Effect Of Manufacturing Process Parameters Research Articles

Effect of manufacturing process parameters on the compression and energy absorption properties of 4D-printed deformable honeycomb structure

Abstract 4D-printed deformable honeycombs can produce pro-programmed shape deformation and different properties under external stimuli, and the manufacturing process parameters are the dominant factors affecting the microstructure and properties of the manufactured honeycomb structures. Although many researchers investigating the effects of manufacturing process parameters on the mechanical properties of printed materials, but still a lack of research on the relationship between manufacturing process parameters and properties of honeycomb structures. Therefore, a novel honeycomb structures which has two configurations under temperature stimuli is proposed, and the optimum manufacturing processes for the printing of this honeycomb are selected considering the compression and energy absorption properties simultaneously. The novel honeycomb is designed and printed with fused deposition modeling (FDM) technology, which have hexagonal configuration (Structure I) and semi-triangular configuration (Structure II) under external temperature stimulus. The energy absorption capacity of Structure I and compressive properties of Structure II are investigated under different manufacturing process parameters. The experimental results indicate that the layer thickness has the most significant impact on the mechanical performance of deformable honeycombs. The combination of a layer thickness of 0.2 mm, printing speed of 40 mm/s, and 100% infill density are the best process parameters for the novel deformable honeycomb structures.

An Innovative Stereolithography 3D Tubular Method for Ultrathin Polymeric Stent Manufacture: The Effect of Process Parameters.

In the last decades, researchers have been developing bioresorbable stents (BRS) to overcome the long-term complications of drug-eluting stents (DES). However, BRS technology still presents challenging limitations in terms of manufacturing, materials, or mechanical properties. At this juncture, companies have developed ultrathin DES that may further improve the efficacy and safety profile of traditional DES by reducing the risk of target-lesion and target-vessel failures until BRS are developed. Nonetheless, the metallic platform of ultrathin DES still presents problems related to their cellular response. The use of polymers as a permanent platform in DES has not previously been studied due to the limitations of current manufacturing technologies. In this work, an innovative manufacturing method for polymeric stent production using tubular stereolithography (SLA) technology is proposed both for BRS and for ultrathin polymeric DES. The effects of manufacturing process parameters were studied by modelling the outcomes (stent thickness and strut width) with the key manufacturing variables (exposure, resin volume, and number of layers). Two different laser setups were used to compare the results. Microscopy results proved the merit of this novel tubular SLA process, which was able to obtain stents with 70 μm strut width and thickness in barely 4 min using only 0.2 mL of resin. Differential Scanning Calorimetry (DSC) results showed the stability of the manufacturing method. The results obtained with this innovative technology are promising and overcome the limitations of other previously used and available technologies.

Effect of manufacturing process parameters on the wear rate of Al 6061–Cu–SiCp alloy composites

In selecting the raw material for the production of machine parts, its wear resistance is considered a key parameter. Stir casting is a highly economical and effective technique for the manufacture of metal matrix composites. In the present research work, the tribological characteristics of an aluminum (Al) 6061 alloy composite reinforced with varying particle sizes of silicon carbide (SiC) (45, 53 and 63 μm) were investigated using a pin-on-disk wear-testing machine. Apart from this, the influence of pouring temperature and stirring speed during stir casting is also taken into account while characterizing the composite’s wear behavior. The analysis of variance test results indicate that the particle size of the silicon carbide reinforcement affects the wear rate of the composite samples. It was observed that the combined effect of stirring speed and pouring temperature significantly influences the wear rate of the test samples. Nevertheless, the combined effect of stirring speed and particle size of the ceramic reinforcement, as well as pouring temperature and particle size of silicon carbide, has no significance as far as the wear rate is concerned. The microstructural study of the worn samples was conducted using scanning electron microscopy analysis.

3D-printed Tubular Scaffolds for Vascular Tissue Engineering

Biomedical engineering is the application of engineering principles and design concepts to medicine and biology for healthcare purposes. Much of the work in biomedical engineering consists of research and development, spanning a broad array of subfields like biomechanics, genetic, neural, pharmaceutical, medical devices and tissue engineering among others. Tissue engineering has emerged as a key discipline for organ and tissue regeneration, in which compatibility with final user and a fast regeneration are still major challenges. Recently, three-dimensional printing has arose as an alternative system for producing biomaterials devices, such as scaffolds for tissue engineering. The proliferation of murine fibroblasts NIH/3T3, widely used in tissue engineering studies, into polycaprolactone scaffolds has been assayed in this paper. This work aim to analyze the effect of different architectures of 3D tubular scaffolds with empty core on fibroblast proliferation, focusing the tissue engineering application. We determined the effect of manufacturing process parameters and scaffold design onto the cell proliferation. From results, it can be concluded that manufacturing parameters (printing speed, temperature, and flow rate) affected fibroblast growth rate up to 40-65%. Narrow pores produced by an increased material extrusion showed less fibroblast growth, possibly due to a hindered oxygen and nutrient exchange. Nevertheless, future experiments using different designs and scaffold's architecture must be done.

