EP1280884A1

EP1280884A1 - Mold and process for stamping detergent bars

Info

Publication number: EP1280884A1
Application number: EP01945067A
Authority: EP
Inventors: Edward Ross Unilever H & P Care USA STORY; Daniel John Unilever H & P Care USA HEINZ; Pasquale Michael Unilever H & P USA BUZZEO
Original assignee: Unilever PLC; Unilever NV
Current assignee: Unilever PLC; Unilever NV
Priority date: 2000-05-10
Filing date: 2001-05-01
Publication date: 2003-02-05
Also published as: WO2001085894A1; AU2001267393A1; MXPA02011026A; BR0110661A

Abstract

The invention discloses a process for stamping a detergent bar which includes a die having at least one bar stamping surface provided with at least one elastomeric coating. The coating is molded with a mold having replaceable indicia.

Description

MOLD AND PROCESS FOR STAMPING DETERGENT BARS

The present invention relates to a process for stamping a plastic material using a die to form a shaped article. In particular, the invention relates to a process for stamping a detergent bar.

By "detergent bar" is meant a tablet, cake or bar in which the level of surface active agent, which comprises soap, synthetic detergent active or a mixture thereof, is at least 20 wt. % based on the bar.

In the manufacture of detergent bars, a preformed composition comprising all components of the bar is typically extruded from a nozzle to form a continuous "rod" which is cut into smaller pieces of predetermined length, commonly referred to as "billets." These "billets" are then fed to a stamper or, alternatively, are given an imprint on one or more surfaces using, for example, a die of the same dimensions as the bar surface. The bar surface is hit with force by, eg., a mallet or a die in the shape of a roller.

Stampers typically have a die formed in two halves each with a surface which contacts the billet during the stamping operation. These surfaces are adapted to close to a preset separation distance, thereby compressing the billet between the die halves to give the bar its final shape and appearance, and then separate. Excess composition is squeezed out from the die halves as they close. This is commonly referred to as "flash." The flash is then separated from the soap bar by transferring the bar through holes in a "deflashing plate."

Conventional die stamping machines include "pin die" shaped machines in which a pair of opposing die members or die halves meet during a compaction step, and a "box die" machine in which a pair of opposing die members stamp a bar held within a through-opening in a box frame but do not meet during compaction, the peripheral face of the bar being restrained by the box frame.

The die halves are often each provided with a die or ejector insert. These are normally held closed within the die halve by springs but can be pushed open by compressed air or mechanical means to assist in the release of the bar from the die. During closing of the die halves a vacuum can be applied to remove air trapped in the die cavity between the detergent bar and die surface and, in the case of rotary dies, this vacuum assists in retaining the bars in place during rotation.

Stamping of detergent bars using a die is carried out to give the bars a reproducible shape, smooth surface and/or to imprint a design such as a logo, trade mark or the like onto at least part of a surface of the bar.

However, as a result of die-blocking, i.e. amounts of residual detergent left on die halves which builds up during continued use of the dies, bars are often formed with visible imperfections on their surfaces or they may not release from the die surface. Numerous solutions to these problems have been proposed. One solution involves chilling the die halves during the stamping operation. Chilling uses valuable resources, particularly energy sources.

Another solution is described in GB-A-746 769 which discloses a die set which includes a die box and a pair of companion die members made of plastic materials comprising polymers with a specified modulus of elasticity. A disadvantage of this system is that a die release agent is necessary to prevent detergent from adhering to and building up on the dies and marring the surfaces of subsequently pressed bars.

WO 98/11194 is directed to a device for handling plastic materials such as a stamping device for stamping detergent bars, comprising at least two elastomeric coatings of different properties and/or compositions. Surface decorations such as uniform shape, smooth surface, design such as a logo, trademark or the like are said to be achievable in an easily reproducible manner in accordance with the invention. An advantage of thin elastomeric coatings is said to be that they can be easily applied in a factory to a conventional die with a built in logo. In describing the figure, it is said that a logo (not shown) may be formed on one or more of the die stamping surfaces if required.

