US2103318A

US2103318A - Culinary utensil of fibrous structure and method of making same

Info

Publication number: US2103318A
Application number: US676401A
Authority: US
Inventors: Albert L Clapp
Original assignee: Individual
Current assignee: Individual
Priority date: 1933-06-17
Filing date: 1933-06-17
Publication date: 1937-12-28
Anticipated expiration: 1954-12-28

Description

Patented Dec.. ,28, 1937 PATENT OFFICE CULINARY UTENSIL F FIBROUS STRUC- TUBE AND METHOD OF MAKING SAME Albert L. Clapp, Danvers, Mass.

No Drawing. Application June 1'], 1933,

- Serial No. 676,401

6 Claims.

This invention relates to plates and other or.

similar culinary utensils constructed of fibrous material and to an improved method of manufacturing such fibrous products and refers particularly to the manufacture of fibrous plates and other culinary utensils which possess, for a predetermined thickness or caliper, relatively great stifiness and rigidity.

Fibrous plates and other similar articles here- 10 tofore constructed, whether stamped from the paper directly or from molded pulp, have very little of the stiffness and rigidity of the articles they are intended to replace. Since nearly all plates or molded articles from paper have a caliper of approximately from 10 to 30 points, this lack of stiffness and rigidity is very noticeable. However, it is desirable to maintain this low caliper in order to obtain relatively light weight products of the desired heat-transfer properties and, at the same time, far more economical and efficient in other respects for manufacturing and selling.

It is one of the objects of my invention to produce these utensils with the same caliper as plates and other articles now produced from paper, but to greatly increase the rigidity; that is, to approach to a maximum degree the characteristics of the articles they are to replace. I Another object of my invention'is to so treat the pulp or paper making material while the same is being disintegrated in a beater engine or the like in the wet state in such a manner that when dry, it will have the hereinbefore mentioned stiff and rigid characteristics.

A further object of my invention is to treat the pulp to render it waterproof for molding articles to be used for cooking or for food products, and to render these articles sufficiently fire-resisting to withstand relatively high temperature when the plates or utensils are used for cooking purposes.

The process of my invention may be carried out in several ways, for instance, the plates or utensils, may be molded directly from the pulp in wire molds which allow for free passage of water under pressure, or the pulp may be beaten out in an ordinary beater engine and run over any standard paper making machine or wet machine, so called.

In carrying out my process, a beater engine may be loaded with pulp or paper making materials, such as ordinaryground wood-pulp, chemical pulps, asbestos, and various combinations of these When the pulp is beaten out to the proper degree of fineness, it is then treated with a stiffening agent. The stifiening agent found most suitable for this purpose is raw starch, such as potato or corn starch.- However, other starchy materials may be used to advantage. It has i been found desirable to mlx-the starch in cold water before adding it to the stock in the beater engine, as this produces a fine milky suspension which readily and uniformly mixes with the pulp. Cold water is used, because it is important not to cook this starch, since cooked starch does not give the stiffness desired, as will be hereinafter set forth. After the starch suspension is thoroughly mixed with the stock, the stock is then sized by any of the well known methods of sizing, such as rosin size, wax sizes, or the like. When the sizing is completed, the stock is then run into paper on any of the standard paper making machines and made into dry rolls or sheets of a desired caliper. This paper is now ready to be molded into the plates or other articles. Before molding the paper, it may be tempered, that is, slightly moistened, and then stamped in hot molds or dies designed for the purpose or those which are now commonly used for molding paper articles. It is necessary that the molds be quite hot, having a temperature of not less than 300 F., or thereabout. It is by means of the hot mold that the starch is modified;' that is, the starch particles which are intimately mixed in the stock burst and swell, which, with the combination of heat and pressure in the molds, cause the finished articles to be rigid and stiff. The effect of 'the bursting and swelling of the raw starch particles completely fills the interstices and pores of the finished product. Various degrees of stiffness can be produced by different proportions of starch used in the prepared stock. It has been found in practice that very large proportions of starch can be added to the stock and retained in the finished article, thereby producing a correspondingly more rigid utensil. made containing as high as 40% starch; however, 10% to 20% of starch gives desirable results.

