Data/hora: 23/06/2024 17:23:59

Biblioteca(s): | Embrapa Florestas.
Data corrente: | 06/06/1995
Data da última atualização: | 16/03/2009
Autoria: | GALVAO, A. P. M.
Título: | Factors influencing the flow of oil into coniferous woods.
Ano de publicação: | 1972
Fonte/Imprenta: | 1972.
Páginas: | 94 f.
Idioma: | Inglês
Notas: | Thesis (Master of Science) - State University College of Forestry at Syracuse University.
Conteúdo: | The superficial air permeability of uncoated and side-coated specimens of Douglas-fir (Pseudotsuga mensiesii (Mirb.) Franco), loblolly pine (Pinus taeda L.) and cypress (Taxodium distichum (L.) Rich) of three different lengths (7.5 cm, 15 cm and 30 cm) were measured. The specimens were impregnated with paraffin oil with a viscosity of 44.5 centipoises by a full-cell process using a impregnating pressure of 40 psig. From readings of the level of oil in a guage glass at different times, the volume rate of flow into the specimens was calculated. Corrections were applied to account for the initial absorption of oil and the effects of the application of pressure to the system. The fraction of voids filled with liquid was plotted against time. Penetration was observed on split surfaces of treated specimens. The results obtained suggested that wood is composed of two or more components having widely different liquid and air permeabilities. Latewood was found more permeable than early wood with the permeability of earlywood varying within the specimen. The air permeability gave a fairly good indication of oil permeability with the exception of cypress. This may be due to the removal of extractives plugging pit openings during storage in a vacum-oven or during impregnation. Absorption calculated from Bramhall's equattion form transient liquid flow, are in good agreement with experimental results in the more permeable, long, coated specimens when slip flow is accounted for. The poor agreement in other cases was atributed to air blockage. It is suggested that the radial and tangential surfaced of specimens be coated when longitudinal flow is studied even in short specimens where a relatively small transverse flow is expected.
Palavras-Chave: | Conífera; Coniferales; Fluxo.
Thesagro: | Madeira; Óleo.
Thesaurus Nal: | oils; wood.
Categoria do assunto: | --
Registro original: | Embrapa Florestas (CNPF)
Exemplares: | CNPF - (29546-1) - ADC - TS - -- - TS0024 -  - TS0024 - DIS