Irradiation of polymers is one of the most effective and economical methods for modifying their properties and for changing their applications. In this study, an extrusion grade polypropylene (PP) was treated by electron beam irradiation to produce a PP suitable for injection molding. Irradiation was carried out at different doses (0-80 kGy) under atmosphere air and at ambient temperature. Melt...

Viscoelastic materials for plastic encapsulated molding compounds invariably exhibit a time-dependent stress response to an imposed constant strain, which is called stress relaxation. Stress relaxation tests with molding compounds used to encapsulate microcircuits have been performed to measure the time dependent non-linear constitutive relation between stress and strain as a function of temper...

open in browser PRO version Are you a developer? Try out the HTML to PDF API IN THIS ARTICLE: Moog Proportional Valves deliver shorter cycle times, increased repeatability and improved part quality on a new generation injection molding machine Fast switching between injection and hold pressure phase is the key to this application Use of simulation software helped optimize final valve characteri...

Statistical process control (SPC) for injection molding typically consists of setting alarm limits on a few important molding variables for real-time part containment. A new multivariate statistical process control (MSPC) method is presented that utilizes the measurement of process variable relationships to achieve a more robust quality control system. This approach not only detects process out...

The importance of maintaining a consistent cushion in the injection molding process is universally agreed upon in the molding industry. However, the size at which the cushion should be set is not unanimously established. As such, several “rules of thumb” or “typical” cushion sizes are recommended and used by processors in the industry. These recommended cushion sizes have been deemed acceptable...

Biodegradable implants of ciprofloxacin hydrochloride for post operative site delivery were prepared using glyceryl monostearate and different concentrations of polyethylene glycol (PEG 6000), glycerol and Tween 80 as erosion enhancers by compression and molding technique. Formulations were subjected to in vitro drug release by the USP dissolution method, while promising formulations were subje...

Research at the Materials Research Laboratory, Pennsylvania State University has demonstrated the potential for improving hydrophone performance using piezoelectric ceramic/polymer composites. As part of an ONR-funded initiative to develop cost-effective manufacturing technology for these composites, Materials Systems is pursuing an injection molding ceramic fabrication approach. This paper bri...

Replica molding of ultra-high-Q toroidal microresonators can produce polymer microresonators with material-limited quality factors (Q). This was demonstrated previously using polymers which cure thermally. In this work, high Q polymer microresonators were fabricated using the replica molding technique from previously uncharacterized polymers which require either a thermal or UV cure. The qualit...

Today, hot embossing and injection molding belong to the established plastic molding processes in microengineering. Based on experimental findings, a variety of microstructures have been replicated so far using the processes. However, with increasing requirements regarding the embossing surface and the simultaneous decrease of the structure size down into the nanorange, increasing know-how is n...