If it is found desirable to mold the paper cold, it can be tempered in a weak alkaline solution and then molded and pressed in cold dies; and when the pulp is dry, it will become rigid and stiff, as the alkaline acts as a medium of modifying the starch. However, this latter process is-not desirable if the paper has been sized to waterproof, as the alkaline reaction affects the waterproofing size in the paper. This alternative is utilizable only when a stiff, rigid plate is desired with little or no waterproof properties. 4

The hereinbefore described method of treating Products have been it under heat and mechanical pressure, or by means of an alkaline solution, also renders the finished article'greaseproof, since a film of dry, modified starch permeates the sheet, and the modified or converted starch has greaseproofing qualities.

In carrying out my process by any of the well known methods of molding in wire constructed molds, the procedure is as follows:

The stock may be prepared in the beater in the usual manner, the starch and sizing being added as previously described, well beaten out-to the desired degree of fineness. This pulp is then diluted with water to a consistency of about 1%, which is generally necessary in molding stock in wire constructed molds. This stock is then flowed into the molds and pressed or formed into the desired shapes, the molds being so constructed as to allow free passage of water and to give the desired shape to the article. When the molding process is completed, the article is still wet, containing practically 60% water. It may now be transferred into another mold of the same design and held in this shape under heat and pressure until dried.- In order to properly convert the starch as above mentioned, it is necessary to have a heat of not less than 300-400 F. or thereabouts. To allow quick evaporation of the water, it may be necessary to have these molds perforated or of reinforced wire construction. Pulp articles having a caliper of 30 points will dry in approximately 15 to 30 seconds; and they have the requisite heat-transfer properties.

If the articles are molded by the well known method of blowing pulp onto molds, or by means of sucking the wet pulp onto molds after forming', they may be placed in conveyors and dried at a longer period of time and at a lower temperature; in this case, it has been found that a temperature of about 200-250 and about 30 minutes is suflicient to convert the starch and to dry the article.

These articles, thus made, are useful for many kinds of plates, dishes, and utensils of substantially all kinds.

When the utensils are to be used for baking or cooking, the stock may be compounded with various proportions of asbestos. For cooking pastry, it has been found that 20% to 25% asbestos or thereabouts is sufficient; for higher temperatures, 50% to 85% asbestos.

The plates and utensils, as described, may be coated with desired well known compounds in order to improve their appearance. These coating compounds are preferably of such character as not to affect food products in any way.

Examples of furnishes which have proved to be practical for cooking utensils are as follows:

Pounds 1. Wood-pulp 60 Sulphite 15 Asbestos 30 To this may be added 10 to 20 pounds of corn starch mixed in sufiicient water to allow a fine suspension. About five pounds of rosin size may then be added. After thoroughly mixing and beating the above material into the desired fineness, about five pounds of aluminum sulphate may be added to precipitate the rosin size. This furnish is suitable for running on a paper machine, either a Fourdrinier or a cylinder machine, the caliper of the finished stock being about from the stock with unmodified starch and modifying 10 to 30 points. The same may be tempered and molded under heat and pressure.

2. 400 lbs. of sulphite 600 lbs. of asbestostreated with from 10 to 20 pounds of starch and sized. The paper may be run to the desired caliper, and molded under heat and pressure. This furnish is suitable for cooking utensils where great heat is required, such as for roast meats, baking fish, or the like.

Pounds 3. Wood-pulp 60 Fine sawdust about from 20 to 40 mesh 15 To this may be added about 25 pounds of asbestos treated with from 10 to 20 pounds of starch sized with about 5 parts of rosin size and 5 parts of alum. This furnish may be used where the article is molded directly from the pulp in a liquid suspension. In molding pulp articles in this manner, it has been found necessary to have a rather free stock, that is, a stock from which the water is easily released.

In order to accomplish this, it has been found desirable to add the above proportion of sawdust, which gives the pulp the desired freeness. This furnish may be suitable for baking pies and pastry.

