US1892138A

US1892138A - Heat and sound insulating material

Info

Publication number: US1892138A
Application number: US381083A
Authority: US
Inventors: Elton R Darling
Original assignee: Pacific Lumber Co
Current assignee: Pacific Lumber Co
Priority date: 1929-07-25
Filing date: 1929-07-25
Publication date: 1932-12-27
Anticipated expiration: 1949-12-27

Description

Patented Dec. 27, 1932 UNITED STATES PATENT OFFICE ELTON R. DARLING, OF DANVILLE, ILLINOIS, ASSIGNOR TO THE PACIFIC LUMBER COM.- PANY, OF SAN FRANCISCO, CALIFORNIA, A CORPORATION OF IMAINE HEAT AND SOUND INSULATING MATERIAL No Drawing.

The present invention relates to an improved dry material for use as a filler and as a thermal and sound insulating substance.

One of the objects of the invention is to provide a material in loose, powdered form that may be placed between the floor of a building to serve as a thermal and sound insulator.

Another object of the invention is to employ a material which, for dearth of a better designation, is here designated as tree sand, which is a waste material resulting from the manufacture of sheathing lumber and wall board from the bark of the California redwood or Sequoia tree.

Another object of the invention is to employ a very lightweight inorganic material known as zonolite, sometimes also called vermiculite, in admixture with the said tree sand in order to obtain a material of lighter specific gravity.

In producing the improved thermal and sound insulating material, I first take the mineral known as zonolite, which is a variety of mica containing water in combination, and heat it to cause it to expand and form a very light and fluffy material. This property of zonolite is peculiar to this mineral and yields a product having a very low specific gravity.

In order to exfoliate or expand this mate rial it serves to heat the same to a temperature of not in exces of 400 0., whereafter it is cooled and preferably roughly ground to disintegrate it.

The so-called tree sand is a natural organic product inherent in the bark of California giant redwood trees, and consists of small discrete, rounded. blackish grains that are substantially incombustible. This tree sand occurs in the bark intermediate of the fibres of the latter and is removed therefrom in the manufacture of sheathing lumber in a dry-sieving operation. The tree sand may, moreover, be separated from the fibres by a process of elutriation in which the fibres and the tree sand are simultaneously suspended in a slowly-moving current of water under such conditions that there is slight agitation, sufiicient to maintain the fibres in suspension but insuflicient to prevent deposi- 1929. Serial No. 381,083.

tion of the tree sand by subsidence. If the tree sand is derived by this elutriation process it is necessary to dry the same, but this is readily accomplished by spreading it loosely in the sun. Of course, a rotary hot-air drier will serve the purpose equally well.

In either case, the preferred thermal and sound insulating composition consists substantially of three parts by weight of tree sand and one part of the exfoliated zonolite, these substances being thoroughly inter mingled by mechanical means and sold to the consumer in bags, barrels and other suit able containers. Other proportions may be used, as, for example, equal parts of zonolite and tree sand, this latter forming a still lighter material. As the tree sand is an absolute waste at present and in the manufacture of sheathing lumber from redwood bark is produced as a by-product in enormous quantities, its price is very low and hence the cost of the composition is very reasonable and the product therefore of distinct commercial value, as fillers of this type must be cheap and effective in order to compete with ordinary sand or industrial wastes hitherto used for similar purposes.

It is to be distinctly understood that the proportions herein recited are not limiting in any sense, since the invention is to be construed only by the hereunto appended claims: r

I claim:

1. A heat and sound insulating composition consisting of substantially three parts by weight of rounded sand-like particles of organic matter derived from redwood bark and one part by weight of exfoliated zonolite. wherein the zonolite prevents excessive packing together of said particles, thereby increasing the sound and heat-insulating value of the individual particles.

2. Composition of matter for use as a sound and heat insulating material, consisting of exfoliated zonolite and tree-sand, the latter being derived from redwood bark.

In witness whereof, I have hereunto subscribed my name.

ELTON R. DARLING.