US2325624A - Treatment of paper and paperboard - Google Patents

Description

Patented Aug. 3, i 1943 2,325,624 TREATMENT or PAPER AND PAPEBBOARD Sidney Musher,' New York, N. Y., assignor to Musher Foundation, Incorporated, New York, N Y., a corporation of New York 1 Serial No. 323,298

No Drawing. Application March 11, 1940,

6 Claims.

This invention relates to the treatment of paper packaging materials with antioxygenic agents in order to retard oxidative deterioration thereof and also to retard the deterioration of packaged products.

Particularlywhere pine is used as the stock in the manufacture of paper and board, the oxidizable oils contained therein make that paper or board very subject to deterioration, whereby objectionable board and other oxidation odors develop which render the paper or board unusable as wrapping materials. In addition, paper and board are used for the packaging of food products which food products are themselves subject to oxidative' deterioration and it is desirable to find means to retard the deterioration of such packaged product without adding foreign substances thereto.

An object of this invention is therefore the retardation of oxidative deterioration of flexible packaging materials such as paper and board, and particularly when made from pine and similar stock that contain objectionable oils that are easily oxidized.

Another object is the retardation of oxidation in packaged products where such papers and boards are used for the wrapping of oxidizable materials.

Still further objects and advantages will appear from the more detailed description set forth below, it being understood, however, that this more detailed description is given by way of illustration and explanation only, and not by way of limitation, since various changes therein may be .made by those skilled in the art without departing from the scope and spirit of the present invention.

In accordance with this invention, there are applied, preferablyas a surface coating, finely divided and substantially oil exhausted spice residues, and particularly clove and cinnamon residues.

For example, the essential and. fixed oils may be removed to a substantial degree by steam distillation, expression or extraction and the residue thus obtained, preferably finely divided to about 50 mesh and desirably to over 100 mesh, used for application to paper and paperboard in the production of antioxygenic packaging materials.

The term spice residue as used in this application and in the claims does not include essential or-flxed oils which are removed to a substantial degree from the spices by steam distillation, expression or extraction, but refers to the residue obtained after these spices have been substantially exhausted of their essential oil content.

The treated paper or paperboard is desirably adjusted to a pH of 4 to 6.9 and preferably to a pH of 5 to 6. The pH is important in order to obtain the maximum stabilizing results of the present invention. Where the pH is above 7.0, the protective effect normally exerted is very substantially reduced.

The paper or paperboard is adjusted to the desired pH in its substantially moist or aqueous condition, the pH determination being made at a time when the paper or paperboard is in substantially aqueous or moist condition, under which conditions the pH may satisfactorily be determined. 2

It is particularly desirable for the, application of the finely divided spice residue to be made to the paper or paperboard as a surface coating. For example, a mixture may be prepared comprising from 2% to 20% by weight of the finely divided spice residue in water,'and preferably about 10%, subjecting such water containing the finely divided spice residue to thorough agitation and admixture, passing the paper or paperboard through such water bath containing the spice residue at the calender boxes orbetween the first drying rolls and the finishing rolls or as part of a tub sizing operation. There may also be present in the tub a small proportion of starch, such as about 0.5%, in order to help hold the spice residue in suspension. There may also be present in the tub rosin wax sizes and other sizing materials.

A particularly desirable methodof application is for the finely divided spice residue in water suspension to be sprayed or allowed to flow on the moving sheet of paper or board at the wet end of the paper machine and immediately before paper or paperboard during the manufacturing operation, there will be applied approximately from 0.2% byweight to 5% by weight of the finely divided spice residue against the weight of the paper or paperboard.

' Where the finely divided spice residue in water suspension is allowed to flow on or is sprayed on the wet end of the paper machine and on to the sheet of paper as it moves to the heated rolls,- there may be applied any desired percentage of example, between 1% and 5% by weightof the spice residue may be mixed with the paper stock in the beaters and the paper manufactured con-, taining the spice residue as part of the finished stock.

In any event, these substantially oil exhausted spice residues are applied so as to be present in a substantially invisible and inappreciable .form. For example, the finished paper or paperboard ner is particularly valuable in connection with paperboard made 01' pine stock'and where the oils normally containedin the pineare subject to such rapid oxidation resulting in very objectionable cardboard and other oil odors that readily oontaminate products with which it comes into contact.

In the case of the pine wood board, the pine wood is first ground to a fine mesh and put is practically completely devoid of the characteristicessential oil aroma of the spice since the spice is first substantially exhausted of its oil and aromatic constituents before being utilized in accordance with this invention. Moreover, the spice residues should become a part of the paper or paperboard so that it cannot be readily removed from the paper or paperboard after manufacture thereof. i

Among the papers that may be treated in this manner are included parchment, greaseproof, glassine, sulphite, prime or secondary stock boards, etc. Such papers may subsequently be v deterioration. i

oiled, paraifined, waxed or otherwise treated folresidue thereto. v I

Particularly where paper is oiled, for example, such oiled paper is normally subject to rapid oxidative deterioration due to the decomposition or oxidation of the oils contained in that paper. This presents a serious problem separate from lowing the application of the finely divided spice the problem that is presented when such oiled r paper is used for the wrapping of fatty meats, for

example, where some of the fat leaves the meat and is adsorbed on the surface of the paper and rapidly becomes rancid in contact with that paper.

The application of a finely divided spice residue to the paper that is subsequently oil impregnated or parafiined will retard not only decomposition and oxidation of the oiled or paraffined paper itself whereby that paper may be stored for much longer periods without developing off odors, but in addition the paper thus prepared will materially improve the keeping quality of meats, crackers, and other products subject to oxidation and which are wrapped in those papers.

