Evaluation of Anastomotic Strength and in-vitro Degradability with Microvascular Anastomosis Coupler Based on Injection Molding Condition made by Biodegradable Polycaprolactone(PCL)

2013 ◽  
Vol 1 (2) ◽  
pp. 167-177
Author(s):  
Geun-Seon Ahn ◽  
Gig-Bong Han ◽  
Seung-Hyun Oh ◽  
Jong-Woong Park ◽  
Cheol-Woong Kim
Keyword(s):  
Injection Molding ◽  
Microvascular Anastomosis ◽  
Molding Condition ◽  
Anastomotic Strength

Mechanical Properties of Jute/PLA Injection Molded Products-All Natural Composites

2011 ◽  
Author(s):  
Masuo Murakami ◽  
Yuqiu Yang ◽  
Hiroyuki Hamada
Keyword(s):  
Mechanical Properties ◽  
Injection Molding ◽  
Density Measurement ◽  
The Other ◽  
Jute Fiber ◽  
Poly Lactic Acid ◽  
Thermoplastic Polymer ◽  
Environmental Friendly ◽  
Molding Condition ◽  
Natural Composites

Natural composites have been important materials system due to preservation of earth environments. Natural fibers such as jute, hemp, bagasse and so on are very good candidate of natural composites as reinforcements. On the other hand regarding matrix parts thermosetting polymer and thermoplastic polymer deriver form petrochemical products are not environmental friendly material, even if thermoplastic polymer can be recycled. In order to create fully environmental friendly material (FEFM) biodegradable polymer which can be deriver from natural resources is needed. Therefore poly(lactic acid) (PLA) polymer is very good material for the FEFM. However, PLA is very brittle polymer, so that polymer chemists have been made the efforts to make tough PLA. In this paper Jute/PLA composites was fabricated by injection moldings and mechanical properties were measured. It is believable that industries will have much attention to FEFM, so that injection molding was adopted to fabricate the composites. Long fiber pellet pultrusion technique was adopted to prepare jute fiber-PLA pellet (Jute/PLA). Because it is a new method which is able to fabricate composite pellets with relative long length fibers for injection molding process, where, jute yarns were continuously pulled and coated with PLA resin. Here two kinds of PLA materials were used including the one with mold releasing agent and the other is without it. After pass through a heated die whereby PLA resin impregnates into the jute yarns and sufficient cooling, the impregnated jute yarns were cut into pellets. Then Jute/PLA pellets were fed into injection machine to make dumbbell shape specimens. In current study, the effects of temperature of heat die i.e. impregnation temperature and the kind of PLA were focused to get optimum molding condition. The volume fractions of jute fiber in pellet were measured by several measuring method including image analyzing, density measurement and dissolution methods. And the mechanical property were investigated by tensile and Izod testing. It is found that 250 degree is much suitable for Jute/PLA long fiber pultrusion process. Additionally the jute fibers seem much effective to increase the tensile modulus and the Izod strength. That is to say, the addition of Jute fiber in PLA, the brittle property can be improved.

Corrosion and Cytotoxicity Evaluation of AISI 316L Stainless Steel Produced by Powder Injection Molding (PIM) Technology

2005 ◽  
Vol 498-499 ◽  
pp. 86-92 ◽  
Author(s):  
Isolda Costa ◽  
Sizue Ota Rogero ◽  
Olandir Vercino Correa ◽  
Clarice Terui Kunioshi ◽  
Mitiko Saiki
Keyword(s):  
Stainless Steel ◽  
Injection Molding ◽  
316L Stainless Steel ◽  
Electrochemical Techniques ◽  
Powder Injection Molding ◽  
Powder Injection ◽  
Cytotoxicity Test ◽  
Aisi 316L ◽  
Aisi 316L Stainless Steel

This study investigates the in vitro corrosion and cytotoxicity response of AISI 316L stainless steel produced by powder injection molding (PIM) technology in a solution that simulates physiological fluids (MEM) by electrochemical techniques and neutral red uptake cytotoxicity assay. The results were compared with those of AISI 316L produced by conventional metallurgy. Both steels showed high corrosion resistance and no toxic effect in the cytotoxicity test. The corrosion products were analyzed by instrumental neutron activation analysis (INAA). The surfaces of the alloys were evaluated before and after corrosion test by scanning electron microscopy and a passive behaviour was indicated supporting the results from other techniques.

Three-Dimensional-Printed External Scaffolds Mitigate Loss of Volume and Topography in Engineered Elastic Cartilage Constructs

Cartilage ◽  
2021 ◽  
pp. 194760352110495
Author(s):  
Xue Dong ◽  
Ishani D. Premaratne ◽  
Jaime L. Bernstein ◽  
Arash Samadi ◽  
Alexandra J. Lin ◽  
...  
Keyword(s):  
Injection Molding ◽  
Type I Collagen ◽  
Three Dimensional ◽  
Type I ◽  
Base Area ◽  
Elastic Cartilage ◽  
3D Printed ◽  
Injection Molded

