SOAP BAR HAVING SEPARATE CONCENTRATED REGIONS OF SPECIFICALLY SELECTED COMPONENTS

Abstract

The present invention relates to bars comprising soap bar matrix comprising predominantly long chain length soap and regions or domains interspersed within the matrix comprising predominantly shorter chain soaps. The novel bars of the invention are sufficiently hard to survive large scale manufacturing while simultaneously delivering benefits of significant foam value enhancement, for example, due to delivery of short-chain soaps from concentrated regions. Surprisingly, even when soaps in concentrated regions comprise small percentage of overall soap oils or fats used, they form observable kappa phase pattern.

Claims

1. A soap bar composition comprising 75 to 97% (based on total volume of the bar) of a matrix comprising long-chain soap; and 3 to 25% (based on total volume of the bar) regions interspersed in said matrix, the regions comprising short chain soaps: wherein long chain soap means soap molecules having a chain length of C.sub.14 or greater and 75% by wt. or greater of the soap molecules in the matrix are long-chain soaps; and; wherein short chain soap means soap molecules having a chain length of C.sub.12 and below and 75% by wt. or greater of the soap molecules in the regions are short chain soaps.

2. A composition according to claim 1, wherein the bar matrix comprises 50-85% by wt. soap.

3. A composition according to claim 1, wherein interspersed regions comprises 50-85% by wt. soap.

4. A composition according to claim 1, wherein matrix further comprise emollients, fillers, adjuvants and water.

5. A composition according to claim 1, wherein region further comprise emollient, fillers, adjuvants and water.

6. A composition according to claim 1, wherein the overall level of C.sub.12 and below chain length soap in entire bar is 3 to 20% by wt.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0039] FIG. 1 is an illustration of the process of mixing the main soap matrix comprising higher chain length soap with short chain soap, which forms separate regions identified as kappa phase domains, even when there is an overall low level of short chain sodium soap as percent total soap used in the bar (as in this example).

[0040] FIG. 2 is a combined small and wide angle X-ray spectrum of a bar formed when soaps of both long and short chain are mixed together, as occurs for formation of matrix noodles (or for bars made in one stream process typically). In the long d-spacing region we see a principal peak at 43.1 , followed by a sequence of diffraction peaks at d.sub.o/2, d.sub.o/3, d.sub.o/4. This d-spacing (around 40 ) is typical for both zeta phase formed by long saturated chain soap (C18, C16), and eta phase, formed by long chain unsaturated chain soap (C18:1) and the mixture of long unsaturated and short saturated soap. In the short d-spacing region we observe peaks characteristic of both zeta phase: 2.75 (medium), 3.20 (weak) and 3.92 (very strong)), and eta phase: 4.10 (very strong, 4.25 (very strong) 4.40 (strong). As seen, when the overall amount of C.sub.12 and below is relatively low (3% to 20% in bars of our invention), there is a mix of zeta and eta phases, but no kappa phase.

[0041] FIG. 3 is a combined small and wide angle X-ray spectrum of the second stream short chain soap. In the long d-spacing region the main peak is observed at d-spacing 31.8 . In the short d-spacing region, the x-ray pattern consists of four peaks: 2.99 (medium strong), 3.60 medium weak), 3.93 (strong), and 4.77 (medium). This pattern is characteristic of kappa phase and is very different from the pattern observed for the main stream soap.

[0042] FIG. 4 is a small angle X-ray spectrum of a bar containing 15% sodium laurate soap added as a second stream. In the short d-spacing region the spectrum shows two principal peaks at 43.1 and 31.8 corresponding to combined zeta and eta phases (main stream soap), and kappa phase (second stream soap) respectively. As can be seen, even though C.sub.12 is small percentage of overall fat stock (3 to 20%), it is concentrated and thus forms an observable kappa phase.

DETAILED DESCRIPTION OF THE INVENTION

[0043] Except in the examples, or where otherwise explicitly indicated, all numbers in this description indicating amounts of material or conditions of reaction, physical properties of materials and/or use are to be understood as modified by the word about. All amounts are by weight of the final composition, unless otherwise specified.

[0044] It should be noted that in specifying any range of concentration or amount, any particular upper concentration can be associated with any particular lower concentration or amount.