Moreover, the treatment of paperboard with the spice residue retards the development of the characteristic cardboard odor that develops particularly with the cheaper grades of paperboard. By reducing the development of the characteristic cardboard odor, there is also reduced the transmission of that objectionable odor to the products packaged in that board. Under these circumstances, where egg case fillers and liners are, for example, prepared with the spice residue and used for the packaging of eggs in cold storage, the eggs will be resistant to the development of the characteristic cardboard odor. Similar results are observed in the packaging of cereals, whole .wheat biscuits, crackers, cofiee, and other oxidizable commodities.

The application of spice residues in this manthrough the usual beater operations. The beater stock consisting in a whole or in part of the pine base is then run on the wet end oi. the board making machine for the fib'resto interlock and the board to form.

The application of the finely divided spice residue should desirably be made immediately be-- fore the paperboard reaches the heated drying rolls so that after the residue has been applied,

the paperboard is subjected to a temperature of 212 F. and preferably at about'250 F. Pa-

perboardmade of ground pine stock treated in this manner is very substantially resistant to It has been observed that where the finely divided spice residue is applied to the paperboard following the heat treatment and.at the very end of the manufacturing operation and where the paperboard is not subsequently subjected to a temperature of as high as about 250 F. for example, retardation of the development of characteristic objectionable paperboard and other off odors is not nearly as great as where the:

residue is applied prior to the high temperature treatment at the drying rolls. It is not known as to exactly how or why the high temperatureof the ground wood containing the finely divided spice residue produces the marked stabilizing action, but it is evident that the high temperature is desirable in order for the maximum stabilizing results to be obtained.

Where, in addition, the finely divided spice residue is added to paper and where that paper is subsequently oiled, the oiling should be 'conducted at an elevated temperature of at least F. and preferably in excess of 200 F. in order for the heat to be 'sufiicient to cause the desired reaction to take place.

Although the spice residue may be added in the beaters, this procedure is normally considered less desirable than where the residue is added as a sizing operation on the surface of the paper or board as above indicated.

It is also possible for-the finely divided spice residue to be added to the paraflin or oil that is applied to the paper, but it has been found that where such addition is made to the paraflin, wax or oil, the presence of the residue in that surface coating reduces moisture protection and makes the paper much more resistant to penetration of moisture than before.

In the packaging of such products as dairy products including ice cream, butter, powdered whole milk, cheese, etc., fats and oils such as lard, oleomargarine, shortening, etc., chocolates, cofiee and tea, candies, caramels, cookies, crackers, cakes and other baked goods, etc., whole wheat biscuits, cereals, bacon and other meat products, etc., the treatment as herein indicated chocolate milk, orange Juice, etc., are packaged, an improvement in the keeping quality of those liquid products is obtained.

A similar application of the finely divided spice residue as here indicated may be made not only to papers and cartons or paperboards, but also to metal containers such as to tin, to cloth containers such as to cloth bags, to cap liners, wooden tubs, etc. Y

Although it is desirable to use clove and cinnamon residues'which have been substantially exhausted of their oil and aromatic content, other spices and residues may be employed including the residues obtained following the removal of the oils and aromatic constituents from nutmeg,

pepper, mustard, ginger, mace, and caraway.

Included with the spice residues there may also be employed their extracts, and particularly those obtained by the use of alcohol as a solvent, al-

' though the extracts may broadly be chosen from board by heating the same to at least aboutboard between about 0.2% and 5% of deoiled spice residue and then heating the paper and paperboard to at least 220 F. to cause a reaction between the deoiled spice residue and the paper and paperboard.

2. Antioxygenic paperand paperboard containing incorporated with the surface thereof between about 0.2% and 5% of deoiled spice residue, said deoiled spice residue having been reacted with the surface of the paper and paper- 220. F., said paper and paperboard having a p of between about 4 and 6.9. V

3. In the method of making antioxygenic paper and paperboard, the steps of providing the paper and paperboard with a pH of between about 4 and 6.9, incorporating with the paper and paperboard between about 0.2% and 5% of deoiled clove residue and then heating the paper and paperboard to at least 220 F. to cause a reaction between the deoiled clove residue and the paper and paperboard.

4. In the method of making antioxygenic paper and paperboard, the steps of providing the paper and paperboard with'a pH of between about 4 and 6.9, incorporating with the paper and paperwherebythe extract substantially free of solvent remains. These extracts may be applied in a manner analagous to that described above for the residues themselves. a

The terms prime and "secondary as applied to stock board are terms which are commonly used in the trade. The term "prime is used particularly in connection with virgin stock whereas the term "secondary" is used in connection with paper stock that consists of secondary or once used materials.

18 Having described my invention, what I claim 1. In the method of making antioxygenic paper and paperboard, the steps of providing the paper board between about 0.2% and 5% of deoiled cinnamon residue and then heating the paper and paperboard to at least 220 F. to cause a reaction between the deoiled cinnamon residue and the paper and paperboard.

5. Antioxygenic paper and paperboard containing incorporated with the surface thereof between about 0.2% and 5% oi deoiled clove resi-' due, said deoiled clove residue having been reacted with the surface of the paper and paperand paperboard with a pH of between about.4

and 6.9, incorporating with the paper and paperboard by heating thesame to at least about 220 F., said paper and paperboard having a pH of between about 4 and 6.9.

6. Antioxygenic paper and paperboard containing incorporated with the surface thereof between about 0.2% and 5% of deoiled cinnamon residue, said deoiled cinnamon residue having been reacted with the surface of the paper and paperboard by heating the same to at least about 220 it, said paper and-paperboard having a pH of between about 4 and 6.9.

srom manna.