US2181439A - Composition wood - Google Patents

Description

Patented Nov. 28, 1939 .umreo STATES COMPOSITION WOOD Charles Roman, Miami, Fla.

N Drawing. Application September 22, 1937, Serial No. 165,185

4 Claims.

My invention relates to composition or fibre boards and the method of making the same.

An object of the invention is to provide a new composition product which can be easily and cheaply made and which possesses substantially all of the desirable qualities of natural lumber without the disadvantages of such natural lumber. Among the objects sought is a lumber that will be light in weight and at the same time will be strong and also a lumber that may be readily machined by ordinary woodworking machinery.

A further object is to provide a new composition wood that is substantially impervious to moisture and which is practically unaifected by temperature and other air condition changes.

A still further more specific object is to provide a composition wood that is adapted for use as a core wood in the making of veneer panels and other boards and especially such veneer products as are used in the manufacture of furniture and other articles,

How these and other objects of the invention are brought about will become more apparent from the specification which follows.

In presenting this invention I am fully aware thatothers have preceded me in the field of composition products of various textures. Such products have heretofore generally been made of asbestos fibers, wood fibers or other fibrous material and have been used generally as wall boards, insulating boards, acoustic boards and plaster boards. Where they have been light in weight they have been correspondingly weak. Such as were made strong were made under heavy pressure and were rather heavy and expensive as Well, and usually ranged in thickness from A3 to of an inch. My boards may be made in almost any thickness as up to one inch or more and possesses great strength and at the same time be light in weight and inexpensively produced.

My composition lumber is made from various fibers and pulps such as wood fibers of various natures and sizes mixed with a suitable binder and formed into sheets or other shapes. In the formation of the product a binder is first made after which the wood fibers are mixed with it and then formed into sheets or other shapes. The'term wood fibers, as used herein, is to be broadly construed. There is no clear line of demarcation between ground wood pulp of trees, upon the one hand, and the woody fibers of the bagasse from sugar cane. There are innumerable plants producing cellulosic or woody fibers susceptible of use in connection with this invention. I

A suitable binder may be made from the following materials and the proportions indicated have been found to be effective. To five gallons 5 of vwater in a suitable container are added eight ounces of powdered animal glue. A compound is then prepared consisting of approximately 19 parts of sodium chloride, 75 parts of sodium bisulphate and 6 parts of silicate of magnesium. The main purpose of the silicate of magnesium is to prevent the sodium chloride and the sodium bisulphate from caking from being stored for some time. Such a compound may be found on the market and is known under the name of 1 Sam-Flush. Three ounces of this compound is then added to the glue and water solution previously prepared and the whole mass heated to the boiling point.

A starch is then made by adding a little cold water to four pounds of tapioca flour, sago flour, potato or other starch. Only enough water is added to the flour to make a soft paste. This paste is then added slowly to the boiling solution of water, glue and the compound mentioned 5 above. As the starch paste is added to the solution the whole becomes at first a thickmass. As this is further stirred and boiled the reaction of the compound'reduces the whole mass to an easy flowing thin fluid. The batch thus formed is then removed from the heat and allowed to cool slightly after which is added one ounce of paraformaldehyde. The binder is then ready for use.

A good binder may be made without the use of the animal glue. The small amount of the animal glue, however, seems to help the paraformaldehyde to mix with the starch and imparts a smooth or creamy feel to the binder.

The wood fibers are then added to the binder and mixed thoroughly until they are soft and pliable. The mass may then be run upon a forming screen to the desired thickness and the surplus binder drawn off by a vacuum in any suitable way to be used over again. The degree of vacuum may be regulated so as to determine the amount of suction on the sheet. A denser board is produced by increasing the degree of vacuum. After being formed in the manner indicated the sheets are dried in a suitable drying oven.

In order to give an even smooth surface and an even thickness to the sheets, they are taken from the ovens when partially dry and hot smooth plates are applied. .In applying the plates, these should be removed at short intervals 55 to permit the steam to escape and to prevent the plates from sticking. The sheets are then finished and may have veneer sheets applied to them in the usual way in which veneer products are made or they may be machined if desired by ordinary wood working tools.

From the foregoing description it should be apparent that the lumber or boards formed by my process can be made from materials heretofore Wasted, such as saw dust and other waste comminuted wood fibers and yet the resulting products are superior to the natural woods. This is especially true of this composition board when used as a core wood for making veneer lumber or sheets.

This composition material has found especial utility as a core wood due to the fact that natural woods which have been suitable as core woods heretofore are fast becoming exhausted. It is well known that the natural high grade woods from which high grade furniture is made have become scarce and consequently expensive. To meet the situation the furniture trades began the making of furniture from veneers having a cheap wood core and a thin veneer of the finer more expensive woods such as mahogany, etc. But the woods which could be used as core wood also became scarce. Chief among such woods is chestnut which due to the fact that it is little affected by weather changes served asan excellent core wood. Because of the increased demands for chestnut and due to the blights and other dis eases that have attacked chestnut, this wood has become difiicult to obtain in sufiicient quantities to meet the needs of the furniture manufacturers. It has been necessary to find other suitable core woods. meet this demand in every respect since it may be machined readily, will receive veneer layers, is unaifected by moisture and other air conditions and is inexpensive.

An alternative way of forming the sheets may be first to form the sheets from water pulp and run them on a forming screen. The binder may then be added to one side of the sheet and vacuum My composition wood has been found to applied to the other side to saturate the sheet with the binder.

An alternative way of forming articles from this new composition is to dampen Wood fibers or wood flour with this binder and then press the mass in a suitable mould. After the materials set the articles are removed from the moulds and dried. In this manner articles may be made very cheaply.

One important characteristic of the binder is that it does not discolor the articles made.

It will be obvious to those skilled in the art to which my invention pertains that various changes may bemade in the invention without departing from the principles thereof, I, therefore, do not limit myself to the invention as specifically de scribed but only as set forth in the appended claims.

What I claim is:

l. A composition Wood comprising wood fibers mixed with a binder consisting of a solution of starch, animal glue, sodium bisulphate, sodium chloride, silicate of magnesium and paraformaldehyde.

2. A new wood composition comprising a formed sheet of comminuted Wood impregnated with a binder consisting of approximately eight ounces of animal glue, approximately three ounces of a compound known as Sani-Flush and one ounce of paraformaldehyde in a solution of approximately five gallons of water.

3. A composition wood comprising comminuted Wood fibers mixed with a binder consisting of a solution of approximately five gallons of water to which has been added eight ounces of animal