Improvements relating to the Production of Useful Products from Sea Weed.
Year: 1899

page_text: Date of Application, 17th Apr., 1899-Accepted, 10th Feb.,
1900
COMPLETE SPECIFICATION.
Improvements relating to the Production of Useful Products from Sea
Weed.
I, AXEL KREFTING, of 18, Kort Adlersgade, Christiania, Norway, Engineer,
do hereby declare the nature of this invention and in what manner the same is
to be performed, to be particularly described and ascertained in and by the
following statement:-
This invention relates to the production of leather like sheets or leather
imitations from sea weed.
In order that the product may be easier transported I have dried the same in
the form of thin sheets on glass or metal plates or on prepared textile material
and I have in this manner produced sheet formed substances which are soluble
in cold or warm water.
These products are remarkable for their great strength and clasticity and can
be made entirely transparent and white. At a very early stage of my manu-
facturing products from sea-weed I made a series of trials with the object of
producing the said plates or sheets insoluble in water and suitable for different
purposes.
I soon found that this could be done if the said plates were laid for a sufficiently
long time in different solutions containing metallic salts the tang-acid forming
with said salts insoluble substances. These solutions must, have a suitable
strength which is different according to the metal which they contain, the
number of these metallic salts is however so great that it is impossible to specify
the strength exactly. If the solution is too weak the said stuffs will swell out,
and the resulting products cannot be used, if the solution is too strong the pro-
cess will take too long a time on account of the forming of semipermeable
membranes.
As an example of the production of imitation leather from sea-weed I may give
the following. The fabric is treated with a solution of tang-acid and soda, con-
taining 10 per cent. of tang-acid and per cent. of animal charcoal to make it
black, the said fabric is then conveyed to the drying, chamber where the water
is evaporated, and the fabric on leaving the said drying chamber will consequently
be covered on one side with a dried black sheet. The fabric is then passed
through a solution of 1-2 per cent. of sulphate of zinc and 4. per cent. of grape-
sugar, whereby the black sheet is transformed into an elastic sheet resembling
leather, and insoluble in water. It is again passed through a drying chamber and
is then ready for use.
The sheets or articles produced in this manner are all together stiff and break-
able after being dried; they are transparent and have the same colour as the salts
of the incorporated metal. Salts of copper, for instance, give the plate a blue
colour, salts of cobalt, a red colour salts of chromium a violet colour, salts of
nickel a green colour and so on.
The salts of calcium, barium, strontium, aluminium and several other metals
make the plates, colourless and insoluble in water.
The different metals give the plates a different degree of brittleness, chromium

page_text: In any of the processes above described of course I may add a suitable dye-stuff
to the mass. Thus I have found, that all aniline dyes can be used as they are
absorbed by the fibres of the sea-weed.
By forming the plates I have found, that for different purposes it is useful to
add some glycerine or syrup to the solution before the drying takes place, thus
avoiding breaking of the plates during the drying process and also by adding
drying oils, metallic soaps or resinous substances to the mass, the plates can be
made so that they will be unaffected by moisture.
For producing the said plates, the best construction of drying apparatus I
have found to consist in the arrangement of endless belts placed on rolls and moved
through a chamber, the drying air moving through the same chamber in a con-
trary direction. The solution of the sea weed is put upon the plate on the same
side, where the endless belt enters the chamber and is rolled upon rollers at
the outlet.
The arrangement is shown on the accompanying drawing, where a is the
drying chamber; 6 is the inlet pipe for hot air and c the exhaust pipe. dd.
are the belts, whereupon the solution of the sea-weed is put, said belts passing
over rollers e e e e in the direction of the arrows and through a vessel f, in which
the solution of the sea-weed is contained. In order now that the bottom of the
vessel may be tightly closed at the entrance of the belts in the chamber, the open-
ings in the bottom are furnished with strips g of leather or other elastic material,
which may bend against the belts during their passing the openings. By means
of rollers hh... the belts are held at a convenient distance from each other. It
will be understood, that the solution in this manner is put upon the belts on
both sides, and at the same time is dried by the hot air in the drying chamber a,
and, after being dried, the mass is now on the outside rolled upon rollers i. In
this manner the produce obtained is of unlimited length.
If the produce should have a greater thickness it is preferred-instead of
passing the belts once through a thick solution-to pass them twice or more
time through a thinner solution. The arrangement then consists of two or
more systems of drying chambers a arranged one after another with vessels f
arranged at the top of each chamber, or if but a limited length is demanded, the
belts may pass around through the same solution two or more times, before it is
rolled upon the rollers i.
As many belts as desirable may be arranged, and the temperature of the drying
air may be different according to the velocity of the belts through the chamber and
to the quality of the produce.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is:
1. A method for producing plates and different articles from sea-weed character-
ized by giving the soluble tangates-(either in a pure state or mixed with veget-
able or mineral substances) a suitable form and after the drying process treating
them with acids or solutions of metallic salts of suitable strength.
2. In the method characterized in Claim 1, the adding of glycerine or sugar to
the solution for the purpose of making the articles flexible and elastic.
3. In the method characterized in Claim 1, the direct grinding of the alkali-
treated sea-weed with all its fibres and treating the mass as hereinbefore described.
4. In the method described in Claim 1 to 3, the application of the stalks of the
sea-weed alone after having removed the outer skins of the same.
5. In the method characterized in Claim 1, the adding to the mass of suitable
dye-stuffs.
6. In the method characterized in Claim 1, the addition of fibrous or mineral
substances to the mass.
7. In the method described in Claim 1, a process for incorporating metals in
the articles, which are to be produced, characterized by the treatment of the
products with acid before the treatment with metal-salts takes place.