×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Use of neoprene gasket to minimize thermal transfer

Use of neoprene gasket to minimize thermal transfer

Use of neoprene gasket to minimize thermal transfer

(OP)
I have a situation where the architect has designed a trellis at a roof terrace that is offset from the main column line of the structure. As a result, it is necessary to affix a tube column to the flange of the main building column to carry the trellis. The architect is concerned about thermal transfer. Instead of welding the tube column to the main building column, I have welded plates to each member and created a moment connection. However, they are requesting a neoprene gasket between the two plates to minimize thermal transfer. Has anyone had any experience with this? I know there will be non-uniform load on the gasket and I don't want it to compress too much, but I don't want anything too thin that the steel will cut it and render it ineffective. It is different from a typical bearing pad because the installation is vertical and not horizontal. Any insight would be appreciated.

RE: Use of neoprene gasket to minimize thermal transfer

Is he dead set on neoprene or will he agree to something like a Teflon plate similar to what would be used at a slide bearing type condition?  I believe Neoprene is going to compress considerably no matter the thickness.

RE: Use of neoprene gasket to minimize thermal transfer

(OP)
They are open to any product that will minimize thermal transfer. The neoprene gasket was the architect's suggestion, but I am open to any rational idea, especially because I only have about 1/2" wiggle room to fit in some kind of thermal barrier. Someone else has suggested Sorbtex to me. Does anyone know about this product?

RE: Use of neoprene gasket to minimize thermal transfer

Consider a bearing grade material (like Delrin), analysis is required to check bearing stresses.

RE: Use of neoprene gasket to minimize thermal transfer

(OP)
Is Delrin something that is readily used in structural applications? And, will the contractor be able to find it? I found a data sheet on the DuPont website, but I need info on compressive strength which was not avialable.

RE: Use of neoprene gasket to minimize thermal transfer

There are many polymers that can be used in this application.  Delrin and Teflon are a two of the most common polymer bearing  materials used.

Delrin® possesses high tensile strength, creep resistance and toughness. It also exhibits low moisture absorption. It is chemically resistant to hydrocarbons, solvents and neutral chemicals. These properties along with its fatigue endurance make Acetal DELRIN® ideal for many industrial applications. I find it is a very cost effective material.  You buy it from McMaster carr.

Some of the factors to evaluate are:
  Good dimensional stability
  Good wear and abrasion properties. With its low
     coefficient of friction and hard and resilient
     surface, Acetal DELRIN® is the material of choice in
     many wear applications.
  High strength and stiffness properties
  Low moisture absorption
  Excellent machinability
  High fatigue endurance
  Superior impact and creep resistance
  Chemical resistance to fuels and solvents
  Temperture range
  Yield strength
  Cost
  Availability



RE: Use of neoprene gasket to minimize thermal transfer

Why not use the fiber material that's used to fabricate gaskets for pipe flanges?
You can buy it in sheets that can be cut to your shape, various thicknesses are available (up to 5 mm I believe), it is done to support high compressions and also should have a high thermal resistance (though I guess you won't find data for that).

prex

http://www.xcalcs.com
Online tools for structural design

RE: Use of neoprene gasket to minimize thermal transfer

What ever material selected make sure it has a very low water absorbsion characteristic.  

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources