DE259075C

DE259075C -

Info

Publication number: DE259075C
Application number: DENDAT259075D
Authority: DE

Description

KAISERLICHESIMPERIAL

PATENTAMT.PATENT OFFICE.

Das vorliegende Verfahren schließt sich — ohne im Hinblick auf ein bekanntes Verfahren die Erde als mitwirkendes, Agens zu benutzen —· einem anderen bekannten Verfahren zur künstlichen Verbräunung .von Hölzern darin an, daß man Ammoniak in gasförmigem Zustande in einem dicht geschlossenen Gefäß bei künstlicher Wärme mit Überdruck auf das Holz einwirken läßt. Das vorliegendeThe present process closes - without regard to a known process using the earth as a contributing agent - another known method of artificial browning of wood in the fact that ammonia is used in gaseous form Condition in a tightly closed vessel with artificial heat with overpressure lets the wood take effect. The present

ίο Verfahren zeichnet sich aber dadurch aus, daß man diese Behandlung in Gegenwart von Kalk oder einem anderen wasseraufnehmenden Mittel vor sich gehen läßt.ίο The procedure is characterized by the fact that that this treatment in the presence of lime or another water-absorbing Means going on.

Dadurch erreicht man eine schnelle durchgreifende Verfärbung unter gleichzeitiger Veränderung .der Saftstoffe des Holzes_ in günstigem' Sinne, im Gegensatz zu dem vorbekannten Verfahren, bei welchem wesentlich nur die ohnedies bekannte Ammoniakräucherung (freilich unter Durchdringung des ganzen Holzes) und auch diese ihrer Natur nach nur bei stark gerbstoffhaltigen Hölzern erzielt wird. Die durch diese Verfärbung erhaltene Farbe ist wenig beständig, und eine wesentliche Veränderung der Saftstoffe findet nicht statt.This results in a rapid, thorough discoloration with simultaneous change .the sap of the wood_ in favorable ' Meaning, in contrast to the previously known method in which essential only the already known ammonia fumigation (admittedly with penetration of the whole Wood) and this, by its nature, can only be achieved with wood that contains a lot of tannin. The color obtained by this discoloration is poorly permanent and a substantial change the juice does not take place.

Die bessere Wirkung des neuen Verfahrens beruht auf folgendem:The better effect of the new procedure is based on the following:

Physikalisch bewirkt gebrannter Kalk durch die Aufnahme von Wasser bzw. Wasserdampf eine Verminderung des Wassergehaltes im Abreitsgefäß und begünstigt somit die Trocknung der eingebrachten Hölzer, die im abgeschlossenen wasserdampfhaltigen Räume sonst nur durch Überhitzung erzielt werden könnte. Hierbei werden beträchtliche Wärmemengen, frei, wodurch selbstverständlich die Heizwirkung der Gase im Kesselinnern unterstützt wird. Da man mit einem gewissen Überdruck und einer gewissen Temperatur arbeiten will, beides aber. durch die fortschreitende Bildung von Wasserdämpfen gesteigert werden würde, so ermöglicht auch der Kalkzusatz eine bessere Innehaltung der gewollten Druck- und Temperaturverhältnisse. Soweit diese Wirkungen auf der Wasseraufnahmefähigkeit des Kalkes beruhen, kann der Kalk natürlich durch andere hygroskopische Mittel ersetzt werden.Burnt lime is physically caused by the absorption of water or water vapor a reduction in the water content in the training vessel and thus promotes drying the wood brought in, the in the closed water vapor-containing rooms otherwise could only be achieved by overheating. Considerable amounts of heat are used here, free, which of course supports the heating effect of the gases inside the boiler will. Because you work with a certain overpressure and a certain temperature want, but both. can be increased by the progressive formation of water vapors the addition of lime enables the desired pressure and temperature conditions to be maintained better. So far these effects are based on the water absorption capacity of the lime, the lime can can of course be replaced by other hygroscopic agents.