Roberts, U.S. Patent No. 3,534,440 discloses bodies of soap, detergent and the like which are pressed to final shape and/or size with indented or raised surface indicia in a die press. A detachable and replaceable section of embossed tape bearing the indicia is mounted on either an upper die pressing face or a bottom of a cavity or both. It is said that the invention may be used for synthetic detergent bars as well. Permanent indicia are said to restrict the dies to one usage run. Dies with replaceable inserts are said to be known. The thin embossable material embossed with the desired indicia may be attached by pressure sensitive adhesive means to one or more pressing faces of a pair of dies. It is said that while the tape seems relatively fragile, it does not rupture or deform under the high soap forming pressures and it is said to be believed that the air trapped in spaces opposite the embossed characters cooperates with inherent resiliency of the strip material effectively to uniformly cushion the strip to prevent destructive localized stress regions.

Cubbitt, U.S. Patent No. 3,522,633 is directed to a die member comprising a rigid metal body having a forming surface provided with a panel receiving recess wherein a plastic design-bearing panel is molded in place. The panel has a surface that is substantially continuous with the die forming surface except for interruption by the design to be imparted to the article formed by the die. The panel is removable and replaceable by a different mold in place panel bearing a different design. The dies are for pressing of soap or similar relatively soft material into bar cakes or any desired compact form. An object of the Cubbitt invention is said to be to provide a novel soap pressing die structure wherein part of the internal soap contacting and forming surface of the die is a specially formed plastic panel for providing a desired design on the pressed soap bars. A further object of the invention is said to be a novel method of making a soap die member having a soap contacting and forming surface wherein an insert panel or the like is formed as by molding or casting into a recessed inset surface, the panel having an exposed surface which except for a design is essentially a continuation of the die pressing surface wherein the incorporated panel is removable for molding or casting a substitute panel. Should a different design be desired, the panel is displaced and replaced with another panel that is identical except for surface design. The replaceable panel may be formed in place on the metal die member using a master blank of hard non-deformable plastic. Preferably the panel material is a thermosetting material although other thermoplastic materials may also be used.

Pinto, U.S. Patent No. 3,127,457 discloses a fluorocarbon film used as a release agent for molding polyurethane articles .

Krugg, U.S. Patent No. 3,539,144 discloses a mold useful for producing polyurethane foams, which includes a structural mold shape and a coating of hot vulcanized silicon rubber disposed on the structural mold as well as a cold vulcanized silicone rubber deposited on the hot vulcanized silicon rubber. Cavanugh, U.S. Patent No. 4,035,122 discloses a soap saving device for compressing remnants of soap bars.

Austin, U.S. Patent No. 4,076,207 discloses a food mold comprising a liner and a rigid holder wherein the liner has a rim for securement to the holder.

Roussel, U.S. Patent No. 4,809,945 discloses a mold cavity for use in molding articles such as soap bars.

atanabe, U.S. Patent No. 5,332,190 discloses an elastic molding die composed of an elastomer laminate film, the innermost layer of which does not contain fillers.

In US Patent No. 5,269,997 it is proposed to provide each of two dies of a soap mold with an elastomeric septum stretched across their surfaces. Such a system would be complex to use at the speed required for commercial manufacture and a thin covering would be prone to tearing and logo reproduction would be expected to be poor.

WO 96/00278 (Adams et al . ) is directed to a device for stamping a detergent bar having at least one bar stamping surface provided with at least one elastomeric coating having a thickness of less than 200 microns. An advantage of the device according to the invention is said to be that the elastomeric coating, being thin, can easily be applied in a factory to a conventional die with a built in logo. One die half is provided with a logo on the bar stamping surface of a rigid member, which is also coated with elastomeric coating. Alternatively, the die cavity includes an injector bearing a logo.

