JP3044391B2 - How to stamp a bar detergent - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for molding an article having a certain shape by stamping a plastic material using a die.
Method and apparatus. In particular, the present invention relates to a method of stamping a bar detergent.

By "bar detergent" is meant a tablet, cake or bar in which the level of surfactant, including soaps, detergents or mixtures thereof, is at least 20% by weight of the bar.

In the manufacture of bar detergents, a pre-formed composition containing all the components of the bar detergent is typically extruded from a nozzle to form a series of "rods" which are then commonly referred to as "billets". Cut into smaller pieces of predetermined length. This "billet" is supplied to a punching machine, or, for example, a die having the same dimensions as the surface of the bar is used and a force is applied with a die having a shape of a bevel or a roller, and the die is stamped on one or more surfaces thereof. Is applied.

Typically, the stamping machine has dies formed as halves, one surface of each half contacting the billet during the stamping operation. The two surfaces are adapted to correspond to a predetermined separation distance. This compresses the billet sandwiched between the halves of the die, and the bars are separated after being given the final shape and appearance. Excess composition is extruded from the die when both halves of the die close. Usually this is called "burr". The burr is separated from the soap bar by moving the bar through the holes in the "burr strip".

Conventional die stamping machines include a "pin die" form machine in which a pair of opposed die members or two die halves come into contact during the compression stage, and a pair of opposed die members are formed through a box frame. Machines in the form of "box dies", in which the bars placed in the opening are stamped but not contacted during the compression stage, with the peripheral surface of the bars being fixed by a box frame.

Die dies often have a die insert or an ejector insert, respectively. Normally, the insert is held in contact in the die mold by a spring, but can be pushed out by compressed air or mechanical means, helping the bar to come off the die. While the two die halves are closed, a vacuum can be applied to remove air trapped in the die cavity between the bar detergent and the die surface. In the case of a rotating die, this vacuum keeps the bar in place during rotation.

Die-based stamping of a bar detergent is performed to impart a reproducible shape and a smooth surface to the bar and / or to engrave a logo, trademark or the like on at least a portion of the bar surface. You.

However, die blocking occurs, i.e., a considerable amount of residual detergent builds up on the surface of the die half during continued use of the die, and the bar is often formed with visible defects on its surface, and May not come off the surface.

Numerous solutions have been proposed for these problems. One solution is to cool the die half during the stamping operation.

Another solution is described in British Patent Application No. A746769. Accordingly, a die set is disclosed that includes a die box and a pair of companion die members made of a plastic material including a polymer having a specified modulus of elasticity. The disadvantage of this system is that a release agent is required to prevent the detergent from sticking and accumulating on the die and thus damaging the surface of the subsequent bar to be compressed.

Japanese Patent Application No. A56124237 and Japanese Patent Application No. A06064054 disclose a mating type mold for reducing unevenness of a contact surface or a finished surface of a mold surface and thereby obtaining a clean finished product. Discloses a method of using an elastomeric film on the surface of the device. However, it does not suggest that the elastomer surface promotes mold release during the production of a bar detergent. The film is probably very thin. (Japanese Patent Application Publication No. A56124237 discloses a film having a thickness of 5 to 10 μm.) Another solution is proposed in European Patent Application No. 276971. According to that method, two die members are used, each including a non-elastomeric portion and an elastomeric portion. The elastomer portion contacts the bar soap during the stamping process, but includes an elastomeric coating having a minimum thickness of 200 μm and an elastic modulus within the specified range.

A disadvantage of thick paints above 200 μm is that such paints generally have to be applied by performing a casting or molding step on a die. As an alternative, there is a method in which the separated portion is molded and then bonded to a die. In this molding step, it is necessary to produce a die in which the depth of the cavity engraved in the die is deeper than the intended finished depth of the bar. In addition, it is often necessary to use a separate coating jig to coat the ejector.

Shrinkage often occurs while the paint cures. Although the volume is not critical, changes in shape can create a gap between the die and the ejector insert.

Thus, the production of thick coating dies is a complex and expensive process. In addition, although it is possible to recoat the die, there are many difficulties associated with this method. That is, specialist equipment is required to compound and mix the paint, air may be trapped in the elastomer during the recoating process, and it is necessary to remove excess elastomer. is there.
In view of these difficulties, it is often necessary to use expensive professional equipment, which is generally only available at locations remote from the bar detergent manufacturing facility.