[0045] For the avoidance of doubt, the word comprising is intended to mean including but not necessarily consisting of or composed of. In other words, the listed steps or options need not be exhaustive.

[0046] The disclosure of the invention as found herein is to be considered to cover all embodiments as found in the claims as being multiply dependent upon each other irrespective of the fact that claims may be found without multiple dependency or redundancy.

[0047] The present invention is directed to soap bar composition comprising about 75 to 97% of the total volume of a matrix comprising predominantly long chain soap. The matrix soaps are made separately and preferably prior to the addition of soaps which are used to make up regions which will be dispersed in the matrix of the final bar. The matrix soaps are made in a stream (which can be called first stream separate from second stream in which predominantly short chain soaps are made) and the two are added later at relatively cooler temperature.

[0048] Some benefit agents (e.g., those which are intended to be mixed in the main matrix and for which it is not critical if delivered in separate domains) can be, and typically are, added in the first stream. They are added during saponification typically although they can be added post saponification (at low temperature) as well. For those benefit agents which have typically lower melting point and which we prefer not to homogenize throughout the matrix, these are preferentially added to the saponification stream where short chain soaps are made, but after saponification (e.g., at lower temperatures, preferably 30 C. to 60 C.); or at the time the second stream is mixed with the first. When the two streams are mixed, the benefit agents will tend to remain with second stream soaps. In fact, this allows certain components (perfumes, antibacterial agents) to be concentrated in the concentrated regions where they can be delivered more impactfully than if they had been delivered from the main soap matrix.

[0049] More specifically, fats selected to make the main matrix soaps are designed specifically to have relatively low concentration of C.sub.12 and below fatty acid soaps formed. For example, 75% or greater, preferably 80% or greater, more preferably 82% or greater, even more preferably 85% or more of chain lengths available for saponification in fats chosen are C.sub.14 and above and 25% or less, preferably 20% or less, more preferably 18% or less, more preferably 15% of chain lengths available are C.sub.12 and below. Most preferably, if possible, 100% of chain lengths are C.sub.14 and higher and 100% of final soaps in the matrix are long chain soaps. It is preferred to form as few short chain soaps in the matrix as possible.

[0050] Because the short chain soap region is made separately, fat materials having high level of chain lengths of C.sub.12 and below, as a percentage of all chain lengths of the starting fat, is low (as percent of overall fat charge) but still forms concentrated low chain soap region where kappa phase is observed. Typically, the level of soap formed having chain length of C.sub.12 and below is 3% to 20%, preferably 7 to 15%. Such low amounts would not typically form a kappa phase region in traditional bars where all soaps are formed together in a one-step process. Surprisingly, however, we are able to form regions where kappa phase is observed even though low levels of short chain soaps are formed overall.

[0051] Counterions used during formation of the long-chain soaps of the first stream are typically sodium, but may be sodium or potassium; soaps which will form the regions or domains of the invention are designed specifically to have predominantly chain length of C.sub.10 and C.sub.12. Typically, of the 50 to 85% soap comprising the concentrated regions, 75% or more are C.sub.12 and lower chain length, although 25% or less, preferably 15% or less may be long chain length. Again, counterion used to form the soap may be sodium and/or potassium.

[0052] Soaps predominantly made from C.sub.10 and C.sub.12 typically have a melting point range such that, when combined with soaps of the main matrix and/or other ingredients at temperatures of about 30 C. to less than 50 C., preferably 30-45 C., the melting temperature of the soaps forming the main matrix is high enough that the soaps forming the concentrated domains will stay in independent regions, i.e., not disperse homogenously with the soaps forming the main matrix.

[0053] Benefit agents can be added to the long-chain length stream (typically higher melting point benefit agents). Some benefit agents (typically lower melting point) are preferably added at the time lower chain length soaps are made (post saponification at lower temperatures, but before the two soaps are combined); or at the time the predominantly short chain soaps are mixed with long chain soaps. The benefit agents added to the lower chain length stream will typically be chosen to have melting points (e.g., 30-45 C.) so that they will not fully melt when added to a mixer at 30-45 C. (for example, at the time the two soap streams are combined) and will thus remain in concentrated areas; simultaneously the melting point of such agents is low enough so that they will not be gritty when collected in the concentrated region. That is, they are soft enough to not cause gritty feel, yet are sufficiently soluble to provide performance in use when delivered from concentrated regions.

