Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

  • Congratulations waross on being selected by the Tek-Tips community for having the most helpful posts in the forums last week. Way to Go!

Search results for query: *

  • Users: nlj
  • Order by date
  1. nlj

    Creep Resistance

    I know that XLPE gets improved creep resistance as compared to just PE. I also understand hat nylons are generally creep resistant due to the crystallinity. I am wondering which would have higher creep resistance at higher temperature (110C); cross-linked polyethylene or nylon 11? The...
  2. nlj

    Solenoid Material

    Thanks for the information. I will look into those things. It is DC and is part of a hydraulic system; controlling flow to a variety of hydraulic equipment.
  3. nlj

    Solenoid Material

    Does anybody have experiences (good or bad) with a certain solenoid potting material? We are having issues with a nylon potting material melting and a polyurethane potting degrading. Other than potting compound are there any suggestions on waht may be causing the solenoid to reach such a high...
  4. nlj

    Foams

    Besides the obvious difference between the base polymer, what is the difference bewtween polyolefin foams and polyurethane foams? In looking at the differences, the processing and therefore cost, appear different. If using as an air seal are there major difference to be aware of? All of my...
  5. nlj

    Blend versus Non-blend

    I have been reading through ASTM D2000 and corresponding standards, however I cannot find specific detail on how composition is controlled. I have field failures of a part specified to be polychloroprene (neoprene) per ASTM D2000 M2BC etc. I have been supplied with third party FTIR revealing...
  6. nlj

    Polymer Seal

    Yes, UHMWPE. Fluid exposure is DOT 4 brake fluid. It is a secondary seal on a mechanical shaft. We are also looking at changing the design to include a mechanical seal such that we are not replying on material properties only.
  7. nlj

    Polymer Seal

    Hello All, We have a UHMW seal that is currently failing when subjected to testing. When exposed to -40F the seal is not reliable. The seal works fine at higher temperatures (200F). I ran TMA on the new versus used seal and found the CTE to be about 30 points lower on the used seal. I am...
  8. nlj

    Wire Varnish Aging

    We suspected overheating however could not get the system to reach temperatures above the wire varnish capabilities using the normal duty profile. Since I posted this we have figured out that the components were not being used per the duty cycle and it is in fact exceeding temperature. I...
  9. nlj

    Wire Varnish Aging

    Hello All, Is anyone familiar with wire varnish aging or degradation over time? I have had failures occuring and we have come to a couple of conclusions that there are two different wire varnishes being used....a polyamide-imide and an urathane acrylate. The other difference is porosity found...
  10. nlj

    Test for Undercured Silicone

    Hello! I have a part that is made of 7 ply aramid fiber silicone. We are having some burst problems and our supplier believes it is an undercure. (I believe their process is very out of control, but that is another conversation). I'm trying to determine some testing that can help us...
  11. nlj

    Galvannealed Steel and Aluminum

    It is vehicle application - so normal road wear and conditions. Sizes vary -- mainly brackets (3-5" mating size).
  12. nlj

    Galvannealed Steel and Aluminum

    Do you need a barrier (protective coating)when galvannealed sheet steel is mounted to aluminum? I would think no, but wanted to confirm. Thank you!
  13. nlj

    ASTM D4000 and ASTM D4066

    Hi! I'm looking to use ASTM D4000-12 or ASTM D4066-01 on some engineering drawings. I have determined that I need the following: ASTM D4066-01 PA 011 B0003___ <--This 5th line item is "to be determined" and I'd like to use this position to add in a brittleness temp/cold temp application...
  14. nlj

    Masticated Rubber Alternative

    Thanks all!! I have to prove "as-good-as-or-better" to my customer...even for a non-critical part like a mudflap. I'll get on pulling up those listed above. Thanks again!!
  15. nlj

    Masticated Rubber Alternative

    The issues spans across several of our parts. Many of the prints just state "Masticated Rubber" but the product shortage is on the Natural Rubber. Our supply base has told us that due to the environmental reasons there simply aren't as many natural rubber sources and they continue to be hand...
  16. nlj

    Masticated Rubber Alternative

    I guess I didn't pose my question correctly - the supply chain shortage of masticated rubber is causing us some headache right now and we are looking for an alternative material to use over Masticated Rubber. I was curious if anybody else was running into the same supply chain issue. Thanks!
  17. nlj

    Masticated Rubber Alternative

    Is anyone else having issues with the masticated rubber shortage? If so, what are your steps forward and alternative materials that you are using? We have been researching a few options, enduraprene and tigerthane, but both have their plusses and minuses. Thank you!
  18. nlj

    High Temp - Pil Resistant Material

    Sorry....typo...It's 424 oil is hydraulic oil. Thank you for all of the responses.
  19. nlj

    High Temp - Pil Resistant Material

    Hi! I've been researching various polymers for a temp range or -40F to 250F, that need to be resistant to 242 oil and 80W90 oil. I've found PEEK as an option, but was hoping to find some less expensive options. Thanks much for your input!
  20. nlj

    FTIR Spectrometer

    Oops...I meant I don't know which requirements you mean. Sorry. Thanks!
Back
Top