Fabrication of porous polymeric matrix drug delivery devices using the selective laser sintering technique

2001 ◽  
Vol 215 (2) ◽  
pp. 191-192 ◽  
Author(s):  
K F Leong ◽  
K K S Phua ◽  
C K Chua ◽  
Z H Du ◽  
K O M Teo
Keyword(s):  
Drug Delivery ◽  
Laser Power ◽  
Selective Laser Sintering ◽  
Laser Sintering ◽  
Polymeric Matrix ◽  
Beam Power ◽  
Blue Dye ◽  
Scan Speed ◽  
Drug Delivery Devices ◽  
Fractional Release

New techniques in solid freeform fabrication (SFF) have prompted research into methods of manufacturing and controlling porosity. The strategy of this research is to integrate computer aided design (CAD) and the SFF technique of selective laser sintering (SLS) to fabricate porous polymeric matrix drug delivery devices (DDDs). This study focuses on the control of the porosity of a matrix by manipulating the SLS process parameters of laser beam power and scan speed. Methylene blue dye is used as a drug model to infiltrate the matrices via a degassing method; visual inspection of dye penetration into the matrices is carried out. Most notably, the laser power matrices show a two-stage penetration process. The matrices are sectioned along the XZ planes and viewed under scanning electron microscope (SEM). The morphologies of the samples reveal a general increase in channel widths as laser power decreases and scan speed increases. The fractional release profiles of the matrices are determined by allowing the dye to diffuse out in vitro within a controlled environment. The results show that laser power and scan speed matrices deliver the dye for 8-9 days and have an evenly distributed profile. Mercury porosimetry is used to analyse the porosity of the matrices. Laser power matrices show a linear relationship between porosity and variation in parameter values. However, the same relationship for scan speed matrices turns out to be rather inconsistent. Relationships between the SLS parameters and the experimental results are developed using the fractional release rate equation for the infinite slab porous matrix DDD as a basis for correlation.

The Optimization Design Study of Selective Laser Sintering Process Parameters on the Pro-Coated Sand Mold

2011 ◽  
Vol 55-57 ◽  
pp. 853-858
Author(s):  
Rong Cheng ◽  
Xiao Yu Wu ◽  
Jian Ping Zheng
Keyword(s):  
Layer Thickness ◽  
Process Parameters ◽  
Laser Power ◽  
Selective Laser Sintering ◽  
Dimensional Accuracy ◽  
Processing Parameters ◽  
Laser Sintering ◽  
Process Variables ◽  
Scan Speed ◽  
Coated Sand

This paper presents experimental investigations on influence of important process parameters viz., laser power, scan speed, layer thickness, hatching space along with their interactions on dimensional accuracy of Selective Laser Sintering (SLS) processed pro-coated sand mold. It is observed that dimensional error is dominant along length and width direction of built mold. Optimum parameters setting to minimize percentage change in length and width of standard test specimen have been found out using Taguchi’s parameter design. Optimum process conditions are obtained by analysis of variance (ANOVA) is used to understand the significance of process variables affecting dimension accuracy. Scan speed and hatching space are found to be most significant process variables influencing the dimension accuracy in length and width. And laser power and layer thickness are less influence on the dimension accuracy. The optimum processing parameters are attained in this paper: laser power 11 W; scan speed 1200 mm/s; layer thickness 0.5 mm and hatching space 0.25 mm. It has been shown that, on average, the dimensional accuracy under this processing parameters combination could be improved by approximately up to 25% compared to other processing parameters combinations.

Direct Selective Laser Sintering of WC-Co Cemented Carbide by Premixing of Additives

2012 ◽  
Author(s):  
Hideki Kyogoku ◽  
Takeshi Uemori ◽  
Akihiko Ikuta ◽  
Kenichi Yoshikawa ◽  
Hitoshi Ohmori
Keyword(s):  
Selective Laser Melting ◽  
Laser Power ◽  
Smooth Surface ◽  
Laser Scanning ◽  
Selective Laser Sintering ◽  
Laser Sintering ◽  
Cemented Carbides ◽  
Sintering Process ◽  
Laser Melting ◽  
Scan Speed

In this study, the fabrication conditions of WC cemented carbides by direct selective laser melting were investigated. The effects of additives, such as Co, Cu-20%Sn and Cu powders, and laser scanning conditions on laser sintering process were examined to fabricate a sound laser-scanned body of WC cemented carbides. The optimum laser power, scan speed and scan pitch were found out by experiments. It was found that the continuously smooth single-scan track can be obtained at a lower laser power and a higher scan speed by the addition of 30% Cu powder. The smooth surface of the laser-scanned body could be fabricated at a laser power of 9 W, a scan speed of 20 mm/s and a scan pitch of 0.05 mm.

