Type
Text
Type
Thesis
Advisor
Venkatesh, T A. | Miriam Rafailovich | Jonathan Sokolov | Vik Bhargava.
Date
2010-12-01
Keywords
Materials Science Polymer Chemistr Plastics | Adhesion, Overmolding, Polycarbonate, TPU
Department
Department of Materials Science and Engineering
Language
en_US
Source
This work is sponsored by the Stony Brook University Graduate School in compliance with the requirements for completion of degree.
Identifier
http://hdl.handle.net/11401/72629
Publisher
The Graduate School, Stony Brook University: Stony Brook, NY.
Format
application/pdf
Abstract
The overmolding process involves the use of two separate materials to form one cohesive component. The final product is a single piece, made out of polymers with very different mechanical properties that must be safe and permanently bonded together throughout its useful life. The first shot is generally a hard plastic and is referred to as a substrate the second material is generally a soft thermoplastic elostomer (TPE) and referred as overmold. The rigid substrate is used for structural purposes, and the softer materials are expected to take care of the user comfort. Overmolding can add immeasurable value to product design by enhancing the comforts for user, ergonomics, and ease of use. It finds applications in household appliances, hand tools, automotive interiors, hand held computers and medical devices. The most common problems with overmolding are insufficient chemical or mechanical bonding of the polymers, incomplete filling of one or more components, and flashing of overmold. This paper deals with adhesion issues and describes the study performed to evaluate the effect of processing parameters on adhesion performance of Polyether based TPU over mold on to Polycarbonate Substrate. The study established the effect of various processing parameters on the adhesion of overmold to substrate. In addition effect of various surface roughness of substrate on adhesion was also determined. Study also describes the criteria used to design specimen and the specimen tool was build. The specimens were molded using design of experiments. The specimens were tested using Inston universal testing machine by establishing the test procedure and test set up to yield consistent results. The force at which constant peel occurred, called peel force was determined for all experiments. The study concludes that melt temperature is the most dominating factor and the specimen molded with lower melt temperature results in good bond. Light roughness on the substrate surface further enhances the adhesion. Scanning electron microscopy was performed on the peeled samples showed higher peel force and lower peel forces. The SEM images were thoroughly reviewed. It was further concluded that the air entrapment at higher melt temperature reduces adhesion. The main source for air entrapment is from the gassing of plasticizers, oils and waxes used in TPE formulations. The author also proposes similar studies for various other combinations of substrate and TPE as a path forward
Recommended Citation
Patankar, Mukund Purushottam, "Evaluation of the Effect of Pprocessing Parameters on Adhesion performance of Polyetherbased TPU over mold on to Polycarbonate Substrate" (2010). Stony Brook Theses and Dissertations Collection, 2006-2020 (closed to submissions). 1832.
https://commons.library.stonybrook.edu/stony-brook-theses-and-dissertations-collection/1832