Der Kalk äußert aber auch chemische Wirkungen, insofern die bei dem »Schmoren« des Holzes gebildeten flüchtigen Säuren (Kohlensäure, Ameisensäure, Essigsäure) aufgenommen werden. Diese flüchtigen Säuren würden durch chemische Bindung des Ammoniaks dessen wirksame Menge rasch verringern, was durch Gegenwart der freien Basis des Kalkes verhindert wird. Dabei wird aber auch das.zunächst an flüchtige Säuren gebundene Ammoniak immer wieder frei und folglich wirksam erhalten.But the lime also has chemical effects, insofar as those in the "braising" of the Volatile acids (carbonic acid, formic acid, acetic acid) formed by the wood are absorbed will. These volatile acids would by chemical bonding of the ammonia of Effective amount quickly decrease, which is prevented by the presence of the free base of the lime will. However, ammonia, which is initially bound to volatile acids, is also used kept free and consequently effective again and again.

Die besagten Umstände ermöglichen es auch, die Hölzer in frischem Zustande zu verarbeiten, während die Beschreibung des vorbekannten Verfahrens gut abgelagertes, ja sogar künstlich getrocknetes Holz voraussetzt. Nicht ohne guten Grund, denn man würde beim Arbeiten ohne Kalk der reichlichen Wasserdämpfe, die die sichere..Handhabung des Verfahrens erschweren und- die Wirkung des Ammoniaks schnell und stark herabsetzen würden, nicht Herr werden.The aforementioned circumstances also make it possible to process the wood in a fresh state, while the description of the previously known method is well-seasoned, even artificial requires dried wood. Not without good reason, because you would while working without lime of the abundant water vapors, which complicate the safe handling of the process and- would quickly and severely diminish the action of ammonia, not master it.

Die Ausführung des Verfahrens kann, unterThe execution of the procedure can, under

Claims

Using the apparatus shown in the drawing. As an apparatus is a such standing construction adopted; boilers are advantageous for large-scale operations horizontal design into consideration.

The vessel η with heating jacket c , which is to be tightly closed by the lid b , is first charged with the discolouring agent, which is in the form of a covering the vessel bottom

ίο shift d is entered. The main discolouring agent used is ammonia. This can be used as carbonate of ammonia, which salt has the advantage of breaking down into its components even at low temperatures, i.e. releasing the effective ammonia. However, ammonia can also be produced from a mixture of sulfuric acid ammonia and carbonate of lime. To name another staining agent, you can, for. B. Mix tobacco waste with slaked lime to generate pyrolysis fumes.

The wooden sticks f are placed on an intermediate floor e, under which there is some free space above the layer d. Intermediate layers or other suitable means hold the pieces of wood firmly in place. On top of this comes an open container h which contains quick lime.

The vessel loaded in this way is hermetically sealed by the lid. The air pump is connected to the pipe socket i on the cover if you want to work with a vacuum. Manometer k and thermometer I must also be attached to the cover.

If necessary, negative air pressure is created first. It does three things. Once it promotes the penetration of the discolouring gases or vapors due to the greater pressure gradient. On the other hand, through partial Taking away the air counteracts the dilution of the active gases or vapors by the air. Third needs one does not drive the heating so far as if the process was at atmospheric Pressure takes its exit. The more the woods are heated, the more likely they are to lean to tear. '

After negative pressure has been established, the heating of the 'vessels' begins Temperature level must in any case be driven so far that the effective gases or fumes are generated. For the reason just indicated, go with the Temperature not unnecessarily high. The gases or vapors penetrate the pores of the wood and cause the intended discoloration in a short time.

Under certain circumstances, the wood is moistened. If this is too dry, overly arid, they expose the gas or vapors to considerable penetration Opposition. The effect of humidification may be based on the one hand on the opening of the pores, on the other hand also on that in the presence of water most chemical processes partly at all are first introduced, sometimes better and easier.

Partial extraction of the air promotes the process in any case, but is recommended especially when processing hard, dense woods.

Pa τ ε ν τ - A N s ρ R υ c η:

Process for the artificial discoloration of wood for the cabinet making by treating the raw wood under pressure and heating with gases or vapors from ammonia, pyrbl or others discolouring substances, characterized in that the not dry, but rather still slightly moist, in the other case artificially moistened wood in the presence of undeleted wood Lime or other water-absorbing substance are treated.

1 sheet of drawings