U.S. Pat. No. 5,269,997 proposes that each of two dies of a soap mold be provided with an elastomeric partition extending over both surfaces thereof. Such systems are complex to use at the speeds required for product manufacturing, and thin coatings will tend to tear. It is also expected that the quality of the reproduction of the logo will be inferior.

The present inventors can be used to manufacture rods,
Another device has been found in which surface decoration can also be achieved in an easily reproducible manner.

Hereinafter, “surface decoration” means a uniform shape, a smooth surface, a logo, a trademark, and other designs.

Thus, according to the present invention, including one die, the die having at least one bar stamping surface, the bar stamping surface is provided with an elastomeric paint, and the entirety of the elastomeric paint is provided. A bar-like detergent stamping device is provided, wherein the thickness is less than 200 μm.

In a preferred embodiment, the elastomeric paint is the only elastomeric material on the bar stamping surface.

By "elastomer" according to the present invention is meant a material defined in ISO (International Organization for Standardization) 1382 as "elastomer" or "rubber". The definition of "elastomer" material according to the invention also includes thermoplastic elastomers, copolymers and mixtures of elastomers with thermoplastic elastomers and rubbers.

Elastomers are macromolecules that have long soft chains, are distinct from their raw materials, and are transformed via a vulcanizing or cross-linking agent that introduces cross-links to form a cross-linked network. It is defined as a substance. This network structure keeps the movement of high molecular chain molecules. As a result, when the external force is distorted after being distorted by the external force, it rapidly returns to almost its original size and shape.

Upon warming, the elastomer softens, passes through the rubber phase, and retains its elasticity and modulus until the decomposition temperature is reached.

Thermoplastic elastomers consist of an amorphous phase and a crystalline phase. The softening range of the amorphous phase is below ambient temperature and therefore acts as an elastic spring. On the other hand, crystal segments whose softening range is above ambient temperature serve as sites for crosslinking.

Preferably, the elastomeric material according to the invention is selected from the classes described in American Society for Testing and Materials, D1418. Such species include:

1 Unsaturated carbon chain elastomers (R class) Natural rubber (eg, standard Malaysian rubber), butadiene (eg, “BUNA” type manufactured by Bunawerke Huls) and butadiene-acrylonitrile copolymer (eg, Bayer) ("Perbunan", manufactured by Bayer).

2-saturated carbon chain elastomers (M class) Ethylene-propylene type (eg DuPont)
"Nordel" manufactured by DuPont and fluorine-containing type (e.g. "Vito" manufactured by DuPont
n))).

Tri-substituted silicone elastomers (Q class) Liquid silicone rubber (eg Dow Corning
ing) "Silastic 9050 / 50p (A
+ B)).

Elastomers containing carbon, nitrogen and oxygen in the four molecular chains (U-class) polyurethane (eg, polyurethane manufactured by Belzona) is included.

Suitable elastomeric paints have a modulus of elasticity after curing of about 2
Silastic 9050 / 50p A + up to 3MPa
Liquid silicone rubber, such as B (manufactured by Dow Corning), and an elastic modulus after curing of about 9 MPa
Diphenylmethane using Belzona PU2221 and phenylmercury neodecanoate catalyst
Polyurethanes such as the two-component product Belzona 2131 (MP flowing elastomer) based on the 4'-diisocyanate (MDI) system can be obtained as material.

As defined above, the "elastomer" material may be pretreated, such as by forming a solution of a commercially available elastomer, before being applied as a coating to the die surface. In general,
Elastomers, rubbers, and their copolymers and mixtures cure or crosslink intact on the die surface. For example, components including other materials such as base elastomeric materials, crosslinkers, and accelerators may be mixed prior to application as a paint. When applied to the die, the paint cures as it is. This may be facilitated by heating or other facilitating steps, such as, for example, pressing, radiation or ultraviolet light.

In some cases, the material may be dissolved in a suitable solvent and applied to the die before evaporating the solvent.

In the case of a thermoplastic material, it can be heated and applied to the die until it is in a molten state, then cooled and solidified again.

Materials suitable as elastomeric coatings of the present invention preferably have an elastic modulus in the range of 0.1 to 50 MPa, most preferably an elastic modulus of 1 to 35 MPa.

