New Plastic that Changes Opacity - What is that effect called??

[Demon3]

Hi Folks,

I had a request from a former colleague to make a thermoplastic that is milky white at room temperature and becomes transparent when heated. We managed to make such a material but I don't know what to call the effect. Thermochromics are well-known but that is changing of color whereas this new material has no color. I was tempted to call it thermo-opacity or thermo-opacic. I'm not sure if that is correct and it sounds a bit clumsy. Anyone have some insight?

The temperature of transparency can be chosen in the range -20C to +85C. The effect is reversible and the mechanicals are similar to ABS. It's being considered for a window in a dishwasher door. The idea is that at room temperature you can't see your dirty dishes because the material is cloudy. When the dishwasher is on, the warm water hits the window and it becomes transparent so you can see the cleaning process. Other applications have been suggested too.

There is not any memory with less satisfaction than the memory of some temptation we resisted.
- James Branch Cabell

 

[patprimmer]

Thermo clarified.

Regards

eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[Demon3]

That sounds pretty nifty. I'm half expecting IR Stuff to come leaping in with a name too long to pronounce.

There is not any memory with less satisfaction than the memory of some temptation we resisted.
- James Branch Cabell

 

[patprimmer]

If it will be commercially available t a marketable price, I might run it past the guys at Duromer and contact you directly if they show interest

Regards

eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[Demon3]

It's been made on a larger scale for trials, e.g. 100kg or more. I'd be happy to explain how it works and send an article. There are no additives and nothing to migrate out. It looks like the patent on it will only be for Germany so I can tell anyone else how to make it you just need an extruder for blending the ingredients. I'd be really happy to see someone use it. I would not get a penny from it but I would like the satisfaction.

There is not any memory with less satisfaction than the memory of some temptation we resisted.
- James Branch Cabell

 

[patprimmer]

Thank's.

I will discus with Dennis this morning and contact you off line.

I GUESS it's about crystals forming, melting and reforming at a melting point where the clarity is required and lower than the melting point of the matrix resin.

Regards

eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[Demon3]

No crystals in this case but that's a good guess and would be another way to do it.

There is not any memory with less satisfaction than the memory of some temptation we resisted.
- James Branch Cabell

 

[btrueblood]

Thermal + translucence = thermo-lucence?

Apologies in advance for any UK/Yankee spelling differential. Nah, strike that. The UK spelling looks too weird.

 

[Demon3]

Thermo-lucence certainly has a great ring to it. I like it!

There is not any memory with less satisfaction than the memory of some temptation we resisted.
- James Branch Cabell

 

[dgowans]

Demon3,

That material sounds cool - to the point that I'm racking my brain trying to come up with an application in my company's products. No luck thus far...

As far as the name of the effect, I'm going to borrow a page from Calvin and Hobbes and suggest "thermal transmogrification"!

 

[Pud]

I would call it "Expensive"

(Joking!)

Harry

 

[Demon3]

Hi Harry,



You would imagine that it's expensive but it's not too bad. The price would be a bit more than MABS.

There is not any memory with less satisfaction than the memory of some temptation we resisted.
- James Branch Cabell

 

[MacGyverS2000]

I'm thinking of engine hoods

Dan - Owner

http://www.Hi-TecDesigns.com

 

[Demon3]

A major freezer manufacturer were interested in the version that becomes transparent when cooled. You could use it for the plastic drawers or doors in a freezer. When the freezer is at the righ temperature it's transparent and you can see the food, when it's too warm the material turns opaque. That way you can see if all is well without paying to have an electrical thermocouple. Of course, you don't need to make the whole part from this material, just a small window would work too.

There is not any memory with less satisfaction than the memory of some temptation we resisted.
- James Branch Cabell

 

[btrueblood]

Sounds like neat stuff, Demon. Can think of a lot of toy applications...

Thermolucent - no charge for the brand name consultation

But, the marketing types will probably want to call it thermoclear, or cool-clear, or something like that.

 

[Demon3]

Thanks btrueblood. I had fun making it and it's fascinating to use. I have some small plaques of it, you can dip them in coffee and the hot part becomes clear. Makes it easy to demontrate in a meeting. One day I am hoping to combine it with thermochromics. Using both effects together you could go from say a milky purple to an intense blue.

There is not any memory with less satisfaction than the memory of some temptation we resisted.
- James Branch Cabell

 

[HDS]

I would classify it under thermochromatic but give it a better brand name.

Thermoptical
Temperview
hotview
coldview


The effect is interesting because most clear plastics get milky with temperature. That is a limiting factor for the applications of clear ABS.