English abstract of Kuo Tsai Wang's's paper
- Apparently several of us are having problems opening Kuo Tsai Wang's
papers. I was able to extract this abstract out of the garbled
symbols. If anyone can open these files correctly, please let me know.
In thinking about Garrett's comments about xanthan gum, I understand
that much like MC, there are different varieties. A new kind has been
developed - "surface treated" if you will, that is apparently mixed up
much more easily for industrial purposes. Perhaps this is what he used?
Nevertheless, some of you will find this paper of interest.
Characteristics of Natural Gums Used as Marbling Size
A variety of vegetable and other materials such as starches, gum
tragacanth, carrageenan, salep, and linseed have been recognized over
the ages as providing substances for marbling size. The experience of
most marblers has indicated that carrageenan size is probably the
best medium for producing finely combed patterns. Besides carrageenan
we examined the characteristics of several natural gums including
sodium alginate, xanthan gum, locust bean gum, and guar gum serving
as marbling size. The results suggest that the viscosity and flow
characteristics are important factors in marbling, especially in
making delicately combed patterns. Due to improper viscosity and flow
characteristics, a gum solution might not meet the requirements of
size by itself; then it is necessary to combine 2 gums with various
viscosities and flow characteristics in a proper ratio to produce a
more suitable marbling size. It is possible, if desired, to
effectively modify the Newtonian flow characteristics of 0.6% sodium
alginate and 0.5% carrageenan moss by combining a pseudoplastic
xanthan gum with them. The combined size allows the most finely
combed patterns to be created and prevents pigments from aggregating.
The air permeability of gum-impregnated Chinese "shuan" papers
indicates the film-forming ability of gum solutions. Good
film-forming indicates that some problems in overmarbling may exist.
Solutions of natural gums serve as food sources for the growth of
common microorganisms. Bio-attack decreases the shelf life of gums.
Where it is necessary to keep gum solutions for a longer time, for
instance, more than 3 d for guar gum and 7 d for xanthan gum,
preservatives may be added to inhibit bacterial growth. The addition
of a sequestrant such as sodium hexametaphosphate at a rate of 2% to
5% is recommended to achieve a good shielding effect. It can either
prevent cations in the pigment dispersion from reacting with sodium
alginate or can sequester the calcium inherent in the sodium alginate
solution. Carrageenan moss and guar gum are more tolerant to cations
than is sodium alginate. In other words, sodium alginate is more
sensitive to cations either inherent in pigments or present due to
extra addition. It is expected that a diversity of patterns can be
created with solutions of sodium alginate due to its sensitive nature.
Key words: marbled paper, sodium alginate, carrageenan, xanthan gum,
Wang, K. T.1998."Characteristics of natural gums used as
marbling size. Taiwan Journal Forestry Science