 |
|
|
|
|
|
| |
| |
|
|
|
|
| |
| |
|
|
On 30/04/2014 2:33 PM, Francois Labreque wrote:
> At this point, this becomes obligatory:
>
> http://www.youtube.com/watch?v=PSxihhBzCjk
Kudos for dredging up that connection. :-)
--
Regards
Stephen
I solemnly promise to kick the next angle, I see.
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
On 30/04/2014 8:14 AM, Thomas de Groot wrote:
> On 29-4-2014 22:19, Stephen wrote:
>> On 29/04/2014 9:09 PM, Stephen wrote:
>>>
>>> Go back another twenty years and they would be mostly lead popes.
>>
>> I think I meant pipes. Lead pipes not lead Popes. :-)
>>
>
> Somehow, those /lead popes/ trigger my imagination... :-)
>
> Thomas
Edgar Allan Poe, anyone? ;-)
--
Regards
Stephen
I solemnly promise to kick the next angle, I see.
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
On 30/04/2014 8:40 AM, scott wrote:
>
> Two more. No annoying metal banging noises when the heating turns on or
> off (light sleepers can have the heating come on before they wake up).
> And because the pipes are somewhat bendy you can move things about
> without having to disconnect pipes. Painting behind my radiators is
> easy, I can just lift them off, rotate through 90 degrees and rest them
> on a bucket or something, no plumbing needed.
>
I've never heard of plastic piping for radiators. O_O
The flexibility of plastic piping is great. I had to do some pipework
when I worked offshore. 1/4", 3/8" and 1/2" stainless steel. You had to
be very accurate with your measurements. It looks better, though.
--
Regards
Stephen
I solemnly promise to kick the next angle, I see.
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
> I've never heard of plastic piping for radiators. O_O
Nor had I until I moved into a house built in this century! The pipes
are on 90 degree exit from the bottom corners of the radiator and bend
back behind in to the centre and through a hole in the wall, it's all
very neat with virtually no pipes visible (and no annoying pipes going
down through the floor).
> The flexibility of plastic piping is great. I had to do some pipework
> when I worked offshore. 1/4", 3/8" and 1/2" stainless steel. You had to
> be very accurate with your measurements. It looks better, though.
You can get chrome plated plastic covers to go over copper pipes, to
match fancy bathroom radiators and that sort of thing :-) But I guess
you were using stainless due to its corrosion resistance rather than its
looks. The stuff we make here is mostly stainless too for the same
reason, but we are gradually changing over to PEEK, I wonder if you can
get PEEK pipes <quick google> yes of course you can, first hit is for
off-shore applications!
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
On 30-4-2014 20:51, Stephen wrote:
> On 30/04/2014 8:14 AM, Thomas de Groot wrote:
>> On 29-4-2014 22:19, Stephen wrote:
>>> On 29/04/2014 9:09 PM, Stephen wrote:
>>>>
>>>> Go back another twenty years and they would be mostly lead popes.
>>>
>>> I think I meant pipes. Lead pipes not lead Popes. :-)
>>>
>>
>> Somehow, those /lead popes/ trigger my imagination... :-)
>>
>> Thomas
>
> Edgar Allan Poe, anyone? ;-)
>
No not really Poe, although dark enough indeed. It combines to me more
with what in Italy were called the /Years of Lead/ (anni di piombo).
Lead popes would suggest to me a period of oppressive religion. An
interesting topic for an SF novel in a distopian world.
Thomas
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
On 29/04/2014 09:23 AM, scott wrote:
>> Interesting. I was under the impression that UV-resistent coatings are
>> just overly-optimistic marketing, and in reality none of these coatings
>> actually work.
>
> One of the first image results from google gave this:
>
> http://www.alpineastro.com/filters/uv_ir_cut_specs.htm
>
> That's a pretty sharp fall-off below 400 nm. Whether it works or not is
> unquestionable, what is usually up for debate is whether it's actually
> useful on a camera. On skin, eyes or paint of course it works and is
> useful.
That's a pretty sharp cuttoff. OTOH, from this scale you can't tell
whether the filter still passes, say, 1% of the UV. 1% UV is presumably
still easily enough to utterly destroy whatever is underneith. (E.g., a
plastic coated in this stuff will get ruined in a few months rather than
a few days.)
I am not a professional chemist, but as I understand it, UV just
destroys absolutely everything it touches, and it's very hard to make it
not do this.
> Then there are all the things the consumer doesn't even notice. Like
> plastics that are easier to mould (more complicated shapes are possible
> to be made faster with finer details), possible to process in thinner
> films, flame retardants that are environmentally friendly, stronger and
> stiffer plastics that enable things to be made with less plastic for the
> same performance etc.
So... essentially you're saying the only real change is that plastic is
cheaper now?
And to think I was under the impression that plastic only exists in the
*first* place because it's cheaper...
