US2267310A - Soap package - Google Patents

Description

]Paiented Deco 23, lllll UNHTED Prat SUI-ll? PACKAGE Walter -V. Shearer,

West Springfield, and Garrison Householder. lBlolyoke, Mass, assignors to The Plastic Coating Corporation, a corporation of Massachusetts 6 Claims.

This invention relates to an improvement in the packaging of articles or materials such as cakes of soap or soap powders and more particularly to an improved wrapper or material from which wrappers or containers for soap may be made.

Most soap as it is commercially made at present contains residual alkali, small portions of unsaponified fatty acids and other ingredients which during the normal course of storage reacts with most all standard types of packaging papers which are retained in direct contact with the soap. The effect of this reaction brings about various types of staining of both the soap and the wrapper. The extent and character of the staining vary with the difierent types of paper selected as a wrapping material and the quality of the packaged soap.

For many years paper manufacturers have made papers which are commonly classed as alkali proof papers. These alkali-proof papers are made usually of neutral pulps, that is those which have neither an acid nor an alkaline reaction, and they are made with starch sizing rather than rosin, glue or other standard sizing materials. These papers have a somewhat less tendency to discolor in contact with soap than other grades of paper. The use of these papers, however, does not eliminate the staining entirely and is only an improvement to a moderate degree over other grades of paper.

Then further in the case of wrappers which have been printed with oil type inks, that is. where the ink pigments or other coloring materials are bonded to the paper surface with a drying oil such as linseed oil, the nature of the reaction between the soap and paper wrapper is such that the oil is saponified. This reaction destroys the binding action of the oil which in turn frees the pigments and other coloring materials which are easily removed in the normal course of handling the packaged soap. The printing then becomes illegible and the reaction may be suificiently complete to cause a general smearing of the ink pigments and coloring materials that the package takes on an untidy appearance. This is undesirable due to the fact that it suggests to the ultimate buyer that the product is shopworn and is not fresh merchandise. There are other types of inks which might be used on which the chemical reaction of the soap would be quite difierent.

More recently, particularly in gravure printing, inks are used in which nitrocellulose is the binding ingredient. Nitrocellulose is unstable in the presence of an alkali. Relatively the same efiect would result on wrappers printed with this type of ink as with wrappers printed with oil type inks.

Then further in the packaging of soap it is desirable to retain a certain amount of moisture depending upon the type and quality of soap packaged.

At the present time it is customary to double wrap the soap, using an attractive but relatively costly outside wrapper and an inner wrapper, the latter serving, in combination with the outer wrapper, to protect the soap from drying out and also protecting the outer wrapper from the action of the alkalies in the soap which as above pointed out, tends to stain the wrapping and saponify the oil binding material used in decorating the outer wrappers, causing the ink to blur and come off on the hands of the user. Because of the increased storage periods, particularly where large quantities of small cakes are purchased these conventional wrapping methods have at best proved inadequate and not susceptible to any substantial cost reduction.

It is the object of our invention to overcome these difiiculties and provide a wrapping for soap which is cheaper to apply, and which will adequately protect the soap over substantial periods, and which is itself unafiected by the soap alkalies over an equal period.

According to our invention we form a wrapper from a specifically treated paper which may be of any suitable character capable of satisfactorily receiving the usual printed matter which is customarily applied to the outer wrapper. Preferably while the paper is in web form, we coat that side which is to contact with the soap with a solution of a mixture of vinyl resins. These resins are polymers of vinyl acetate and/or vinyl chloride, or conjointly polymerized vinyl acetate and vinyl chloride. They are commercially available under various trade names. Vinylite and Gelva resins are commercial plastics of this class which we find suitable for our purpose. Preferably we reduce the plastic material to a solution which may be applied to the paper in a conventional coating machine. We have found organic solvents, such as acetone and toluol are suitable solvents, together with a suitable plasticizer such as dibutyl phthalate, for the plastic in preparing it for use in coating machines. Other suitable plasticizers are dibutoxy ethyl phthalate, diethyl phthalate, and methyl phthalyl ethyl glycollate. Alternatively the'plastic may be similarly brought to a paste consistency and spread on the paper, but we prefer the coating method since thinner coatto release. Our proposedcoating is colorless and trans-,- L

lngs are more easily obtained and we find that a coating of the order of .00025 inch thick is adequate for our purpose. We prefer to work within a range of from .00015-.0005 inch thick although we are not limited to this film thickness. Upon evaporation of the solvent a coating of the plastic mixture is left on the papen which coating is sufiiciently resistant to the alkalies of the soap to protect the paper and printing applied to the outside of the wrapper.

