# Thermoplastic Elastomer



## waimser (Sep 4, 2018)

Found some resistance bands in the local shop today and decided to try them out. The only info I have on them is "made from tpr for added durability". I fully expected them to be utterly terrible.

They are utterly terrible.

They are exactly what I need right now 

Don't have a catchbox set up here yet, just a sheet hanging at the end of the hallway, so all my shooting is indoors. I've been trying to get a less powerful setup to reduce chances of damage, I even tried out a single cut #32 office rubber of terrible quality and it was still to fast with the lightweight ammo. This stuff is perfect.

I don't know yet if its because the material is slow or if its just quite weak. It could be either way, the stuff stretches about an inch just from the weight of the slingshot which is quite small. The draw weight is pretty close to zero at 600% stretch so its super easy and fun to shoot.

I'm positively delighted with this stuff, no longer fearing taking chunks out of the brickwork. Who'd have thought shooting at slower speed could be so enjoyable.

I think the material is super interesting after reading about it, seems like it is really easy to make it quite consistent, which the stuff I have is. I'd really like to find some that is made for a purpose closer to slingshots, where retraction speed is needed. It seems like it should be possible to make it that way. When I google it, several studies on the properties are listed, I might read some of them to see if the retraction rate is mentioned at all.


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## The Norseman (Mar 5, 2018)

Now I’m interested! Pics?


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## SLINGDUDE (Aug 15, 2018)

The Norseman said:


> Now I'm interested! Pics?


I concur! We need pics, or at least a name to google.


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## waimser (Sep 4, 2018)

Here you go. You guys now know pretty much exactly wwhat I know about the stuff 



http://imgur.com/SyAZDal


Thickness looks to be about .3mm, .4mm, and .5mm. Its seems really consistent.

Just found this which is interresting.

"tensile properties are affected by the orientation of the polymer molecules upon molding. Thus tensile properties can vary widely depending on whether the stretching was done in the direction of the polymer flow during molding, or in the transverse direction."

Ive made these bandsets by just cutting a strip off the end of the piece, Ill cut some the same direction the band is intended to be used and see if its any different. Who knows if this applies to the exact material I have here though, will see.


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## waimser (Sep 4, 2018)

Ive had some time to mess around today, so some notes.

-Im certain this material I have is slow retracting. Even Much thicker bands and shooting butterfly made very little, if any, difference to the speed.

-Cutting it the other way made no percievable difference.

-Longevity is not greqat at all. Im getting maybe 50 shots at best.

-The slow speed and non existent draw weight make it a nice safe way to try out shooting butterfly style.

Im certain there is a formula for this material that will produce something at least close to latex. The problem is finding something made this way, since noone uses retraction speed as an advertised property.


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## The Norseman (Mar 5, 2018)

Too bad it doesn’t last very long.


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## JPD-Madrid (Apr 2, 2013)

Tried some years ago. Very low retraction speed.

Sent from my EML-L29 using Tapatalk


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