US2207122A - Parchmentized paper - Google Patents

Description

July 9, 1940. R. A. HAYWARD PARCHMENTIZED PAPER Filed Aug. 25, 193'? m m O T T A INVENTOR. /Fafm 02E-.mao

.NI NNW Patented July 9, 1940 ,UNITED STATES PAPER Ralph A. Haywa Parchment, Mich., assignor to Kalamazoo .Vegetable Parchment Company,

Parchment, Mich.

Application August z5, issa'serial No. 160,133

2 Claims.

This invention relates to improvements in parchmentized paper.

'I'his invention relates to an improved paper and method of making the same, and particu- 5 larly parchmentized paper` designed for wrapping products and for other purposes where substantial strength is desirable.,

The main objects of this invention are:

First, to provide an improved parchmentized paper having substantially increased bursting strength, both wet Vand dry, as compared to standard parchmentized paper of similar stock and weight.

Second, to provide an impr'ved method o! manufacturing my improved'paper.

Objects relating to details` and economies of the invention will appear from the description to follow. The invention is deiined and pointed out in the claims.

In the accompanying drawing Fig. 1 is a conventional illustration of parts of an apparatus by which my improved product may be produced, the parchmentizing apparatus other than the washing notbeing indicated.

Fig. 2 is a plan view of a web of paper illus- .trating the various steps of my method'.

In considering the drawing, it will be appreciated that no attempt has been made toshow the parts in proportion and that it is not practical to illustrate with great accuracy the creped material or the nished product.

In the shipping and merchandising of various products, parchmentized paper is desirable as, for example, in the crating and shipping of lettuce which is crated wet and frequently with ice enclosed. Also, in packing, the paper is placed in the press with the lettuce with ice and the press actuated to compress the contents into the crate dimensions and this places asevere strain on the paper. Therefore, it is desirable to increase the strength of the paper for this and various other uses. The bursting strength of my paper is very greatly increased over that of paper of similar grades produced by other methods, both as to dry tests and greater increases are found on wet tests, that is, as compared with similar paper produced by other methods.

In the accompanying drawing I represents a web of paper to be treated and 2 the washing apparatus for washing the web of paper after it has been subjected to a parchmentizing solution. The apparatus for accomplishing that step is not illustrated as it is well known in the art:

While the paper is wet and preferably while it is still wet from the washing step as illustrated in Fig. l, it is passed to a creping apparatus shown conventionally at l from which which the creped paper is passed to a drying apparatus. I This drying apparatus and particularly the support of the paper during the drying step is of primary 5 importance. When parchment paper is dried by ordinary methods it shrinks very substantially, at least ten inches in a hundred inch width of web. By the usual method of drying parchment `paper the paper is held against the nat surface 10 of the drier and instead of the paper shrinking to this i'ull extent there is a tendency for strains to be set up in the paper-which reduces the ultimate strength of the sheet.

By my method of vthis application the 'parch-4 15 mentized sheetor web is creped and the creped web is fed to the driers so that it reaches them with the crinkles resulting from the creping still retained therein. The paper is so supported during this drying operation that as the paper zo shrinks the shrinkage is absorbed by the puckers and issues from the driers with the crinkles of the creping step substantially eliminated. As there has been no strain developed during the drying, the strength of the paper is greatly in- 25 creased infact, commonly as much a's 25% above that of parchmentized paper produced by ordinary methods.

In Fig. 1 of the drawing I illustrate two sections of the driers, that designated by the nu- 30 meral 4 being provided with the paper felt 5 and that designated by the numeral 8 being provided with a paper carrying felt 1. The crinkled paper indicated at 8 is delivered from the creping rolls to the drier unit 4 which is driven ata certain 35 speed, the speed being controllable by a suitable variable speed drive shown conventionally at 9. The second unit 6 is provided with a variable speed control drive shown conventionally at I0.

The paper is passed from the creping machine 40 directly to the unit 4 which has its individual felt 5. It is passed from the unit 4 to the unit 8 which has its individual felt 1. The unit 4 does not suiciently heat or dry the paper to result in i any substantial shrinkage but as it passes to the '45 unit 6 the-paper is subjected to a complete drying which results in shrinkage. However, in view t of the paper having been previously creped and being fed through the driers without substantial Dull or tension thereon, the shrinkage is com- 50 pensated for or taken up by the crinkles of the creping step, with the result that by suitably controlling the relativev speeds and supporting the paper during the drying the crinkles of the creping step are substantially eliminated, andthis without subjecting the bers to stresses which tend to weaken the sheet or web. I1 desired the dried sheet may be subjected to a calender stack as indicated at Il from which it is passed to the winding roll l2.

In Fig. 2 I show a web of paper illustrating the various steps performed thereon, the acid bath step being indicated at, I3, the washing at I4, the crinkling at l5 and the dryingat |6. I have attempted toy illustrate at I6 the gradual elimination of the crinkles by the drying step. 'I'he i'ln' ished paper indicated at I1 is substantially without crinkles resulting from the creping step, although it will be understood that the method may be carried out to such degree asdesired.`v

My parchmentized paper has much greater strength, both wet and dryl tests, than paper of`v the same weight and stock manufactured by corn-4 monly practiced methods of making parchment-.lf

ized paper or any method with which I am familyiar. This increased strength, vparticularly 4the bursting strength, iseas'ily 'demonstrated under Mullen tests, vboth dry tests and wet tests.

While I prefer to' use kraft paper, any suitable grade I of bleached or 1unbleached or partially bleached stock suitable for parchmentizing may be used. The paper may be: manufactured and parchmentized in the usual Way, or any preferred way, and is then subjected to the steps which result in the advantage of greatly increased strength as I have set forth.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

1. The method of making substantially smooth parchmentized kraft paper comprising the steps of subjecting a formed sheet or webof kraft paper to a parchmentizing solution, washing, creping the paper while wet, and drying while supported so as to permit shrinkage thereof and the absorption of the shrinkage by the crinkles produced by the creping step and their substantial kelimination by such shrinkage.

2. The methodl of producing a substantially smooth parchmentized paper comprising subjecting a form, sheet or web of paper to the steps of parchmentizing, creping, and drying while supported so as to permit shrinkage thereof and the absorption of the shrinkage by the crinkles pro-r i duced by the crepi'ng step and their substantial elimination by such shrinkage, the paper having a Mullen test bursting strength substantially higher than parchmentized paper not subjected to such crinkle eliminating, drying and shrinking steps.

RALPH A. HAYWARD.

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