Another solution is proposed in EP 276 971 and U.S. Patent Nos. 4,793,959 and 4,822,273, which involve the use of two die members, each comprising a non-elastomeric and an elastomeric part. The elastomeric part, which contacts the soap bar during the stamping process, comprises an elastomer coating of at least 200 microns and having a modulus of elasticity within a specified range.

The manufacture of thick coated dies is a complex and expensive process. Therefore, it is highly desirable to maximize the working life of such coatings.

Hoppes, U.S. Patent No. 3,474,498 discloses an indicia forming device for attachment to an article-forming surface portion of a mold, as for imprinting 3-dimensional medallion designs, or other indicia, in articles formed in the mold, as by blow molding methods. A thin, flexible pad or plate of rubber like plastic material is provided with appropriate 3-dimensional design configurations on one side thereof.

The Hoppes plate is positioned and adhered to an article forming surface portion of the mold. An object is to provide an indicia forming device which is quickly and efficiently interchangeable with like indicia forming devices to avoid undue expense and delays in the production of the blow molded articles. The medallion plate is a small rectangular piece of thermoplastic of thermo resin sheet material and may be firmly, but removably adhesively attached to the article forming wall surface of the mold path. When replacement or renewal of the medallion plate is required, it may be peeled, scraped or otherwise removed from the mold cavity surface. It is said that the invention permits the dealer indicia to be changed as often as desired with only brief interruptions in production of the blow- molded articles. The medallion plate material may be made of any natural or synthetic rubber-like material capable of resisting blow molded temperatures, for example polyacrylic rubber.

Cerone, U.S. Patent No. 4,781,564 discloses an apparatus for reforming soap bars. A lower shaping form and an upper shaping form, which ^'may be replaced by another form to define a differently shaped or highlighted press chamber, are disclosed. The components are preferably formed of a durable structural material such as a hardwood or a molded plastic.

Dietterich et al., U.S. Patent No. 5,413,472 discloses a molding device including first and second mold inserts.

Chittenden et al., U.S. Patent No. 3,380,121 discloses a mold with replacable inserts so that the exterior appearance of a container blown within a mold may be changed without changing the basic shape and capacity of the container. The mold is for blow molding thermoplastic containers. It is said to be standard practice in the mold making industry to use inserts and molds for embossing figures, letters or designs on the article to be produced. Within recesses are provided removable metal inserts defining the walls of mold cavity and forming a surface onto which an article being blown is expanded. Means are provided for securing the inserts within the mold recesses so that the inserts can be easily and readily replaced within and removed from the recesses. It is preferred that the inserts be made of a metal having good thermal conductivity with respect to iron. The inserts themselves may be made of many different materials. The mold sectional body is usually produced from steel .

WO 99/23198 discloses a soap mold for pressing or stamping soap bars. Soap molds are described as having at least one dished cavity to accommodate one-half of the soap bar. An elastomeric part of the soap mold comes in contact with the soap mass to enable the soap to be more readily released. The soap mold of the '198 invention is characterized in that it has a coating that is insertable into the cavity as a prefabricated detachable insert. The insert does not adhere to the mold, but can be removed from the mold substantially in one piece once it has become worn or damaged. The insert of the invention can usefully be provided with markings, for example the name of the soap. Usefully, the insert of the invention has at least one opening for an ejector pin which passes through the opening. The ejector pin ejects soap from the mold after pressing or stamping. Advantageously, the ejector is also coated. The ejector with the coating of the invention can also be formed as a plate or insert. Plastics which may be used to fabricate soap mold inserts can generally be elastomers or non-elastomers. Bakewell, U.S. Patent No. 170,464 discloses a jointed mold with an interchangeable plug for producing words, figures or designs upon the gross article.

The present invention is directed to a modular mold design for molding a detergent bar die elastomeric layer in which the logo forming parts are removable to allow rapid die logo changes without investment in new dies or molds or re- machining and to a process for its use, especially for making elastomeric liners for soap/detergent bar dies. In addition, the mold and dies can be returned to the original design at no additional cost. A key benefit is the capability to rapidly redesign and/or customize soap bars at substantially lower cost.

