GB2048296A - Preparation of Marbled Soap - Google Patents

Abstract

A method of producing marbled soap comprises mixing in a plodder one part by weight of a colour base with at least 50 parts by weight of soap base and extruding marbled soap from said plodder, said colour base having a viscosity of at least 5,000 cps at 20 DEG C. The colour base may e.g. comprise water, pigment and a gelling agent.

Description

SPECIFICATION Improvements in or relating to Soap This invention concerns improvements in or relating to soap and more particularly concerns the production of marbled or striped soap.

Soap comprising two or more colours in a striped, veined or marbled effect (hereinafter for convenience called 'marbled soap') strongly appeals to the buying public and commands a premium price. At present such soap is produced by one of two processes. In the first process, about 1030% of the soap to be produced is mixed with colour, perfume and other ingredients, milled, plodded and extruded into ribbons and stored in such a way that the moisture is retained. In production practice, this part of the batch is usually processed a day earlier than the production of the marbled product.

The rest of the batch is mixed with the perfume and other ingredients (colour is ad wd as well, if the other colour intended is not white), and milled. The freshly milled soap is introduced into the hopper of an extrusion plodder together with the coloured ribbons in the above mentioned ratio. The marbled soap is extruded in the form of billets which are stamped into tablets. According to the second method, two soap lines are used at the same time to produce the above two colours of soap, and the soaps are brought together either in the hopper or in the extrusion cone, to extrude marbled soap billets directly. if the soaps are mixed in the extrusion cone care must be taken to equalise the pressures between the two incoming soaps.

The first mentioned process requires nearly twice as much time to produce a marbled soap as a solid coloured soap. Moreover the coloured ribbons cannot be stored for long periods since on drying they become difficult to combine with freshly milled soap. The process using two soap lines and a special plodder clearly requires much more plant and factory space to produce a marbled product.

If colour could be combined with the incoming soap mixture in the final plodder it would be possible to produce marbled soap at the same rate as plain coloured soap and with very little more plant.

However, if commercially available soap pigments are added to the hopper of the final plodder in their original form (generally powder or liquid) a soap is produced where the colour is not uniformly distributed but a marbling or striped effect is either not present or is unattractive and inconsistent. The visual effect is that the colouring of the soap is sub-standard; commercially a process of this kind is virtually useless.

One aspect of our invention provides a method of producing marbled soap which comprises mixing in a plodder one part by weight of a colour base with at least 50 parts by weight of soap base and extruding marbled soap from said plodder, said colour base having a viscosity of at least 5,000 cps at 200 C.

Our invention is based on the discovery that a colour base can be added very conveniently in the final plodder provided that the viscosity of the composition is high enough. As has been explained above, when a fluid colour base composition is added in the plodder hopper the result is unacceptable, but we have found that when the composition has a high viscosity an excellent marbled effect is produced. The minimum viscosity for the colour base which produces a significant marbling effect is about 5,000 cps but we prefer the colour base to have a viscosity of at least 25,000 cps and more preferably at least 50,000 cps.As stated we have found that improved marbling effects may be obtained by increasing the viscosity of the composition, but a threshold is reached above which no significant improvement in marbling effect is obtained for an increase in viscosity and thus from an economic point of view it is not advantageous to increase the viscosity of the composition substantially above the abovementioned threshold level. Thus although marbling effects may be obtained with compositions having, for example penetrometer values of 300 units (at 8 second interval and at 200 C) and above, the best marbling effects are obtained with gelled pigment compositions having the consistency of a soft or medium rubber (e.g. corresponding to penetrometer values in the range 300 to 150, more preferably 260 to 200).

The weight ratio of colour base to soap base does not exceed 1:50 and is preferably in the range 1:100 or 1:150 to 1:500 by weight. The quantities of colour base to be supplied to the plodder are therefore very small compared to the quantity of coloured ribbon required in the conventional method for making marbled soap.

The colour base composition can be dispensed by conventional pumping equipment. Furthermore it can be prepared in conventional mixers in bulk and stored indefinitely, unlike coloured soap in ribbon form which rapidly becomes unusable.

The colour base will comprise a pigment and a carrier of the required viscosity. The proportion of pigment is e.g. in the range 0.1% to 25% by weight, preferably 1% to 5% by weight of the colour base composition. The viscous carrier may be water or other topically acceptable liquid containing a gelling agent. Preferred gelling agents are cellulose derivatives such as cellulose ethers and esters. Examples of suitable agents are hydroxyethyl cellulose (which is the preferred gelling agent), sodium carboxymethyl cellulose and alkyl celluloses such as methylcellulose or ethylcellulose. Other thicking agents include seaweed derivatives such as alginates; carragheen; furcellaran; agar; starch; gelatine; natural or synthetic gums such as gum tragacanth or polyvinyl alcohol; or gelling clays such as bentonite or montmorillonite.

Another carrier material which can be used is soft soap (potassium soap) having a suitable consistency. Where compatible, any combination of gelling agents can be used. Preservatives such as formaldehyde can be included to inhibit microbiological attack on the gelling agent.

Surfactants may be present to maintain dispersion of the pigment.

