Narrow Neck Press and Blow (NNPB) process is used to produce light weight bottles. The gob of molten glass is delivered to the blank mold and a specially designed narrow diameter plunger is used to form the finish or mouth and the parison as it presses upwards. Invert and final blow takes place followed by take-out and annealing. Anchor Glass Container Corp. (AGC) uses NNPB technology in their glass making plants. The problem experienced by AGC in the process is that the heat dissipation through out the mold is not uniform and hence there is a non uniform temperature distribution in the finished bottle extracted from it. Specifically the shoulder region of the bottle stays at a higher temperature when compared with the other regions, becoming the limiting factor in determining the rate of bottle production. Excessive temperatures in any region leave the glass insufficiently rigid, allowing the bottle to sag or lean. An increased rate of production which demands faster and effective cooling of the bottle is desired and is the ultimate goal of this research effort. This problem can be effectively solved by increasing the amount of heat transferred from the mold to the cooling air, which can be done by increasing the surface area of the cooling passages. A mathematical model for calculating the amount of heat transferred to the cooling air is proposed in this thesis. The air properties at the exit of the mold and the amount of heat transferred by each cooling passage were obtained by using MATHCAD. A 2 dimensional numerical simulation for the final molding was carried out using ANSYS and the temperature distribution for the mold and glass were obtained.

Lean production has become a widespread production system to address the need of being more productive. Since three decades ago that some big automotive manufacturers started to adopt lean, many SME’s has adopt it and enjoy the outcomes. Literature have investigated the successful implementation of lean in these organizations, yet, very few papers have addressed the challenges toward adopting lean. In this thesis research a plastic package manufacturer is chosen as the case of study to implement some initiatives of lean production and study the challenges and outcomes of lean adoption. The efforts during the making the changes were focused on adopting the SMED and Root-Cause Analysis techniques, and also to reduce defect rate in one of the products. The findings indicate before any effort to implement lean production techniques, some social issues must be considered to reduce the risk of failure. The Rosti AB case indicated that promoting motivation among operators and resolving mistrust between managers and operators is essential to encourage them to participate in improvement changes. In order to promote motivation and eliminate mistrust to encourage operators to participate in improvement changes it is necessary to empower them in decision makings in improvement implementations.

Mechanical rubbing alignment is the most common used method in the liquid crystal display manufacturing process. However, it may cause dust and electrostatic problem. In this study, we investigate effects of low surface free energy Polydimethylsiloxane (PDMS) on orientation of liquid crystal molecules in a confined structure and fabricate alignment layer using PDMS. In the present study, we show that liquid crystal molecules are arranged in consistency without rubbing process and it may be a new homogeneously aligned mode in liquid crystal display. In this thesis, liquid crystal textures were observed using polarizing optical microscopy (POM). It was found that liquid crystal molecules were homogeneously aligned in PDMS holes. In addition, this thesis indicated that how liquid crystal alignment affected by PDMS layer thickness and surface treatment. We learned that using treatment of JALS-9800 film on the bottom substrate from liquid crystal texture can obtain the arrangement of expected liquid crystal molecules. The liquid crystal device can be produced using PDMS structure. The measurement of electro-optic characteristics showed that the circular shape in the confined structure had better transmittance and contrast ratio.

The objective of this thesis is to apply semiconductor etching process technologies on 6 inch P-type Si substrate and produce a mold of Light Guiding Plate (LGP). After evaporate chromium (Cr) onto the Si substrate as etch mask, the thin films were then patterned and subsequently etch by plasma. Different powers were used to compare the cross-sections of the patterns. The results would be the references of Si molding process. Another objective is to fabricate Si-V grooves which can connect the fibers and accurately position fibers. Anisotropic etching of Si-V grooves were formed using EDP solution, and sputtered Ta2O5 was used as the etch mask. At a etching temperature of 1100C, the under cut is 2.5~3mm . Additionally using SiO2 as etch mask by thermo evaporation at 1050¢J .Use EDP solution at 1100C, the under cut is 2.25mm which had a better result.

Thesis (Ph. D.)--University of Alabama at Birmingham, 2008. / Title from PDF title page (viewed Feb. 8, 2010). Additional advisors: J. Barry Andrews, Kathryn Brannon, Derrick R. Dean, Gregg M. Janowski, Mark L. Weaver. Includes bibliographical references (p. 158-161).

published_or_final_version / Mechanical Engineering / Master / Master of Philosophy

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The thermomechanical history experienced by plastics melts and solids during processing leads to the development of microstructure, which directly influences the ultimate properties of the plastic articles. Therefore, besides the predictions of thermomechanical history, the prediction of microstructure represents an important aspect of the modeling of plastics processing. / A comprehensive model has been developed to describe the behaviour of thermoplastic polymer melts during the injection molding process. The model, which deals with the three stages of the process (filling, packing and cooling), employs a viscoelastic constitutive equation and incorporates crystallization kinetics. All the properties of the material employed are based on experimental data. The model predicts fill times, velocity, temperature and pressure distributions, the distribution of shear and normal stresses, and stress relaxation. The predictions of the model are compared to experimental data relating to pressure distributions and variation with time, fill times, and the distributions of crystallinity, orientation and tensile modulus.

No description available.

No description available.