The invention provides a low cost rapid system of changing soap bar logo designs. The invention preferably utilizes a mold in which the part(s) that form the logo on an elastomer die surface (inserts) comprise one or more separate pieces secured in a common mold body. The insert (s) may be removed and replaced with alternatives of varying logo and surface designs. The elastomeric liners for the dies are then remolded to provide new linings for the stamping surfaces.

The invention reduces the time and cost currently required to deliver a bar logo change. Preferably, only the die mold inserts are changed; the dies and majority of the mold are common to each design. This allows bar logo flexibility at a fraction of the resource of the existing procedure. The invention is also directed to the process of using the molds to make inserts for stamping soap detergent bars of the invention.

The invention is also directed to elastomer layers having surface indicia thereon, dies coated with such layers and the process of using such dies and layers to stamp detergent bars and thereby impart to said bars surface indicia or ornamentation from the elastomeric layer. The elastomer may be formed using the modular molds of the invention.

For a more complete understanding of the above and other features and advantages of the invention, reference should be made to the following detailed description of preferred embodiments and the accompanying drawings.

The invention is also directed to multicavity dies in which entire cavities may be replaced to change surface indicia.

Brief Description of the Drawings

Fig. 1 is a perspective view of multicavity dies which may be utilized in the invention.

Fig. 2 is a cross-sectional side view of a die according to the invention prior to the application of the elastomeric layer.

Fig. 3 is a cross-sectional front view of a die useful in the invention.

Fig. 4 is a cross-section of the die according to Fig. 3 wherein the die has been lined with the elastomeric layer. Fig. 5 is a perspective view of a mold for preparing the elastomeric layer.

Fig. 6 is a perspective view of the mold of Fig. 5.

The use of thick elastomeric coatings in soap bar stamping is described in EP 276971 and U.S. Patent Nos. 4,793,959 and 4,822,273, the disclosures of which are herein incorporated by reference.

Hereinafter by "surface decoration" is meant a uniform shape, smooth surface, a design such as a logo, trademark or the like.

By "elastomeric" according to the invention is meant a material as defined in ISO (International Standard Organization) 1382 as an "elastomer," or a "rubber." Also included in the definition of "elastomeric" materials according to the invention are thermoplastic elastomers and copolymers and blends of elastomers, thermoplastic elastomers and rubbers.

Elastomers are defined as polymers with long flexible chains, independent in the raw material and transformed via vulcanizing or crosslinking agents which introduce crosslinks and form a crosslinked network structure. The network structure retains the movement of the macro- molecular chain molecules and as a result returns rapidly to approximately its initial dimension and shape after deformation by a force and release of the force. With increasing temperature an elastomer goes through a rubbery phase after softening and retains its elasticity and elastic modulus until its decomposition temperature is reached.

Thermoplastic elastomers comprise amorphous and crystalline phases. The amorphous phase has a softening range below ambient temperature and thus acts as an elastic spring while the crystalline segments whose softening range is above ambient temperature, act as crosslinking sites.

Preferably the elastomeric material according to the invention is selected from those classes described in American Society for Testing and Materials D1418 which include:

1. Unsaturated carbon chain elastomers (R class) including natural rubbers e.g. Standard Malaysian Rubber; butadiene e.g. "BUNA' type ex Bunaweke Huls; and butadiene acrylonitrile copolymer e.g.

"Perbunan" ex Bayer.

2. Saturated carbon chain elastomers (M Class) including ethylene-propylene types e.g. "Nordel" ex DuPont and fluorine-containing types e.g. "Viton"

DuPont .

3. Substituted silicone elastomers (Q Class) including liquid silicone rubbers e.g. Silastic 9050/50 P (A + B) ex Dow Corning. 4. Elastomers containing carbon, nitrogen and oxygen in the polymer chain (U Class) including polyurethanes e.g. polyurethanes ex Belzona.

