Papers by Keyword: Rapid Prototyping (RP)

Abstract: The study of nanocrystalline calcium phosphate physical-chemical characteristics and, thereafter, the possibility to imitate bone mineral for the development of new advanced biomaterials is constantly growing. The availability to use synthetic biomimetic hydroxylapatites (HA), since they are the most important inorganic constituents of hard tissues in vertebrates, represents a great turning point in bone tissue engineering because of their chemical similarity to the biological mineral component. The ability to control the architecture and strength of a bone tissue engineering scaffold is critical to achieve a harmony between the scaffold and the host tissue. The scaffold attempts to mimic the function of the natural extracellular matrix, providing a temporary template for the growth of target tissues. Scaffolds should have suitable architecture and strength to serve their intended function. Rapid prototyping (RP) technique is applied to tissue engineering to satisfy this need and to create a scaffold with fully interconnected pore structure directly from the scanned and digitized image of the defect site. In this study, we developed a biomimetic mineralized collagen/Polycaprolactone composite by self-assembling process of collagen fibers and nucleation of a nanostructured HA mimicking the natural bone. This new solution provides a hybrid material, based on natural components of bone (collagen and HA) and the support of the widely-tested PCL (polycaprolactone) giving the scaffolds ideal characteristics such as resorption, biocompatibility and 3-D printability. CAD design of the microstructure and bioprinting fulfills the need to finely control the scaffold’s shape to best fit the anatomical defect, the possibility of customization and the ability to perfectly control spatial distribution of pores and their morphology. The results allowed the conclusion that these scaffolds are biocompatible and allow the colonization and proliferation of MSC (mesenchymal stem cell). The in vivo results confirm the scaffold’s biocompatibility and its composition and structure create the basis for bone tissue regeneration.

Abstract: Support structure plays a vital role in Rapid Prototyping system in producing quality and dimensional accurate prints for a product having bridges or overhangs in a Rapid Prototyping product. The paper reports the selection of best support structure for any given model based on build time, material requirement and quality output of the prints. It also discusses the effects of introducing raft layers on a given model. A CAD model in STL (stereo lithography) format is an input to the Rapid Prototyping system. The CAD data is sliced for 3 different support structures by keeping constant printing parameters. Based on the build time, material consumption and part quality obtained, thebest support structure of any given model is experimentally found.

Abstract: The stress concentration of the circular hole within the mechanical mart can easily derived by the photo-elastic technique if the testing specimen is sufficiently developed. The testing specimen using the characteristic of the photo-elastic coefficient, with actual form like the mechanical part by rapid prototyping forming is thus used in this paper. The rapid mold for prototype is made by the RTV-2 silicone gel associated with the vacuum chamber to remove the air within it. The testing scheme is by way of the simply supported beam where the load is imposed on the middle of the specimen. Results show that the smaller diameter of hole on specimen provides a larger stress concentration effect. When the diameter of the hole is small, the stress concentration effects caused by the machined hole and the forming hole have almost no difference. However, the stress concentration effects of the larger diameter of the machined hole and of the formed hole give significant difference, the stress concentration caused by the machined hole is much greater than one of the formed hole. In this paper, the actual shape of the specimen which is as same as the original mechanical components can be quickly obtained by the rapid prototyping technology for the photoelastic technique to reveal the experimental mechanics of real applications.

Abstract: In order to solve the problem that the design and manufacture method for letters product in traditional ways has a long period and high cost, a new design and manufacture method based on RP technology was proposed. Firstly, Rhinoceros software was used to design the initial model, and then the initial model was put into SolidWorks software for model processing. After that, the established model was put into RPdata software for data processing. Finally, by using RP450B rapid prototyping machine, a rapid prototype of the model was achieved. Through the study, some key problems such as model design, processing of model data and manufacturing process were discussed. The new design and manufacture method has greatly shortened the design and manufacture cycle of the letters product, and it provides the reference for the design and manufacture for other art works.

Abstract: This paper 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 layer thicknes, surface roughness and hardness value. These works also prove that photo absorber composition solution gave a different mechanical properties effect for 3D microstructure fabrication.

