US2400871A - Process for forming separable bar of detergent and resulting product - Google Patents

Description

J. W. BODMAN EI'AL May 28, 1946 PROCESS FOR FORMING SEPARABLE BAR OF DETERGENT AND RESULTING PRODUCT Filed Feb. 10, 1943 2 Sheets-Sheet 1 FIG. 3.

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ATTORNEYS Patented May 28, 1946 UNITED STATES PROCESS FOR FORMING SEPARABLE BAR OF DETERGENT'AND RESULTING PRODUCT John W. Bodman, Winchester, and Fred Forrest Pease, Squantum, Mass, assignors to Lever Brothers Company, a corporation of Maine Application February 10, 1943, Serial No. 475,432

11 Claims.

This invention relates to the forming of a weakened or cleavage zone or plane in a detergent mass such as soap, to facilitate the subdivision of the mass into a plurality of smaller units. More particularly, the invention is concerned with a cake of such a detergent having a weakened or cleavage zone or plane permitting the cake to be broken at such zone or plane with relative ease and without the formation of unsightly rough surfaces in the break.

It is known that framed soaps for household use, for example, have been customarily molded and sold in relatively large cakes and are often cut or broken into more convenient sizes when used. Thesame method may be used, although it is less commonly applied, in the case of other soaps such as milled soaps. In order to facilitate this sub-dividing of the cake it has been a common practice to s re or notch the cake during molding to ma'ii timmmd be broken and to facilitate the subdividing to a small extent. This practice has proven unsatisfactory for several reasons. The resulting fracture usually fails to follow the score marks and results in an uneven break so that the resulting subdivided cakes are irregular in size and shape. Also the broken portions of the bar have unattractive rough fractured surfaces which collect dirt and which are harsh to the touch. In many instances, particularly where soaps have become dry and hardened with age or are initially hard due to the method by which they are formed, the cakes cannot be broken into two parts by the user, at least without considerable effort, even though the cake has been notched or scored to indicate the place where it is to be broken.

In our copending application Serial No. 348,008, filed July 27, 1940 (which matured as Patent No. 2,310,931 on February 16, 1943), and of which this application is a continuation-in-part, we have described a process in which a detergent mass, such as soap, may be treated along a plane or zone passing through it such that a weakened zone or cleavage plane is formed permitting a clean even break and one which is effected with relative ease. This is accomplished by movement of the said mass relative to a treating surface and it is thought that this apparently acts to modify the crystalline fibers or other texture of the mass in such a manner as to cause a zone of weakness or cleavage in the detergent.

In accordance with the invention described in this application a weakened or cleavage zone or plane may be accomplished at least in part by the introduction into said zone of a material which is dissimilar to the detergent and which interferes with the cohesion of the detergent at the spaces occupied by said material so as to permit ready cleavage in the zone or plane in which said material is introduced.

The material introduced to form the weakened or cleavage zone will be referred to hereinafter as a dissimilar material and will be described more fully later.

The invention will be described as applied to soap, but it may be applied to other detergents as defined hereinafter.

The dissimilar material may be continuously or discontinuously spaced in the cleavage zone or plane in the soap cake, and the character of the dissimilar material may be varied depending upon the manner of introduction and the ease of cleavage desired. If the dissimilar material extends continuously throughout the zone or plane, it should be of such a character as to permit a partial bonding, fusing or uniting of the soap to such an extent that the cake may be handled in the usual manner without separation in the zone or plane; but the soap should cohere less firmly in the zone or plane because of the presence of the dissimilar material so that upon the application of the breaking force, the soap mass will be severed in the cleavage zone or plane. Alternatively the dissimilar material may act as a mild adhesive which unites the partially or completely separated soap masses at the cleavage plane or zone.

If, on the other hand, the dissimilar material is discontinuous in the cleavage zone or plane,

it may permit the soap to be partially united as described above, or it may go so far as to prevent any uniting of the soap in the discontinuous areas occupied by the dissimilar material. In this latter instance the soap will be secured as a single cake by reason only of the cohering of the soap in the discontinuous portions of the cake not occupied by the dissimilar material. In the case of certain dissimilar materials, which may evaporate or otherwise leave the cake, the weakened zone may be caused by the mere lack of cohesion at the designated areas.

