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HAYHHOTEXHHSEOKAII BMB71MOTEKA COOP
ONK-MOVkWk^T PROCESS KOR Im PREC N ATI N(i WITH ZINC CHLORIDE AND PETROLEUM
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By A. M. Howald vxtrial Fellow, Mellon Institute of Industrirtl Itexrurrh,
University of Pittsburgh, Pittsburgh, Pa.
During the last 20 years considerable experimental work has been done in attempts to develop a wood-treating process in which the well known preservative effect of zinc chloride should be prolonged by an additional treatment with petroleum or its products, such as crude fuel oils.
These investigations have been stimulated by a growing recognition that a preservative treatment of .wood, in addition to preventing decay, must act to minimize checking, splitting, brooming, and other manifestations of natural wear, or weathering of unprotected timbers.c
Several combination treatments with zinc chloride and petroleum oils have been developed2 and used experimentally. These treatments have been carried out by a variety of methods, which will be summarized as follows:
1. Crossties were treated .with zinc, chloride solution, as in the usual Burnett process, seasoned, and finally treated with petroleum oils, either by an open-tank or pressure process.
2. Crossties were first treated with crude oil by the Rueping empty-cell process, then, without removing from the cylinder, treated with zinc chloride solution by the full-cell process.
3. Crossties were treated by the Rueping emnty-eell rrocess, using a more concent: itod solution of z:ne e'-V-rMe lh:i.: '« ■•■v-dinarily employed for :';e Burnett treatment. Then, with'.'it, removing from the cylinder, a subsequent treatment with nefro-leum oil was given by . ither the Rueping: empty-cell or the full-cell process.
These processes are a!' «nn.ipet. in gronter or lessor degree, to
■ie disadvantage, nam'
if thr Tw- i : - " "- ' 11 ri it n 1 ?.t f.-rs" As*'!fi-" ■ i """'. ; '.v cf*. !' "■ i tVKt
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