US1998190A - Manufacture of paper - Google Patents

Description

Patented Apr. 16, 1935 UNITED STATES- Lassa-so MANUFACTURE 1*- rerun Herman J. Finder and David H. Greene, Jolietflll. 7

o D aw n Application Au u t 8114 3 Serial No. 6837,24,? I

12 Qlairnsl This invention relates to improvements in the manufacture of paper and the products obtained, by such improved method.

One of the objects of our invention is to produce ,a relatively inexpensive rough paper or chipboard.

Another object is to produce a paper having such characteristics that it may present the desired finished condition by the use of less sizing material than hitherto required and present a greater degree, of strength.

Another object is to provide improvements in the'methods of producing paper, to the end that it may be produced more economically and the resultant product present the desired characteristic's.

We have found that the hulls of various cereal gra ia Such as oats, barley, wheat, and the like, in finely divided state constitute a suitable filler in the manufacture of paper. Excellent results,

' for example, have been obtained by the use of oat hulls,

Generally stated, the hulls from which the filler is to be made are first subjected to treatment for thoroughly comminuting or dividing the fibres and reducing them to the desired sizes, without the use of any chemicals, whereby all or substantially all of the mineral and organic material originally contained in the hulls are retained in the finished stock, as contrasted with the ordinary practice in the manufacture of paper stock, which involves the adding of strong chemicals for thoroughly digesting the hulls, which process requires the thorough washing out of the chemicals with a substantial loss of the original weight of the hulls.

According to the preferred manner of producing such paper, the hulls are ground to pass a 30 to mesh screen. The shredded material is then added to the beater, pulper or any other suitable mixing device along with the paper stock and is subjected to heat treatment in the presence of a weak alkali.

It will be understood that in any method of producing paper pulp by a digesting process, the capillary bores of the fibres become thoroughly filled with the digesting liquor and that, of course, the exteriors of the fibres become coated with such liquor. In like manner, we believe that the silicates and vegetable fats of the filler become a part of the paper in that they coat and enter into the capillary bores of the individual fibres and add a valuable quality to the finished sheet. The employment of cereal grain hulls as a filler has been particularly successful in closed systems, sinceonly small amounts, of the valuable organic and mineral materials disappear through the sewer. Consequently, the total shrinkage isgreatly lessened, resulting in'a saving in cost of materials. At the. same time, it is not necessary to add as much sizing as in the usual practice, when a fsizedf. paper is desired.

In practice, we have found that a very satis factory light-weight chipboard may beproduced;

by adding finely divided hulls as .a fillerto a charge, of Waste paper in the pulper or d-igester in the proportion of 9 parts ofwaste. paper to one: of fil er and t eat ng the furnish for approximately 70. minutes at, a temperature of- 1-30? in the presence of soda: ash, equal to 1%. by. weightof the total: furnish in the pulper.v It, is essential that the soda ash solution be compara-. tively weak in order that, the. filler is not. more han l ght y di es ed- T e paper. tock may b h n form d; i to a, web in any suitable way, as, for example, in accordance with, the common prac: tice. There may also be some variations in the length of treatment and the temperature. When the paper is to be run on a cylinder machine, the filler may very satisfactorily constitute 35% of the total furnish.

The variation of the above-described process is to treat the cereal grain hulls with soda ash before grinding or concurrently with the grinding operation.

A very satisfactory light weight chipboard has been obtained by using comminuted oat hulls. Of the various cereal grains, oat hulls have been found particularly satisfactory, since they contain large proportions of silicates and vegetable fats which readily enter into an intimate relation with the other fibers of the furnish. Paper containing-10% to 15% of finely divided oat hulls as a filler, when tested on the Mullen machine, has been found to be as strong as paper made with the ordinary more expensive fillers. Suitable results have also beenobtained by employing finely divided wheat, rye, barley, and rice hulls as a filler.

While best results have been obtained by employing finely divided grain hulls, it is to be understood that it is impractical to prescribe grain hulls of certain size, since it is obvious that a uniform size cannot be obtained in the ordinary grinding processes. Grain hulls in the range of 40 to 60 mesh have been found suitable. A screen test of satisfactory comminuted oat hulls revealed that 12.2% of the hulls were retained on 20 mesh 5. The method of producing paper which comscreen prises finely dividing cereal grain hulls and form- !4% of the hulls were retained on 40 'mesh ing a web thereof with a paper stock.

screen 6. The method of producing paper which com- 12.2% of the hulls were retained on mesh pris c mminutin at hu n heating i screen comminuted oat hulls with a paper stock in the 7.3% of the nulls were retained on 30 h presence of a weak solution of alkali carbonate.

screen 7 7. The method of producing paper which com- 4.8% of the hulls were retained on 10 mesh prises comminuting cereal grain hulls containing screen silicates, mixing said comminuted hulls with a 19.5% of the hulls were passed thru 100 mesh paper p p and forming a Web t e eof Wit out screen the loss of said silicates. Paper including our new comminuted grain e mBfihOd of producing p p which @0111- hull filler has proven to be most satisfactory, particularly when produced in a substantially closed system in which the silicates and vegetable fats of the filler are retainedin the paper web. Furthermore, the cost of manufacturing'it is lower than that of making paper according to ordinary practice.

While we have described a certain product constituting one phase of the invention and have described certain methods or processes for producing such product, we do not wish to be understood as intending to limit our invention -there-' to as the product and methods or processes may be variously modified and altered without departing from the scope of the invention.

What we regard as new, and desire to secure by Letters Patent, is: e

1. As an article of manufacture, paper containing as a filler finely divided cereal grain hulls.

2. As an article of manufacture, paper con tainlng as a filler comminuted oat hulls in which the silicates and vegetable fats of the oat hulls are substantially retained in the paper web.

3. As an article of manufacture, paper comprising 5 to 30% by weight comminuted cereal grain hulls as a filler, and 95 to paper pulp.

4. As an article of manufacture, paper containing as a filler cereal grain hulls ground to pass a 30 mesh screen.

.prises finely dividing cereal grain hulls containing vegetable fats and silicates, mixing said finely divided hulls with a paper stock, heating said mixture in the presence of soda ash, and forming 'a web thereof all without removal of said silicates and vegetable fats.

9. The method of producing paper which comprises treating cereal grain hulls with alkali carbonate, comminuting said treated hulls and mixing said hulls with a paper stock to form a web thereof.

.10; The method of producing paper which comprises comminuting cereal grain hulls to pass a 30 mesh screen and forming a web thereof with a paper stock.

11. The method of producing paper which comprises comminuting cereal grain hulls, mixing said cornminuted hulls with waste paper pulp, and forming a web thereof with a paper stock.

' 12. The method of producing paper which comprises comminuting cereal grain hulls containing silicates and vegetable fats, mixing said comminuted hulls with a paper pulp, subjecting said furnish to a mildly digestive treatment, and forming a web thereof retaining substantially all of said silicates and vegetable fats.

HERMAN J. FINDER. DAVID H. GREENE.