US1237011A - Process of manufacturing adhesives. - Google Patents

Description

UNITED STATES PATENT QFFTQE.

WALTER ALEXANDER, OF NEW YORK, N. Y., ASSIGNOR T0 NATIONAL GUM & MICA COMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

PROCESS OF MANUFACTURING ADHESIVES.

No Drawing.

To all whom it may concern Be it known that I, WALTER ALEXANDER, a citizen of the United States, residing in the borough of Manhattan, city, county, and State of New Yorln have invented certain new and useful Improvements in Processes of Manufacturing Adhesives, of which the following is a specification.

My invention has reference to improvements in the manufacture of adhesives, and is-directed more particularly to an improved, rapid process for the production of a dry product. Heretofore, it has .been a common practice to mix the several ingredients with a relatively large quantity of water, and, when a mass of thin, or jelly-like consistency containing a relatively large amount of water has been attained, to spread the mixture into trays or on nets in the form of films or layers for drying. Numerous disadvantages have attended this method, however; among which may be mentioned the great difficulty in obtaining a sufficiently rapid drying of the jelly, due to the large quantity of water present. The moist jelly being extremely sensitive to the destructive action of bacteria and molds, large quantities are often spoiled before complete evapo ration Has taken place. This is especially true in summer and damp weather, when, owing to the unfavorable climatic conditions, it has been found practically impossible to dry the jelly rapidly enough to prevent spoiling, and hence, necessary to abandon the manufacture of gelatinous adhesives atsuch times. It is my purpose to obviate these difficulties, and, at the same time. to obtain a vastly increased output, by reducin to a minimum the time heretofore required in drying the product. I have discovered that, by subjecting the several ingredients to the action of a mixing machine of high power, similar to the type often used for making dough, it is possible to reduce to a minimum the initial quantity of water required for the formation of the mixture, and after thoroughly mixing the'co'mponent parts inthe machine, to obtain a very highly concentrated product by pressing it out into thin sheets, as by passing the mixture through a pair of pressure rolls. The bulk of the moisture remaining in the product will be expelled by the action of the rolls, so that drying takes place in a comparatively short time, the actual time consumed de- Speoification of Letters Patent.

Application filed December 6, 1913.

Patented Aug. 141, 1917.

Serial No. 804,990.

pending upon the thickness of the sheet obtained.

Acharacteristic of my process is that the required ingredients are mixed in the presence of the smallest practicable quantity of water which may be used and still permit the necessary interaction and intermingling of the ingredients. Such an operation is made possible by utilizing a mixing machine which is sufiiciently heavy and powerful to handle a stiff and essentially non-fluid mass. The mixing process therefore commences with a maximum of dry material. During this process evaporation is promoted mechanically by the mere stirring effect of the blades or agitators. As the ingredients become more and-more intimately mixed, the presence of a solvent or agent for promoting fluidity is less and less required, so that the operation is ideal in that the water content, necessary at the outset but detrimental at the conclusion of the process, progressively diminishes, and eventually becomes so small that it may readily be removed by evaporation after the stiff mass is reduced to sheet form by the rolls.

In carrying out my invention, I place the several ingredients in the trough of a mixing machine of high power, together with only enough water to form a stiff, pasty mass. This water content may range as low as five per cent. It will be obvious that the actual quantity of water required depends upon the character of the materials used in preparing the adhesive. here desirable, I may employ heat or cold to assist a rapid mingling of the substances in the machine. The mass having been thoroughly mixed by the action of the machine, the product is converted into. thin sheets of highly concentrated, nearly dried material. This may be accomplished by running the mass through a pair of pressure rolls. The thickness of the sheets may be regulated by adjustment of the rolls, or by employing several consecutive pairs of rolls whose spacing progressively diminishes, which will reduce the sheet to such a slight thickness that evaporation of the remaining moisture con tained in the material takes place almost immediately upon exposure to the atmosphere. If desired, the drying of the sheets may be hastened by the employment of artificial heat; for instance, the sheets may be led from the rolls upon an endless conveyer and passed through a heated chamber, from which they will emerge completely dry.