[0054] In short, the bars of the invention provide certain concentrated regions or domains containing predominantly short chain length fatty acid soaps and further optionally containing certain selected benefit agents (typically added in when soaps are combined) having defined melting points. Typically, as indicated, these adjuvants would remain in the region of the short chain soaps. Without wishing to be bound by theory, it is believed the benefit agents are entrapped in the regions. By adding these separately formed lower and higher chain length soaps, and optional benefit agents, at a point when they are mixed at lower temperatures, these concentrated regions are not mixed homogeneously into the bar matrix soaps. Benefits of the concentrated lower chain length soaps (e.g., enhanced foaming), as well as benefits of the optionally added benefit agents entrapped within (perfume, antibacterial), which benefits (enhanced perfume burst, enhanced antibacterial activity) are associated with those concentrated regions, can thus be efficiently delivered.

[0055] The overall percent C.sub.12 and below chain length available for saponification from fats used in both streams is typically about 3 to 20%, preferably 7 to 15%. Thus, this is the amount of C.sub.12 soap which will form upon saponification. Typically, at C.sub.12 soap amount of 20% or less in total bar, no kappa phase would be seen in x-ray. However, since we make separate streams, the soap of chain length C.sub.12 or less is concentrated and kappa phase pattern is seen. FIG. 1 is an illustration of this overall FIG. 2 is an x-ray of bar matrix and shows how typically, in main matrix (as in bars made by one step process, especially where overall amount of soap charge is 20% or less), kappa phase is not seen. FIG. 3 shows concentrated regions that form kappa phase. FIG. 4 shows an x-ray of bar comprising 15% of sodium laurate added as a separate stream; here we see the presence of kappa phase and the mixture of eta and zeta phases.

[0056] The invention also comprises bars obtainable from, preferably obtained from process defined.

Brief Description of the Process

[0057] The process is briefly described below:

First stepmain stream production: Saponification (typically with sodium counterions) of primarily non-lauric oils with caustic soda (by non-lauric is meant long saturated (primarily C.sub.16 and C.sub.18) and unsaturated (C.sub.18:1, C.sub.18:2, traces of C.sub.18:3) fatty acids found in palm oil, palm oil stearine, tallow, etc.). As indicated earlier, fats having broad chain length of C.sub.14 to C.sub.24 may be used, but those of chain length C.sub.16 to C.sub.18 are preferred. Higher melting point benefit agents (and/or those for which it is not critical or important if they are homogeneously distributed throughout the bar matrix) can be separately added to this main stream. Benefit agents may also be added after saponification.
Second stepSaponification of fatty acids or lauric oils (i.e., C.sub.8 to C.sub.12, palm kernel oil, coconut oil, etc.) with selected alkali (Na.sup.+ and/or K.sup.+); soap fats comprising C.sub.8 to C.sub.12 are preferred Typically, no high melting point benefit agents are used at saponification here. Lower melting point benefit agents may be added either post saponification at later stage when temperature is lower, but before mixing with soaps formed in the high soap stream, or at mixing step; at mixing the benefit agents will tend to remain in the concentrated areas.
Third stepMixing between the main stream (comprising saponified longer chain soaps and optional higher melting point adjuvants) and second stream (comprising saponified lower chain soaps and optional lower melting point adjuvants, preferably only lower melting point adjuvants). Typically, the two streams are mixed for 1 to 15 minutes, preferably 2 to 10 minutes. The streams may be mixed for much longer than this (although this would prolong the process) without, applicants have found, affecting lather enhancement delivered from the concentrated regions. The mixing occurs in a finishing line step (for example, a Z-blade mixer) where the temperature profile is maximum 50 C., preferably 30-45 C. Lower melting point benefit agents can separately be added during mixing (or as noted, at lower temperatures found at the later stage when second stream soaps are formed but before both streams are mixed). Typically, these are agents which are preferably not homogenized throughout the product and which will be more efficiently delivered from the domain regions.

[0058] It should be understood that first and second steps are interchangeable and not necessarily in a time sequence.

