From: "Gordon J. Holtslander" <holtsg@duke.usask.ca>
Subject: temperaprint & foaming
Date: Mon, 13 Feb 2006 12:15:39 -0600
> Read more about antifoaming agents. Looks like Dimethylpolysiloxane is a
> commonly used food grade antifoaming agent. Its seems to be a suspension
> of very fine silicone particles that alter the surface tension so that
> foam bubbles can not form.
>
> Does anyone have experience with any antifoaming agents?
Emulsions of dimethylpolysiloxane is a very common antifoaming
agent. Those antifoaming agents often contain hydrophobic solid
particles, such as silica (in size of a couple of microns), which is
important in ensuring good antifoaming property. Also, the antifoaming
properties of this type of emulsion varies greatly, depending on the
type and amount of surfactant used together. There are some published
studies, but considering the nature of the subject, I suppose much of
important knowledge is confidential.
One problem with this type of antifoaming agent is that, the emulsion
and particles tend to separate during storage. The one I use can be
readily mixed again by heating and vigorously stirring. In coating
sizing and silver halide emulsions, I experienced more coating defects
when this type of antifoaming agent is used to suppress foaming.
If you don't mind temporary foam which will collapse quickly, there
are more options.
Received on Tue Feb 14 20:56:26 2006
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