Typical formula I Parts Vinyl res 20 Dibutyl phthala 2 Acetone 39 Tolunl 39 economical type 'of printing methods.-

We have found that even under rigid tests soap packaged in ourwrapper has a much less tendency to lose its moisture than soap packaged in untreated wrappers. v

Further, dueto the nature of our coating, the

. wrappers may be sealed by moistening' the coated surface with suitable organic solventssuch as,

acetone, ethylene-glycol-mono-ethyl-ether and ethylene-glycol-ethyl-ether acetate, or it may be heat-sealed. The coated film becomes sticky when moistened with these solvents and thus serves as an adhesive for completely sealing the packaged soap. The nature of this sealing is such that it will not be. affected by moisture as in the case of water soluble adhesives which are used to a large extent for sealing merchandise packed in paper wraps. The sealed joints will not come apart in ordinary storage and will keep the wrapper intact over long periods of normal storage conditions. In extremely humid weather and due to the hygroscopic action of some soaps,

particularly those which contain varying amounts of glycerine and other similar materials. the ordinary glued joints would have a tendency parent. This is an advantage in that it does not discolor the paper to which it is applied; whereas other materials which might have asimilar protective feature are apt to be colored and this we believe is undesirable. I

- The coating is also odorless and has no efiect on the perfumes often used in the toilet soaps.

The length of storage time which our wrapper permits solves one serious diiilculty in the sale of soap-cakes. It further reduces wrapping costs by permitting the safeuse of a Single wrapper and further simplifies the wrapping operation itself since the coated wrapper may be solvent-sealed or heat-sealed. v

The solvent sealing properties of the resinous,

coating simplifies the sealing of the wrapper on the soap cake and secures a much moreefllcient sealing of the wrapper than is afforded by the usual adhesives, and therefore greater assurance that the soap will not dry out during storage. Furthermore, the resinous coating increases the strength of the paper permitting the use of a relatively cheap grade of paper without danger of tearing in the wrapping machine or in the subsequent handling of the soap.

We claim:

1. A package comprising abar of soap sealed in a sheet of wrapping material provided on one side with a moisture-, acid-, and alkali-resistant coating of vinyl resin adapted to counteract the emission of characteristic constituents of the soap for reducing wastage and deterioration thereof.-

2. A package comprising a bar of domestic soap sealed in a sheet of wrapping paper having printing thereon, the paper on one side being provided with a coating of moisture-, acid-, and alkali-resistant coating of vinyl resin adapted to counteract the emission of characteristic constituents of the soap for reducing wastage and deterioration thereof, said vinyl resin coating further serving to prevent alkali properties in the soap from attacking the ink bases in the printing on the wrapper to preclude running of the printed matter.

3. A package wmprisin'g a bar of soap sealed in a sheet of wrapping material provided on one side with a moisture-, and alkali-resistant coating of vinyl resin adapted to counteract the emission of characteristic constituents of the soap for reducing wastage and deterioration thereof.

4. A package comprising'a bar of soap sealed in a sheet of wrapping material provided on one side with a moisture-, and alkali-resistant coating of vinyl resin adapted to counteract the emission of-characteristic constituents of the soap for reducing wastage and deterioration thereof, said wrapping being heat sealed about the soap;

5. A package comprising a .bar of soap heat sealed in 'a sheet of wrapping material provided on one side with a moisture-. and alkali-resistant coating of vinyl resin adapted to counter- WALTER V.'SHEAR.ER.

GARRISON HOUSEHOLDER.

CERTIFICATE OF CORRECTION. Patent No. 2,267,510. December 25 1911.1.

WALTER V. SHEARER, ET AL.

It is hereby certified that error appears in the above numbered patent requiring correction as follows In the grant, line 2, name of co-inventor,

for "GARRISON HOUSEHOLD" read GARRISON HOUSEHOLDER-; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office. Signed and sealed this 27th day of January, A. D. 19m.

Henry Van Arsdale,

(Seal) Acting Commissioner of Patents.

CERTIFICATE OF CORRECTION.

Patent No. 2,267,510. December 25, 19in.

WALTER v. SHEARER, ET AL.

It is hereby certified that error appears in the above numbered patent requiring correction as follows In the grant, line 2, name of co-inventor,

for "GARRISON HOUSEHOLD" read -GARRISON HOUSEHOLDER-; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office. Signed and sealed this 27th day of January, AQ D. 19L 2,

Henry Van Arsdale, (Seal) Acting Commissioner of Patents.