scholarly journals Effects of various processing parameters on the mechanical properties of sisal fiber/PES composites produced via selective laser sintering

BioResources ◽  
2020 ◽  
Vol 15 (3) ◽  
pp. 5710-5724
Author(s):  
Aboubaker I. B. Idriss ◽  
Jian Li ◽  
Yangwei Wang ◽  
Yanling Guo ◽  
Elkhawad A. Elfaki
Keyword(s):  
Mechanical Strength ◽  
Laser Power ◽  
Low Cost ◽  
Selective Laser Sintering ◽  
Scanning Speed ◽  
Processing Parameters ◽  
Laser Sintering ◽  
Sisal Fiber ◽  
Preheating Temperature ◽  
Scan Speed

A new type of sustainable material, i.e., a sisal fiber/poly-ether sulfone composite (SFPC), which is energy-efficient, environmentally friendly, and has a low cost, was developed for laser sintering additive manufacturing. This study was performed to explore the effects of the processing parameters on the SFPC composite parts produced via selective laser sintering (SLS). The effects of the laser sintering processing parameters, i.e., the preheating temperature, laser power, and scan speed, were studied. Bending and tensile testing of the SFPC specimens was successfully performed via SLS. The effect of the processing parameters on the SLS in terms of the mechanical strength of the laser-sintered parts was investigated. The results determined that the processing parameters had a significant effect on the mechanical strength of the sintered SFPC parts. When the preheating temperature and laser power were increased in the processing SLS system, the mechanical strength of the sintered SFPC parts was significantly increased. However, the scanning speed had an inverse proportional relationship to the mechanical strength of the SFPC SLS parts.

Structure and Mechanical Properties of PCL/PG Devices Prepared by Selective Laser Sintering for Drug Delivery Applications

2013 ◽  
Author(s):  
Gean V. Salmoria ◽  
Priscila Klauss ◽  
Carlos R. M. Roesler ◽  
Luiz Alberto Kanis
Keyword(s):  
Drug Delivery ◽  
Selective Laser Sintering ◽  
Rapid Prototype ◽  
Laser Sintering ◽  
Laser Beams ◽  
Powder Materials ◽  
Layer By Layer ◽  
Medical Field ◽  
Rapid Prototype Process ◽  
Drug Delivery Devices

Selective laser sintering (SLS) is a rapid prototype process that creates objects, layer by layer, using infrared laser beams to process powder materials [1–8]. In recent years, the SLS process has shown great prominence in the medical field, and several researchers have conducted studies showing a wide diversity of materials and applications, such as the manufacture of porous drug delivery devices (DDDs) [9–12].

Development of functionally-graded reservoir of PCL/PG by selective laser sintering for drug delivery devices

2012 ◽  
Vol 7 (2) ◽  
pp. 107-115 ◽  
Author(s):  
G.V. Salmoria ◽  
P. Klauss ◽  
K. Zepon ◽  
L.A. Kanis ◽  
C.R.M. Roesler ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Selective Laser Sintering ◽  
Laser Sintering ◽  
Functionally Graded ◽  
Drug Delivery Devices

scholarly journals Fabrication of porous bioactive structures using the selective laser sintering technique

2007 ◽  
Vol 221 (8) ◽  
pp. 873-886 ◽  
Author(s):  
M M Savalani ◽  
L Hao ◽  
Y Zhang ◽  
K E Tanner ◽  
R A Harris
Keyword(s):  
Laser Power ◽  
Laser Scanning ◽  
Selective Laser Sintering ◽  
Negative Relationship ◽  
Vertical Plane ◽  
Laser Sintering ◽  
Custom Made ◽  
The Matrix ◽  
Scan Speed ◽  
Liquid Displacement

Hydroxyapatite, a ceramic with which natural bone inherently bonds, has been incorporated into a polymer matrix to enhance the bioactivity of implant materials. In order to manufacture custom-made bioactive implants rapidly, selective laser sintering has been investigated to fabricate hydroxyapatite and polyamide composites and their properties investigated. One objective of this research was to identify the maximum hydroxyapatite content that could be incorporated into the matrix, which was sintered at various parameters. The study focused on investigating the control of porosity and pore size of the matrix by manipulating the selective laser sintering parameters of the laser power and laser scan speed. The interception method was used to analyse the internal porous morphology of the matrices which were cross-sectioned through the vertical plane. Most notably, all structures built demonstrated interconnection and penetration throughout the matrix. Liquid displacement was also used to analyse the porosity of the matrices. The laser power showed a negative relationship between porosity and variation in parameter values until a critical power value was reached. However, the same relationship for laser scan speed matrices was inconsistent. The effects of the laser power and laser scanning speed on the features of porous structures that could influence cell spreading, proliferation, and bone regeneration are presented.

