glyoxal yellowing

Praise was too early! An offlist remark (thanks erich) pointed me to a
typo I made in my densitometer readings list (I had swapped sample 3 and 5).
these are the correct values:

sample 1: M 0.06, C 0.06, Y 0.07 (unsized, unhardened)
sample 2: M 0.06, C 0.06, Y 0.07 (sized, unhardened)
sample 3: M 0.06, C 0.06, Y 0.07 (sized, soaked for 3 minutes in 1
liter water with 15 ml formalin(37%), dried )
sample 4: M 0.06, C 0.06, Y 0.08 (sized, soaked for 3 minutes in 1
liter water with 15 ml glyoxal (40%), rinsed for 5 minutes in running
water, dried )
sample 5: M 0.06, C 0.06, Y 0.12 (sized, soaked for 3 minutes in 1
liter water with 15 ml glyoxal (40%), dried )
sample 6: M 0.06, C 0.06, Y 0.07 (sized, soaked for 3 minutes in 1
liter water with 50 ml Maco Geladur (this is a 2.5 - 5% glutaraldehyde
solution), dried )

Conclusion stays unchanged: unrinsed glyoxal hardening yellows paper,
rinsed glyoxal hardening gives no visible yellowing on the surface but
slicht yellowing at the edges. All other hardening does not yellow paper.

kees

Judy Seigel wrote:

>
> On Mon, 31 Jan 2005, Kees Brandenburg wrote:
>
>> sample 1: unsized, unhardened
>> sample 2: sized, unhardened
>> sample 3: sized, soaked for 3 minutes in 1 liter water with 15 ml
>> formalin(37%), dried
>> sample 4: sized, soaked for 3 minutes in 1 liter water with 15 ml
>> glyoxal (40%), rinsed for 5 minutes in running water, dried
>> sample 5: sized, soaked for 3 minutes in 1 liter water with 15 ml
>> glyoxal (40%), dried
>> sample 6: sized, soaked for 3 minutes in 1 liter water with 50 ml
>> Maco Geladur (this is a 2.5 - 5% glutaraldehyde solution), dried
>
>
> etc.
>
> Bravo. Thank you.
>
> Judy
>
Received on Thu Feb 3 02:03:49 2005