As a-specific example of the operation of my improved process, I place about 500 pounds of dry starch, together with onequarter of one per cent. of a suitable acid, such as nitric acid or hydrochloric acid, in the trough of the mixing machine. Heat may be applied to the trough by any suitable means, and the blades then set in motion, whereupon the starch is converted into soluble starches or deXtrins, the kind depending upon the temperature and the length of time the starch is exposed to the action of the acid. The required quantity of dextrins having been produced, a suitable neutralizing agent, such as ammonium hydrate, may be used to stop further conversion of the starch. I then add a quantity of commercial glucose, approximately seventy-five pounds, together with one pound of phenol crystals, four ounces of oil of cloves, and only sufficient water to produce a stiff but coherent mass. The necessary quantity of water will vary in accordance with the operating conditions and the quantity de sired in the finished product. Five to ten per cent. of water based on the total mass mentioned will give satisfactory results. The blades continue to act upon the several ingredients until they are thoroughly incorporated. When this stage is reached, the product, now in the form of a very stitl mass, is passed through suitable rolls or a series of rolls of suflicient power to reduce it to thin sheets, which may be placed upon suitable trays or nets for drying. The quantity of moisture present, however, is so small that very little time is consumed in the drying operation. In fact, in the case when the sheet has been reduced to the minimum practical thickness, complete evaporation takes place almost immediately upon exposure to the atmosphere. I find it desirable to roll the material into sheets which are less than one-eighth of an inch thick. I have found that a vastly increased production is possible, due to the fact that by employing a minimum of water in the process, only a very small amount remains to be evaporated. This results in saving an immense amount of time, expense and space heretofore required for evaporating the large quantity of moisture from the films or'layers of adhesive materials. The use of artificial heat to dry the product issuing from the rolls is not necessary in carrying out my improved process, although it maybe employed with adhesives which tend to retain their entrapped moisture.

It will be noted that my invention is not to be limited in any way to the specific form of apparatus referred to in this specification, nor to the formation of the particular adhesive described, but on the contrary is of wide application and may be used in many forms, and for the production of other adhesives, without departing from the spirit and scope thereof.

Having thus described my invention, I claim:

1. The process of making adhesives which consists in mechanically combining the several adhesive ingredients into a concentrated, heavy mass capable of being formed into thin sheets, and converting the product thus formed into thin sheets.

2. The process of making adhesives which consists in mechanically combining the several adhesive ingredients into a concentrated, heavy mass capable of being formed into thin sheets, and rolling out the product thus formed into thin sheets.

3. The process of making adhesives which consists in mechanically combining the adhesive ingredients, adding suiiicient moisture to form a stiff, pasty mass, capable of being formed into thin sheets and then mechanically reducing the product thus formed and while in this state into thin sheets.

4. The process of making adhesives which consists in mechanically combining dry adhesive ingredients, adding suiiicient moisture to form a stiff, pasty homogeneous mass capable of being formed into thin sheets and then rolling the product thus formed and while in this state into thin sheets.

5. The process of making adhesives which consists in mechanically combining the adhesive ingredients in the presence of only suiiicient moisture to form a. stifi', pasty mass, capable of being formed into thin sheets, mechanically promoting the evaporation of said moisture, and then reducing the product thus formed into thin sheets.

6. The step in the process of making adhesives which consists in mechanically intermingling the adhesive ingredients in the presence of only sufiicient moisture to form a stiff, pasty mass, capable of being formed into sheets.

7. The process of producing adhesives in solid form, consisting in mechanically com bining at atmospheric temperature adhesive ingredients having a chemically inert nature with respect to one another into a homogeneous mass, and mechanically converting the product thus formed into thin sheets or the like.

8. The process of producing adhesives in solid form, consisting in mechanically combining several adhesive ingredients at atmospheric humidity into a homogeneous mass. and mechanically converting the product thus formed into thin sheets or the like.

9. The process of making solid adhesives which consists in mechanically combining adhesive ingredients having a substantially chemically inert nature with respect to one another Without substantially raising the temperature during the combination inthe presence of only sufiicient moisture to form a stiff pasty homogeneous mass, and then mechanically reducing the product thus formed and while in such state into thin sheets or the like.

10. The step in the process of making adhesives which consists in mechanically intermingling, without application of heat, pulverized adhesive ingredients having a substantially chemically inert nature'with respect to one another in concentrated homogeneous form with a small percentage of moisture but slightly in excess of that desired in the finished product.

11. The process of making adhesives in solid form from vegetable substances having a substantially chemically inert nature with respect to one another consisting in mechanically reducing said ingredients to miscible condition, mechanically combining the ingredients in such reduced condition, adding thereto a small amount of moisture, slightly in excess of the amount that will remain in the finished product, forming the resultant mixture into a stiff and homogeneous mass, reducing said mass to thin sheets or the like, and expelling any excess moisture therefrom.

12. The process of making adhesives in solid form from vegetable substances having relatively chemically inert natures consisting in grinding said several substances separately to pulverulent condition, adding to one of said substances a small amount of moisture, slightly in excess of the amount that will remain in the finished product, mechanically combining the several substances into a homogeneous mass, and passing said mass between pressure rolls adapted to expel any excess moisture therefrom and to reduce said mass to the form of thin sheets or the like.

WALTER ALEXANDER.

Witnesses:

' Lonn'rro O. TUCKER, MAE R. HARTMANN.