Balling Process in Selective Laser Sintering 316 Stainless Steel Powder

2006 ◽  
Vol 315-316 ◽  
pp. 357-360 ◽  
Author(s):  
Yi Fu Shen ◽  
D.D. Gu ◽  
Y.F. Pan
Keyword(s):  
Stainless Steel ◽  
Laser Power ◽  
Selective Laser Sintering ◽  
Steel Powder ◽  
Laser Sintering ◽  
Stainless Steel Powder ◽  
Surface Tension Effect ◽  
316 Stainless Steel ◽  
Scan Speed ◽  
Moderate Range

Balling process in selective laser sintering of 316 stainless steel powder was investigated. It showed that the balling phenomenon was ascribed to the higher liquid viscosity and surface tension effect during laser sintering. The effects of laser power and scan speed on the balling initiation was studied. It was found that increasing laser power and scan speed within a moderate range can reduce balling effect. However, care should be taken to control laser powers and scan speeds that can be used since their excessive increase may give rise to detrimental effects.

scholarly journals A QbD Approach for Evaluating the Effect of Selective Laser Sintering Parameters on Printability and Properties of Solid Oral Forms

Pharmaceutics ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1701
Author(s):  
Yanis A. Gueche ◽  
Noelia M. Sanchez-Ballester ◽  
Bernard Bataille ◽  
Adrien Aubert ◽  
Jean-Christophe Rossi ◽  
...  
Keyword(s):  
Energy Density ◽  
Drug Release ◽  
Layer Thickness ◽  
Process Parameters ◽  
Laser Power ◽  
Heating Temperature ◽  
Selective Laser Sintering ◽  
Laser Sintering ◽  
Disintegration Time ◽  
Scan Speed

The aim of this work was to investigate the effect of process parameters on the printability of a formulation containing copovidone and paracetamol, and on the properties of solid oral forms 3D-printed through selective laser sintering. Firstly, the influence of the heating temperature was evaluated individually, and it was revealed that this parameter was critical for printability, as a sufficiently high temperature (100 °C) is necessary to avoid curling. Secondly, the effects of laser power, scan speed, and layer thickness were determined using a Box–Behnken design. The measured responses, printing yield, height, weight, hardness, disintegration time, and percentage of drug release at 10 min showed the following ranges of values: 55.6–100%, 2.92–3.96 mm, 98.2–187.2 mg, 9.2–83.4 N, 9.7–997.7 s, and 25.8–99.9%, respectively. Analysis of variance (ANOVA) proved that the generated quadratic models and the effect of the three–process parameters were significant (p < 0.05). Yield improved at high laser power, low scan speed, and increased layer thickness. Height was proportional to laser power, and inversely proportional to scan speed and layer thickness. Variations in the other responses were related to the porosity of the SOFs, which were dependent on the value of energy density. Low laser power, fast scan speed, and high layer thickness values favored a lower energy density, resulting in low weight and hardness, rapid disintegration, and a high percentage of drug release at 10 min. Finally, an optimization was performed, and an additional experiment validated the model. In conclusion, by applying a Quality by Design approach, this study demonstrates that process parameters are critical for printability, but also offer a way to personalize the properties of the SOFs.

Research on Warpage of Polystyrene in Selective Laser Sintering

2010 ◽  
Vol 43 ◽  
pp. 578-582 ◽  
Author(s):  
C.Y. Wang ◽  
Q. Dong ◽  
X.X. Shen
Keyword(s):  
Layer Thickness ◽  
Process Parameters ◽  
Laser Power ◽  
Selective Laser Sintering ◽  
Scanning Speed ◽  
Laser Sintering ◽  
Main Process ◽  
Influence Of Process Parameters ◽  
Temperature Changes ◽  
Hatch Spacing

Warpage is a crucial factor to accuracy of sintering part in selective laser sintering (SLS) process. In this paper, The influence of process parameters on warpage when sintering polystyrene(PS) materials in SLS are investigated. The laser power, scanning speed, hatch spacing, layer thickness as well as temperature of powder are considered as the main process parameters. The results showed that warpage increases with the increase of hatch space. Contary to it, warpage decreases with the increase of laser power. Warpage decreases with the increase of layer thickness between 0.16~0.18mm and changes little with increase of the thickness. Warpage increases along with the increase of scanning speed but decreases when the speed is over about 2000mm/s. When the temperature changes between 82°C-86°C, warpage decreases little with the increase of temperature. But further increase of temperature leads to warpage decreasing sharply when the temperature changes between 86°C-90°C.

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