When designing components made of PTFE, the relatively high degree of thermal expansion must be taken into consideration:
20-100 °C: = 16 · 10-5 1/K
20-200 °C: = 23 · 10-5 1/K
Recordings of the coefficient of linear expansion reveal two conspicuous transitions:
At 19°C there is a conversion...
sda97
Have a look at ASTM Standard D1785-03 entitled "Standard Specification for Poly(Vinyl Chloride) (PVC) Plastic Pipe, Schedules 40, 80, and 120". There are additional references in this standard.
Regards,
Peter P
Not true Pat - the ban has been lifted. See
http://www.millenniumchem.com/Products+and+Services/Products+by+Type/Cadmium+Pigments/r_Whats+New/Cadmium+Pigments+Whats+New_EN.htm Good News for users of Cadmium Pigments
Regards,
Peter P
Not true Pat - the ban has been lifted. See
http://www.millenniumchem.com/Products+and+Services/Products+by+Type/Cadmium+Pigments/r_Whats+New/Cadmium+Pigments+Whats+New_EN.htm Good News for users of Cadmium Pigments
Regards,
Peter P
Nigel,
Sorry that should have been plane strain.
See http://www.sv.vt.edu/classes/MSE2094_NoteBook/97ClassProj/exper/mcmurtry/www/matt.html#planestr
Regards,
Peter P
Nigel,
Fracture toughness (or K1C as it is often referred to) is a parameter based on Linear Elastic Fracture Mechanics (LEFM), Which means that your sample must have a linear stress/strain curve up to the point of fracture. This being the case it means that only brittle polymers such as PS or...
It's an old book, probably out of print, but it has the best analysis of calendering I have ever found.
"Polymer Processing" by James M McKelvey, Published by John Wiley and Sons Inc. 1962.
Chapter 9 'Hydrodynamic Analysis of Calenders' - excellent, well worth searching it out.
If...
HDPE is very susceptible to Enviromental Stress Cracking (ESC) and is known to embrittle over time. LDPE is less susceptible
I would think that the bottles are so cheap that you could afford to replace them, say annually.
Regards,
Peter P
You are looking for something like the Vicat Softening Temperature.
See the URLs below
http://www.astm.org/cgi-bin/SoftCart.exe/DATABASE.CART/REDLINE_PAGES/D1525.htm?E+mystore
http://www.tiniusolsen.com/products/p-hd94.html
http://www.ptli.com/testlopedia/tests/Vicat-D1525.asp...
What's the polymer? Most are viscoelastic and undergo stress relaxation and creep under load. This is why you will not find design criteria you are looking for and I don't think you will be able to easily compute them.
Regards,
Peter P