Our invention may be practiced with respect to a soap or other detergent mass in such a manner that a partitioning plane or weakening zone in no way detracts from the appearance of the cake.

The invention may be understood in connection with the following description and thedrawings forming a part of this specification, and in which:

Figure 1 is a perspective of one form of a portion of an apparatus for carrying out the invention;

Figure 2 is a diagrammatic indication including a cross section of the apparatus showing the flow of a detergent mass therethrough;

Figure 3 is a cross section taken on line 33 of Figure 1;

Figure 4 is a perspective view of a bar issuing 0 from the apparatus illustrated in Figure 1 and showing the weakened or cleavage zone or plane and lines at which the bar is cut into soap cakes;

Figna 5 is a perspective view of a cake of soap having its display face upwards and made in accordance with the invention and susceptible for partitioning in accordance with the invention;

Figure 6 is a vertical elevation partially in cross section, illustrating another apparatus for applying the weakened or cleavage zone in a bar of 1 Figure '7 is a section taken on line 1-1 of Figure 6; and

Figure 8 is a view in perspective of another form of the apparatus for practicing the invention.

The mass of soap or detergent to be treated may be discharged directly into a conduit I illustrated in Fig. l. The conduit may be of any cross section, but it is usually related to the size of the cake of soap to be formed. In the embodiment of the invention illustrated in Figs. 1 to 5, the shape and size of the conduit I0 corresponds to the display face a of the soap cake as shown in Figs. 4 and 5. In the conduit III is positioned a. vane II which temporarily divides the stream of soap as it passes through the conduit III. The vane II is illustrated as of a streamlined type to turbulence in the flowing soap. The vane I I is provided with a number 01 small orifices 12 located on one or both sides thereof, through which orifices the dissimilar material referred to heretofore may be ejected. This may be accomplished by means of pipe I3 and I4 and suitably controlled valves I5 and I6 together with pumps or other apparatus for controlling the pressure, rate of flow, and the amount of the dissimilar material ejected. After the soap mass passes the vane II it reforms into a single stream as illustrated by the arrows in Fig. 2.

If the orifices I2 are so positioned as to impart a continuous film or layer of the dissimilar material upon one or both sides of the divided soap stream, the soap will be rebonded with the layer of dissimilar material in between. In this instance the dissimilar material may act as an adhesive uniting the two halves of the soap stream, or as an ingredient for minimizing the natural cohesion of the soap upon reuniting.

If the openings I2 in the vane are spaced further apart in a vertical direction, the dissimilar material may be applied as a plurality of lines or stripes, so that the dissimilar material is discontinuous over the area of the cleavage zone or plane. The portions of the opposed faces of the divided soap stream to which the dissimilar material is not applied will rebond or coalesce. However, the crystalline fiber or texture of the soap in these portions, as well as in all portions in the zone to the same or to a lesser extent, may be arranged also in the manner described in our copending application referred to heretofore.

After the soap passes the vane II and exits from the conduit Ill it may be further formed, molded, shaped or otherwise treated. The soap, however, preferably should be further treated so that there is a minimum of disturbance to the cleavage zone or plane. After solidification, the soap bar will have a plane or zone as indicated at H in Fig. 4 in which there exists a weakened structure relative to the general mass of the soap bar, and coinciding with the plane along which the soap mass was divided by the vane II. The bar may be out along lines I8 of Fig. 4 to form a plurality of cakes of the desired thickness, as hown in Fig. 5. The weakened zone in the cake as illustrated in Fig. 5 permits the partitioning of the cake with relative ease and with a clean smooth break. The vane 11 should be positioned in the conduit ID in such a way as to be effective to form the partitioned plane in the desired position in the final product. This position of the vane would of course depend upon the number and manner of units into which the finished cake is to be separated.

