Jefferson Chemical
WHATS NEW or IMPROVED
Photograph courtesy of E. C. Bishop & Son, Inc., Gunstocks, Warsaw, Missouri,
POLYETHYLENE OLYCOL g i v e s n e w dimensional stability and working quality to w o o d The U. S. Forest Products Laboratory has examined the use of polyethylene glycol for its ability to dimensionally stabilize wood and to prevent or reduce degradation (checking and splitting) of the wood during the drying process. Polyethylene glycol is preferred in this application because of its high water solubility and relatively low cost. It is absorbed in wood fibers and serves to retain a desired level of moisture in the wood. Dimensional stabilization requires a high degree of penetration of polyethylene glycol into the wood, with a uniform uptake of 25 to 30 per cent of chemical based on the weight of the dry 86
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wood. On the other hand, reduction of degradation during drying requires only impregnation of the outer wood surface by polyethylene glycol. Some advantages obtained in the treatment of wood with polyethylene glycol are: • A high degree of dimensional stability in critical areas of precarved wood; shrinkage and swelling can be reduced to a negligible amount, substantially less than the thermal expansion of most plastics. • PEG treated wood can be shaped, sawed and inletted more easily than seasoned untreated wood . • • practically eliminates
PHYSICAL PROPERTIES OF POLYETHYLENE GLYCOLS The following properties are representative of typical production: Polyethylene Glycol . . . . 200^ 300 400 Water Solubility @ 25° C, wt. % 100 100 100 Hygroscopicity, Glycerine = 100% .. 70 60 55 Viscosity, SUS 100° F 118 163 207
210° F
40 45
Fire Point, °F
53
600 1000a 1450a 4000 6000
100 100b 100b 100b 10040
30
—
—
—
299 Solid Solid Solid Solid 62 88 131
373 3734
360 435 500 535 580 584 590 Flash Point, °F 340 385 435 475 490 494 515 Weight, lbs./ gal., 20° C. 9.39 9.39 9.40 9.37c g.05d 9.03d 9.04d Freezing SuperPoint,°C. cools —10/—17 4-12 18-23 37-39 43-46 53-56 Color, Maximum Pt-Co 25 25 25 25 25 25 50e
600 520 9.07; 60-65 50*
a
Sold only in bulk quani ities b Above melting point c@ 25° C. d@ 70° C. e
2 5 % aqueous solution
Semi-inletted gun stocks shaped from green wood may be intensively treated with polyethylene glycol and safely dried from dripping wet to 6 per cent moisture conditioning in 20 days. Critical areas around the action and barrel groove are more easily worked and have excellent dimensional stability.
splits, checks, and other degradation during seasoning. • PEG treatment permits kiln drying on an accelerated schedule . . . although treated stocks can be air dried over a longer period with equally good results. More common uses for polyethylene glycol are as detergents; textile, leather, and metal lubricants; emulsifying agents; and vehicles for certain therapeutic agents. Samples of Jefferson's PEG 200, 300, 400, 600, 1000, 1450, 4000, and 6000 and additional information are available from Jefferson Chemical Company, Inc., 1121 Walker Ave., P. O. Box 303, Houston 1, Texas.
JEFFERSON CHEMICALS HOUSTON • NEW YORK
• CHICAGO • CLEVELAND
CHARLOTTE • LOS ANGELES • SAN FRANCISCO
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