Enhancing thermal conductivity of poly-hydroxy-alkanoates (PHA) to reduce flash in injection molded parts
by Daga, Rahul, M.S.Eng., UNIVERSITY OF MASSACHUSETTS LOWELL, 2008, 52 pages; 1461624

Abstract:

Enhancement of thermal conductivity in a polymer not only makes it suitable for a variety of applications like heat sinks, ICs, heat pipes but could also improve the part aesthetically by getting rid of flash or shrinkage.

One such polymer that exhibits flashing in molding is PHA (Poly-hydroxy-alkanoate). A thermal and shear sensitive polymer, PHA, is a good example for studying the above concept.

Talc (a low thermal conductivity filler) and boron nitride (BN) (a very high thermal conductivity filler) were incorporated into PHA at loading levels of 5, 10, 15, 20, 30 and 40% by weight. Boron nitride due to its very high thermal conductivity and its ability to form thermally conductive channels, eliminate hot spots in melt, and uniformly distribute heat throughout the melt gave better results in terms of flash reduction.

The filler loading levels of talc and BN with matching viscosities were tested for thermal conductivity of the melt supporting the idea that it is solely the thermal conductivity of the melt which is instrumental in flash reduction. The thermal conductivity of BN-filled polymer was 0.279 W/m-K while the thermal conductivity of talc-filled PHA was 0.188 W/m-K which was only slightly higher than the thermal conductivity of unfilled PHA which was 0.178 W/m-K.

 
AdviserStephen P. McCarthy
SchoolUNIVERSITY OF MASSACHUSETTS LOWELL
SourceMAI/ 47-04, p. , Mar 2009
Source TypeThesis
SubjectsPlastics
Publication Number1461624
Adobe PDF Access the complete dissertation:
 

» Find an electronic copy at your library.
  Use the link below to access a full citation record of this graduate work:
  http://gateway.proquest.com/openurl%3furl_ver=Z39.88-2004%26res_dat=xri:pqdiss%26rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation%26rft_dat=xri:pqdiss:1461624
  If your library subscribes to the ProQuest Dissertations & Theses (PQDT) database, you may be entitled to a free electronic version of this graduate work. If not, you will have the option to purchase one, and access a 24 page preview for free (if available).

About ProQuest Dissertations & Theses
With over 2.3 million records, the ProQuest Dissertations & Theses (PQDT) database is the most comprehensive collection of dissertations and theses in the world. It is the database of record for graduate research.

The database includes citations of graduate works ranging from the first U.S. dissertation, accepted in 1861, to those accepted as recently as last semester. Of the 2.3 million graduate works included in the database, ProQuest offers more than 1.9 million in full text formats. Of those, over 860,000 are available in PDF format. More than 60,000 dissertations and theses are added to the database each year.

If you have questions, please feel free to visit the ProQuest Web site - http://www.proquest.com - or call ProQuest Hotline Customer Support at 1-800-521-3042.