US2494891A - Process and apparatus for making floating soap - Google Patents

Description

Jan. 17, 1950 D. E. MARSHALL 2,494,891

PROCESS AND APPARATUS FOR MAKING FLQATING SOAP Filed May 2, 1945 2 Sheets-Sheet l INVENTOR v z, 772M ATTORNEY Jan. 17, 1950 MARSHALL 2,494,891

PROCESS AND APPARATUS FOR MAKING FLOATING SOAP Filed May 2, 1945 2 Sheets-Sheet 2 Hm- 1 A llmnl. x2; 1

| 1 M III I i N w g v n m m i "r M m a w I an N 1 N l QUORNEY Patented Jan. 17, 1950 PROCESS AND APPARATUS FOR MAKING FLOATING SOAP Donald E. Marshall, Summit, N. J., assignor to Colgate-Palmolive-Peet Company, a corporation of Delaware Application May 2, 1945, Serial No. 591,553

14 Claims. 1

This invention relates to an important improvement in soap manufacture. With this invention floating toilet soap is produced that has texture and plastic characteristics that have been present heretofore only in fine hard-milled soaps.

Soap finishing processes can be compared to I candy making to explain the importance of crystal formation. A hard-milled soap is like a smooth creamy fudge. Hot framed floating soaps, or, to a somewhat lesser extent, the new forms of hot mixed and quick-cooled low moisture float- ,ing soaps are like a sugary fudge. In both known in the trade as hard-milled soap, and

scientifically as Beta phase crystal structure.

- When a plasticized, milled textured soap mass is overheated, it reverts to a, hard crystal structure and loses much that has been gained by milling.

,The conventional-way of incorporating air in low-moisture, floating soaps is by working air into the soap while it is heated above a point where it is fluid enough to beat and then, in some instances, quickly cooling while it is still being mixed. This does not produce the desired results of good water-cooled milling of the present invention, but yields a different soap structure which is not like the present moldable plastic milled soap which, because of its crystalline structure, cannot be stamped into toilet soap tablet shapes.

With the present invention smooth, plastic textured ribbons are taken from the conventional milling process and are passed through a special multi-barreled, water-cooled plodder in such a manner that finely divided bubbles of air are incorporated in the soap without working or beating the soap mass materially. In this way the crystalline structure that would result from overheating is avoided.

In carrying out this invention a milled soap mass is plodded and extruded into very fine threads of, say about 0.030" diameter without I materially elevating its temperature, and a measured, though very small amount of air is introduced within this finely Shredded soap mass. Then while the soap is kept under regulated air pressure, the shredded soap mass is compacted progressively so as to become hard Without allowing the escape of the occluded air.

The stages of successive shredding, aerating and compacting are repeated one or more times to provide uniformity. Then the aerated mass of soap is extruded through a nozzle and a sizing plate to obtain the cross-section that is desired for the out bar, preliminary to stamping.

In carrying out the process, the soap is repeatedly shredded, aerated and compacted under moderate air pressure, and the air is not allowed to escape at any step, until the air is uniformly dispersed and locked into the milled soap mass, without materially elevating the temperature of the soap. Overheating is avoided by the minimized working of the soap mass and by utilizing water-cooling to dissipate the heat of friction along the plodder barrel and worm.

It is well known in this art that the process of de-aeration consists of reducing a liquid cream or plastic material to be de-aerated to a finely divided form and then subjecting the finely divided material to a vacuum.

With the present invention air is occluded in soap by adapting this procedure of first reducing the plastic soap mass to threads, and then injecting air into the threads and slowly compacting the same under air pressure.

In carrying out the present invention for manufacturing milled floating soap, conventional :practices are used for processing the soap up to the plodder stage. With such processes kettle soap is passed over chilling rolls to congeal and deliver the soap in ribbons onto a screen conveyor of a drying oven where moisture is removed under moderate heat and ventilation, so that the flakes are dried as uniformly as possible to a moisture content of approximately 10-18%, depending on the quality of the finished bar desired. The dried flakes are then mixed with the desired perfume and preservatives and milled to an extensive de- 7 gre'e and at reduced temperatures.

The extensive. milling to which I refer is obtained by passing the flake mixture through two sets of Lehman #916 5-roll steel mills in tandem, set closely and so as to get good coverage and yet deliver only 3,000#-3,300 pounds per hour of milled ribbons. Also, I prefer to keep the cooling water so that the ribbons are maintained at room temperaturesapproximately F. All of this is conventional practice where high quality fine textured hard-milled toilet soap is manufactured, but particular emphasis is placed on the temperatures necessary to get the micro-crystalline amorphous texture desired.

