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The purpose of this work is to extend the life of plastic injection molds made by stereolithography through the use of gas‐assist technology.

Polypropylene parts were made by injection molding in stereolithography molds with and without gas‐assist technology. The mold life was evaluated by observing the number of parts produced before the breakage of each of small core pins and the ejection force was measured.

When using gas‐assisted injection molding (GAIM), the core pin life was approximately doubled, the average cavity pressure and the average mold temperature were reduced, and there was a three‐fold increase in ejection force. Also, the core pin location had a very dramatic effect on the life.

This study suggests research into understanding the relationship between ejection force and mold failure, testing the mechanical properties of the parts and identifying reliable design rules for parts produced by GAIM. Research into other low pressure injection techniques and the viability of using a wider set of polymer materials also appears promising.

The result of this research encourages molders who have abandoned the use of stereolithography tools after a few unsuccessful attempts to consider using GAIM with stereolithography molds.

This is a novel use of GAIM technology to extend the lives of molds fabricated by stereolithography.

The commercialization of new products integrating many functions in a small volume requires more and more often the rapid prototyping of small high‐resolution objects, having intricate details, small openings and smooth surfaces. To give an answer to this demand, the stereolithography process has started to evolve towards a better resolution: the “small spot” stereolithography technology allows to reach a sufficient resolution for the manufacturing of a large range of small and precise prototype parts. Microstereolithography, a technique with resolution about an order of magnitude better than conventional stereolithography, is studied by different academic research groups. The integral microstereolithography machine developed at the Swiss Federal Institute of Technology in Lausanne is described in this paper, and potential applications are presented. The resolutions of conventional, small spot and microstereolithography technologies are compared and the potential of the microstereolithography technique is shown for the manufacturing of small and complex objects.

The purpose of this study is to synthesize a new kind of a cationic-type UV-curing prepolymer diepoxycyclohexylethyl tetramethyldisiloxane, which is used to replace the current prepolymers’ common cycloaliphatic epoxy resins to prepare a novel 3D printing stereolithography material.

Diepoxycyclohexylethyl tetramethyldisiloxane was characterized and analyzed by FT-IR and 1HMR. Diepoxycyclohexylethyl tetramethyldisiloxane was compounded with a polycaprolactone polyol, some acrylates and photoinitiators to prepare a novel 3D printing stereolithography resin (3DPSLR11). Optical properties of 3DPSLR11 were investigated by HRPL-150A stereolithography apparatus and INITELLI-RAY400 UV-curing system. Tensile mechanical properties of printed 3DPSLR11 specimens were tested by WDW-50-type universal testing machine, and the glass transition temperature (Tg) was determined by DMA. Rectangle plates and double-cantilever parts were fabricated by using the stereolithography apparatus with 3DPSLR11 as the printing material, and the dimension shrinkage factors and the curl factors of the parts were investigated.

The experimental results showed that the critical exposure (Ec) of the 3D printing 3DPSLR11 was 11.6 mJ/cm², its penetration depth (Dp) was 0.18 mm, the tensile strength of the cured 3DPSLR11 was 40.1 MPa, the tensile modulus was 1,741.4 MPa, the elongation at break was 15.3%, Tg was 113°C, the dimension shrinkage factor was less than 0.85% and the curl factor was less than 8.00%.

In this work, a novel 3D printing 3DPSLR11 was prepared with diepoxycyclohexylethyl tetramethyldisiloxane as a main prepolymer. The novel 3DPSLR11 possessed excellent photosensitivity, and its cured products had good mechanical and thermal properties. The accuracy and resolution of the fabricated parts were high with 3DPSLR11 for stereolithography in 3D printing, which showed that 3DPSLR11 has potential application value as 3D printing material.

The characteristics of PZT suspensions have been studied and fit to stereolithography restraints. On one hand, researches concern the influence of fillers contents, dispersant concentration, temperature and resins nature and amount on suspensions rheological behaviour. On the other hand, the influence of photoinitiator and PZT concentrations, density of energy and nature of the resin on suspension reactivity was investigated. These experiments have led to the choice of two photosensitive suspensions suitable for stereolithography purpose; which use depend on the fillers content. Furthermore, the stereolithography process has been modified owing to the balance between suspensions rheological and photochemical properties in order to shape piezoelectric ceramics. Thanks to these improvements, PZT ceramics/polymer composites dedicated to transducers and medical imaging applications have been fabricated.