[0059] The compositions and the process for making this are described in more detail below.

Main Matrix

[0060] The main soap bar matrix (in which regions or domains are interspersed) is made predominantly from longer molecular weight (C.sub.14 to C.sub.22) fatty acid soaps as discussed above which are typically insoluble and do not readily generate foam.

[0061] Specifically, this region is the brick and mortar of the bar and is designed to have as relatively little C.sub.12 and below chain length soaps as possible.

[0062] More specifically, this main region may comprise a level of 75 to 97% of total bar volume. The main matrix region comprises typically 50 to 85%, preferably 60 to 85% by wt. soap and typically 75% or greater, preferably 85% or greater more preferably 95% by wt. of these soaps should be C.sub.14 or greater, preferably C.sub.14 to C.sub.24, more preferably C.sub.16 to C.sub.24. This includes partially unsaturated chain lengths such as unsaturated C.sub.8. At these low levels of short chain length, kappa phase is not typically seen (FIG. 2).

[0063] Further, the counterion used during saponification of the starting soap bar material (starting fat or oil) may be, for example, sodium or potassium.

[0064] Typically, main stream benefit agents (especially high melting point benefit agents) are added at saponification. They may also be added after saponification, but should be added before the main stream soaps are mixed with second stream. When mixed with second stream soaps, lower melting point benefits may typically be added, and these will tend to stay in the concentrated regions.

[0065] As noted, the matrix soaps are prepared separately from soaps making up regions or domains of the invention (added to what we are calling second stream). It is an important part of the invention that when soaps forming domains of the invention are made and mixed with the matrix soaps later, the mixing temperature is lower than the mixing temperature at which either of the two soaps are formed. As such, the matrix soaps do not melt and mix homogeneously with the domain soaps. Typically, two soaps are mixed from 1 to 15 minutes, preferably 2 to 10 minutes.

[0066] Typically, main stream soaps are made by saponifying non-lauric oils and unsaturated fatty acids found, for example, in palm oil, palm oil stearine, etc.

[0067] The main matrix, as noted, comprises 50 to 85% by wt. soaps. In addition, there may be found emollients, fillers, adjuvants and water all added as noted above.

[0068] Typically, applicants may include silicones and other emollients. Silicones include linear, cyclic and substituted silicones. Other emollients include polyols, fatty acids and vegetable, mineral and animal oils.

[0069] Glycerin and sorbitol are preferred polyols. Preferred fatty acids include babassu fatty acid and lauric acid. Typical vegetable oils include sunflower oil, corn oil and almond oil.

[0070] Emollients may comprise 1-15% by wt. of the matrix.

[0071] Fillers such as talc, starch, calcium carbonate, may comprise 1-25% by wt. of the main matrix.

[0072] Adjuvants may include perfumes and dyes and comprise typically up to 0.1-5% by wt. of the main matrix.

Domains or Regions

[0073] A critical aspect of the subject invention is the preparation of soaps which will form concentrated regions or domains which are prepared separately from the soaps which will form main matrix. These regions comprise predominantly lower molecular fatty acid soaps (C.sub.12, preferably C.sub.8 to C.sub.12 chain length and below).

[0074] More specifically, the regions may comprise about 3 to 25%, preferably 5 to 20%, more preferably 5 to 15% of the total bar volume. The concentrated regions typically comprise 50 to 85% soap, and typically 85% or greater, more preferably 90% or greater by wt. are C.sub.8 to C.sub.12 (preferably C.sub.10 to C.sub.12) soaps.

[0075] Although regions comprise high levels of C.sub.12 and below, they represent typically only about 3 to 20% by wt. of all soaps in the bar. However, since the C.sub.12 and below is concentrated, a kappa phase is seen (FIG. 4).

[0076] Further, the counterion used to saponify the fats may be sodium and/or potassium. Use of certain counterions can help alter characteristics.

[0077] Typically, this step includes saponification of fatty acids or lauric oils (e.g., C.sub.8 to C.sub.12, palm kernel oil, coconut oil) and alkali such as sodium and/or potassium.

