Redwood Bark Made Into Cloth

The Pacific Lrumber Company Finds New Use for Redwood Barh Fibre

The giant California redwoods coming to the rescue of the textile industry in helping to alleviate the wool shortage is envisioned in a patent just assigned to The Pacific Lumber Company, San Francisco, for combining redwood bark fibre with sheep's wool.

Woolen blankets and fabrics for overcoats and suitings on display at the company's headquarters at 100 Bush Street, San Francisco, containing from thirty to forty per cent redwood bark fibre show no noticeable difierence from ordinary wool fabrics.

The idea of using this by-product of the redwood hrmber industry for textile purposes began with the discovery of the felting characteristics of the short fibres in the bark as they collected in mats and spun balls on the screen-belts which segregate the long fibres used for Palco Wool insulation. As far as can be determined, this was the first demonstration of felting characteristics ever discovered in vegetable fibre.

This discovery led to the development of processing equipment for recovering and segregating the short fibre, and also to a search for new markets for the material. The research staff of The Pacific Lumber Company, headed by C. L. Thompson, conducted a series of tests in conjunction with a leading woolen company which showed that the redwood bark fibres interfelt and intermat with the wool fibre to form strong fabric. The present wool shortage hastened completion of these tests, which culminated in the granting of a patent on the process and its assignment to The Pacific Lumber Company.

In the process for making the new combination fabrics, the short fibres from the redwood bark are combined with the natural wool fibres in the textile mills. The resulting blend is carded, combed and spun into yarn which can be woven or knitted into fabrics having properties similar to pure wool textiles. The blended fibres can also be combined into felts for making felt mats. Lighter weight blankets and clothing are said to result from the combination of material. Combinations range from fifteen to sixty per cent of the bark fibre in the finished product, thus enabling a substantial saving in wool as well as effecting a considerable saving in the cost of the final product.

Interest in the development has been evidenced by the O.P.M. which is depending on the ingenuity of American industry to supply substitute materials to overcome the shortages which exist in various commodities. According to Edric E. Brown, manager of the Bark Products Division, immediate steps are being taken to make the new process as well as the raw material, available to textile manufacturers throughout the Country.

Up until a decade ago the rugged bark of the redwoods, which grows up to ten inches in thickness, was a waste product in the production of redwood lumber. At that time while the research department of The Pacific Lumber Company was conducting experiments in recovering the fibres from the bark some crudely shredded redwood bark was discovered intact after eighty years' gse as insulation in the walls of an old milk house near Petaluma, California. This confirmed the theory of the permanent resilience of the wiry fibres of the bark, an exceedingly important factor for insulating purposes. Further tests indicated that the long fibres recovered from the bark had practically all the bther desirable properties of insulation, being non-settling, moisture and fire resistant and distasteful to vermin and insects. Conductivity tests made by J. C. Peebles of Armour Institute of Technology showed a very high heat resistance with a .26 R.t.u. efficiency rating.

After a development period of several years during which a refinement process was evolved and application methods perfected, this material was named Palco Wool insulation and national distribution was obtained. ft is now in general use in the cold storage and meat packing industries and according to Pacific Lumber offiicials, has been installed in over one thousand cold storage locker plants. fn recent years mechanical blower equiprnent has been developed for applying the material in the walls and ceilings of homes.

Both Palco Wool and its new by-product, "Fibre A" for textiles, are produced at The Pacific Lumber Company's mills at Scotia, California. Both are compressed into bales for economical shipping and handling. The resilience of the insulating material is said to be such that when released from the bales and fluffed to the proper density, it quadruples its volume. Obviously, the ability of the product to be compressed for shipping is a distinct advantage under the present conditions of limited shipping facilities.