Objective: A major obstacle in the clinical translation of engineered auricular scaffolds is the significant contraction and loss of topography that occur during maturation of the soft collagen-chondrocyte matrix into elastic cartilage. We hypothesized that 3-dimensional-printed, biocompatible scaffolds would “protect” maturing hydrogel constructs from contraction and loss of topography. Design: External disc-shaped and “ridged” scaffolds were designed and 3D-printed using polylactic acid (PLA). Acellular type I collagen constructs were cultured in vitro for up to 3 months. Collagen constructs seeded with bovine auricular chondrocytes (BAuCs) were prepared in 3 groups and implanted subcutaneously in vivo for 3 months: preformed discs with (“Scaffolded/S”) or without (“Naked/N”) an external scaffold and discs that were formed within an external scaffold via injection molding (“Injection Molded/SInj”). Results: The presence of an external scaffold or use of injection molding methodology did not affect the acellular construct volume or base area loss. In vivo, the presence of an external scaffold significantly improved preservation of volume and base area at 3 months compared to the naked group ( P < 0.05). Construct contraction was mitigated even further in the injection molded group, and topography of the ridged constructs was maintained with greater fidelity ( P < 0.05). Histology verified the development of mature auricular cartilage in the constructs within external scaffolds after 3 months. Conclusion: Custom-designed, 3D-printed, biocompatible external scaffolds significantly mitigate BAuC-seeded construct contraction and maintain complex topography. Further refinement and scaling of this approach in conjunction with construct fabrication utilizing injection molding may aid in the development of full-scale auricular scaffolds.

Injection Molding of ProNectin®F Dispersed in Polystyrene for The Fabrication of Plastic Ware Activated Towards Attachment of Mammalian Cells

1993 ◽  
Vol 330 ◽  
Author(s):  
Erwin R. Stedronsky ◽  
Joseph Cappello ◽  
Samuel David ◽  
David M. Donofrio ◽  
Tina Mcarthur ◽  
...  
Keyword(s):  
Injection Molding ◽  
Mammalian Cell ◽  
Mammalian Cells ◽  
De Novo ◽  
Cell Attachment ◽  
Biologically Active ◽  
Polymeric Surfactant ◽  
New Paradigm

ABSTRACTProNectin®F is a recombinant engineered protein polymer of de novo design which incorporates the RGD epitope recognized by mammalian cell integrins. It is biologically active as a cell attachment protein, manifests properties of a planar polymeric surfactant, and is extremely resistant to thermal degradation. ProNectin®F was dispersed onto polystyrene powder, fabricated into plastic ware through injection molding, and the plastic ware was shown to have cell attachment activity. This technology represents a new paradigm for the production of plastic ware useful for mammalian cell culture under serum free conditions; and more generally, for the production of molded devices for use in contact with cells in vitro or in vivo.

scholarly journals Dielectric Spectroscopy of PP/MWCNT Nanocomposites: Relationship with Crystalline Structure and Injection Molding Condition

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 550
Author(s):  
Marco Monti ◽  
Marta Zaccone ◽  
Alberto Frache ◽  
Luigi Torre ◽  
Ilaria Armentano
Keyword(s):  
Injection Molding ◽  
Crystalline Structure ◽  
Processing Condition ◽  
Mold Temperature ◽  
Dielectric Behavior ◽  
Multi Walled Carbon Nanotube ◽  
Molding Condition ◽  
Frequency Independent ◽  
Injection Molded ◽  
Independent Behavior

In this paper, we study the correlation between the dielectric behavior of polypropylene/multi-walled carbon nanotube (PP/MWCNT) nanocomposites and the morphology with regard to the crystalline structure, nanofiller dispersion and injection molding conditions. As a result, in the range of the percolation threshold the dielectric behavior shifts to a more frequency-independent behavior, as the mold temperature increases. Moreover, the position further from the gate appears as the most conductive. This effect has been associated to a modification of the morphology of the MWCNT clusters induced by both the flow of the molten polymer during the processing phase and the variation of the crystalline structure, which is increasingly constituted by γ-phase as the mold temperature increases. The obtained results allow one to understand the effect of tuning the processing condition in the frequency-dependent electrical behavior of PP/MWCNT injection-molded nanocomposites, which can be successfully exploited for an advanced process/product design.

scholarly journals Novel Analysis Methodology of Cavity Pressure Profiles in Injection-Molding Processes Using Interpretation of Machine Learning Model

Polymers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 3297
Author(s):  
Jinsu Gim ◽  
Byungohk Rhee
Keyword(s):  
Injection Molding ◽  
Pressure Profile ◽  
Polymer Materials ◽  
Quality Analysis ◽  
Injection Molding Process ◽  
Cavity Pressure ◽  
Molding Process ◽  
Part Quality ◽  
Analysis Methodology ◽  
Molding Condition

The cavity pressure profile representing the effective molding condition in a cavity is closely related to part quality. Analysis of the effect of the cavity pressure profile on quality requires prior knowledge and understanding of the injection-molding process and polymer materials. In this work, an analysis methodology to examine the effect of the cavity pressure profile on part quality is proposed. The methodology uses the interpretation of a neural network as a metamodel representing the relationship between the cavity pressure profile and the part weight as a quality index. The process state points (PSPs) extracted from the cavity pressure profile were used as the input features of the model. The overall impact of the features on the part weight and the contribution of them on a specific sample clarify the influence of the cavity pressure profile on the part weight. The effect of the process parameters on the part weight and the PSPs supported the validity of the methodology. The influential features and impacts analyzed using this methodology can be employed to set the target points and bounds of the monitoring window, and the contribution of each feature can be used to optimize the injection-molding process.

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