Parameter optimization for photo polymerization of mask projection micro stereolithography

This study presents a research on 3D part fabrication from composition of photo initiator (Phenylbis(2,4,6-trimethylbenzoyl)), photo absorber (Sudan I) and 1, 6- Hexanediol polymer effect based on curing parameters. A DLP projector was used as energy light source which initiated the photo reactive polymer at three different light source distances with three different exposed time to evaluate photoreactive polymer solidification phenomena. The experiment results obtained shows that Sudan I composition, light intensity value and exposure time of the varied photo absorber give significant effect to mechanical properties such layer thickness, dimensional accuracy, surface roughness and hardness value. These works also prove that photo absorber composition solution gave a different mechanical properties effect for 3D microstructure fabrication

Evaluation on performance of square finned conformal cooling channel (sfccc) fabricated by selective laser melting (slm) on plastic moulded part

In plastic injection moulding (PIM) process, the cooling stage is the most important phase because it significantly affects the productivity and quality of the molded part. Thus, the cooling system need to be emphasized in designing the injection mould system. The application of conformal cooling channels which only can be fabricated by additive manufacturing technology (AM) are proven to increase the injection moulding performance and able to reduce the quality issues. This research introduced the Square Finned Conformal Cooling Channel (SFCCC) in the PIM as a way to enhance the performance of square shape conformal cooling channel (SSCCC) in PIM. The mould insert with SFCCC has been designed, simulated via finite element analysis software, fabricated (by combination of High Speed Machining and Selective Laser Melting (SLM)), and tested using a front panel housing as the injected part for the case study. Eight types of variate SFCCC design (SFCCC 1 to SFCCC 8) employing finned and sub groove concept were analysed via simulation work to determine the best design in terms of shortest cooling time. The results showed that the shortest cooling time recorded by SFCCC 8 was at 7.621 sec, an improvement of 16.44% compared with SSCCC. In terms of cycle time, the SFCCC is able to improve the SSCCC by 8.33% to 10.26%. Meanwhile, in comparison with industrial mould using Milled Groove Conformal Cooling Channel (MGCCC), the SFCCC showed an improvement of 19.60% to 39.36% based on the coolant temperature. The experimental results showed the greatest shrinkage in the X-direction at 0.93% and the smallest shrinkage at 0.6%. For the Y-direction, the greatest shrinkage is 0.97% and the smallest shrinkage is 0.39%. In comparison with the injected part via MGCCC, the SFCCC had a slightly greater overall shrinkage in relation to the shrinkage and warpage at points X and Y direction. Most front panel housing shrinkage and warpage values in the experimental study were smaller than those of the simulative study. However, the experimental results were in line with the simulative results, proving that the SFCCC design had better cycle times and acceptable quality for an industrial mould

Effects of selective laser melting parameters on relative density of AlSi10Mg

Selective Laser Melting (SLM) is an advance Additive Manufacturing (AM) technique in which a component is manufacturing in a layer by layer manner by melting the top surface of a powder bed with a high intensity laser according to sliced 3D CAD data. AlSi10Mg alloy is a traditional cast alloy that is often used for die-casting. Because of its good mechanical and other properties, this alloy has been widely used in the automotive industry. In this work, the effects on the relative density is investigated for SLM-produced AlSi10Mg parts on one factor at a time (OFAT) basis by keeping constant various parameters such as laser power, scanning speed and hatching distance. It is shown that AlSi10Mg parts produced by SLM having best relative density values are at 350 watt laser power, 1650 mm/s of scanning speed and hatching distance of 0.13mm

Porosity effects of AlSi10mg parts produced by selective laser melting

Selective Laser Melting (SLM) is one of the powder-based manufacturing processes that has a wider established uses in the production of metallic alloy parts. It is capable of producing a high-density part through the melting of powder to form the desired shape. Fabrication of the AlSI10Mg part relies on several process parameters such as the laser power, laser scan speed, hatch distance, layer thickness and scanning strategy. They are specially designed and monitored to achieve optimum level. In this paper, porosity percentage were obtained from manipulating the hatch distance of fabricated SLM parts. The results appeared that smallest percentage obtained when the hatch distance was 0.13mm which is 0.46%. However, the highest porosity obtained when the lower hatch distance applied

The Thermal Effect of Variate Cross-Sectional Profile on Conformal Cooling Channels in Plastic Injection Moulding

Cooling system is an important role in designing a productive plastic injection moulding (PIM). The selection of geometry and layout for plastic injection moulding cooling channels strongly influences the cooling performance such as cooling time and thermal distribution that leads to shrinkage and warpage. This paper presents the study to determine the best cooling channel layout and cross-sectional profile which include circular straight drilled cooling channels, circular conformal cooling channels, square shape conformal cooling channels, elliptical conformal cooling channels and diamond conformal cooling channels. The cooling time and thermal distribution were simulated by Moldflow Insight (MFI) software. Results are presented based on ejection time and temperature variation by using transient analysis in MFI. The results found the best cross-sectional of cooling channels indicated by square shape conformal cooling channels, compare to others due to the shortest cooling time that recorded from simulation. The conformal cooling channel layout also resulted greater thermal distribution compared to straight drilled cooling channel design. Â

Plastic waste and its method of recycling

Plastics waste is one of the major problems the world is currently facing due to the increase in plastic production and their demands in emerging economies. One of the concerns of plastic is unsystematic disposal problem that leads to an increase in plastic waste accumulation which can last forever in the environment and causing sever pollution.

