GB2108144A - Soap - Google Patents

Abstract

A process of eliminating both surface stress cracks and wet surface cracks in soap bars and cakes comprising the steps of rotating extruded plodder banks through ninety degrees about their longitudinal axis, then introducing the rotated blanks into the soap press to produce soap bars and cakes.

Description

SPECIFICATION Soap The present invention relates to the art of soap making, and more particularly to a process for elimination of objectionable cracking in soap.

New test methods for evaluating soap bar and cake wet cracking problems are disclosed in United States Patent No. 4,147,053. Based on the application of these new tests and the observations of the results, it has been discovered that toilet soap bars made by the single extrusion process showed a somewhat laminar or parallel crack pattern in the cross sectional test described therein. These bars, in general, did not develop severe wet surface cracks when subjected to wash room usage tests. Contrastingly, bars made by the dual extrusion process have a generally non-parallel crack pattern with radial spurs radiating always preferentially to one side and across the short axis of the bars. These bars, when field tested, would consistently develop severe wet surface cracks always significantly more on one side than the other.The problem existing in the prior art dual extrusion wet surface cracking was to devise a means for imparting a laminar or parallel crack pattern to the finished bars.

Further, in the past, high moisture containing soap bars have been produced by plodding of the soap mass through a cone nozzle with two extrusion ports so that two streams of plodder blanks can be fed into a duplo-press for sustaining higher line speed and efficiency.

However, changes in formula and bar shape generally result in unusual and excessive surface cracks on the face of the bars with one side more pronounced that the other. This problem is directly related to the dual extrusion soap plodding process and the conventional method of pressing the soap blanks on the internal cut face and external face.

By means of a series of plodder blank shape and pressing experiments, it has been discovered that by pressing square or semi-square plodder blanks, which were intentionally re-oriented or rotated by ninety degrees about their longitudinal axis, the bar surface cracks disappeared.

Semi-square means of essentially square cross section but having rounded corners and slightly curved sides.

Subsequently, these bars were subjected to the cross sectional wet cracking test according to United States Patent No. 4,147,053. The results showed the desirable formation of a laminar or parallel cracking pattern. In wash room tests, prior toilet soap bars with this type of cracking pattern have consistently exhibited no tendency to develop objectionable wet surface cracks.

Accordingly, the present invention comprises the steps of extruding plodder blanks and then rotating these blanks about their longitudinal axis to obtain the unexpected formation of a laminar pattern and eliminate both stress surface cracks and wet surface cracking when the soap is introduced in its rotated state into the soap press.

The present invention allows for formation by dual extrusion of pairs of soap plodder blanks for every formula of soap now in production while forming in the finished soap bars a laminar or parallel pattern of a sound soap bar or cake thereby eliminating stress surface cracks and objectionable wet cracking. This permits dual extrusion to be used in all soap production thereby speeding up production while reducing cost and obtaining a better product.

The soap mass is extruded through a dual extrusion head on the nozzle cone of a plodder forming dual extruded plodder blanks. Obviously, the process according to the invention is adaptable when necessary to singly extruded plodder soap blanks of special or changed formula.

The plodder blanks are rotated through ninety degress about their longitudinal axis so as to stand on edge before insertion into a conventional soap press.

Unexpectedly, the rotation step and subsequent pressing operation impart a laminar or parallel crack pattern to the soap bar or cake thereby eliminating stress surface cracks and wet surface cracking in soap bars.

The soap bars are pressed in the conventional dual soap presses under conventional conditions of temperature and pressure.

The wet cracking or wash room tests referred to above are carried out as follows.

An extruded toilet soap bar has approximately three-sixteenths of an inch shaved off the obverse (head) and reverse (tail) of the bar. Variations plus or minus approximately one-sixteenth of an inch are within allowed limits. Then, a hole is drilled in the soap bar approximately one-sixteenth or oneeighteenth of an inch in diameter approximately one-quarter to one-half inch of any end of the bar.

Then the soap bar is suspended on a rod which is positioned through the hole. The soap bar is then immersed in a water bath at 750F for one-half hour.

Upon completion of the desired one-half hour water bath, the bar is removed and then allowed to hang and air dry at least 24 hours. After the bar has dried, the cracking performance of the head and tail sides of each bar is rated on a scale of O to 5 and the wet crack test results are recorded by making a photostatic copy by placing the shaved side of the bar on a photocopier, such as a Minolta 101 flat bed copier or similar apparatus.

Another test for the soap bar is to cut or shave one-half to one inch off the end of the bar to provide a shaved end which is preferably drilled to allow a rod to be inserted therein to suspend the soap bar in a water bath for approximately one hour at 750F. Then, the soap bar is air dried for 24 hours and the bar's unique cross-sectional crack results. The end face is placed on a flat bed photocopier and the graphical representation similar to the cross-sectional grain pattern of a tree trunk is graphically reproduced.

Claims (5)

Claims

1. A process for producing soap bars comprising the steps of extruding soap from a plodder as at least one extruded blank, rotating the said blank through ninety degrees about its longitudinal axis, and then pressing the said blank in its rotated position to form bars of soap.

2. A process as claimed in Claim 1 in which the said blank is extruded by dual extrusion so that two streams of blanks are formed.

3. A process for producing soap cakes comprising the steps of extruding two plodder soap blanks, rotating the said blanks through ninety degrees about their longitudinal axis, and then pressing the said blanks to form soap cakes.

4. A process for eliminating wet surface cracks and surface stress cracks in soap bars and cakes comprising the steps of extruding a plodder blank of selected cross sectional configuration, then rotating the said blank through ninety degrees about its longitudinal axis so that it stands on edge, then pressing the said blank in a press under pressure to form the said blank into a soap bar or cake.

5. A process for elimination of both surface stress cracks and wet surface cracks in dual extruded soap comprising the steps of dual extrusion of a pair of plodder blanks each of predetermined cross sectional shape rotating eachof the said blanks through ninety degrees about its longitudinal axis, and introducing the said plodder blanks on their edges into a dual press to form soap bars and cakes having laminar pattern.