REX OXFORD TUMBER CO.

Nqils thol "Grow" to Wood

Nails that "grow" to the wood in which they are driven are object of a research program currently in progress at Quantum, Inc., a Wallingford, Connecticut, research laboratory.

By using a chemical principle known as crosslinking, Quantum scientists are attempting to solve the problem of how to make a nail "stay put" in wood. Most nails now ussd-svsn including the so-called cement-coated (resin-coated)-tend to work loose with vibration, humidity changes, and aging.

The ultimate goal is a simple, plain-shank nail with a polymer coating that would react both with the metal and the cellulose of wood fibers to form a chemical bridge between the two. If the reaction with the wood fiber takes place gradually, the nail would in a sense "grow" or become grafted to the wood. Nails incorrectly driven, however, could be extracted with ordinary ease before the crosslinking reaction takes place.

The polymer coating which the laboratory is developing would also be applicable to staples, screws, and other types of wood fasteners.

Current developmental work on this novel approach to a commonplace problem of the building, shipping crate, and furniture industries is being self-sponsored by the laboratory while it proves enough feasibility to interest industrial sponsorship.

"The theory of using chemical bonds to effect attachment between metal and cellulose is outside the experience of many building product manufacturers," states Dr. C. M. Doede, president of Quantum. "What we have to do is prove some degree of practicality before we can interest a manufacturer to take un the idea and sponsor the resealch needed to develop it for commeibial practice." -

According to Dr. Edward T. George, Quantum's director of research, feasibility may already have been demonstrated. "While we haven't definitely proved chemical attachment," he states, "we have made coated nails that give more than one hundred times the holding power of common nails under severe wood shrinkage conditions.

Crosslinking refers to the ability of reactive sections of resin molecules to link up with reactive sections of adjacent molecules. Thus, a specimen of a resin may be so crosslinked that the whole specimen is in itself one giant molecule. The reactive sections of resin molecules may also attach themselves to other unrelated polymers, such as cellulose, or to particles of metals-in which case the unrelated polymer or the metal becomes essentially a part of a gross molecular entity. Chemical bonds are usually much stronger than physical bonds against forces of a physical nature-such as the forces that cause nails to Ioosen in u'ood.

The problem of nails or staples working loose has long defied human ingenuity. For purposes where sure-holding is mandatorysuch as in nailing plywood for linoleum underlayment-mechanically deformed nails (helically or annularly grooved, for example) have been developed, and these all work well. However, they cost several times as much as common nails and, because of cost, are used only in critical applications It is the hope of,Quantum that nails costing only slightly more than common nails but with a holding power equivalent to that of the most costly mechanically deformed designs will result from its research.

Quantum, Inc., specializes in the development of materials "tailored" for specific functions. Many of the products it has developed for the building, automotive, aircraft, communications, and metals fabricating industry are based upon the adaptation of advanced concepts in polymer chemistry to practical engineering problems.