Sciencemadness Discussion Board

PTFE / Teflon labware inclusions - normal or not?

GammaFunction - 5-10-2020 at 15:35

I got some PTFE beakers from China, for culinary purposes (zero wastage, easy cleanup). They're not cheap, even from China.

But seem to have tons of inclusions in the PTFE.

Is this normal? Are they using recycled dirty PTFE? I want to know whether to gripe and demand a return and/or partial refund. Or if it is typical I'll just put up with it.

The US-made Teflon stoppers and thermometer holders I've seen are pristine.




[Edited on 5-10-2020 by GammaFunction]

beakers_small.jpg - 336kB

macckone - 5-10-2020 at 20:19

my guess is that these are 'seconds'.
During manufacturing 'seconds' are rejects that are still usable, for some definition of usable.
These are often sold at large discounts.

GammaFunction - 6-10-2020 at 12:58

Quote: Originally posted by macckone  
my guess is that these are 'seconds'.


That's possible, but they were advertised as first quality. "100% High Quality".

Also, the interior is a bit rough, which slightly defeats the purpose of PTFE. I'd say bottom part of interior is not machine finished like other brands advertise. (Adamas-Beta, another Chinese brand, advertises such machine finishing).

So if it's a 2nd, it's a 2nd that didn't go through final finishing.

I'd like a description of a good beaker from someone who has these, preferably from a US/Euro/Japanese supplier, or a higher quality Chinese one.

Heptylene - 6-10-2020 at 13:23

Maybe you can sand the inside and dissolve whatever the inclusions are? Though you would need very thorough cleaning after that if you want to use them for food.

GammaFunction - 6-10-2020 at 15:01

Quote: Originally posted by Heptylene  
Maybe you can sand the inside and dissolve whatever the inclusions are? Though you would need very thorough cleaning after that if you want to use them for food.


Total cost was $35. It's not worth my time doing anything but complaining. They're good enough, but I might supplement with a better grade. I might buy a US overstock one just to compare.

The inclusions are buried under Teflon, *mostly*. One at the surface looks like a sand grain. I suspect that it's dirty scrap Teflon blocks going in, or similar.

Panache - 7-10-2020 at 00:45

Nah.....they are seconds, or their qc is crap. What size are they, a decent 250ml teflon beaker is considerably more expensive than this, however l imagine labour is not a considerable contributer to the cost, the cnc machine and the teflon raw material cost being most of it.

Actuslly is teflon labwear still machined from billet or is there a sintering process figured out now for it. Its been two decades since i thought ab

GammaFunction - 7-10-2020 at 20:44

Quote: Originally posted by Panache  

Actuslly is teflon labwear still machined from billet or is there a sintering process figured out now for it. Its been two decades since i thought ab


I'm sure it is sintered or pressed. It doesn't look machined.

A 'decent' beaker is probably USA, Europe, Korea, or Japan but I'm sure China could produce a decent one for less. The question is if they want to sell an honest product at reasonable profit, or not.

I can get USA-sourced 300 ml for $25, with shipping. Not sure if USA manufacture, but at least USA-responsibility for quality.

Mateo_swe - 13-10-2020 at 09:44

Many of the lab glassware and other things from the popular cheap china sellers on ebay are quality rejects, test series made during setup runs and similar.
Sometimes the items are excellent, sometimes missing labels, sometimes minor defects that doesnt matter and sometimes unfortunately with flaws that do matter.
If its an obvious flaw one usually can get a replacement, its a gamble that mostly turns out well.
If i hadnĀ“t bought cheap china lab glass i would have a lot less glassware and i have had no issues using my items.
I rather go cheap on the glass and go quality on a hotplate stirrer and other items where quality really pays off more.
There are really excellent stuff, very good quality, made in China now.
But the high quality stuff is as expensive as any other well known good quality brand.

macckone - 29-10-2020 at 08:38

Some cheap sellers have good quality, you see them mentioned for glassware all the time.
It isn't the best quality but it isn't rejects, although sometimes there are flaws, ie. less qc than expensive stuff.

itsallgoodjames - 2-11-2020 at 11:29


Quote:

they were advertised as first quality. "100% High Quality".


Not to reopen a dead thread, but 100% high quality doesn't really mean anything.

zed - 3-11-2020 at 13:10

Pffft. I bought lots of things from China. Sometimes good quality and inexpensive. Sometimes highly questionable quality.

Don't know if I would use that stuff for food prep. The Chinese don't subscribe to the same standards we do in the West. Especially so for export stuff.

I have friends that eshew food from places like the "Dollar Tree" if the food it is of Chinese Origin.

Quality is unknowable. Do you suppose the fish meets some standard for Mercury contamination?

Cadmium? PCBs? PST? Well, probably not.

unionised - 3-11-2020 at 14:43

I have good news:
You can wash the teflon with almost anything you like.