The vane I I need not extend through the entire mass under treatment, such as shown in Figs. 1 and 3, but may extend in from the outer surfaces of the conduit I0, and may be supported in the middle of the stream so that the weakening plane does not extend out to the edges of the bar. Also, the vane may be adjusted and shaped suitably for different thicknesses of the stream and different positions within the stream. These variations in the position and form of vane are dependent in part upon the extent or type of partitioning or weakening that is desired in the final product and to permit suitable adjustment for the characteristics of the stream, such as, for example, viscosity or plasticity of the soap, the rate of flow, temperature, composition and other factors. If desired, more than one vane may be used, for example, a series of vanes may be positioned one after the other in the stream. Also, two or more vanes may be positioned across the stream so as to form in the soap under treatment two or more weakening or partitioning planes.

In the embodiment illustrated in Figs. 1 to 5 the cross sectional shape of the conduit I0 corresponds to the size of the display face a of the soap cake. Alternatively, the shape of the conduit It] may correspond with the side of the soap cake as illustrated at b in Figs. 4 and 5. The vane would be similarly positioned in the conduit, but the continuous bar would be cut at distances corresponding to the width of the soap cake rather than its thickness.

When the soap cake is formed in a conduit or ejected from a forming apparatus so that the continuously moving soap bar has a cross section corresponding to the end of the soap cake, as shown at c of Figs. 4 and 5, the weakened zone cannot be accomplished by means of a vane as described heretofore if the zone is to be positioned as described. A method in which the partitioning plane or zone may be incorporated into soap of this type is illustrated in Figs. 6 to 8.

Referring more particularly to Fig. 6 a conventional soap plodder or mixing or agitating device for forming the soap is illustrated at 20 and the soap bar 2| issued therefrom continuously with a cross section corresponding to the end of the bar (face a in Fig. 5). The cleavage plane or zone may be imparted by means of a plurality of hollow needle-like members 22 which are moved into soap bar, and while so positioned in the soap, the dissimilar material may be ejected from orifices 23 contained in the hollow needles. An apparatus for accomplishing this is diagrammatically illustrated in Fig. 6 in which the needles are supported on a movable member 24 which is operated by a cam 25 to move the needles synchronously with the continuous movement of the soap bar while the needles are being inserted and withdrawn. The needles are lowered by means of an eccentric crank 26 which forces the dissimilar material through openings 21 in the upper end of the hollow needles. The material not entering the needles may be absorbed in an expansion chamber 28 so as to have substantially constant force applied to eject the dissimilar material through the openings 23. The dissimilar material may be delivered from a supply tank 29 through a conduit 30 and a check valve 3|. The soap as it moves forward is positioned on a conveyor 32 which supports the cakes that are obtained by cutting the bar at the lines 34. The partition zones are indicated at 33.

In the embodiment shown in Figs. 6 and '7, the soap ejected from the plodder or mixer is shape retaining at the time the dissimilar material is ejected into the cleavage zone or plane, and any holes remaining after the removal of the needles may be finally eliminated when the soap is pressed in a conventional soap press.

Fig. 8 shows an additional embodiment in which the partition zone may be applied to a mass of soap exiting through a conduit 40 having a shape corresponding to the end of the bar or cake as shown at c in Fig. 5. A hollow blade-like member 4| may be lowered by means of crank 42 and pressed through a slot 43 in the conduit 40. As the blade is pressed into the soap mass or while in the depressed position, the dissimilar material may be ejected from the openings 44. The dissimilar material may be applied through a flexible hose 45, and a valve 46 may be operated by hand or automatically for controlling the time and the amount of the dissimilar material to be ejected.

Ordinarily the mass to be treated should be in a heated, plastic or semi-fluid condition, that is, it should be at a sufficiently high temperature so that under the pressure conditions prevailing at the time, it will be a reunited, rebonded or coalesced mass to the extent that this is permitted by the introduction of the dissimilar material and any orientation of crystalline or fibrous texture of the soap.

The mass, of course, may be in an aerated condition and the final bar formed may have a specific gravity of less than 1 and so will float in water.