Accurate build‐time prediction for making stereolithography parts not only benefits the service industry with information necessary for correct pricing and effective job scheduling, it also provides researchers with valuable information for various build parameter studies. Instead of the conventional methods of predicting build time based on the part’s volume and surface, the present predictor uses the detailed scan and recoat information from the actual build files by incorporating the algorithms derived from a detailed study of the laser scan mechanism of the stereolithography machine. Finds that the scan velocity generated from the stereolithography machine depends primarily on the system’s laser power, beam diameter, materials properties and the user’s specification of cure depth. Proves that this velocity is independent of the direction the laser travels, and does not depend on the total number of segments of the scan path. In addition, the time required for the laser to jump from one spot to another without scan is linearly proportional to the total jump distance, and can be calculated by a proposed constant velocity. Most profoundly, the present investigation concludes that the machine uses a velocity factor which is only 68.5 per cent of the theoretical calculation. This much slower velocity results in an undesired amount of additional cure and proves to be the main cause of the Z dimensional inaccuracy. The present build‐time predictor was developed by taking into account all the factors stated above, and its accuracy was further verified by comparing the actual build‐time observed for many jobs over a six month period.

The development of a physical model of cancellous bone whose structure could be controlled would provide significant advantages over the study of in vitro samples, making repetitive or comparative testing possible. This would enable the relationship between the mechanical integrity (and hence fracture risk) of cancellous bone and its structural properties to be more exactly defined. Whilst the use of RP to generate these porous objects was a considerable challenge such objects would have been impossible to manufacture using any other approach. This short technical note describes how stereolithography was used to create over 25 accurate models, which were required to perform physical experiments to validate the results of the FEA. The note highlights how problems associated with STL and SLC file formats, support generation and software limitations were overcome to produce stereolithography models of highly complex, naturally occurring three‐dimensional structures.

Most stereolithography systems use a blade to accomplish the recoating of the part being built with a new layer of resin. States the problems associated with this technique and describes experiments conducted to determine how recoating parameters should be controlled. Differentiates between recoating over an entirely solid substrate and over one consisting of solid and liquid, i.e. the “trapped volume” condition. Discusses parameter control for both of these conditions. Concludes that recoating is an important part of the stereolithography process which must be optimized to ensure accuracy of prototype parts.

To describe the development of a novel polyether(meth)acrylate‐based resin material class for stereolithography with alterable material characteristics.

A complete overview of details to composition parameters, the optimization and bandwidth of mechanical and processing parameters is given. Initial biological characterization experiments and future application fields are depicted. Process parameters are studied in a commercial 3D systems Viper stereolithography system, and a new method to determine these parameters is described herein.

Initial biological characterizations show the non‐toxic behavior in a biological environment, caused mainly by the (meth)acrylate‐based core components. These photolithographic resins combine an adjustable low Young's modulus with the advantages of a non‐toxic (meth)acrylate‐based process material. In contrast to the mostly rigid process materials used today in the rapid prototyping industry, these polymeric formulations are able to fulfill the extended need for a soft engineering material. A short overview of sample applications is given.

These polymeric formulations are able to meet the growing demand for a resin class for rapid manufacturing that covers a bandwidth from softer to stiffer materials.

This paper gives an overview about the novel developed material class for stereolithography and should be therefore of high interest to people with interest in novel rapid manufacturing materials and technology.

The purpose of this paper is to investigate the applicability and effectiveness of Stereolithography rapid prototyping to the field of scale modelling for architectural design evaluation and demonstration purposes. Two scale models concerning a modern renovated track and field sports facility and a reconstructed ancient stadium are examined. Both models were constructed by assembling together resin parts fabricated with Stereolithography instead of milling. Critical issues encountered during the building phase of the two models are addressed and presented in detail. Comments are made on the CAD requirements of the parts geometry, on the part building and the post‐processing phases as well as on the end achieved accuracy. Problems associated with the computational time, related to the 3‐D solid modelling, and with the physical properties of the parts, are also discussed. The present Stereolithography methodology is compared to conventional model building techniques by investigating efficiency and productivity factors, quality matters and time requirements.

Presents the results of an investigation into the feasibility of producing models of human anatomy by linking MRI and stereolithography. Begins by describing the requirements for developing a link between the two technologies together with the major problems that this involves. Describes the processes undertaken to enable the creation of a model of a human brain. The model showed excellent anatomical details and demonstrated that the technique of linking MRI and stereolithography is entirely feasible. However, the preparatory work required prior to building the model showed that there are many difficulties associated with transferring and processing the imaging data. Recommendations are made as to how this technique needs to evolve.