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Plastic Sectioning fixture

Plastic Sectioning fixture

(OP)
I have a plastic tube type part that I need to repeatedly and reproducibly section. The material is LLDPE Dowlex 2517. I am trying to design/build an automatic sectioning fixture so our operators/inspectors don't have to do anything but put part/s on this sectioning fixture and push go, and the fixture automatically cuts the part without distorting said part/s. I've been doing some pretty diligent research on the interweb and have been striking out. Have any of you designed or built any type of fixture like this? Or do you know anyone that does?

RE: Plastic Sectioning fixture

Axially, radially, something else?

OD, ID, length?

RE: Plastic Sectioning fixture

(OP)
The part is just over 6.5" long, and has a diameter of 0.875" and needs to be radially cut about 4" down from one end.

RE: Plastic Sectioning fixture

You say fixture, but it sounds like you need fixture plus cutting equipment. Do you have a preference on the cutting method? Linear or circular saw, laser, other? How thick is the plastic? For the fixture, how about a drill press vice:

http://www.palmgren.com/index.php?cPath=4_6

RE: Plastic Sectioning fixture

(OP)
Thickness is 0.075". Yeah there will have to be a saw or some sort of cutting device. I'm envisioning a two handed button type operation, punch press like. Safety is a key factor. I have to ensure that there is absolutely no way possible for a person to be able to touch any moving parts or blades. This device is going to be the first of many for me.

RE: Plastic Sectioning fixture

Quote (OP)

without distorting said part

Essentially that's impossible. So you'll need to define the types of distortion at amount that are acceptable.

Google "plastic tube cutting machine" yields 1.4 million hits. One might do exactly what you need.

RE: Plastic Sectioning fixture

(OP)
I've spent about 3-4 hours googling and researching this morning, unfortunately I have jobs that NEED to get now so I just don't have the research time. Thank you for the advice though. I'll get 'er figured out, then possibly share it here.

RE: Plastic Sectioning fixture

You don't have time to research the possible existence of something that does what you need, but you have the time to design what you need from scratch?

Without any quantified criteria?

To cut thin walled plastic tubing mechanically with limited distortion will require some sort of internal support.

Thermal methods will likely distort or create blobs of melted material.

Cheap and simple and "good enough" for many applications:



What short comings does it have for your application?

RE: Plastic Sectioning fixture

Buehler may be able to provide a turnkey machine,
pretty much meeting the specs revealed so far,
to section your parts:

http://www.buehler.com/Products/Sectioning

While you are undergoing a wallet biopsy,
be realistic about what it really costs to roll your own.

Mike Halloran
Pembroke Pines, FL, USA

RE: Plastic Sectioning fixture

(OP)
I miss typed earlier. I don't have any more time today to search.

I have looked at a PICO155 with variable speeds and a blade designed for plastic/rubber. The problem with bigger units like this is they are more for a solid core type of tubing.

I think I am going to go with a guillotine type cutter for now...

RE: Plastic Sectioning fixture

(OP)
So this is the design my machine house and I came up with. I started with a concept on paper and this was the final design. I have some inserts that fit inside the part to keep it from crushing. I am getting a distortion free cut. It also cuts like butter, you don't even know the part is being cut.


RE: Plastic Sectioning fixture

That is very nice. I just have to ask, though; how much did it cost, including your time?

RE: Plastic Sectioning fixture

Very nice.

Thank you for following up and posting pictures. Too few people take the time to do that.

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