Has anyone worked in Plastic Extrusion?

[Chris DentonParticipant @chrisdenton53037]

Just wondering why you would build a hug from steel rather than brass?

Presumably cost reasons?

[Chris DentonParticipant @chrisdenton53037]

[Richard MarksParticipant @richardmarks80868]

What!

[Chris DentonParticipant @chrisdenton53037]

Should say jig not hug.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Chris Denton on 07/11/2015 14:13:09:

Should say jig not hug.

.

Chris,

That's a wonderful typo … it conjoured-up all sorts of images.

Unfortunately, I remain confused by your thread title:

Do you mean 'Has anyone worked in the manufacturing process of Plastic Extrusion?'

or: 'Has anyone worked in Plastic Extrusion as a material?'

.

… It's not your fault that "Extrusion" is used both as a verb and a noun; but it does lead to ambiguity.

MichaelG.

 

Edited By Michael Gilligan on 07/11/2015 15:12:17

[Old SchoolParticipant @oldschool]

I have done over 20 rears in the plastics product manufacturing including extrusion don't know what you mean by a jig for extrusion are you talking about the die head or the down stream equipment.

[Chris DentonParticipant @chrisdenton53037]

Posted by Old School on 07/11/2015 15:39:34:

I have done over 20 rears in the plastics product manufacturing including extrusion don't know what you mean by a jig for extrusion are you talking about the die head or the down stream equipment.

You sound like a good person to know. I've been in the industry for 10 years but I have had a 10 year break from it.

They may also be called calibrators, downstream of the die, their purpose is to keep the shape of the semi molten plastic while it cools. They can either be brass plates or longer brass 'jigs'.

I've recently been at a factory that has very slow line speeds, Even a basic profile runs at 2 meters per minute. Most of the jigs are made from steel, I'm wondering if this is the reason everything runs so slow.

[Boiler BriParticipant @boilerbri]

I went to a company in Prestwich in Cheshire. They were extruding filament for bandages etc. There was a tank with water in and an extrusion nozzle submerged on the horizontal. You could not see anything at the nozzle but as you looked along the tank the filament was showing opaque as it set . At the furthest end of the tank was a set of rollers and the filament was then pulled through them and onto a winding drum.

It was strange not to be able to see it as it left the nozzle.

Brian

[Chris DentonParticipant @chrisdenton53037]

Yes, sometimes the die is right against the jig.

[Old SchoolParticipant @oldschool]

All our calibrators were made of brass either the plate type or tubular, the extruder output controlled the speed but you needed to cool the product as its produced on our faster lines we had a series of cooling tanks the first one under vacuum when producing pipe the rest just water sprays.

[Chris DentonParticipant @chrisdenton53037]

Posted by Old School on 07/11/2015 19:47:22:

All our calibrators were made of brass either the plate type or tubular, the extruder output controlled the speed but you needed to cool the product as its produced on our faster lines we had a series of cooling tanks the first one under vacuum when producing pipe the rest just water sprays.

That sort of setup is what I'm used to. We ran tile trim at around 8-10 meters per minute.

But where I am now things run at about 1/5 the speed, I'm wondering if the steel jigs are the reason, I've tried asking but people either don't know or are deliberately awkward.

[BazyleParticipant @bazyle]

More likely due to the cross section and cooling rates and they run it as fast as they can without warping and distortion. Should be in the set up instructions and engineer's records for the first few runs. If it isn't in the Process you will fail an ISO9000 audit by your customers. Choice between brass and steel might be due to corrosion from the plastic outgassing.

This thread is an interesting glimpse into the diverse experience and skills of the forum members aside from the usual industrial scale bending bits of metal and poking around circuit boards.

[Peter TuckerParticipant @petertucker86088]

Hi Chris,

I worked in an extrusions factory in the mid 1970s, all cooling gigs were steel and the product was drawn at 90+ metres per hour (approximately 1.5 m/min.).

Peter.

[TrevorhParticipant @trevorh]

Hi All

I still work in the blown film and cast extrusion side of the industry – i get to build the machines and try to run them, Mainly German made nowadays

Trevor

[mickParticipant @mick65121]

Calibrators eh, back when god was a boy we called them formers and yes they were made of brass, mainly because the cooling trays were full of water.

[Author]

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