AN IMPROVED PROCESS OF IMPREGNATING WOOD FOR ITS PRESERVATION
Year: 1882

page_text: "
LETTERS PATENT to Friedrich Carl Glaser, of Berlin, in the Kingdom of
Prussia and Empire of Germany, Engineer and Patent Solicitor, for an
Invention of AN IMPROVED PROCESS OF IMPREGNATING WOOD FOR ITS
PRESERVATION A communication to him from Peter, Johannes, Friedrich,
Röper, a person resident at Pinneberg near Hamburgh, Germany.
"
PROVISIONAL SPECIFICATION left by the said Friedrich Carl Glaser at
the Office of the Commissioners of Patents on the 8th August 1882.
FRIEDRICH CARL GLASER, of Berlin, in the Kingdom of Prussia and Empire of
Germany, Engineer and Patent Solicitor, "AN IMPROVED PROCESS OF IMPREG-
NATING WOOD FOR ITS PRESERVATION " A Communication to me from Peter
Johannes Friedrich Röper, a person resident at Pinneberg near Hamburgh
Germany.
This Invention relates to a new and useful process for impregnating wood.
In the processes hitherto used to protect wood against the pernicious influence
of moisture and temperature, by means of impregnation with certain substances,
the moisture was first driven out of the wood by means of a vacuum and it was
then impregnated direct, with or without pressure; it being desired to effect
the preservation of the wood by filling its pores as completely as possible with
liquid.
These processes only partially effect the object in view which can only be
thoroughly attained when the substance protecting the wood is produced by a
chemical reciprocal action taking place within the pores of the wood itself.
In the process the subject of this Invention, in order to effect this chemical
process the wood is acted upon twice, firstly it has to be impregnated with a
solution of Zinc-Vitriol, and secondly with Chloride of Calcium, so that by the
final action of each of these substances on the other a process of decomposition
takes place within the pores of the material to be preserved, and the desired object
is thus obtained in the most complete manner.
The carrying out of this Invention does not differ substantially from the
operation used hitherto for the same purpose, excepting in the one essential
modification, namely, that the two substances used are employed the one after
the other.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Friedrich Carl Glaser in the Great Seal Patent Office on the
2nd February 1883.
"
OF
FRIEDRICH CARL GLASER, of Berlin, in the Kingdom of Prussia, and Empire
PROCESS
"AN IMPROVED
of Germany, Engineer and Patent Solicitor,
A communication to me from
IMPREGNATING WOOD FOR ITS PRESERVATION
Peter Johannes Friedrich Röper, a person resident at Pinneberg near Hamburgh,
Germany
This Invention relates to a new and useful process for impregnating wood.
In the processes hitherto used to protect wood against the pernicious influence
of moisture and temperature by means of impregnation with certain substances;
the moisture was first driven out of the wood by means of a vacuum and it was
then impregnated direct, with or without pressure; it being desired to effect the
preservation of the wood by filling its pores as completely as possible with the
liquid.
These processes only partially effect the object in view, which can only be
thoroughly attained when the substance protecting the wood is produced by a
chemical reciprocal action taking place within the pores of the wood itself.
In the process the subject of this Invention, in order to effect this chemical
process the wood is acted upon twice; firstly has to be impregnated with a
solution of Zinc Vitriol, and Secondly with Chloride of Calcium, so that by the final
action of each, of these substances on the other a process of decomposition takes
place within the pores of the material to be preserved, and the desired object is thus
obtained in the most complete manner
The carrying out of this Invention does not differ substantially from the
operation used hitherto for the same purpose, excepting in the one essential
modification, namely, that the two substances used are employed the one after
the other.
The special process may be generally described as follows:-
The wood to be impregnated is first steamed, that is to say, it is exposed for
about two hours to the action of steam at a pressure of from 5 to 8 atmospheres,
until the condensed water flows off clear and the pores of the wood have become
fully opened. Then a vacuum of about 27. c. m. is formed in the vessel containing
the wood, by means of an air pump, and by this means the moisture in the wood
is expelled. Impregnation is then effected with a solution of Zinc Vitriol (Sulphate
of Zinc) of 6° "Beaumé," which acts upon the wood during about 5 hours at a
pressure of about 8 atmospheres. By again producing a vacuum with the air
pump, the moisture now in the wood is drawn out, whereupon the treatment with
a weak solution of Chloride of Calcium during from 2 to 3 hours is effected, also
at a pressure of 8 atmospheres. Finally, the moisture is again drawn off by the
air pump and in the meanwhile the preservative coating will have formed both
within the pores of the wood and on the surface thereof by the action of both of
the substances used for impregnation.
Having now Described and ascertained the nature of the Invention communi-
cated to me as aforesaid and in what manner the same is or may be performed, I
would have it understood that I do not limit myself to any precise pressures or
proportions of chemicals in carrying out this improved process, as such may be
varied to suit the material under treatment, and that what
I Claim as of this Invention and as secured to me by the hereinbefore in part
recited Letters Patent is :-
An improved process of impregnating wood for its preservation, consisting in

page_text: first treating the wood with a solution of Zinc Vitriol and then with a solution of
Chloride of Calcium in the manner described, so that the preservative coating is
formed upon the wood by the chemical action of both substances on one another,
substantially as set forth.
In Witness whereof I the said Friedrich, Carl Glaser have hereunto set my
hand and seal this Twenty Seventh day of January in the year of Our
Lord One thousand Eight hundred and Eighty three.
F. C. GLASER. (L.S.)