The strength of the rebonding in the zone is controllable not only by the amount and nature of the dissimilar material, and the areas in the zone to which it is applied, but also by means of the condition of the soap at the time the zone is formed. If the material is in a heated, plastic or semi-fluid condition, a relatively strong bond will result.

For a sodium soap of a fat composition of about 80 parts tallow and 20 parts coconut oil and about 15 to 20% moisture, a suitable temperature range by way of example would be between 150 or 160 F. to 190 F. although higher as well as lower temperatures may be used. As to an upper temperature limit, the soap should not be at a temperature where the partition zone or the dissimilar material will be lost or disturbed because of excessive fluidity, turbulent flow or for other reasons. Temperatures as low as 120 F. may be used providing other conditions such as increased pressure are present for a satisfactory uniting of the soap material. A soap of soft fat composition or high moisture content could ordinarily be processed at a lower temperature than a soap having a characterizing hard fat composition or relatively low moisture content.

The temperatures of the surface of the soap mass at the itme of treatment are more critical than the temperature of the entire mass of soap. In view of this the dividing vane, or needles or -blade may be heated in any convenient manner so as to put the adjacent soap mass in a suitable condition for treatment. The dissimilar material may be introduced in the form of a heated vapor or steam may be introduced with it for the purpose of heating the surfaces if the mass of soap is not of a sufllciently high temperature to cause adequate bonding. The dissimilar material may be a heated liquid and may be continuously circulated for the purpose of maintaining it at the desired temperature.

The soap mass under treatment need not be a divided stream but may comprise two separate streams and either one or both of the surfaces to be bonded may be treated with a suitable dissimilar material prior to or substantially at the point of bonding. The separate soap streams or their critical surfaces would be put or maintained in a condition for bonding as already described.

The dissimilar material is not critical and the invention is not limited to the selection of any particular material for this purpose, except, as explained heretofore, that the selected material is dissimilar to the detergent or the soap of which the cake is formed and that the selected material also has the effect of weakenin the cake in the partition plane. A wide variety of materials may be used, for example, any salt solution, suitable gases, mineral or vegetable oils, acids, such as acetic or sulfuric acid, fatty acids, alcohols, glycerine, alone or in admixture with salt solutions and acids. Substantially any material which is dissimilar to the soap or other detergent may be used, particularly those which are not volatile soap solvents, which decreases the cohesion of the soap material. A selection of the material will depend upon the type of detergent mass treated, conditions 01' the soap as to temperature, pressure, and the amount and position of the dissimilar material el'ected into the zone, etc.

If desired, a further weakening of the partition zone may be accomplished by cutting the edges of the cake at the cleavage zone by means of thin knives. After this the cake may be pressed, molded, or stamped in such a way as to render invisible the narrow supplementary slits.

We have described our invention primarily in connection with soap, but it is applicable to other detergent substances that may be placed in cake form. The detergent compositions may include, for example, the animal or vegetable fatty acid soaps as described heretofore and the so-called non-soap detergents such as the Igepon, Gardinol and Nacconal types derived "from vegetable and mineral sources or admixtures of the non-soap detergents and soap as well as other non-soap detergents having similar characteristics. Various compositions or blends of soaps and detergents may be used including potassium as well as sodium soaps in admixture with soaps derived from organic bases and mixtures of any of these with the non-soap detergent type dependent upon the characteristics desired in the final product and the factors involved in costs and manufacturing conditions. Aerated as well as non-aerated soaps may be utilized as well as soap of the so-called framed and milled types and other types of soaps made by agitating soap or other detergent of any moisture content at any temperature at which it is in a condition for treatment as described.

It will be appreciated that our invention is capable of many variations and specific modes of application depending upon the established manufacturing techniques and it is intended that all of the same are to be included as falling within the following claims.

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We claim:

1. A method of treating a detergent selected from e group consisting of soap and non-soap t e detergents to facilitate partitioning thereof, which comprises dividing at least a portion of a mass of said detergent along a plane thereof while in a heated plastic to semi-fluid condition, contacting only-a portion of at least one of the divided surfaces with a material dissimilar to the detergent being treated and capable of reducing the natural cohesion of the detergent mass, and reuniting said surfaces of said separated portions, and forming the mass into cakes containing said reunited surfaces.

