Transparent Crushable O ring?? Can it be done?

[atto40]

Hello All


I am working on a project where i need to develop a standard micro transparent ring. The material needed can be anything, providing it can tick the following criteria:

1 - Must be transparent
2 - can be crushed using pliers etc and stay crushed just like a metal or copper ring would stay crushed.

I have searched and asked quite a few companies, all of which explained it cannot be done. However, they may not be professional engineers in the plastic or materials industry.

I have attached pictures of the small copper/metal rings which can be crushed using pliers. In the pictures, the rings have been placed next to a 1pence British coin (diameter 20.33mm) for size reference purposes.

The idea is to replace the colored copper rings with a transparent version which must perform in the same way as the copper rings

Pleas note, i am not an engineer nor do i have any experience in specialized materials so any responses, please try your best to explain any possible solutions without technical jargon

Many Thanks All
Atto40

 

[atto40]

here is the 2nd picture ..............

 

[MikeHalloran]

The coin in the photo is probably mostly copper.

The small crimp rings in the photo appear to be white pigmented PVC or something similar, lined with a translucent polyolefin or something similar. They could have been neatly sliced from a length of adhesive-lined shrinktubing.

Do you assert that the outer part of the ring is painted copper? Either the paint is very durable and very elastic, or the crimping tool is extremely gentle.

Given that the inner part of the ring is translucent, why insist that the outer portion be transparent?


When you say "... perform in the same way", well, in which way(s) do you mean? Should the putative plastic behave like copper with respect to:
electrical conductivity
thermal conductivity
biotoxicity
elastic modulus
ultimate strength
yield point
corrosion
attack by solvents
change of properties with temperature
melting point
...

Sorry for including the jargon; you can find most of the words in Wikipedia.

Or you can save time this way: I am aware of no plastic that has particularly good mechanical properties after enduring severe plastic deformation. Nylon is possibly the least awful plastic in that regard; it can survive being crimped over a brass terminal, and retain its as-crimped shape well enough to not fall off, so it's used as crimpable insulation on wire terminations. I think some forms or alloys of polypropylene and PVC can do nearly as well. Before and after deformation, none are as strong as the copper. Dynamit Nobel sells some transparent nylons.




Mike Halloran
Pembroke Pines, FL, USA

 

[atto40]

Hi Mike

Many Thanks for the reply.

I agree with you i need to explain my self a little better, so here it goes:

1 - ignore the 1p coin, it was just used for size reference for the rings.

Now when you look at the 1st pic i posted (posted again below), you can see the outer ring is a blonde colour, this is the part i need to replicate to clear/transparent (completely transparent inside and out). I cannot confirm exactly what material the outer blonde ring is made from, however we can assume its copper or something similar.

FYI - the inner plastic/rubber ring sits inside the blonde outer ring, but has no relevance to the outer blonde ring. The reason its used is to cushion the contents of what goes inside the ring when it is crushed (the video below will show it better)

SO when i say it should perform in the same way as the "blonde copper ring" what i mean is simply:

1 - when crushed using pliers, it stays crushed just like the photo. The amount of force that is currently needed to crush the blonde ring is similar to the force needed in using a pair of wire cutter for say a plug socket (not the outer wire, but the smaller wires with the plug cable)

You will be asking yourself why do i need this and what is it used for?

You can download the video below which shows a demo of how the rings are used and crushed.

There is no other performance requirements such as the ones you mentioned in you list since the end user will be using it for something as simple as the video demo


PIC 1 -

http://files.engineering.com/getfile.aspx?folder=bf0b2797-ba78-4f84-8ff8-eef163a64f17&file=pic1.jpg

VIDEO DEMO -

http://files.engineering.com/getfile.aspx?folder=468eb7b9-2a9d-46c6-b6bd-acaa4f676786&file=ring.MOV

Hope this clear things up a little more
Thanks

 

[atto40]

also, please can you clarify Dynamit Nobel. I presume they are a company specializing in plastics or similar?

I'm from the UK so I have not heard of Dynamit Nobel before.

Many Thanks

 

[berkshire]

Dynamit Nobel is a Swedish company.
B.E.

You are judged not by what you know, but by what you can do.

 

[MikeHalloran]

Diagonal cutting pliers are not really the proper tool for crimping anything, especially in the hands of an amateur.
Crimping tools for electrical wire terminals are widely available and inexpensive.
So are crimped butt connectors for wire. A large one would allow passage of the two copper strips you are trying to splice, and give you a redundant lap connection.

I.e., I don't understand why you are attempting to reinvent this particular wheel.


Mike Halloran
Pembroke Pines, FL, USA

 

[MacGyverS2000]

Do you need the transparent material to provide the holding power of the original copper piece when crushed?

I have a box full of electrical connectors at home with transparent plastic outer shells (in several colors, depending upon gauge) and metal inner cores. the outer plastic shell will crush and keep its crushed shape after going through the crimper... but I doubt it would hold any pressure itself.

Dan - Owner

http://www.Hi-TecDesigns.com

 

[atto40]

MacGyvers2000 - yes your 100% correct in saying "Do you need the transparent material to provide the holding power of the original copper piece when crushed"

However, you say that it has metal inner cores, so i presume the metal will not be transparent and therefore wont be ideal in what i am looking to achieve. Also if the metal core was taken out and you crushed the transparent material (which i presume is round), would it keep it crushed shape and have some kind of holding power?

Many Thanks

 

[MacGyverS2000]

My last sentence provided that answer.

Dan - Owner

http://www.Hi-TecDesigns.com

 

[MikeHalloran]

Would it be okay to set your splice with heat, e.g. from a butane lighter, rather than crimping? If so, try this:

http://www.heatshrink.com/heat_shrink_tubing/o2c_4ft.asp

You probably want one of the smaller sizes.

This stuff may be available at a local supplier, e.g. one who sells submersible pumps.

It's not water clear, but probably more transparent than the stuff used on crimp terminals.

I have no idea if the completed splice will meet your so far unspecified pull strength test, so you will have to just buy some and try it.




Mike Halloran
Pembroke Pines, FL, USA

 

[Dougt115]

Does it have to crimp?

You may be able to find a small transparent line clip. It looks like a 'V' and when squeezed the open end clips together to hold it closed. Sorry I can't come up with the name.