These milled ribbons are then fed to an aerating plodder, in accordance with this invention in which Fig. 1 is a longitudinal view partly in section through an illustrated embodiment of the invention, parts being shown diagrammatically;

Fig. 2 is a broken-away section of Fig. 1 shown on a larger scale;

Fig. 3 is a section along the line3-3 or Fig.2?

Fig. 4 is a section on a large scale along. the line 4-4 of Fig. 3.

In the drawings, reference .ch'aractenl indicates a screw that is revolubly located in the barrel 2 of a plodding machine that is provided with a feed opening 3. A cooling jacket 4 surrounds the barrel 2 and fins 5 are provided in this jacket:'

A drive shaft 6 is attached to the worm I and a pulley 1 is provided on the shaft. A compressed air supply 9 is provided withair-lines |0,"a'calibrated orifice ill, a-manometer ll, gauges l2 and valves l3 and suppli'escompressedair in regulatedamounts as indicated.

A longitudinal central opening H isprovided in=the-worm i and an inlettub'e 'for the compressedair with a proper gland is connected to theouter'end. Acomminuting head 16 (Fig; 3) is connected by pins 11 "(Fig. 2) so as to revolve with the worm I. Radial channels I! are provided -in the head- [Wand communicate with axially-extending branches'lfii These channels als'o communicate with the central opening M through portsd 4 1' The channels lfl extend inside of: the comminuting blades-20 and 2| of the" head 16.

A'foraminous plate ZZKFi'g; 2)- with numerous small. holes 23 theret-hroughi is anchored by clamping rings 24 which holditin close proximity to the'headlt. A thick pressure plate which serves as abackingfor the-plate 22 is provi'ded. It is anchored in-contact with this plate'.- Conicall'yeshaped :openings 25 extend transversely through the pressureIplate ZS; Cutter blades 21 which are attached soas to revolve with the-"- screw"! are'inconta'ctnwith the outerside of the pressureplate 25. A -studscrewz281and spring 29 areprovided tokeepathe blades 21. resiliently in place.

Thepassageway provided-"by ansairtight removable-closure-30a extends from the exit: end of the first plodder to azsecond-stage plodder that is like it. Corresponding parts of this plodderz-are referred to by the' same reference characters with primes, as used above; A passageway 3| also provided by an airtight removable-closure 302a leads-from the=exit end of'thesecond stage plodder tothebarrel 32 that is. providedwitha worm. 1a.

At the outlet of .barrel 32 a convergingsection' 33 is. provided with asizingand shaping outlet 34 having an.orifice 33 that. is shapedinsuch a manner that the cross-sectionof the-soapthat is extruded therethrough has the desiredshape and size. Reference character 35 indicates aheater at the end of section 33.

Reference character 36 indicates tubes for circulating coolihgwater in contact with the fins 5, 5 and 5a to keep the soaprthat is beingtreated at the proper temperature.

The enlarged partly broken away detail, Fig. 4, shows .how the blades 20 of the comminuting wheel 16 wipe the soap and air that is introduced through channels. is through holes 23. The blades 2! scrape the plate surrounding these openings clean. This Fig. 4 also shows how the extruded threads 38 of soap are compacted gradually as they pass through the tapered holes 26 of the pressure plate 25. This figure also shows how the threads become integrated before they emerge and are cut oif as compacted pellets by the. blades 21.

Glands 40 are provided 'on the worm shafts I, i and la to prevent the escape of air.

In carrying out this process the milled soap ribbms produced'as described above are fed to the first plodder stage through opening 3 and are compacted by worm i into a solid soap mass and the pressure developed in forcing the soap through. the pressure plate 25 effectively seals the space between Worm l and barrel 2 so as to prevent-backwardescape of air that is introduced through the comminuting head l6. This head l6 works the soap mass through the foraminous plate 22,.which is provided with holes or openings 23'(Fig'. 4), assisted by the pressure developed by "theworrn I. The'blades ZO'are soinclined that the soapunass ispositively forced through the openings 23. At the same time air entering through'branches I9 is pocketed as small bubbles inthe isoap threads. The-exits of the-air orifices are oiiset so that bubbles oi air are entrained with'the flowing soap;-

The edges of the blades 2i are at right angles to the plate 22 sothat the surface of this plate is scraped'clean or obstructions as very frequent intervals. Also, air is introducedat the trailing edges of these blades 2 I- so astodistribute theair more evenlyjin' the soap mas. In" order toobtain a uniformly textured'soap; the *plate- 22 should have about 300'to400holes per'square-inch and this plate is about 18 gauge metal.

The extruded andaerated-threads leaving the holes 231pass into the 'conical openings 26 in the "pressure plate 25"where this restriction is "sumcient to compact the aerated threads into pellets. The pressure in exit chamber Mia-is suflicient to prevent de-aerationoi these pellets.

