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| Author | Topic: Making tubes out of zytel |
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rnb Member Posts: 3 |
posted November 14, 2005 10:29 AM
   
Hi, Ok I need some help, I've been asked to run some (zytel 101L n) Tube size .230 O.D. -.190 I.D. I have a 1" 24:1 machine I tried running it with a 2-1 draw and when following the Tech. sheet for the Temp. profile the material would either freeze off or it would look to hot and I was not able to sting it up.do I need to do a reverse profile or a higher draw. Thanks RNB IP: Logged |
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louis33 Senior Member Posts: 139 |
posted November 14, 2005 11:26 AM
1/4 x 190 zytel on a 1" machine might be pushing it. That tube would run quite well on a 2" or 2 1/2" machine. At any rate, nylons have a sharp melting point, 101 is around 505 degrees F if I recall correctly, so you might want to run it around 540 or a little higher. Therefore, if you freeze off, you went too cold. It does run kind of "soupy" when at the right temperature as it has a low viscosity. You are drying it right? Moisture will drop the viscosity further. I am curious, how are you sizing it? IP: Logged |
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rnb Member Posts: 3 |
posted November 14, 2005 01:08 PM
Thanks for the input. I'm just running it from the head to the trough and as far as I know my dryer is working, I found out this morning that the zytel 101 is a molding grade and that zytel 42a is the same material but it has a higher viscosity so I'll try that. any input on draw down 2-1 or 5-1 IP: Logged |
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Kevin Duggan Member Posts: 2 |
posted November 18, 2005 02:06 PM
You are attempting to extrude an injection moldable grade of nylon 66. By the time you have the resin properly melted (even at the lowest melt stock temperature possible and this process window is narrow) you will be dealing with a very fluid material with very little melt strength. Extrusion processors that successfully make tube from Zytel 101 use a grade that has been solid state polymerized. This enhaces the melt strenght greatly, so when you have proper melt temperature you can string the line up through your calibrator and the tube Tell your people at Dupont you want the extrudeabe grade of 101(the higher the relative viscositry the better). This should make your job a whole lot easier. IP: Logged |
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alpertl Senior Member Posts: 45 |
posted November 19, 2005 12:04 PM
quote: I believe Mr Duggan has given you sound advice. While you can make what you have work, unless you have a lot of experience and the right equipment, it will be difficult, at best with the melt viscosity you are dealing with. IP: Logged |
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rnb Member Posts: 3 |
posted November 19, 2005 06:39 PM
quote:Ok,I've got the size I need .230x.190 I'm using zytel 42a extrusion grade. I'm having troubles holding roundness and I don't have a vacuum sizer,any suggestions.Thanks rnb IP: Logged |
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Kevin Duggan Member Posts: 2 |
posted November 22, 2005 05:25 PM
If you do not intend to use a vac sizer you might try extruding (at an angle of 90 degrees to your extruder, down) your extrudate directly into a water bath. This will allow gravity to work uniformly on the tube, hopefully maintaining the roundness. You will need a fairly deep bath relative to your trough, to allow the tube to set-up before you loop back up to leave the tank. Also be carefull not getting the die to close to the water or having much turbulence in the tank as splashing the die will freeze you off. IP: Logged |
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