Improvements in Cork Washers for Bottle Stoppers and the like.
Year: 1898

page_text: Date of Application, 17th Dec., 1898-Accepted, 4th Feb., 1899
COMPLETE SPECIFICATION.
Improvements in Cork Washers for Bottle Stoppers and the like.
We, SALO RADLAUER, Merchant, of Seydelstrasse 3, PAUL SCHROEDTER, Merchant,
of Oranienstrasse 65, both of Berlin, and AUGUST SCHROEDTER, Manufacturer,
of Rixdorf, near Berlin, all in the Empire of Germany, 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:
For the hermetical stoppering of bottles, cans and other vessels for beer,
milk, soda water, and other liquids various kinds of mechanical stoppers are
employed, such as screw stoppers for instance, in the covers of which thin discs of
india rubber or cork are inserted. From a sanitary point of view, cork is preferable
to india rubber but on the other hand cork is a porous material which has in
one direction the natural pores associated with its structure and in the other is
perforated with worm holes. In order to make such inserted pieces of cork
absolutely impermeable so that liquid cannot exude through them from within
or air penetrate them from without, the following process according to this inven-
tion is carried out.
Large sheets or layers of cork, somewhat thinner than the small discs to be
inserted are taken and the mealy element which is retained in the pores eliminated;
they are then beaten or boiled in hot, water and dried, after which they are
thoroughly impregnated with some adhesive substance, this being effected by
boiling them for a long time in the impregnating fluid, which penetrates into the
worm-holes as well as into the natural pores running transversely thereto, thus
rendering the layers of cork absolutely impermeable.
These impregnated layers are then covered above and below with very thin
sheets of cork about millimetre in thickness these thin sheets being previously
freed from their mealy element. All three layers of cork are then united together
by means of a press whilst the impregnating liquid is still warm. The liquid
penetrates the pores of the thin covering sheets of cork and makes them likewise
impermeable. Out of the large sheets of cork so obtained the small circular
discs are stamped. As a matter of course, the three several parts can be stamped
out previously purified and impregnated and then be united together. For manu-
facture on a large scale, however, it is preferable to make the discs out of large
layers of cork.
Resinous substances (resinous pitch for instance) are suitable for use as im-
pregnating and adhesive materials as they do not in any way affect the health.
These substances can be used in their pure state, that is to say, without any
addition, if the pieces of cork for use are made of thin discs previously stamped out.
They however require some suitable addition when produced from large sheets
which have already been impregnated and united together as pure resinous sub-
stances besmear the stamps or cutters and soon render them unserviceable.
In the latter case use is made of resinous pitch thoroughly mixed with some
farinaceous substance in the proportion of from about 3 to 1 to 4 to 1. Both sub-
stances are boiled without water until the mass, which during the boiling forms
a quantity of froth or scum, becomes free therefrom and settles down into a clear

page_text: this light brown liquid. From the experiments hitherto made, rice flour is
found to be the best farinaceous substance for the purpose. This addition has
the following advantages; The adhesiveness is increased, so that the several
layers of cork cannot be separated from one another even by force. When dry,
the adhesive material is more supple, it clings better to the pores and does not
adhere to the flat edges of the vessels. It does not besmear the stamp or cutter
and therefore renders it possible to employ the process for manufacture on a large
scale.
In certain cases, the addition of farinaceous matters is not suitable, for instance
when, as in the case of beer being "pasteurised," higher temperature comes into
consideration. In such cases, the farinaceous matter swells, in consequence_of
the starch contained in it, and the thin covering layers easily become loose. For
this reason a substitute is employed, which consists of an intimate mixture of
resinous pitch with a small quantity of white of egg and beeswax. These three
substances are united together by being boiled for a long time. The white of
egg imparts to the adhesive material the property of remaining solid when in
contact with liquid at a high temperature and therefore of keeping the layers of
cork firmly united together. The addition of beeswax makes the whole more
supple.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is:-
1. An impermable cork layer or inserted piece for bottle stoppers and the like
consisting of a layer of cork which after the mealy element has been removed
from it is thoroughly impregnated with some pure adhesive material such as
resinous pitch, then covered on each side with another thinner layer of cork and
united with the other two thinner layers by means of pressure.
2. In the production of layers or inserted pieces of cork according to Claim 1
the employment of an adhesive material obtained by intimately mixing resinous
substances (resinous pitch for instance) with some farinaceous matter such as
rice flour.
3. The replacing of the adhesive material according to Claim 2 by a material
of the same kind obtained by intimately mixing resinous substances, white of
egg and beeswax.
Dated this 17th day of December 1898.
WHEATLEY & MACKENZIE,
40, Chancery Lane, London, W.C., Agents.