In order 'to' aeratethe soap" to the degree of fineness desired," one or more additional aerating stagesmay be utilized as indicated by barrel 2' andworm. I" whlchoperate. similarly to the precedingwone. However, in this stage the feed is already under pressure and leakage near the shaft is prevented by packed gland '40.

When the'aerated Isoap; which'is still held under..the desiredpressure, enters the final plodding stage'it' isgradually compressed by the worm la which is shaped so as to compress the soap sufiicientlyjso that .Lwhenithe mass reaches the exit 'end.it is well. compacted and is extruded as a homogenousstream which is free from cracks or striations. The. soap thenhas a structurethat retains the exceedingly fine particles of air, even though a certain amount of expan sion takes placeas the soap stream leaves. the orifice plate33.

Witlrthis' multi-stage. Dlodder the soap mass is processed withoutheating the soap materially since the soapispreferably kept at a temperature below- F. duringv the plodding .and aerating operation.

The floating, milled soap. produced by this process, possesses most of the qualities imparted by low-temperature hard-milling; it can be stamped or molded into tablet shapes, and in addition .possesses the quick solubility and white color of high quality floating soaps.

With'this inventionsoap is compacted around (Ismail air particles instead 'of air particles being beaten into the soap mass. The resulting product is an extruded uniformly aerated soap that has not been heated enough to make it sticky. Therefore it can be immediately cut and stamped after it has been produced without any need of further drying or cooling.

While this invention is particularly described in connection with making a low moisture floating soap, it is obvious that it can be used in difierent ways. For example, it may be used to produce a high moisture, say between 18% and 30% floating soap that has not been milled nor dried to milled soap water content, by extruding chilled ribbons of such soap and by omitting most or all of the drying and all of the milling operation. Also, an

aerated laundry bar formulated in the usual manner using "builders" and having a moisture content of between 18 and 42 per cent can be extruded from chilled ribbons of such soap by omitting most or all of the drying and all milling operation. In the latter case the resulting soap may not float but the aeration increases the size of the bar and produces a desirable texture.

In the case of built laundry soap the ingredients must be strained through a very fine screen before chilling so as to avoid stopping the holes in the plodder plate 22.

In some cases of formulas containing over 18% moisture it may be necessary to skin dry the extruded and cut soap before stamping.

What is claimed is:

1. In an apparatus for homogenizing, compacting and extruding a material such as soap, the combination which comprises a plodder having a barrel and a worm operating in the barrel for compacting and feeding forward a material supplied to the plodder, a comminuting head located at the end of the worm for spreading the material being fed forward by the worm, a drive for said comminuting head, a foraminous plate located behind the comminuting head and upon which the material is spread and then forced through by said comminuting head, means located at the comminuting head for injecting a compatible gas into the material as said material is spread on and forced through the foraminous plate whereby particles of the gas are incorporated in and uniformly distributed throughout th material.

2. An apparatus as defined in claim 1, including mechanical compacting and extruding means for integrating the material discharged from the foraminous plate under mechanical pressure, a sealed, pressurized chamber connecting said lastmentioned compacting means with the discharge side of the foraminous plate and means for supplying a gas to said pressurized chamber whereby the material being compacted may be maintained under pressure to prevent the escape of the gas particles incorporated in the material due to the mechanical pressures of compacting and extruding the material.

3. An apparatus for homogenizing, compacting and extruding a material such as soap, which comprises the combination of a plodder having a barrel and a worm operating in the barrel for compacting and feeding forward a material supplied to the plodder, a comminuting head including a radially extending blade located at the end of said worm for progressively spreading the material being fed forward by the worm, a drive for said comminuting head and a foraminous plate located behind the comminuting head and upon which the material is spread and forced through by the blade of the comminuting head, said blade having outlet ports connected to a supply of gas along one face thereof for' injecting a gas into the material spread on and forced through the foraminous plate whereby particles of the gas are incorporated in and distributed throughout the material.

4. An apparatus for homogenizing, compacting and extruding a material such as soap, which comprises the combination of a plodder having a barrel and a worm operating in the barrel for compacting and feeding forward a material supplied to the plodder, a comminuting head including a radially extending blade located at the end of said worm for progressively spreading the material being fed forward by the worm, a drive for said comminuting head and a foraminous plate located behind the comminuting head and upon which the material is spread and forced through by the blade of the comminuting head, said blade having outlet ports connected to a supply of gas along one face thereof for injecting a gas into the material spread on and forced through the foraminous plate whereby particles of the gas are incorporated in and distributed throughout the material, a mechanical compacting and extruding means for integrating the material discharged from the foraminous plate under mechanical pressure and a sealed chamber connecting said mechanical compacting means with the discharge side of the foraminous plate, said chamber being connected to a supply of gas under pressure for maintaining a gas pressure in said chamber to prevent escape of the particles of gas incorporated in the material under the pressures of theme-- chanical compacting.