[0078] These soaps are formed in a separate second stream. As noted, the regions comprise 50 to 85% soap. In addition, there may be found emollients, fillers, adjuvants and water. Emollients, fillers and adjuvants are as defined for matrix above. In one preferred embodiment, the region comprises 70 to 90% soap; 1 to 15% emollient (especially glycerin), 5 to 15% water and 0.1 to 5% adjuvant. Typically high melting point benefit agents are not added during saponification of fats forming short chain soaps although, theoretically, they may be. Typically, the lower melting point benefit agents are added to second stream at later stage (where there are lower temperatures). These are typically added before the soaps made in the main stream are combined; when the two streams are later combined, the lower melting point agents will tend to stay in second stream soaps. As mentioned, it is also possible to add lower melting point benefit agents at the actual mixing of the two streams.

[0079] Once formed, the short chain soaps forming the domains (and optionally low melting point adjuvants) are mixed with long chain soaps which form the main matrix. Specifically, in the finishing line (mixer) the domain soaps are mixed with the main stream soap. The soaps incorporate well but they do not mix at the microstructure level due to the low temperature conditions. It is believed that it is this lack of extreme homogenization which causes the formation of the micro domains. More particularly, the streams are mixed at a temperature of about 50 C. and below, preferably at 30 C. to 45 C. so that the lower-chain length soaps will homogenize but stay as separate domains interspersed throughout the matrix. These domains can thus more effectively deliver benefits associated with lower chain length soaps (e.g., foaming), as well as benefits of any adjuvant/benefit adjuvant which were optionally added as noted above. The mixing time is typically 1 to 15 minutes, preferably 2 to 10 minutes.

[0080] It should be noted that, rather than second stream short chain soaps, it is also possible to make second stream solid non-soap detergent bits. These can then be mixed with main stream soap at lower finishing line temperatures to form separate regions of non-soap detergent.

Process

[0081] As described previously, the process to produce the soap (main stream and domains) is split in two steps:

First stepmain stream is produced using only long carbon chain (C.sub.14), preferably with caustic soda. Unsaturated fatty acids (e.g., oleic) may be used.
Second stepthe domain is produced using short carbon chain (C.sub.12 and below) with caustic soda and/or caustic potash.

[0082] The first and second steps are run independently and not necessarily in that order.

[0083] It is only in the finishing line that the short chain soaps that will form the domain are mixed with the main stream. The domain soap is preferably the last ingredient/base added in the mixer, preferably a Z-blade mixer.

[0084] A typical finishing batch would be:

about 92% main stream soap 1-2% dye+perfume (mix for 9-12 minutes);
Add about 7% domains (mix for 1-10 minutes).

[0085] After the mixing stage, the soap mass is unloaded from the mixer and the mass is passed through the roll mills and plodder.

[0086] After the plodder, soap billets are cut and stamped.

[0087] The resulting bars will typically have a hardness value (measured at mm/s (Kg) at 40 C.) of at least 3 and preferably in the range of 3.0 to 5 Kg.

Protocol

Hardness Testing Protocol Principle

[0088] A 30 conical probe penetrates into a soap/syndet sample at a specified speed to a pre-determined depth. The resistance generated at the specific depth is recorded. This number can be related to the yield stress.

[0089] Hardness (or yield stress) can be measured by a variety of different penetrometer methods.

Apparatus and Equipment

TA-XT Express (Stable Micro Systems)

[0090] 300 conical probePart #P/30c (Stable Micro Systems)

Sampling Technique

[0091] This test can be applied to billets from a plodder, finished bars, or small pieces of soap/syndet (noodles, pellets, or bits). In the case of billets, pieces of a suitable size (9 cm) for the TA-XT can be cut out from a larger sample. In the case of pellets or bits which are too small to be mounted in the TA-XT, the compression fixture is used to form several noodles into a single pastille large enough to be tested.

Procedure

Setting Up the TA-XT Express

[0092] These settings need to be inserted in the system only once. They are saved and loaded whenever the instrument is turned on again.