2. A method of treating soap to facilitate partitioning thereof, which comprises dividing at least a portion of a mass of soap along a plane thereof while in a heated plastic to semi-fluid condition, applying to only a portion of the divided surfaces a material dissimilar to the soap being treated and capable of reducing the natural cohesion of the soap, reuniting the separated portions, and hardening the soap.

3. A method of treating a detergent selected from the group consisting of soap and non-soap type detergents, which comprises introducing into a mass of the detergent in discontinuous areas along a predetermined plane therein a material dissimilar to the detergent being treated to reduce the cohesion of the detergent in said plane, whereby a bar or cake of the detergent made from the soap so treated may be partitioned along said plane.

4. A method of treating soap, which comprises introducing into a mass of soap in discontinuous areas along a predetermined plane therein a material dissimilar to the soap being treated and capable of reducing the cohesion of the soap, whereby a cake or bar of soap made from the soap so treated may be more readily partitioned.

along said plane.

'5. A method of treating a detergent selected from the group consisting of soap and non-soap type detergents to facilitate subsequent separation thereof in a solid state, comprising providing a continuous flow of a mass of the detergent in a deformable condition, obstructing the flow along a predetermined plane in the detergent mass to cause division of at least a portion of the flow into separate streams, and injecting an agent over at least one of the divided surfaces of the separated streams capable of reducing the natural cohesion of the detergent mass, reuniting the said streams with a minimum of turbulency, and hardening the detergent.

6. A method of treating soap to facilitate subsequent separation thereof in a solid state, comprising providing a continuous flow of a mass of soap in a plastic to semi-fluid condition, frictionally obstructing the flow along a predetermined plane in the soap mass to cause division of at least a portion of the flow into separate streams. subjecting the surfaces of said stream to frictional contact and injecting a material dissimilar to the soap being treated and capable of reducing the natural cohesion of the soap mass over at least a portion of the surface of at least one of the separated streams, reuniting the said stream with a minimum of turbulency, and hardening the soap.

7. A method of treating a detergent selected from the group consisting of soap and non-soap type detergents to facilitate partitioning thereof, which comprises providing a moving stream of said detergent in a heated plastic to semi-fluid condition, causing the detergent to flow past an immovable member for dividing said mass, applying to at least one of the divided surfaces a material dissimilar to the detergent being treated, reuniting the divided surfaces to form a bar having a partition zone therein, and forming the bar into cakes.

8. A method of treating soap to facilitate partitioning thereof which comprises providing a moving stream of soap in a heated plastic to semi-fluid condition, causing the soap to flow past a perforated immovable member for dividing said soap, forcing a dissimilar material through said perforation to contact at least one of the divided surfaces, reuniting the divided surfaces to form a bar having said material in a planar zone therein, and forming the bar into cakes.

9. A method of treating soap to facilitate partitioning thereof which comprises dividing a moving stream of said soap in a heated plastic to semi-fluid condition and causing the opposed surfaces to flow past a perforated immovable member, applying a dissimilar material through said perforations to contact both of the divided surfaces, reuniting the divided surfaces to form a bar having a planar partition zone therein, formill ing the bar into cakes, placing notches or cuts in the cakes at a point corresponding to the partition zone, and subsequently pressing the cakes to close the cuts and render them substantially invisible.

10. A bar of detergent selected from the group consisting of soap and non-soap type of detergents having distributed discontinuously in a planar zone in said bar a material dissimilar to the detergent and capable of reducing the natural cohesion of the detergent, whereby said bar may be readily partitioned in a plane in said zone.

11. A cake of soap having distributed discontinuously substantially throughout a planar zone in said cake a material dissimilar to soap and capable of reducing the natural cohesion of the soap, whereby said cake may be readily partitioned in a plane in said zone.

JOHN W. BODMAN. FRED FORREST PEASE.

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