Title:
Method for the impregnation of logs
United States Patent 2297273


Abstract:
It is known to impregnate logs by the sap displacement process. This is effected by providing for example at the butt end of the log a pressure chamber into which the impregnating substance is forced by the application of pressure. From this chamber the impregnating substance passes into the...



Inventors:
Karl, Wolman
Application Number:
US22126538A
Publication Date:
09/29/1942
Filing Date:
07/25/1938
Assignee:
Karl, Wolman
Primary Class:
Other Classes:
427/297
International Classes:
B27K3/06
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Description:

It is known to impregnate logs by the sap displacement process. This is effected by providing for example at the butt end of the log a pressure chamber into which the impregnating substance is forced by the application of pressure. From this chamber the impregnating substance passes into the sap conducting passages of the wood and displaces the sap which passes out at the top end. It is, however, known that this method is open to the objection that the impregnating takes a long time, on the average ten days but often much longer. Furthermore the concentration of the impregnating liquor decreases very quickly on its travel through the interior of the log, so that a uniform impregnation at the butt and top ends is practically impossible to attain. These objections can be overcome by the method hereinafter described.

To effect a uniform impregnation of the particularly Jeopardized butt end and the equally 20 shortened, Jeopardized top end a ring 20 to 50 centimetres in width is exposed in the middle of the log by disbarking and incising. The incising must, according to the invention, be carried out so that at least the whole cambium is removed and if possible also the first two annual rings are cut into.

Hereupon pressure chambers are fitted one at the butt end and the other at the top end of the log and these chambers connected in known manner to a liquor container. The impregnating liquor thus enters the log at both ends and displaces the sap towards the middle where it passes out.

The method can also be carried out by accelerating the out-flow of the sap in the middle by surrounding the exposed ring by a suction U chamber, from which the sap is sucked off. It is also possible, to apply pressure selectively at the butt end or at the top end of the log while the sap is being sucked off at the middle and no pressure is applied at the end opposite that at which pressure is applied.

The method can also be reversed, in that the Impregnating substance is Introduced at the middie of the log by the application of pressure and displaces the sap in two opposite directions, that is towards the butt.and top ends of the log where it flows out. Another modification of this procedure is, to suck off selectively at the one or other end of the log the impregnating substance introduced under pressure at the middle.

An apparatus for carrying out the invention is illustrated by way of example in the only figure of the accompanying drawing, in which: I designates a log, 2 a chamber at the top end, 3 a chamber at the butt end and 4 a chamber surrounding the exposed ring, 5, 6, 7 being connections.

If pressure is applied at 2 and 3 without any suction in the middle, the chamber 4 is superfluous and can be omitted.

The method offers the following advantages: (1) The impregnating period is considerably (2) The points most Jeopardized are impregnated equally effectively and (3) The speed of impregnation can be regulated within wide limits.

Furthermore the practical advantage is attained that the exposure of the ring in the middie of the log requires very little work and time.

I claim: 1. A method for the impregnation of logs of any length according to the sap displacement process, consisting in disbarking the log in the middle of itA length and incising the disbarked portion to a depth only sufficient to remove the entire cambium and thereby produce an exposed ring and introducing impregnating liquor at the butt and top ends of the log and at the same time withdrawing the sap at the exposed ring.

2. A method as specified in claim 1, consisting in forcing the impregnating liquor into one end of the log under pressure.

KARL WOLMAN.