Faq Temperature Resistance Of An Adhesive For A Bonded Assembly, youtube mp3 indir
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FAQ | Temperature resistance of an adhesive for a bonded assembly
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This is a question we often get from customers that doesn’t have a good, clean answer because it depends. There isn’t a single number to provide, and there are a few things that you should consider when you think about temperature exposure.
How cured is the adhesive?
If the adhesive has just reached handling strength or is still somewhat liquid, temperature exposure will do something different than if it’s fully cured three weeks or six months after you assembled it.
What is the absolute magnitude of temperature that will be seen in the application?
How high is the high and how low is the low? This helps understand whether there will be any thermal degradation issues due to the adhesive reaching those extremes.
How long does the assembly see those temperature extremes and every point in between?
If a part sees an absolute high of 150°C, it makes a difference whether it sees that high for five minutes or five weeks, so you have to think about total temperature exposure and any degradation effects based on that. Frequency is also relevant: how often does the part move to the temperature extremes? An outdoor application in the desert that cycles every 24 hours between 40°F at night and 115°F during the day is very different from something that sees the same extremes but for months at a time with a year-long cycle.
What is the actual load being applied to the adhesive while it’s exposed to the temperature?
This last question may be the most important. Even if the adhesive doesn’t suffer from thermal degradation, it’s still a polymer and will undergo physical changes. Specifically, as temperature increases past a certain point (the Glass Transition Temperature) it will go from a glassy rigid state through a transition to a softer, rubbery state. Physical properties of the adhesive will change as it warms and cools through the transition stage, including rigidity, thermal expansion coefficient and heat capacity, among others, and this can affect the load-bearing ability of the adhesive.
Learn more about structural adhesives
https://www.3m.com/3M/en_US/bonding-and-assembly-us/structural-adhesives/
Search Tech Data Sheets
https://3m.citrination.com/search?locale=en-US
Tech Bulletin (see pages 11-19)
https://multimedia.3m.com/mws/media/328280O/3mtm-scotch-weldtm-structural-adhesives-sel-gd.pdf