 and 300 mm). Composites filled up to 30% WSD exhibits improved mechanical properties but the value dramatically decreased above 30% filler loading. The evidence of fiber-matrix interphase is analyzed using scanning electron microscope (SEM).

An experimental and finite element analysis of the static deformation of natural fiber-reinforced composite beam

This paper describes the application of the shadow moire method for direct measurement of the whole-field deformation of a cantilever beam, made from natural fiber-reinforced composite (NRFC) material, under static loading and comparison of the experimental results with those predicted using finite element analysis (FEA). The material properties required in the FEA were obtained by calculating the mean of the property values determined from three-point bending tests on several standard test specimens made from the material. The classical phase-shift technique was used in the shadow moire method to increase the measurement resolution. The comparison shows the existence of a non-zero gradient at the base of the cantilever in the measured deformation profiles probably due to the clamping conditions of the cantilever. However, the difference in deformation at the free edge is only 0.4 mm over a length of 160 mm.

Machine vision method for non-contact measurement of surface roughness of a rotating workpiece

Purpose – This paper aims to propose a non-contact method using machine vision for measuring the surface roughness of a rotating workpiece at speeds of up to 4,000 rpm. Design/methodology/approach – A commercial digital single-lens-reflex camera with high shutter speed and backlight was used to capture a silhouette of the rotating workpiece profile. The roughness profile was extracted at sub-pixel accuracy from the captured images using the moment invariant method of edge detection. The average (Ra), root-mean square (Rq) and peak-to-valley (Rt) roughness parameters were measured for ten different specimens at spindle speeds of up to 4,000 rpm. The roughness values measured using the proposed machine vision system were verified using the stylus profilometer. Findings – The roughness values measured using the proposed method show high correlation (up to 0.997 for Ra) with those determined using the profilometer. The mean differences in Ra, Rq and Rt between the two methods were only 4.66, 3.29 and 3.70 per...

Polyester Composites Filled Carbon Black and Activated Carbon from Bamboo (Gigantochloa scortechinii): Physical and Mechanical Properties

Carbon black and activated carbon were produced from bamboo (Gigantochloa scortechinii) using pyrolysis (at 900°C) and zinc chloride (ZnCl2) chemical activation (at 700°C) and used as a filler in polyester composites. The composites were prepared at 10, 20, 30, and 40% filler loading. The effects of water absorption, water content, and density of composites were determined. Results showed that water content and water absorption slightly increased as filler loading increased, while density value decreased as filler loading increased. Tensile, flexural and impact tests were performed at different filler loading. The results indicated that tensile and flexural strength, elongation at break, toughness and impact properties decreased as filler loading increased. However, the tensile and flexural modulus exhibited the reverse phenomenon. The filler-matrix bonding from impact fracture was analyzed by scanning electron microscopy (SEM).

Wood Filler-recycled Polypropylene (WF-RPP) Composite Pallet: Study of Fastening Method

Materials handling pallets were developed using wood filler-recycled polypropylene (WF-RPP) composite in our previous work. An important stage in the development of the full-size pallet is the assembly of the various components that make up the pallet. The objective of this work is to find a suitable fastening method, fastener type, and size to assemble the stringer-class pallet made from the composite. The following investigations were carried out: (i) comparative study on the ease of fastening screws with and without pre-drilling, (ii) determination of minimum depth to which pilot holes need to be drilled to enable screws of various sizes (#3 to #10) to penetrate into the composite, (iii) comparison on the ease of fastening the components using different screw types, (iv) determination of the minimum distance between screws and minimum distance of screw from the edge required to assemble the components without cracking, and (v) comparative study on the ease of fastening of composites having different filler loading. The results of the study showed that it is not possible to use wood screws or tapping screws to fasten the various parts of the pallet without pre-drilling. A pilot hole of diameter 2.5 mm and depth more than 6.0 mm was found to be suitable for screws with nominal sizes ranging from gauge #3 (2.515mm) to gauge #8 (4.166mm) to penetrate into the composite without difficulty.

Determination of tool nose radii of cutting inserts using machine vision

Purpose – The nose radii of cutting inserts are normally measured using a profile projector or toolmakers microscope. Since only a sector of a circle is available for the measurement using such instruments, the radii determined from these methods are inaccurate. The purpose of this paper is to present an alternative method of determining the nose radii more accurately using machine vision.Design/methodology/approach – The 2D images of the cutting inserts were captured using a CCD camera with the aid of back lighting. The tool nose center in each digitized image was located based on the tool geometry. The curved nose profile was transformed into a linear profile using polar‐radius transformation. The nose radius was then varied within ten pixels of the nominal radius and the average deviation from a straight line profile in the nose region in the polar‐radius plot was evaluated. The radius corresponding to the minimum average deviation is identified as the most accurate radius value.Findings – For the 15 ...

Wood Filler(WF)-recycled Polypropylene (RPP) Composite Pallet: Study of Static Deformation using FEA and Shadow Moire

Pallets used in materials handling are mostly made from wood. Wood pallets can, however, undergo degradation and fungal attack when used in the open. Composite materials derived from waste wood sawdust and recycled plastic have significant potential for use in the manufacture of pallets. In this study, wood filler (WF)-recycled polypropylene (RPP) composite was used to fabricate a one-fifth scale model of a pallet. For mechanical property testing, several composite boards were prepared with filler of particle sizes 100 μm and 300 μm and filler content varying from 10% to 40% (by weight). The mechanical properties were used in the finite element analysis (FEA) to predict the deformation of the pallet under static load. An experimental rig using shadow moiré method was developed to measure the actual deformation of the pallet. Close agreement in the deflection profile was observed at the center of the pallet, though there was a greater difference at other points.

Study of three-dimensional deformation of a pallet using phase-shift shadow moiré and finite-element analysis

We present the results of a comparative study on the static deformation of a pallet, made from oil-palm fiberreinforced composite material, using the phase-shift shadow moiré method and finite-element analysis (FEA). The pallet was designed and analyzed using a commerical software package. The effect of various joint types on the deformation profile was studied to obtain a simplified model to represent the actual design. A one-fifth scale model of the pallet was fabricated and the deformation due to static loading was measured using the phase-shift shadow moiré method. The comparison between the measurement and FEA results on the deformed profile showed a maximum difference of 13.7% at the center of the some of the deck boards, but a smaller difference at other deck boards. The FEA results also produced a larger deformation gradient compared to the measurements.