Set test method

Press MENU

Select TEST SETTINGS (Press 1)

Select TEST TPE (Press 1)

[0093] Choose option 1 (CYCLE TEST) and press OK

Press MENU

Select TEST SETTINGS (Press 1)

Select PARAMETERS (Press 2)

Select PRE TEST SPEED (Press 1)

[0094] Type 2 (mm s.sup.1) and press OK

Select TRIGGER FORCE (Press 2)

Type 5 (g) and Press OK

Select TEST SPEED (Press 3)

[0095] Type 1 (mm s.sup.1) and press OK

Select RETURN SPEED (Press 4)

[0096] Type 10 (mm s.sup.1) and press OK

Select DISTANCE (Press 5)

[0097] Type 15 (mm) for soap billets or 3 (mm) for soap pastilles and press OK

Select TIME (Press 6)

Type 1 (CYCLE)

Calibration

[0098] Screw the probe onto the probe carrier.

Press MENU

Select OPTIONS (Press 3)

[0099] Select CALIBRATE FORCE (Press 1)the instrument asks for the user to check whether the calibration platform is clear
Press OK to continue and wait until the instrument is ready.
Place the 2 kg calibration weight onto the calibration platform and press OK
Wait until the message calibration completed is displayed and remove the weight from the platform.

Sample Measurements

[0100] Place the billet onto the test platform.
Place the probe close to the surface of the billet (without touching it) by pressing the UP or DOWN arrows.

Press RUN

[0101] Take the readings (g or kg) at the target distance (Fin).
After the run is performed, the probe returns to its original position.
Remove the sample from the platform and record its temperature.

Calculation & Expression of Results

Output

[0102] The output from this test is the readout of the TA-XT as force (RT) in g or kg at the target penetration distance, combined with the sample temperature measurement.

[0103] The force reading can be converted to extensional stress, according to Eqn. 2.

[0104] The equation to convert the TX-XT readout to extensional stress is

[00001]$=\frac{1}{C}.Math.\frac{R_T.Math.g_c}{A}$

where: =extensional stress [0105] C=constraint factor (1.5 for 300 cone) [0106] G.sub.c=acceleration of gravity [0107] A=projected area of cone=(d tan ).sup.2 [0108] d=penetration depth [0109] =cone angle

[0110] For a 300 cone at 15 mm penetration Eqn. 2 becomes

(Pa)=R.sub.T (g)128.8

[0111] This stress is equivalent to the static yield stress as measured by penetrometer.

[0112] The extension rate is

[00002]$\stackrel{.}{\mathrm{.Math.}}=\frac{V}{d.Math..Math.\tan \left(\frac{1}{2}.Math.\right)}$

where {acute over ()}=extension rate (s.sup.1) [0113] V=cone velocity

[0114] For a 300 cone moving at 1 mm/s, {acute over ()}=0.249 s.sup.1

Temperature Correction

[0115] The hardness (yield stress) of skin cleansing bar formulations is temperature-sensitive. For meaningful comparisons, the reading at the target distance (RT) should be corrected to a standard reference temperature (normally 40 C.), according to the following equation:

R.sub.40=R.sub.Texp[(T40)]

where R.sub.40=reading at the reference temperature (40 C.) [0116] R.sub.T=reading at the temperature T [0117] =coefficient for temperature correction [0118] T=temperature at which the sample was analyzed.

[0119] The correction can be applied to the extensional stress.

Raw and Processed Data

[0120] The final result is the temperature-corrected force or stress, but it is advisable to record the instrument reading and the sample temperature also.

Lather Volume Protocol

Definitions

[0121] Lather volume is related to the amount of air that a given soap bar composition is capable of trapping when submitted to standard conditions.

Principle:

[0122] Lather is generated by trained technicians using a standardised method. The lather is collected and its volume measured.

Apparatus and Equipment:

[0123] Washing up bowl1 per operator capacity 10 litres
Soap drainer dishes1 per sample
Surgeons' rubber glovesBritish Standard BS 4005 or equivalent (see Note 14ii).
Range of sizes to fit all technicians
Tall cylindrical glass beaker400 mL, 25 mL graduated (Pyrex no 1000)
ThermometerMercury types are not approved
Glass rodSufficiently long to allow stirring in the glass beaker

Procedure:

Tablet Pre-Treatment:

[0124] Wearing the specified type of glove well washed in plain soap, wash down all test tablets at least 10 minutes before starting the test sequence. This is best done by twisting them about 20 times through 180 under running water.

[0125] Place about 5 litres of water of known hardness and at a specified temperature (see Note) in a bowl. Change the water after each bar of soap has been tested.

