Faster Trees, Strong Straws

It is almost a law that farmers must rise early, work late, receive little return for their labor. If the prediction of Dr. Ralph McKee of Columbia University, made last week before The Franklin Institute in Philadelphia, comes true, this routine will be upset.

Dr. McKee, financed by Oxford Paper Co., has worked for four years on new hybrid poplar trees which will mature rapidly, be suitable for paper manufacture. Aided by New York Botanical Garden experts, he has developed 101 hybrids from the 21 species of poplar. Fourteen of the hybrids are specially suited to papermaking by virtue of their precocity: in eight years they attain a growth which takes normal poplars 45 years to reach. A crop of this kind would allow a farmer eight years between harvests, would yield him a crop far more valuable than similar crops of wheat or corn. The cost of McKee poplar seedlings is about $5 per acre. In eight years the crop is worth $600 per acre. Over a like period, $240 per acre would be a fair return for wheat crops. Poplars can also be grown on barren soil that now produces nothing. In addition to being valuable for papermaking, tree harvests could be sold as cellulose for rayon manufacture.*

When trees become crops, forest conservation will cease to be a problem. And in the February issue of Cellulose, a new trade magazine, the late Dr. Edwin Emery Slosson of Science Service gives the answer of the Woodman who was asked to spare-that-tree. "Sure," says Woodman, "I can spare them all, for I can grow wood quicker in weeds and shrubs. Trees are not the only means of producing cellulose."

Dr. Slosson predicted that crop trees, which grow at the rate of 10% per year for the first 15 years and at the rate of 4% as they approach maturity, will never be allowed to reach their full growth. When they are allowed to mature, only 50% of them is used at the sawmill. Sapling forests will be harvested--perhaps by Paul Bunyanesque mowing machines--and put through a process which will reduce their fibres to a mossy mat; then remolded, remade into wood, of any dimension, any hardness. This process is now being used in Mississippi to manufacture "Masonite" from sawdust, chips and other refuse lumber.

Research workers, practical men, have ever been on the search for means to utilize waste material. "Bagasse," the refuse material left after the sap has been removed from sugar cane, used to present a problem because it was expensive to dispose of. This is now being made into board called Celotex, which is used as the plaster base and insulator. Reversing the old order, sugar is now the by-product in some places where cane is planted to yield the board material. Cornstalks are used to produce paper and a kind of lumber, "Maizewood"' (TIME, Dec. 24, 1928). Straw, virtually valueless as a fertilizer. has always been a problem. Farmers burn a large percentage of the 50 million tons produced each year. Some is being used (250.000 tons) to produce an insulating board whose heat conductivity is comparable to balsa wood and cork. Also from straw an artificial lumber will soon be produced which will have tensile strength of hickory. The current issue of Industrial and Engineering Chemistry predicts that this ''straw'' lumber will soon be in plentiful production and use. Thus plains regions, where trees are scarce and lumber expensive, may in time be able to grow their barns and houses with their wheat.

Another new product is Zalmite, named for Zalmon Simmons, president of Simmons Co. (beds). Similar to Bakelite, this new synthetic resin will take a high gloss, will make strong, tough beds which can be stamped out by single clips of ponderous machines. Carefully guarded is the secret process by which this Zalmite is made. Zalmon Simmons when questioned, facetiously replies that it consists of "peanut shells and burlap bags.''

Synthetic resins (like Zalmite) are basically a chemical synthesis of phenol (carbolic acid), formaldehyde and some form of nitrogen. Wood flour is used as a filler. Zalmite is rendered light and porous by sending a blast of air through the soft uncast material.

*Rayon is produced from any form of cellulose, primarily cotton. When made of wood (viscose rayon) it is treated with sodium hydroxide which reduces it to alpha cellulose. After this it is treated with carbon bisulphide. After one more step an orange-colored, syrupy liquid results which is forced through tiny holes, forming filaments, which after being treated in baths become rayon thread. From a laboratory invention, rayon has grown to be the world's third largest textile.

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