Scott,
A paper was published at the second national conference on Developments
in Rapid Prototyping and Tooling, titled 'Effect of humidity on the
properties of stereolithography parts manufactured from SL5180 epoxy
resin' by T S Peng, D I Wimpenny and S Windsor.
They found that at 95% humidity the tensile strength fell from 57MPa to
36MPa after one week, then to 18MPa after 2 weeks, and to 14MPa after 4
weeks. I've taken these values from a graph, so they may be out by
1-2MPa. They also have information on parts swelling when exposed to
high humidity for long periods of time.
This paper was published anout a year ago, so they may have more recent
results, so it may be worth contacting them directly. They are based at
the Advanced Manufacturing Centre, which is part of the Warwick
Manufacturing Group, at Warwick University. Their web site is
http://www.warwick.ac.uk/atc/
John
-- John Male Research Student Centre for Rapid Design and Manufacture Buckinghamshire University College Queen Alexandra Road High Wycombe Buckinghamshire England HP11 2JZTel 01494 605085 Fax 01494 538593
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