The Relationship Between Plastic Virginity and Engineering Properties of Wood Plastic Composites
4 Abstract: This study attempted to investigate the relationship between plastic virginity and physico-mechanical properties of wood plastic composites. To meet this objective, wood flour was mixed with either virgin or recycled polypropylene at 40%, 50% and 60% by weight fiber loading. The samples were made by melt compounding and then injection molding. The amount of coupling agent was fixed at 2% for all formulations. Then physical and mechanical properties of composites were measured according to ASTM standard. Then, all the experimental data were collected and analyzed with the analysis of variance techniques and suitable model was selected with the simple's linear regression model. Results indicated that the flexural strength, flexural modulus, tensile strength and tensile modulus of composites of recycled plastic composites were higher than those of virgin plastics. Also, the water absorption and thickness swelling of samples decreased with the increase of recycled plastic loading. Furthermore, optimization processes have been carried out to determine the suitable combinations of plastic virginity variables in order to attain desirable physical and mechanical properties of wood plastic composites.
Water Absorption Behavior of Composites from Sawdust and Recycled Plastics
The water absorption of wood plastic composites (WPCs) prepared from sawdust and virgin and/or recycled plastics (HDPE and PP) was studied. Wood flour was prepared from sawdust and mixed with different virgin or recycled plastics at 50% by weight fiber loading. The mixed materials were compression molded into panels. Long term water absorptions of manufactured WPCs were evaluated by immersing them in water at room temperature for several weeks (up to 1750 h). Water diffusion coefficients were also calculated by evaluating the water absorption isotherms. Results indicated that the maximum water absorption and diffusion coefficients increased by increasing the proportion of recycled HDPE and/or PP. Time to reach saturation also decreased at higher recycled plastic contents. Water absorption of the studied composites was proved to follow the kinetics of a Fickian diffusion process.
Design of a Ceiling Glass Installation Robot
Building materials and components are much larger and heavier than many industrial materials. Ceiling glass is a type of building material for interior finishing. The demand for larger ceiling glass has increased along with the number of high-rise buildings and an increased interest in interior design. The objective of the study is to introduce robotic technology for installing ceiling glass on construction site. Robotically installed ceiling glass is receiving special attention because of the difficulties in moving to high installation positions and handling fragile building materials. Below, we describe the design of a ceiling glass installation robot. After analyzing a target project, we establish a design concept for a proposed robot. Finally, we describe the detailed design of the robot.