Production time per batch is greatly reduced compared with the known method, since a separate run to make the coloured ribbon is not required. If desired the soap line can make marbled soap continuously. A conventional soap line can be converted to marbled soap production very simply and at low cost. The colour base composition is suitably fed into the hopper of the final plodder, which may be open or under vacuum (to avoid entrainment of air in the soap).

The colour base composition can be fed into the plodder at some other point if desired provided that there is a suitable degree of mixing to give a satisfactory colour effect in the soap product.

However we have found it is perfectly satisfactory simply to feed the colour base into the plodder hopper. Other advantages of our invention are that the marbling effect has an excellent colour contrast and is easily controlled by altering the feed rate of the colour base relative to the feed of soap base. The whole process is much more flexible than the known process for making marbled soap; one can change production between marbled and plain soap, or change the colour of the marbling, in a few minutes and with the minimum loss of output.

In order that our invention may be better understood the following Examples are given by way of illustration only.

In the following Examples the Unisperse Blue GE paste is obtainable from Ciba/Geigy and the formaldehyde is used as a 40% solution. The hydroxyethyl cellulose used in Examples 2 to 5 is Natrosol MR and is obtainable from Hercules Powder Company Ltd. The penetrometer readings in Examples 4 and 5 were made on a Stanhope Seta 1 731 Standard Penetmmeter with Cone No.

1808.

The following soap base was used in the Examples: No. 2 Soap Milling Base 1 50 kg Titanium Dioxide 0.15 kg Sopanox 0.06 kg Perfume Lavender 1.50 kg The above ingredients were mixed in a blender, plodded twice on Mazzoni plant and made ready for blending with the various pigment compositions described below.

Example 1 (Comparative) The pigment composition had the composition by weight: Unisperse Blue GE paste 5.0% Formaldehyde 0.2% Water to 100% Unisperse pigments are available from The pigment composition was a mobile liquid.

When added to the plodder hopper, the soap produced showed no marbling effect but emerged with unsightly blue patches.

Example 2 The pigment composition comprised: Unisperse Blue GE paste 5.0 Formaldehyde 0.2% Hydroxyethyl Cellulose 2.0% Water to 100% The viscosity was approximately 5,000 cps at 200 C. The composition was added to the plodder hopper in the ratio of one part by weight to 300 parts of soap base. When added as a discontinuous stream the product exhibited some marbling but large blue patches were also seen.

Example 3 The pigment composition comprised: Unisperse Blue paste 5.0% Formaldehyde 0.2% Hydroxyethyl Cellulose 4.0% Water to 100% The viscosity was about 100,000 cps at 200C.

The composition was added manually in small lumps (about 1.3 cm in diameter) to the plodder hopper in the same ratio as in Example 2. The product exhibited satisfactory marbling although the veining was somewhat blurred.

Example 4 The pigment composition comprised: Unisperse Blue GE paste 5.0% Formaldehyde 0.2% Hydroxyethyl Cellulose 10.0% Water to 100% The composition had the consistency of a soft rubber (penetrometer reading:-- 255 units at 8 second interval and at 200C). When introduced to the plodder hopper as in Example 3 an excellent marbling effect was observed.

Example 5 The pigment composition comprised: Unisperse Blue GE paste 5.0% Formaldehyde 0.2% Hydroxyethyl Cellulose 12.5% Water to 100% The composition had the consistency of a medium hard rubber (penetrometer reading: 207 units at 8 second interval and at 200C).

When used as in Example 3 an excellent marbling effect was seen in the product.

Claims (14)

Claims

1. A method of producing marbled soap which comprises mixing in a plodder one part by weight of a colour base with at least 50 parts by weight of soap base and extruding marbled soap from said plodder, said colour base having a viscosity of at least 5,000 cps at 20 C.

2. A method according to claim 1 wherein said colour base has a viscosity of at least 25,000 cps.

3. A method according to claim 1 wherein said colour base has a viscosity of at least 50,000 cps.

4. A method according to claim 1 wherein said colour base has a penetrometer value (at 8 second interval and at 200C) in the range 300 to 1 50.

5. A method according to claim 4 wherein said penetrometer value is in the range 260 to 200.

6. A method according to any of the preceding claims wherein the weight ratio of colour base to soap base is in the range 1:1 50 to 1:500.

7. A method according to any of the preceding claims wherein said colour base comprises 0.1 to 25% by weight of pigment.

8. A method according to claim 7 wherein said colour base comprises 1 to 5% by weight of pigment.

9. A method according to any of the preceding claims wherein said colour base comprises water or other topically acceptable liquid containing a cellulose ether or cellulose ester gelling agent.

10. A method according to claim 9 wherein said gelling agent comprises hydroxyethyl cellulose.

11. A method according to claim 9 wherein said gelling agent comprises sodium carboxymetyl cellulose, methyl cellulose or ethyl cellulose.

12. A method according to any of claims 1-9 wherein said colour base comprises potassium soap as a carrier material.

13. A method according to any of the preceding claims wherein said colour base is fed into the hopper of said plodder.

14. A method according to claim 1, substantially as hereinbefore described.

1 5. A method according to claim 1, substantially as hereinbefore described with reference to any one of the Examples.