US1869491A - Method of producing sheeted compounds - Google Patents

Description

Patented Aug. 1932 UNITED STATES JOHN HUIRSCH, OF TEAN'ECK,

mnrrron or raonucme snan'rnn comronrfns ll'o Drawing.

The present invention relates to the pro duction of sheet materials from compounds employing waste fibre such as newsprint, rags or, the like, combined with abinding material in the nature of a synthetic resin.

6 In the broadest aspect of my invention, I

propose to initially prepare the waste fibre,-

as waste newsprint, in a dry form, this imtial preparatory step consisting in the reduction of the material to a state of comparatively uniform sub-division, as m a hammer mill. I next propose to thoroughly and efi'ectually impregnate the complete'fibrous mass with uncured resin, either by application of the resin in the form of a liquid varnish, or by developing the resin from liquid ingredients within the fibrous mass itself.

Having thus secured a complete impregnation of the mass, I may reduce a mass whlch go is either dry or in a plastic condition to a form in whlch it may flow as a liquid, this reduction being accomplished preferably through the addition of a snfiicient'amount of water to dilute the mass and separatethe fibres. This loosening of the fibres after the addition of water may be accomplished by a relatively gentle agitation or mixing to separate the fibres without destroying or break-.

ing up the fibres themselves, or removing 3 more than a minimum amount of impregnatinto a coherent sheet, which may thereafter .be treated either for the production of molded products, or in sheet form as board. In either case the uncured sheet is subjected to curing temperatures which convert the resins into an insoluble product having the waste fibre as an essential ingredient. By suitably altering the proportions of fibre to resin and controlling the degree of sub-division of the lTEW JERSEY, ASSIGNOB TO J'OSEPH GATTI, OF NEW YORK, N. Y i

7 Application filed April 29,

'terial, I preferto develop the resin directly ATENn OFFICE 1931. Serial No. 533,795.

dry fibre, the resulting product maybe varied within desired limits, the type and character of the finish depending in part, at least, upon the proportions employed.

According to one method of practicing the invention which has resulted in suitable products, I first reduce the waste paper or the like, which may be in the. formof newsprint or book-paper, into a finely ground condition through the employment of a hammer mill. This hammer mill is a familiar article of commerce, and comprises rotating ham mers which are capable of beating out and grinding the loose dry mass of paper into finely divided form. Having thus prepared 65 the fibre for impregnation with the resin main the fibre itself, and to this end I thoroughly mix at room temperatures the following proportions of material:

2 pounds of paper 7 pounds of formaldehyde 7 pounds of cresylic acid 2 pounds of caustic soda 8 pounds of water The acid and caustic soda are caused to thoroughly penetrate the fibre and thereafter the water is added. The operation is preferably carried out in a steam-heated kettle at five so to ten pounds steam pressure, the'resin developing directly within the fibre.

'When the reaction has been completed, it will be found that the resulting mixture is somewhat plastic, and that the individual fibres are'thoroughly and effectually impregnated with the uncured resin. To this material may be added a suflicient amount of water to make the resulting material flowable, and permit its being delivered or flowed on go i to a vacuum screen in the form of a sheet.

. As an alternative method of producin the impregnated fibre, I may mix the dry, finely divided waste paper or the like with a liquid resin varnish. In this case the dry waste and 96 resin varnish are thoroughly mixed to secure as nearly a uniform impregnation of the dry ingredients as possible. Having thus impregnated the material, itis dried below curing temperatures, if desired, and to this ma- 100 terial may be added a suflicient amount of water to dilute and cause it to flow, this reduction to a flowable condition being preferably accomplished through agitation. Although this method of producing a wet, flowable mass may conceivably be employed,nevertheless it is not as efi'ective as the method previously described, which results in the development of the resin directly within the fibre itself. This is due to the fact that imuniform in the first method, and in the second place less of the resinous material is removed froin the fibre with the added water with the first method than with the second.

With either method of production, the wet,

- mobile, flowable mass is delivered to ascreen curing temperatures combined with whatever pressure may be desired to provide a finished I product with a hard, smooth surface.

and a vacuum drawn therethrough for removing the surplus water and other liqulds, and converting the mass into a reasonably duced directly from the impregnated fibre in a dry, loose condition, this fibre being placed directly into a mold and then subjected to curing temperatures and pressures.

As an alternative to the formation of the coherent sheet on the vacuum screen, the liquid mass can be drawn ofi on the felt vacuum'rolls of paper machines of the wet type. Regardless of whether the sheets are presteam-heated racks. The heat employed in sufiicient to dry off moisture without promoting any curing of the resin. This semi-cured sheet, as it may be termed, merely requires What is claimed is:

pounds which consists in' reducing dry waste cured resin, reducing. the impregnated fibrous mass to a'flowable condition, forming ing intoa coherent sheet.

bre to a finely divided condition, thoroughpregnation of the fibre is more complete anddry, coherent sheet. This sheet may be cut proved as compared with the product profibre to a finely divided condition, thoroughby impregnating the divided fibre withan un- 1y impregnating the divided fibre with an uncured resin, reducing the impregnated fibrous mass to a flowable condition, forming a uniform film of the flowable mass, drying into'a coherent sheet, and finally subjecting the sheet or a part thereof to temperatures sufliciently elevated to cure the resin.

3. The method of producing sheeted compounds which consists in reducing dry waste fibre to a finely divided condition,-thoroughly impregnating the divided fibre with an uncured resin, reducing the impregnated fibrous mass to a flowable condition, delivering the liquid mass on to a screen, and drying the mass into a coherent sheet through vacuum.

- 4:. The method of producing sheeted compounds which consists in reducing dry waste fibre to a finely divided condition, developing a synthetic resin directly within the mass of fibre to produce a somewhat plastic mass, reducing the mass through the addition of water and mixing to a flowable condition, forming a film while in this condition, and drying the film to produce a coherent sheet of fibre impregnated with uncured resin.

5. The method of producing sheeted comounds which consists in reducing dry waste bre to a finely divided condition, developing a synthetic resin directly within the mass of fibre to produce a somewhat plastic mass,

water" and mixin to a flowable'condition, forming a film while in this condition, drying the film to produce a coherent sheet of fibre impregnated with uncured resin, and curing the sheeted material at a temperature sufliciently high to convert the resin into an insoluble material.

In testimony whereof I name to this specification.

JOHN

mason.

pared'on a vacuum screen or felt, the drying is subsequently completed in an oven or with p the subsequent drying operation is merely 1. The method of producing sheeted com- 7 a uniform film of the flowable mass, and dry- Y 2. The method of producing sheeted comp1 runds which consists in reducing, dry waste have signed my reducing the mass through the addition of