5. An apparatus as defined in claim 4 including a cutter located on the discharge side of the foraminous plate and a drive for said cutter.

6. An apparatus for aerating and extruding a material such as soap without beating or appreciably working the mass of said material, comprising an extrusion Worm operating in a plodder barrel for initially compacting and feeding a particulated material, a comminuting head associated with said worm for moving compacted material across the openings in a foraminous plate and to spread said material and force it into said openings, a gas-introducing means for causing gasto be introduced into said openings together with said material whereby particles of the gas are enveloped by said material forming aerated shreds of the material being forced through openings in said foraminous plate, a sealed chamber for receiving the aerated material passing through said foraminous plate, means for mechanically compacting and extruding said aerated material and means for maintaining gas pressure in said sealed chamber for preventing escape of the gas cells under the mechanical pressure of compacting and extruding said material.

7. An apparatus as defined in claim 6, wherein said gas is introduced through openings in the blades of said comminuting head so as to be entrained with the materials in the openings of said foraminous plate.

8. Apparatus for aerating and compacting a material such as soap which comprises a plodder having a barrel and a worm operating in the barrel for compacting and feeding forward a material supplied to the plodder, a foraminous plate at the end of the worm, a comminuting head rotatable with said worm including alternate spreading blades and cleaning blades, each spreading blade having a forwardly inclined leading face operating to progressively spread the material being fed forward by the worm over the fcraminous :plate and force the same therethrough and having gas supply passages with outlet ports on saidzinclined leading face for injecting gas into the material spread on and forced through the foraminous plate, and said cleaning blades operating to scrape the surface of the foraminous plate clean and having gas supply passages with outlet ports on the trailing side thereof for distribution of gas in th soap mass, whereby particles of gas are incorporated in and distributed through the material.

9. A process for aerating milled soap, comprisin: the steps of continuously compacting unheated milled soap chips and progressively feeding said compacted soap chips forward, shredding and aerating thesoap by forcing the compacted soap through openings in a foraminous plate extending across the direction of flow of said soap and forcing particles of gas with th soap through said openings whereby the particles of gas are envelopcd by said soap to form aerated shreds of saidsoap, maintaining gas pressure on the gas containing soap shreds leaving said plate to retain cccludedgas, and then mechanically compacting said shreds into bars of aerated milled soap which float, said process being carried out while maintaining the soapin solidified condition.

10. Theprocess of claim 9, wherein said aerated shreds are mechanically compacted under gas pressure, said gas pressure opposing the escape of gas cells from said aerated shreds due to said mechanicalcompacting until a suflicient mass of said shreds is integrated to prevent such escape,

and then extruding the soap as uniformily aeratedmilled soap which floats.

11. The process of claim 9, wherein the temperatureof the unheated milled soap chips is kept below 80 F. during the shredding and aerating whereby the aerated soap retains the micro-crystalline state and compactness of a hard milled S039.

12. The process for continuously producing an aerated soap having the compactness and crystalline structure of a milled soap which comprises the steps "of progressively compacting milled soap flakes into a mass and feeding the compacted soap mass forward, then shredding the soap mass while maintaining the soap in solidified condition by progressively spreading the compacted soap mass on a foraminous plate, forcing it through the openings in said foraminous plate to form threads or shreds while simultaneously supplying a gas to and occludingiparticles of gas in the soap threads or shreds, and mechanically compacting and extruding the soap threads or shreds with particles of gas occluded therein while maintaining the soap under a gas pressur sufficient to prevent escape of the gas particles from the compacted mass due to the pressure of said mechanical compacting.

13. The process of continuously producing an aerated soap which comprises compacting a soap stock into a uniform mass while feeding the compacted mass progressively forward, shredding said compacted mass of soap stock by progressively forcing the soap stock through a foraminous plate while maintaining the soap stock in solidified condition and supplyinga gas thereto adjacent to said foraminous plate and prior to passage therethrough, whereby a gasis passed through said foraminous plate with the soap to incorporate and uniformly distribute particles of gas in the soap i shreds, then mechanically compacting the comminuted and aerated soapshreds into 'a uniform. integrated mass while maintaining the soap under a gas pressure sufficient to prevent escape due to the mechanical pressures of the compacting of the occluded gas particles and then extruding said mass through a discharge orifice.

14. The process as defined in claim 13 wherein the aerated soap mass is cut and formed into finished bars as it is extruded.

DONALD E. MARSHALL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,048,286 Pease July 21, 1936 2,210,924 Hood Aug. 13, 1940 2,295,594 Mills Sept. 15, 1942 2,377,424 Ittner June 5, 1945 2,398,776 Bodman s Apr. 23, 1946

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