CHEMICAL ANALYSIS DENDROCALAMUS ASPER BAMBOO AND SUITABILITY FOR PULP AND PAPER

The chemical analysis of bamboo species, namely Dendrocalamusasper or popular named as BuluhBetong has been evaluated. From the age of 3 years, this species shows different chemical properties related to holocellulose, cellulose, solvent extraction, alkali solubility, lignin, hot water solubility, cold water solubility, ash, silica and pentosan. Holocellulose content of about 60.48% to 64.75%, cellulose content of about 35.73% to 43.14%, for all bamboo segments indicated as a suitable material for pulp and papermaking. Low level of solvent extractive of about 5.09% to 6.23%, hot water soluble of about 6.29% 9.49% and cold water soluble of about 9.35% to 10.49% also produced the content that cannot interfere with the paper-making process. In addition, the low ash and silica content for all sections of bamboo will indicate a normal alkali consumption and give little challenge to the operational process. High pentosan content in the middle and top sections between 16.32% and 20.88% and lignin content of around 39.27% to 32.51% also promise little challenge for pulping as compared to the bottom section. Therefore, based on the overall findings, the middle section, and the top section had an advantage over the bottom section. As a result, the middle and top sections are best used as a new material in pulp and paper making process

CHEMICAL ANALYSIS DENDROCALAMUS ASPER BAMBOO AND SUITABILITY FOR PULP AND PAPER

RACT The chemical analysis of bamboo species, namely Dendrocalamusasper or popular named as BuluhBetong has been evaluated. From the age of 3 years, this species shows different chemical properties related to holocellulose, cellulose, solvent extraction, alkali solubility, lignin, hot water solubility, cold water solubility, ash, silica and pentosan. Holocellulose content of about 60.48% to 64.75%, cellulose content of about 35.73% to 43.14%, for all bamboo segments indicated as a suitable material for pulp and papermaking. Low level of solvent extractive of about 5.09% to 6.23%, hot water soluble of about 6.29% 9.49% and cold water soluble of about 9.35% to 10.49% also produced the content that cannot interfere with the paper-making process. In addition, the low ash and silica content for all sections of bamboo will indicate a normal alkali consumption and give little challenge to the operational process. High pentosan content in the middle and top sections between 16.32% and 20.88% and lignin content of around 39.27% to 32.51% also promise little challenge for pulping as compared to the bottom section. Therefore, based on the overall findings, the middle section, and the top section had an advantage over the bottom section. As a result, the middle and top sections are best used as a new material in pulp and paper making process

CHEMICAL ANALYSIS DENDROCALAMUS ASPER BAMBOO AND SUITABILITY FOR PULP AND PAPER

The chemical analysis of bamboo species, namely Dendrocalamusasper or popular named as BuluhBetong has been evaluated. From the age of 3 years, this species shows different chemical properties related to holocellulose, cellulose, solvent extraction, alkali solubility, lignin, hot water solubility, cold water solubility, ash, silica and pentosan. Holocellulose content of about 60.48% to 64.75%, cellulose content of about 35.73% to 43.14%, for all bamboo segments indicated as a suitable material for pulp and papermaking. Low level of solvent extractive of about 5.09% to 6.23%, hot water soluble of about 6.29% 9.49% and cold water soluble of about 9.35% to 10.49% also produced the content that cannot interfere with the paper-making process. In addition, the low ash and silica content for all sections of bamboo will indicate a normal alkali consumption and give little challenge to the operational process. High pentosan content in the middle and top sections between 16.32% and 20.88% and lignin content of around 39.27% to 32.51% also promise little challenge for pulping as compared to the bottom section. Therefore, based on the overall findings, the middle section, and the top section had an advantage over the bottom section. As a result, the middle and top sections are best used as a new material in pulp and paper making process

Printing and Curing of Conductive Ink Track on Fabric using Syringe Deposition System with DLP Projector and Hot Plate

Printing is a technique to transfer ink onto substrates to create pattern and syringe deposition system has shown some great potential in printing due to its ability to produce filamentary bead tracks which is important concerning conductivity and easily adopted on conformal surfaces which could not be realized by conventional technique. Fabrics with integrated electrical features able to create intelligent articles and may potentially open up new perspective areas of application in textile printing. However, the applicability of this technique on fabrics remains unknown which the ink used has to meet certain requirements including high electrical conductivity, resistance to oxidation, dry out without clogging, good adhesion with suitable viscosity and surface tension. Thus, there is a need to do this study which is to determine the feasibility of syringe deposition system to print a conductive ink tracks using silver epoxy-based conductive ink on fabric substrate via lycra material. This study is also aim to investigate the feasibility of using DLP projector with hot plate as another source of heat to be used in curing the ink tracks on fabric. The effect of printing and curing parameters to the characteristics and conductivity of the ink track is investigated. Several mechanical and electrical tests were also administered to determine the cure, hardness, adhesion and resistance level of the ink tracks. The results obtained were as expected which higher printing speed and lower deposition height used, a narrower and thinner ink tracks were produced. Sample with 4 mm/s of printing speed and deposition height of 1 mm resulted in dimension closer to the targeted dimension. The longer curing time and higher temperature used, a lower resistance is produced. The lowest resistance achieved is 0.9 Ω cured at 150°C for 60 minutes. The conductivity of the ink track was affected by curing process and cross-sectional area of the ink track. It is proven that a syringe deposition system is capable of printing the ink track and DLP projector with hot plate is suitable to cure the ink track properly on fabric