Re: paper sizing agents (was Re: fabriano paper)

I've used this (internally) with paper making. Just a quick note: it
takes DAYS to set (become a "hard" size) at room temps. You can speed
it up by heating the paper.

I haven't tried (or don't remember trying) it as a surface size.

On Friday, May 7, 2004, at 12:38 AM, Ryuji Suzuki wrote:

> From: "Christina Z. Anderson" <zphoto@bellsouth.net>
> Subject: Re: fabriano paper
> Date: Thu, 06 May 2004 10:27:36 -0400
>
>> Ryuji asks> Besides gelatin and "starches" what are used as sizing
>> material?
>>> I wonder if the sizing in this paper is retained in my processing,
>>> where the sensitizer is coated at 35-40C.
>>
>> Now THAT'S the question to ask. I know there are such things as:
>> alkyletene dimer or aquapel, whatever the heck that is. You chemists
>> can
>> tell us laypersons.
>
> Dimeric alkylketenes can form strong covalent bond with hydroxyl
> groups of cellulose under certain conditions to make the fiber
> hydrophobic or less absorbent (Weisgerber, C. A. and Hanford, C. B.,
> 1960. Tappi, Vol 43, No 12) so it's a useful sizing agent. Indeed,
> this seems to be one of the preferred neutral internal sizing agent
> for silver gelatin paper stocks, as paper that is heavily sized with
> this agent doesn't absorb too much processing chemicals and wash more
> readily (Of course typical commercial baryta papers have surface
> sizing and baryta sizing on top of that.) It seems that Aquapel is a
> product consisting of blends of dimerric alkylketenes in emulsion form
> and maybe some other additives.
>
> Why gelatin sizing isn't used so much? I couldn't find an answer to
> that, but it seems to be related to that the way papers are made in
> industry is rather incompatible with gelatin.
>
> Why dimeric alkylketenes are preferred as the internal sizing agent?
> I think older materials used aluminum sulfate or some other things in
> part, and this rendered the paper acidic, and the paper became brittle
> over time -- archival problems.
>
> Anyway, Aquapel-type internal sizing is most likely safe with my
> coating temperature, but I'm not certain about other sizing agents
> that are often used in conjunction with these material. (such as
> modified starches)
>
> --
> Ryuji Suzuki
> "All the truth in the world adds up to one big lie." (Bob Dylan 2000)
>
>
--------------
Tom Ferguson
http://www.ferguson-photo-design.com
Received on Fri May 7 08:23:40 2004