The "elastomeric" material, as hereinbefore defined, may be pretreated, such as by forming a solution of a commercially available elastomer, prior to it being placed in a mold. The elastomers, rubbers, and copolymers and blends thereof are generally cured or crosslinked, in-situ in the mold. For example, the components including the base elastomeric material, cross-linking agents and other materials such as accelerators may be mixed prior to application to the mold. Once applied to the mold the coatings are cured in-situ. This may be aided by the application of heat or other accelerating processes, for example pressure; radiation or UV light.

The elastomeric material may be applied as either a liquid or a semi-solid. For instance, when applied as a liquid, the two halves of the mold are held apart at a predetermined spacing to permit the elastomer to occupy the space between the two parts. Preferably, the mold is filled with elastomer under pressure.

In some cases, materials may be dissolved with an appropriate solvent, applied to the die and the solvent subsequently driven off.

Thermoplastic materials may be heated to melt condition, applied to the mold, cooled and resolidified. Materials suitable as elastomeric coatings in the present invention will preferably have a modulus of elasticity in the range of 0.1 to 50 MPa, most preferably 1 to 35 MPa.

The modulus of elasticity of an elastomeric coating may be measured by recording the force required to indent the coating as a function of the indentation depth. Typically, an indentor with a spherical tip may be employed and the slope, s, of the force as a function of the indentation depth to the power 3/2 is determined. The indentation depth is the movement of an indentor into the coating after it first contacts the surface of the coating. In general, it is necessary to correct the measured indentation depth for the compliance of the measurement apparatus. That is, the actual indentation depth, d, is related to the measured apparent value d' by the following expression

d = d¹ -(F.C)

where F is the indentation force. The compliance C is determined by compressing the indentor against a rigid surface and recording the apparent displacement as a function of the applied force which had a slope equal to C. The modulus of elasticity E is calculated from the following expression

2.

E = H s 1/(R)^1/2 (1 - b ) 3/2 where s = F / d , R is the radius of the spherical tip of the indentor and b is the Poisson's ratio of the coating which is equal to about 0.5 for elastomers.

Under certain conditions to be described hereinafter, the above indentation method may give falsely large values of the elastic modulus due to the influence of the rigid material onto which the coating is applied. In order to avoid this problem it is necessary to ensure that the contact radius of the indentor with the coating does not exceed about 1/10 of the thickness of the coating. The contact radius, a, is related to the indentation depth by the following expression

1/2 a = (dR)

For coatings less than 200 μm, it is recommended that a nanoindentor is used which is capable of measuring indentation forces at small indentation depths using indentors with tips having a small radius. An example of such equipment is the "Nanolndenter II" (Nano-instruments) . The alternative is to make thick (greater than 200 μm) test coatings so that more conventional measurement equipment such as an Instron tester, (eg Model 5566) may be employed.

Preferably, the molds and the dies comprise a rigid material selected from metals and their alloys, for example brass and other copper alloys, aluminum, and steels including carbon and stainless steel; and other non-elastomeric materials such as thermosetting and thermoplastic resins, for example polyester, epoxy resins, furan resins; hard cast polyurethanes; ceramics; composites and laminates.

Additional materials, for example fillers, can be added to the elastomeric material to modify its mechanical and processing properties. The effects of filler addition depends on the mechanical and chemical interaction between the elastomeric material and the filler.

Fillers can be used to modify the elastomeric material such that desirable properties, for example tear resistance, are achieved. Suitable fillers include carbon blacks; silicas; silicates; and organic fillers such as styrene or phenolic resins .

Other optional additives include friction modifiers and antioxidants .

An edge or flange may extend from the die wall to cover the thickness of the cavity coating and preferably the thickness of the coating outside the cavity. The dimensions of the edge for optimal performance are therefore determined by the desired elastomeric layer thickness.