[0126] Take up the tablet, dip it in the water and remove it. Twist the tablet 15 times, between the hands, through 180. Place the tablet on the soap dish (see Note).

[0127] The lather is generated by the soap remaining on the gloves. [0128] Stage 1: Rub one hand over the other hand (two hands on same direction) 10 times in the same way (see Note). [0129] Stage 2: Grip the right hand with the left, or vice versa, and force the lather to the tips of the fingers. [0130] This operation is repeated five times. [0131] Repeat Stages 1 and 2 [0132] Place the lather in the beaker.

[0133] Repeat the whole procedure of lather generation from paragraph iii, twice more, combining all the lather in the beaker.

[0134] Stir the combined lather gently to release large pockets of air. Read and record the volume.

Calculation & Expression of Results:

[0135] The data obtained consists of six results for each bar under test.

[0136] Data analysis is carried out by two way analysis of variance, followed by Turkey's Test.

Operators:

[0137] Experienced technicians should be able to repeat lather volumes to better than 10%. It is recommended that technicians be trained until they are capable of achieving reproducible results from a range of different formulation types.

Notes:

[0138] Water temperature should reflect local conditions, or alternatively tests may be done at more than one temperature. Once decided upon, the water temperature should be adhered to and should be reported with the results.

[0139] Similarly, water hardness should be constant for a series of tests and should be recorded. Where possible, it is preferable to adhere to suitable water hardness.

[0140] It is important to keep the number of rubs/twists constant.

Examples

[0141] In order to compare lather and rheology results (hardness), applicants prepared the following bars:

TABLE-US-00001 Comparative A Comparative B Example 1 Example 2 Example 3 100% main Bar where all 7% C.sub.10 sodium 7% C.sub.12 sodium 7% C.sub.10-C.sub.12 stream soap soap fats/oils soap; 93% main soap; 93% main sodium soap; base: stearic- mixed together stream soap stream soap 93% main oleic soap from are palm oil-palm base (same as base (same as stream soap palm oil-palm stearin/palm A) A) base (as A) stearin oil; kernel oil; No short chains Short chain mixed Short chains in Short chains in Short chains in with long chains concentrated concentrated concentrated regions. regions regions Example 4 Example 5 Example 6 Example 7 7% C.sub.10 7% C.sub.12 potassium 7% C.sub.10-C.sub.12 7% capric-lauric- potassium soap; soap; 93% main potassium soap; oleic potassium 93% main stream soap base 93% main stream soap; 93% main stream soap (same as A) soap base (same stream soap base base (same as as A) (as A) A) Short chains in Short chains in Short chains in In concentrated concentrated concentrated concentrated regions regions regions regions

[0142] Bars 1-7 were prepared as per the invention wherein the main stream soap base was prepared separately from shorter-chain soap stream and the two streams were combined and mixed with temperatures ranging from 30 to 45 C. In comparatives A & B, all chain-length fats/oils were saponified at once.

[0143] Applicants next compared lather volume and rheology results for the various bars:

TABLE-US-00002 Lather Volume Hardness (Kg) at 40 C. in 15 mm Bar (mL) penetration A 190 5.38 B 220 4.00 1 271 3.43 2 266 4.55 3 287 4.37 4 359 3.40 5 334 3.12 6 324 3.27 7 355 4.63

[0144] As seen from the data above, the bars of this invention, having separate regions or domains interspersed in soap matrix, have hardness values comparable to comparative bars where soap fats/oils are saponified altogether. This ensures that bars can be extruded and shaped in high throughout manufacture. Typically, hardness values are in a range of 3.00 to 5.00 Kg measured at 40 C. in 15 mm penetration. This is an acceptable range for industrial production of bars.

[0145] Further, the bars maintain sufficient manufacturing hardness while providing greatly enhanced lather volume relative to comparative bars. Specifically, comparative bars had lather volume of 190 and 220 milliliter, while bars of invention had lather ranging from 266 to 355 milliliter.

[0146] While not wishing to be bound by theory, it is believed that delivery of lower chain-length soaps in domains or regions allows the bars to maximize foaming effect of the low-chain length soaps and thereby increases foaming values of the entire bar.