> The software we use here for simulating the moulding of a plastic part
> (to make sure it will fill correctly and not leave any sink marks, weld
> lines etc) has a built-in database of plastic materials to choose from.
> There are over 10000 of them, and there are plenty not in the list. They
> have all been developed for a specific reason, and most of them recently
> (not 30 years ago).
I knew there were at least 6 main plastic types. But 10,000? Really? I
can imagine you could have 10,000 different compounds, with different
additives in them to adjust how springy or brittle they are, etc. But
10,000 fundamentally different molecules? Really?
Actually, I just thought of something. One thing we didn't have when I
was a kid: oven bags. As in, plastic bags that you cook things inside. I
still can't quite wrap my mind around how this works; most plastics melt
if you pour boiling water on them, never mind heating them to *hundreds*
of degrees...
(Also, if this plastic as such a high melting point, how do you mould it
in the first place??)
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
> Second, you worked in the chemical industry for over 10 years. I'm sure
> you're familiar with the names 3M, Dupont and BASF, just to name those.
> Don't think for a second that these companies don't have large R&D depts
> that work round the clock trying to come up with newer compounds
I was under the impression that 3M's main business is *manufacturing*
plastics, not designing new ones. (Actually, I was under the impression
that 3M manufactures finished products that have plastic _in_ them, but
I guess they probably sell raw plastic to other people...)
> Have you noticed how nowadays most eye glasses are made of plastic?
> Clear plastics with higher IOR (sorry for getting slightly on-topic for
> P.O-T) than glass were unheard of 30 years ago. The progresses made in
> the domain of contact lenses is even more impressive than that of
> conventional glass lenses.
Really? I thought *all* transparent materials have an IOR different than
air. As in, it's impossible to *avoid* this (e.g., if you wanted to make
a kind of "invisible glass", you can't do it.)
> The "technical" garment industry has also greatly benefited from these
> new polymers. You're a skier, so you've most certainly seen the
> 74732327523 tags that are sewn or attached on a new ski jacket or
> gloves, touting the amazing breathability, yet still impermeable,
> feather light, yet warm as a mammoth pelt, machine washable, yet won't
> fade properties these clothes now offer.
I thought that all of those claims were radically exaggerated marketing,
and that these materials are basically identical to what we had 40 years
ago.
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
On 29/04/2014 03:21 PM, scott wrote:
> Or surely you've heard about 3D printers recently? The materials they
> use (the professional ones, not the hobby ones) are state-of-the-art
> polymers to give the final piece properties as close as possible to
> traditional injection moulded plastics. It's not like those materials
> existed 30 years ago.
Granted I don't work in the manufacturing industry. But I would have
expected that the market for rapid prototyping is utterly *tiny*
compared to the market for actual finished goods.
Does anybody really use 3D printers much? I mean, I can imagine there
are products for which this might be really useful, but if you're just
making (for example) plastic sandwich boxes, do you really need to
prototype that?
Also: I was given to believe that 3D printed objects have approximately
the structural rigidity of jellybaby. It's strong enough to see if
various printed parts will fit together right, but if you stare at it
too hard you're gonna break it. But hey, it's only a *prototype*, right?
It's not like the finished item will be made of the same gel...
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
On 01/05/14 18:41, Orchid Win7 v1 wrote:
> Granted I don't work in the manufacturing industry. But I would have
> expected that the market for rapid prototyping is utterly *tiny*
> compared to the market for actual finished goods.
>
> Does anybody really use 3D printers much? I mean, I can imagine there
> are products for which this might be really useful, but if you're just
> making (for example) plastic sandwich boxes, do you really need to
> prototype that?
>
> Also: I was given to believe that 3D printed objects have approximately
> the structural rigidity of jellybaby. It's strong enough to see if
> various printed parts will fit together right, but if you stare at it
> too hard you're gonna break it. But hey, it's only a *prototype*, right?
> It's not like the finished item will be made of the same gel...
YABAMBA
--
Protect the Earth
It was not given to you by your parents
You hold it in trust for your children
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
On 01/05/14 18:37, Orchid Win7 v1 wrote:
>
> I was under the impression that 3M's main business is *manufacturing*
> plastics, not designing new ones. (Actually, I was under the impression
> that 3M manufactures finished products that have plastic _in_ them, but
> I guess they probably sell raw plastic to other people...)
>
YABAMBA
>
> Really? I thought *all* transparent materials have an IOR different than
> air. As in, it's impossible to *avoid* this (e.g., if you wanted to make
> a kind of "invisible glass", you can't do it.)
>
YABAMBA
>
> I thought that all of those claims were radically exaggerated marketing,
> and that these materials are basically identical to what we had 40 years
> ago.
YABAMBA
Sorry Andy but it has to be said
John (recovering from his stroke)
--
Protect the Earth
It was not given to you by your parents
You hold it in trust for your children
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
|
|