The Effect of Bonding Temperature and Curing Time on Peel Strength of Anisotropically Conductive Film Flex-On-Board Samples

Today, flex-on-board (FOB) attachments are commonly used in a variety of applications. By using anisotropically conductive adhesives (ACAs), low-cost flex materials that could not withstand typical soldering temperatures can be utilized. This paper examines the effect of manufacturing process parameters on the peel strength of a FOB assembly with an ACA attachment. The effects of bonding time and temperature on the curing properties of the ACA were also studied. The mechanical strength of the assembly was studied using a 90° peel strength test. The results showed that, by elevating curing temperature, better peel test results were obtained due to the higher degree of cure of the ACA. Additionally, longer curing time increased the peel strength. However, it also caused a considerably higher deviation in the results. Failure analysis using scanning electron microscopy showed that, with a higher degree of curing, the failure location in the peel strength test changed from the flex-adhesive interface toward the adhesive-substrate interface.

Optimal synthesis and characterization of Ag nanofluids by electrical explosion of wires in liquids

Silver nanoparticles were produced by electrical explosion of wires in liquids with no additive. In this study, we optimized the fabrication method and examined the effects of manufacturing process parameters. Morphology and size of the Ag nanoparticles were determined using transmission electron microscopy and field-emission scanning electron microscopy. Size and zeta potential were analyzed using dynamic light scattering. A response optimization technique showed that optimal conditions were achieved when capacitance was 30 μF, wire length was 38 mm, liquid volume was 500 mL, and the liquid type was deionized water. The average Ag nanoparticle size in water was 118.9 nm and the zeta potential was -42.5 mV. The critical heat flux of the 0.001-vol.% Ag nanofluid was higher than pure water.

Effect of manufacturing process parameters on virus inactivation by dry heat treatment at 80 °C in factor VIII

Dry heat treatment at 80 degrees C for 72 h is used as a virus inactivation step for some coagulation factor concentrates such as Bio Products Laboratory's (BPL) factor VIII 8Y. In the current study, the effect of this process has been tested on a range of viruses. In addition the effect of various manufacturing process parameters on virus inactivation has been investigated. Samples of product intermediate were obtained from manufacturing, spiked with virus and subjected to freeze drying and dry heat treatment. Virus inactivation was determined by infectivity assay. Freeze drying followed by dry heat treatment was effective for inactivating a wide range of enveloped and nonenveloped viruses. Sucrose or protein concentration had no effect on virus inactivation. Product presentation or the interruption of heat treatment also had no effect. The inactivation of some of the viruses was greater at higher residual water content but under such conditions the stability of the product was reduced. This virus inactivation step was effective for a wide range of viruses and over the range of process conditions encountered in manufacturing. This demonstrates the robustness of this process step.

Analysis of catalyst particle strength by impact testing: The effect of manufacturing process parameters on the particle strength

The mechanical strength of porous alumina catalyst carrier beads, used in the reforming units with continuous catalytic regeneration, was measured by impact testing. With this testing method particle strength can be measured at higher strain rates than the traditional crushing test method, hence providing a better simulation of pneumatic conveying and chute flow conditions, and also a large number of particles can be tested quickly. This is important for particles with a brittle failure mode such as the alumina particles used in this work as a wide distribution of mechanical strength usually prevails. Extensive impact testing was carried out first with an industrial sample, in order to understand the failure mechanism of this type of particle s and to develop a methodology for analysing the extent of breakage by impact. Then the method was used to analyse the effect of a number of process parameters, such as filler, macroporosity and drying procedure on the particle strength with the aim of optimising the manufacturing process. The impact test results were then used to test the model of breakage behaviour of particulate solids proposed by Vogel and Peukert [Vogel and Peukert, Breakage behaviour of different materials—construction of a mastercurve for the breakage probability. Powder Technol., 129 (2003) pp. 101–110].

SCREEN PRINTING PROCESS DESIGN OF EXPERIMENTS FOR FINE LINE PRINTING OF THICK FILM CERAMIC SUBSTRATES

Screen printing has been the dominant method of thick film deposition because of its low cost. Many experiments in industry have been done and many models of the printing process have been developed since the 1960's. With a growing need for denser packaging and a drive for higher pin count, screen printing has been refined to yield high resolution prints. However, fine line printing is still considered by industry to be difficult. In order to yield high resolution prints with high first pass yields and manufacturing throughput, the printing process must be controlled stringently. This paper focuses on investigating the effect of manufacturing process parameters on fine line printing through the use of statistical design of experiments (DOE). The process parameters include print speed, squeegee hardness, squeegee pressure, and snap-off distance. Response variables are space widths of 10 mil, 8 mil, and 5 mil lines in both parallel and perpendicular directions relative to the squeegee travel direction. It is concluded that the squeegee hardness and print speed have statistically significant effects on print quality. The harder the squeegee hardness and the lower the print speed within the range of values tested, the better the printed results. It was observed that the space width between perpendicular lines is narrower than that of parallel lines. The implementation procedures of the experimental design are also presented. The analysis of a 2k factorial design with center points pertaining to the fine line printing experiment is discussed in detail.