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
I have found the Lloyd instument to be reliable. Tell your friend that the only only way that the machine can give a wrong modulus is if the load cell has not been calibrated properly. Tell him to have the cell recalibrated. The only other way is to use the wrong dimensions for the test...
The size of the machine depends on what you are going to test - the load cell for testing thin sheet and film will be much smaller than for something as big and strong as gas pipe. Have a look at Lloyd Instruments as well, at http://www.lloyd-instruments.co.uk/ Regards,
Peter P
Physics tells us that, at constant temperature (constant melt viscosity), if the flow lengths of all your runners are the same and the runner diameters are all the same, the flow must be balanced. The only thing that can disrupt this is if your runners are blocked in some way or if there is a...
You might be thinking of linear friction welding (also known as vibration welding). See http://www.metalwebnews.com/howto/plastics/welding-plastics.pdf . Or visit The Welding Institute at http://www.twi.co.uk/j32k/protected/band_3/pjkfwplast.html Regards,
Peter P