The thickness and hardness of the elastomeric coating may be varied according to the detergent bar composition, processing temperature and/or process parameters such as the shape of the cavity in the die halves, speed of the stamping equipment and separation distance of the die halves, in order to achieve the desired result, for example, good release of the detergent bar from the die. Similarly, for a bar composition which is inherently more difficult to stamp, acceptable die release may be achieved with a thicker elastomeric coating and/or one having a lower modulus of elasticity.

The process of the invention may be used to stamp a detergent bar comprising a surface active agent which comprises substantially soap or a synthetic detergent or a mixture of soap and synthetic detergent. It finds particular application in the stamping of soft and/or tacky detergent and/or mild bars which contain synthetic surfactants, translucent and transparent soap bars having a reduced fatty matter content, for example, in the range 63- 78% wt . with respect to the total bar weight, and those bars containing skin beneficial agents such as humectants, polyols, oils, fatty acids and fatty alcohols.

According to a further aspect of the invention there is provided a process for stamping a detergent bar comprising

i) forming from a mold with a replaceable surface indicia an elastomeric coating layer having a surface decoration therein;

ii) inserting the layer on a die having an edge for delaying tearing of the elastomeric layer;

iii) feeding a detergent bar composition to the die of step ii; iv) stamping the composition in the die to form a stamped bar; and

v) releasing the bar from the die such that a surface decoration is applied to the bar in an easily reproducible manner.

Preferably, the elastomeric layer is bonded to the die stamping surface by mechanical and/or chemical means to increase the adhesion between the die and the layer.

Figure 1 shows die halves 10 comprised of individual dies 12. Each die half is provided, on the bar stamping surface 14, with an elastomeric coating 16 respectively (Fig. 4). Elastomeric coating is also provided on the non-stamping surface 18 of the die halves. One die half is provided with a logo 20 on the elastomeric layer. (In some cases both die halves will incorporate a logo) .

Die 12 includes metal edge 30 which projects inwardly from the upper periphery of the detergent bar cavity 32. As seen in Fig. 4, edge 30 covers the upper edge of the generally vertically ascending section of the coating 16.* Preferably, surface 34 of edge 30 which faces the cavity 32 is at least flush with the surface 36 of elastomer 16 which likewise faces cavity 32. Still more preferred is an arrangement wherein edge 34 of metal edge 30 extends slightly beyond the surface 36 of coating 16.

Using the edge or flange of the invention, the die is constructed so that the soft elastomer near the cutting edge is not damaged when the die cuts into the soap. This is accomplished by shielding the soft elastomer near the die edge with a rigid and stronger material. The shielding acts like an umbrella around the die edge slightly overlapping the soft elastomer preferably by approximately 0.001" to 0.015". This protects the soft material from excess forces in shear and tension which would accelerate damage to the soft material and render the die inoperative.

While the stress relieving edge of the die has been described as being metal, this will generally depend on the material from which the die is made and other materials may be equally suitable. Typically, the edge will be the same as the material from which the die is made. However the edge will typically be fairly rigid to protect the elastomer.

The invention may be used with conventional stamping equipment, such as Binacchi USN 100.

The elastomeric layer 16 is made using mold 80 (Figs. 5 and 6)

Mold 80 includes replaceable section 82 bearing indicia 84. Mold 80 imparts to the elastomeric layer indicia, formed by contact of indicia 84 with the forming elastomeric layer.

Thus, elastomeric layer 36 includes indicia 20 which upon contact with the forming soap and/or detergent bar forms indicia in the soap/detergent bar. When it is desired to change the logo, mold section 82 is slid outwardly and a replacement section with a new logo or other surface indicia is slid into the mold in its place. Stamping of a soap and/or detergent bar with a die lined with an elastomeric formed from the mold will bear the new logo or other surface decoration.