Pounds 4. Asbestos 85 Sawdust 15 Parts Starch 10 to 20 Rosin size and alum 5 be used and are not intended to be construed as a limitation of my invention.

In my process it will be noted that the starch is the medium for producing the stiffness and rigidity and also imparts the grease-resisting properties, and should not be confused with the methods of sizing paper with the Well known method of cooking starch. The cooked starch size does not give the desired stiffness and rigidity, nor does it impart the slightest degree of grease-resisting properties; it is by incorporating the raw starch in the stock in the beater in the proportion mentioned that this rigidity and grease-proofness is obtained. Cooked starch sizes are unsatisfactory because they are modified before being added to the stock. It is the bursting or modifying of the raw starch particles that renders the finished product stiff and much stronger than is possible in the case of ordinary starch sizes. Furthermore, it is possible to introduce into the beater a much larger proportion of starch than could be used by the cooked starch size methods, thus obtaining various degrees of rigidity and strength. Whenever 15% or 20% is used, it is possible to produce a very high luster finish.

The term "starch or starchy materials as used in the specification and claims is intended to include such materials as tapioca, sago and cereals such as fiour, fine corn meal, or in general, any material which may produce the bursting ac tion hereinbefore described. The term points is used herein as it is customarily used in the paper-making industry-to connote thickness in thousandths of an inch.

I claim as my invention:

1. A culinary utensil shaped and adapted to hold foodstuff during cooking and baking operations and of a relatively stiff and rigid molded structure comprising interfelted fibrous material of a thickness not exceeding about 0.030

inch, the pores of which contain swelled starch particles derived from rawstarch modified to a swelled condition in situ in the pores, said starch being present in the amount of at least based on the dry weight of the fibrous material, and said amount of starch serving to stiffen said structure sufficiently to keep its molded shape when handled and to render said structure substantially greaseproof.

2. A culinary utensil shaped and adapted to hold foodstuff during cooking and baking.operations and of heat-withstanding, comparatively thin, relatively stiff, molded, fibrous structure of a wall thickness not exceeding about 0.030 inch and comprising asbestos and alkali modified and swollen starch, said starch having been modified and swollen in situ in such structure and being present in the amount of at least about 10%, based on the dry weight of fibrous material, and said amount of starch serving to stiffen said structure suificiently to keep its molded shape when handled and to render said structure substantially greaseproof.

3. A culinary utensil shaped and adapted to hold foodstufi during cooking and baking operations and of heat-withstanding, relatively stiff, molded fibrous plate structure of a thickness not exceeding about 0.030 inch and comprising asbestos and alkali modified and swollen starch, said starch having been modified and swollen in situ in such structure and being present in the amount of at least about 10%, based on the dry weight of fibrous material, and said amount of starch serving to stiffen said plate structure sufiiciently to keep its molded shape when handled and to render said structure substantially greaseproof.

4. A method of making relatively stifi, molded, fibrous culinary utensils shaped and adapted to hold foodstuff during cooking and baking operations, which comprises mixing unmodified starch and a fibrous pulp in an aqueous vehicle to produce a mixture containing at least about 10% starch, based on the dry weight of the pulp, formingsaid mixture into such molded culinary utensil of a wall thickness not exceeding about 0.030 inch, and modifying the starch included in the structure by moist heat and pressure, thereby stiffening such structure sufficiently to keep its molded shape.

5. A method of making relatively stiff, molded, fibrous culinary utensils shaped and adapted to hold foodstuff during cooking and baking operations, which comprises mixing unmodified starch and a fibrous pulp in an aqueous vehicle to produce a mixture containing at least about 10% starch, based on the dry weight of the pulp, forming said mixture into' such molded culinary utensil of a wall thickness not exceeding about 0.030 inch, and modifying the starch in said structure in the presence of alkali and moisture and drying such structure, thereby stiffening such structure sufficiently to keep its molded shape.

6. A method of making thin but still fibrous culinary utensils shaped and adapted to hold foodstuff during cooking and baking operations, which comprises mixing with fibrous pulp in an aqueous vehicle'raw starch in the amount of at