Abstract: The development of Rapid Prototyping (RP) gave the consumer the ability to form prototype or a component of the prototype that can be directly used in assemblies and product testing for short or medium production with the least time consumed. The purpose of this paper is to study the dimensional accuracy and surface roughness for RP part as a master pattern for Investment Casting (IC) process. The material that been used is Polylactic acid (PLA) using a technique of Fused Deposition Modeling (FDM). The effects of internal pattern structure and part orientation during fabrication on the part master pattern can analyze from the response analysis. Results shows that PLA/FDM produced better accuracy and surface roughness when the part is fabricated with internal pattern structure compare to hollow structure. The internal pattern structures improved the quality of part and capable to supporting the design so that less warping or shrink. Part that built with 90o part orientation produced better accuracy and surface roughness compare to 0o part orientation.

Abstract: The purpose of this paper is to give an overview of radiofrequency procedure, the main components of the procedure, critical issue concern with existing cannula design and proposed methodology in design and enhancement. The literature on radiofrequency procedure has been reviewed. The main issue or problem in existing design related to placement of cannula to target nerves which are ability to firmly hold the cannula and adjustment of the cannula to the target nerve. This study proposes the fabrication prototype cannula hub using Fused Deposition Modeling (FDM) machine. Essentially, this study may benefit a lot in providing alternative design of the cannula hub while promising a better performance of RF cannula.

Abstract: This Report Describe the Development of a New Polymer Nano-Composite Material that Tobe Used as an Altenative Material for Fused Deposition Modeling (FDM) Process. this New Type Ofpolymer Nano-Composites is a Mixture of Polycaprolactone (PCL) as a Main Resin, Montmorillonite(MMT) and Hydroxyapatite (HA) as a Filler. the Compunding Process is Done Using Single Screwextruder Nanomixer Machine. then the Compounded Polymer Nano-Composites is Crushed and Fedinto Single Screw Extruder which is Design to Produce a Filament. A Polymer Nano-Compositesfilament with 1.7 Mm of was Successfully Produced by Assisted of Water Bath and Puller Machine.The Temperature Setting for Heater 1, Heater 2, Heater 3 and Heater 4 on Extruder Machine Are78°C, 114°C, 113°C, and 79°C Respectively. the Spindle Speed for Extruder Machine was Set to 3.0Hz, while the Puller Machine Speed is 2.5%.

Abstract: The term direct investment casting represents the employment of pattern fabricated by rapid prototyping technique have been reduce the cost and production lead time. The non-wax materials having robust ability on producing pattern in accuracy stability and clean burnout. However 3D printer (3DP) parts are powder based materials and not easily burnout during firing process. The purpose of this investigation were to evaluate the ZP150 powder materials as a sacrificial pattern to be used in investment casting (IC) process. Result shows powder based patterns of 3DP process failed to disintegrate completely even at high temperature during collapsibility investigations. However the pattern become brittle and easily remove by water pressure. Therefore the ceramic mould can be used for metal casting.

Abstract: Selection of the most suitable Rapid Prototyping (RP) and manufacturing process for a specific part creation is a difficult task due to the development of RP processes and materials. Most current RP processes can build with more than one type of material. The paper presents the evaluation on Acrylonitrile Butadiene Styrene (ABS) and Polylactic acid (PLA) part produced from Fused Deposition Modeling (FDM) as a master pattern for Investment Casting (IC) process. The main purpose of this research is to evaluate the dimensional accuracy and surface roughness for hollow and solid part of FDM pattern for IC process with different layer thickness. The value were taken for both before and after the casting process. Results show that model fabricated with hollow internal pattern structure (ABS material) that produced by low layer thickness is better than other models in terms of its dimensional accuracy (-0.19666mm) and surface roughness (1.41μm). Even though the ABS built part performed better as the model, the PLA build part produces better overall casting result. Final part fabricated with solid pattern (PLA material) that produced by high layer thickness is better than other final parts which its dimensional accuracy (-0.12777mm) and surface roughness (3.07μm).