PROPHETIC EXAMPLE

A range of die halves are manufactured in carbon steel and spark eroded to a range of surface roughness values (Ra) degreased with acetone, treated with a primer and lined with a range of elastomeric materials.

A series of brass die halves are also used in the examples. Similarly, these are degreased with acetone, treated with a primer and then elastomeric layers are applied.

Elastomeric layers are formed from polyurethane in molds according to the invention. The polyurethane is prepared starting with

a) Andur 80-5AP - Polyether based liquid isocyanated-terminated prepolymer; and

is cured using b) Voronal 234-630 curative - Triol

The bar compositions used in the examples are as follows Formulation A % wt .

Anhydrous tallow soap 52.3

Anhydrous coconut soap 29.9 Coconut fatty acid 5.2 Water and minors to 100

Formulation B % wt.

Sodium cocyl isethionate 27.00

Cocoamidopropyl betaine 5.00 Polyethylene glycol, M.Wt. 33.12

Fatty acid 11.00

Sodium stearate 5.00

Water + minors to 100

Formulation C % wt .

Sodium cocyl isethionate 49.78

82/18 Soap 8.31

Sodium Stearate 2.98

Alkyl Benzene sulphonate 2.02 Stearic acid 20.15

Coco fatty acid 3.08

Sodium Isethionate 4.68

Water + minors to 100

The dies contain metal edges as illustrated at 34 in Fig 4. It is found that the replaceable sections 82 of the molds may be readily replaced with sections leaving different surface ornamentation to yield well-formed, but different surface ornamentation in the soap/detergent bars. It should be understood, of course, that the specific forms of the invention herein illustrated and described are intended to be representative only as certain changes may be made therein without departing from the clear teachings of the disclosure. Accordingly, reference should be made to the following appended claims in determining the full scope of the invention.

Claims

1. A process for stamping a detergent bar comprising: a) preparing an elastomeric layer in a mold having a replaceable indicia, b) the replaceable mold indicia effecting formation of layer indicia on a surface of the elastomeric layer, c) lining a stamping surface of a stamping die with the elastomeric layer, d) stamping a billet with the lined die to form a detergent bar having detergent bar indicia formed from the elastomeric layer indicia.

2. A process according to claim 1 wherein the replaceable indicia includes a logo.

3. A process for stamping a detergent bar comprising:

lining a stamping surface of a stamping die with an elastomeric layer made in a mold having a replaceable indicia, said layer including indicia formed by the replaceable indicia, and stamping with said lined die a billet to form a detergent bar having detergent bar indicia formed from said layer indicia.

4. A process for stamping a detergent bar comprising:

stamping a billet with a die lined with at least one elastomeric layer made in a mold having a replaceable indicia on a molding surface, said layer including indicia formed by the replaceable indicia, to form a detergent bar having detergent bar indicia formed from said layer indicia.

5. A process according to claim 1 further comprising replacing the replaceable indicia with a different indicia prior to or after preparing the elastomeric layer.

6. A process according to any of the preceding claims wherein the elastomeric layer is chemically adhered to the die stamping surface.

7. A process according to any of the preceding claims wherein the die comprises a rigid material selected from metals and their alloys, thermosetting and thermoplastic resins, hard cast polyurethanes, ceramics, composites or laminates .

8. A process according to any of the preceding claims wherein the die is made of a metal.

9. A process according to any of the preceding claims wherein the elastomeric layer is selected from elastomers, rubbers, thermoplastic elastomers, and copolymers and blends thereof.

10. A process according to any of the preceding claims wherein the elastomeric layer has a thickness within the range of from 25 microns to 10 millimeters.

11. A process according to Claim 10 wherein the thickness of the elastomer layer in said die ranges from 200 to 2,000 microns .

12. A process according to any of the preceding claims wherein the elastomeric layer has a modulus of elasticity within the range of 0.1 to 50 MPa.

13. An elastomeric layer having a surface indicia formed therein.

14. A layer according to claim 13 wherein the indicia is formed by an insert in a modular mold.