9:30 am – 10:00 am:
Synthesis of High Hardness Polyester Resin for Powder Coatings
Junseop IM, Samyang Corporation
Since powder coatings do not use VOCs, much research has been studied as eco-friendly paints. Among these powder coatings, hybrid type is widely used in home appliances and furniture. Therefore, it is very important to meet both aesthetic characteristics and mechanical properties such as gloss and hardness. However, it is difficult to maintain high gloss with high hardness because of the inorganic filler of powder coatings.
10:00 am – 10:30 am:
Effects of Molding Conditions on Mechanical Behavior of Direct Injection Molded PLA/Wood-fiber Composites
Gangjian Guo, Bradley University
Polylactic acid (PLA), derived from bio-resources, is an environmentally friendly plastic which has attracted tremendous interests in both academia and industry. This paper investigates the feasibility of direct injection molding of PLA/wood fiber composites and their mechanical behavior. Response surface methodology was adopted to study the effects of molding parameters, as well as their interacting effects, on the tensile strength of the composites. Melt temperature, hold pressure, injection speed were chosen as the molding parameters studied. Additionally, the analysis of variance was applied to identify the most significant factors. The statistical model would improve our understanding of the tensile strength behavior of PLA/wood fiber composite, and provide the guidance for selecting proper molding parameters to maximize the tensile strength.
10:30 am – 11:00 am:
Hierarchical Micro/Nanostructures of Poly (lactic acid) Scaffolds for Medical Applications
Shujie Yan, University of Wisconsin-Madison
Although tissue engineering has shown great advances in recent years, creating proper mechanical properties and cell growth microenvironments is still challenging. In this study, electrospun poly (lactic acid), PLA, nanofibrous membranes were hot embossed to develop 3D hierarchical micro/ nanostructures. Human umbilical-vein endothelial cells (HUVECs) were then cultured on these structures. The hot-embossed membranes exhibited not only superior mechanical properties (the tensile strength was 7.01 ± 0.18 MPa and the tensile modulus was 166.91 ± 15.54 MPa), but also better cell viability as evaluated through a CCK-8 assay and fluorescent dye. The grating arrays of the micropatterned fiber mats encouraged the HUVECs to proliferate. The approach proposed here—combined electrospinning and hot embossing—has great potential for biomedical applications, including for use as polymer scaffolds in tissue engineering.
11:00 am – 11:30 am:
Wheat Protein as a Participant in the Sulfur-curing of Isoprene Rubber
Barbara DeButts, Virginia Tech
In this study, trypsin hydrolyzed gliadin (THGd) from wheat was used as a curative and reinforcing filler in synthetic isoprene rubber (IR). Curing kinetics of the THGd compounds demonstrated that THGd was most effective when utilized as an activator in place of zinc oxide and stearic acid (ZnO/STE). The THGd vulcanizates exhibited comparable or higher moduli to the control, but lower crosslink densities and slower curing kinetics. THGd was able to facilitate crosslinking, as shown by swelling experiments, but further study is needed to match/exceed the kinetic properties of the control. Interestingly, THGd was very effective as a reinforcing filler and reinforcement increased as a function of molding time. Thus, rubber processing was favorable to the self-assembly of hydrolyzed protein into a reinforcing phase.
8:00 am – 10:30 am:
(Moderator: Ken Carter)-Room S320H
8:00 am – 8:30 am:
Development of a Rapid Thermal Cycling Blow Molding Technology and Mold Heating System Optimization
Cheng-Long Xiao, University of South China
More and more industrial plastics parts used in automobile are turning to be produced by extrusion blow molding (EBM). For directly obtaining high-gloss part in mold, a rapid thermal cycling extrusion blow molding (RTCEBM) technology was developed by integrating the dynamic mold temperature control strategy into the traditional EBM. The process principle was presented and process optimization by executing some molding operations in parallel was analyzed in detail. A typical automotive plastic part, i.e. spoiler, was taken as an example to illustrate the application of RTCEBM in actual production. The corresponding blow mold was designed and a two-step method was proposed and applied to optimizing the heating systems arranged in the mold cavity and core plates simultaneously. Finally, a prototype blow mold of spoiler was manufactured and used for molding the parts, it was found that the molded spoilers exhibit high-gloss surface appearance and could be directly used for the final assembly process without any secondary processing, as well as the molding cycle time was also in the accepted range.
8:30 am – 9:00 am:
Simulative Preform Optimization for Improved Topload Behavior of PET-bottles Manufactured in the Two Stage Stretch Blow Molding Process
Benjamin Twardowski, IKV Aachen
Biaxial stretch blow molding is a process for producing a plastic container from a preform or parison that is stretched in both circumferential and axial direction when the preform is blown into its desired container shape. It is well established for the large scale production of high quality PET bottles with excellent mechanical and optical properties. The concept of “virtual prototyping” is nowadays well established in the stretch blow molding industry in order to improve the containers properties during the design phase. Still, a virtual optimization is yet connected with much manual work. Therefore, a process simulation and a testing simulation for stacking strength was integrated into an optimization cycle to design a preform geometry for improved mechanical properties of the corresponding bottle. The optimization performed with Newton based algorithms however lead to suboptimal mechanical properties. The investigations show, that the objective function indicating the mechanical properties of the bottle has several local maximum values which prevent the determination of a global maximum. Further investigations will focus on different optimization algorithms.