Art of testing softness of paper products

March 26, 1957

J. T. SOBOTA

2,786,352

ART OF TESTING SOFTNESS OF PAPER PRODUCTS

Filed Nov. 18, 1953

<img file="US2786352A_D0001.tif" />

MZTOANEVS.

2,786,352

Patented Mar. 26, 1957

United States Patent Office

2,786,352

ART OF TESTING SOFTNESS OF PAPER PRODUCTS

John T. Sobota, Green Bay, Wis., assignor to Fort Howard Paper Company, Green Bay, Wis., a corporation of Wisconsin

Application November 18, 1953, Serial No. 392,948

Claims. (Cl. 73—159)

This invention relates to improvements in the art of testing the softness of paper products.

In certain types of paper products such as paper napkins, facial tissue and toilet paper, the feel, texture or softness of the paper is an important property. In the textile industry a similar property is referred to as the “hand” of a fabric. Heretofore the paper industry has had no satisfactory way of testing or measuring this property of paper.

It is a general object of the present invention to provide a method whereby the softness of paper products may be quickly determined and measured so that comparisons of various papers may be quickly made.

A more specific object of the invention is to provide a method of testing the softness of paper products which includes a determination of the force required to urge a sheet of paper through a circular opening.

A further, more specific object of the invention is to provide a method as above described wherein a sphere of somewhat less diameter than the diameter of the hole in a support is employed, and wherein the amount of force required to cause the sphere to drive the sheet a predetermined distance into the hole is determined in order to provide a measure of softness.

A further object of the invention is to provide improved apparatus for effecting commercial exploitation of the above described method.

With the above, and other objects in view, the invention consists of the improvements in the art of testing the softness of paper products, and all of its steps, parts and combinations, as set forth in the claims; and all equivalents thereof.

In the accompanying drawings, illustrating an embodiment of apparatus for carrying out the improved method, Fig. 1 is a perspective view of an apertured support for carrying out the test; Fig. 2 is a perspective view of said support showing a weighted sphere as it starts to drive a sheet of paper through the hole in the support; Fig. 3 is a view similar to Fig. 2, showing the parts as the paper has been driven a substantial distance through the hole; and Fig. 4 is a perspective view of a rack containing a set of testing spheres of progressively increasing weight.

Referring more particularly to the drawings, the numeral 10 designates a suitable stand, having a base 11, and having a supporting shelf 12 supported in vertically spaced position above the base, the shelf having a circular hole 13 extending therethrough, which hole is preferably located centrally of the shelf. For use with the stand a suitable rack 14 containing a series of progressively weighted members 15, may be provided. It is preferred to utilize plastic spheres, such as those used in a ping pong game, with each sphere having a predetermined weight therein. In the rack shown in Fig. 4, the spheres are weighted from 7½ grams to 45 grams in increments of 2½ or 5 grams.

It is preferred, in testing paper napkins, facial tissue, toilet paper, or the like, to have the hole 13 two inches in diameter and to have the spheres one and one-half inches in diameter. In any event the weight or sphere must be of somewhat less diameter than that of the hole 13, to leave ample room around the sphere for the crumpled paper to be pulled through.

The method of testing which is used in conjunction with the apparatus of Figs. 1 to 4, inclusive, consists in placing a flat sheet 16 of the paper to be tested on the shelf 12, with the hole 13 reasonably well centered below the sheet. For accurate tests it is preferred to use a sheet 4¹/4 square placed symmetrically over the hole 13. Next the spheres are placed carefully on the center of the sheet over the hole, and one after another of the spheres of Fig. 4 is tried in order until a sphere drives the sheet through the hole 13 in substantially the manner as shown in Fig. 3. A recording is then made of the weight of the sphere which is required to accomplish this result. In using the spheres one of the lighter ones is used at first and then progressively heavier spheres.

In testing commercial toilet paper it is found that there will be a variance between a 10 gram test result for facial quality toilet paper, and a 60 gram test result for a relatively cheap and hard sheet.

The testing apparatus shown in Figs. 1 to 4 may be advantageously carried by paper salesmen and used in the field to demonstrate the softness of their various products or make comparisons between various papers.

From the above it is apparent that the softness of the paper is determined by the force which is required to cause a weight, preferably in the form of a sphere, to drive a sheet of paper through a circular hole which is somewhat larger than the sphere. While only one type of apparatus has been illustrated for carrying out the improved method it is obvious that other devices may be employed to accomplish the same purpose.

Various other changes and modifications may be employed without departing from the spirit of the invention, and all of such changes are contemplated as may come within the scope of the claims.