scholarly journals Mechanical properties, volumetric shrinkage and depth of cure of short fiber-reinforced resin composite

2016 ◽  
Vol 35 (3) ◽  
pp. 418-424 ◽  
Author(s):  
Akimasa TSUJIMOTO ◽  
Wayne W. BARKMEIER ◽  
Toshiki TAKAMIZAWA ◽  
Mark A. LATTA ◽  
Masashi MIYAZAKI
2018 ◽  
Vol 9 ◽  
pp. 158
Author(s):  
Ellyza Herda ◽  
Nadia Safira Ninda ◽  
Mia Damiyanti

Objective: This study aimed to identify post-cure’s effect on the depth of cure (DOC) of a short fiber-reinforced resin composite (SFRC).Methods: Six EverX PosteriorTM shade A3 specimens were cured with a light-emitting diode light curing unit with 800 mW/cm2 of light irradiation for 20 s. The specimens were divided into two groups. The first was measured immediately post-cure and the second was measured 24-h post-cure. They were measured with a Vickers microhardness profile test. An independent t-test was used to analyze the significance of the differences between the DOC value and different variables.Results: The DOC of the specimens measured immediately post-cure was 3.02±0.02 mm. The DOC of the specimens measured 24-h post-cure was 3.93±0.03 mm.Conclusion: The DOC of the specimens measured 24-h post-cure was significantly higher than the DOC of the specimens measured immediately post-cure. Post-cure polymerization (24-h post-cure) can increase the DOC values of an SFRC.


2016 ◽  
Vol 124 (5) ◽  
pp. 480-489 ◽  
Author(s):  
Akimasa Tsujimoto ◽  
Wayne W. Barkmeier ◽  
Toshiki Takamizawa ◽  
Hidehiko Watanabe ◽  
William W. Johnson ◽  
...  

Author(s):  
Antony Paul ◽  
Jeffery M. Gallagher ◽  
Raymond J. Cipra ◽  
Thomas Siegmund

Fiber reinforced composite materials are now frequently being used over conventional materials for their ability to achieve tailored properties and performance characteristics. With the recent advancements in manufacturing techniques, short-fiber composites are coming into prominence in this sector, with their cost advantage and their capability for large throughput. Randomness of fiber orientation is inherent to short fiber composite manufacturing processes. In order to effectively manipulate the mechanical properties of a short-fiber reinforced composite, it is imperative to adequately control the orientation of the fibers during the deposition stage. A process is currently developed to acquire geometrical data of the target object and to utilize it to create a short-fiber reinforced component with controlled fiber orientation. The topological data acquisition of the object is made possible using non-contact 3D imaging techniques. The geometric data is then transferred to a commercial CAD package for the added capability to manipulate the geometry as may be required for specific applications. Subsequently, geometric data constitutes the basis of path planning for the tooling processes. In our process, a novel rapidly re-configurable tooling and molding technology is employed by which a 6-axis robotic arm is used to sculpt a pin-device vacuum surface. After the tooling is completed, the robotic arm will use a deposition nozzle to orient a steady stream of initially random short-fiber from a feeder into a unidirectional output, onto the tool surface. By controlling the position and orientation of the deposition nozzle, it is possible to control the orientation and density of fiber in each section of the near-net shaped composite pre-form. The fiber pre-form is then impregnated with a suitable matrix medium and cured to create the required component. The outlined process is thus capable of manufacturing a near-net shaped short-fiber reinforced component with highly specific mechanical properties. One of the many applications envisaged using this process is the manufacture of custom form-fitting braces, masks and guards for use in healthcare products. A patient intervention can have his or her features acquired using stereo-imaging and have corrective measures incorporated into the device prior to manufacturing. By controlling the orientation and density of the fiber at different portions of the device, it is possible to provide adequate support at specific areas or to restrict movement in specific directions while providing compliance to movement in the others.


2000 ◽  
Vol 2000.3 (0) ◽  
pp. 393-394
Author(s):  
Kiyoshi MIZUUCHI ◽  
Masami SUGIOKA ◽  
Masao ITAMI ◽  
Yoshihira OKANDA ◽  
Kenichi HAMADA ◽  
...  

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