The modulus of elasticity of an elastomeric paint can be measured by recording the external force required to indent the paint as a function of indentation depth. In a typical example,
Using an indentor with a spherical tip, the slope s of the external force is determined as a function of the indentation depth to the power of 3/2. The indentation depth represents the movement in the paint after the indenter first contacts the paint surface. Generally,
Due to the compliance of the measuring instrument, the measured depression depth needs to be corrected. That is, the relationship between the actual recess depth d, the measured apparent value, and the value d 'is expressed by the following equation.

d = d '-(FC) In the above equation, F is a concave external force. Compliance C
Presses the indenter against the rigid body surface and changes the apparent displacement to the slope C
By recording as a function of the applied external force. The elastic modulus E is calculated by the following equation.

In the above equation, s = F / d ^{3 ] 2} , R is the radius of the spherical tip of the indenter, b
Is the Poisson's ratio of the paint, which is about 0.5 for elastomers.

Under certain conditions described below, using the indentation method described above may result in an erroneously large modulus of elasticity due to the effect of the rigid material to which the paint is applied. In order to avoid this problem, it is necessary to ensure that the radius at which the indenter contacts the paint does not exceed 1/10 of the paint thickness. The relationship between the contact radius a and the depth of the depression is expressed by the following equation.

For paints smaller than 200 μm, it is recommended to use nanoindenters. Since the tip of the nano-indenter has a small radius, it is possible to measure the indentation external force with a small depression depth. An example of this device is "NanoIndenter II" (NanoInstrument). Another method is to use an Instron tester (eg, 5566).
Thickening (greater than 200 μm) the test paint so that relatively traditional measuring instruments such as molds can be used.

An advantage of the device according to the invention is that the elastomeric paint is thin and can be easily applied in a factory to a conventional die with a logo engraved. For example, it can be applied using a brushing technique or a spray painting technique such as air-assisted spray painting, airless spray painting or electrostatic painting. If necessary, a plurality of techniques may be used in combination. This is the case when different parts of the die need to be painted with different thicknesses. For example, if a very precise part of the die, such as a logo, requires a special thickness, a spray painting technique can be used with a logo ejector off the die body.

The paint can cure on the die at ambient or higher temperatures, depending on the elastomeric material. High temperatures can be used to evaporate the solvent of the solvent-based elastomer. Other methods, such as UV curing, can be used to accelerate the curing process.

Yet another advantage of the present invention is that the elastomeric paint can be applied to a conventional die. Thus, there is no need to manufacture new dies, as would generally occur when thick paints are used. For thicker coatings, the elastomeric sites typically wear or become damaged during use, which can damage the stamped bar detergent. In that case, the paint must be stripped, the die must be cleaned, fresh paint must be prepared, and remolded on the die surface using expert equipment. By contrast, in the case of the device according to the invention, for example, a suitable chemical treatment (for example, a potassium hydroxide solution in a mixture of ethanol and toluene for silicone paints, and ethanol and / or Or with the help of potassium hydroxide solution in methanol), remove the old paint by mechanical means, etc., treat the die surface, easily replace the old paint with new material and easily recoat the place Is possible. This results in significant savings in both manufacturing time loss and recoating costs.

Preferably, the die is made of metal and its alloys (e.g., brass and other copper alloys, and steels including carbon steel and stainless steel), other non-elastomeric materials such as thermosets and thermoplastics (e.g., polyester, epoxy, etc.). Resins and furan resins), hard cast polyurethanes, ceramics, composites, and rigid materials selected from laminates.

Auxiliary materials, such as fillers, can be added to the elastomeric material to adjust its mechanical and processing properties. The effect of filler addition depends on the mechanical and chemical interactions between the elastomeric material and the filler.

Fillers can be used to modulate elastomeric materials such that desired properties such as tear resistance are achieved. Suitable fillers include carbon black,
Organic fillers such as silica, silicate, and styrene or phenolic resins are included.

Other optional additives include friction modifiers and antioxidants.

Preferably, the thickness of the elastomer coating is 1 μm to 200 μm.
m, preferably at least 10 μm
It is 150 μm, most preferably 15 μm to 100 μm. If the thickness is less than 1 μm, the elastomer coating on the die surface may not be uniform in its application range. 200μm thick
When the value exceeds, it may be difficult to apply the elastomer paint by a simple application technique such as brushing, and the logo may not be reproduced clearly.

One advantage of the present invention is that the thickness and hardness of the elastomeric paint can be reduced by changing the composition of the bar detergent, the processing temperature, and / or the It can be varied by processing parameters such as the shape of the cavity, the speed of the stamping equipment and the separation between the dies.
When certain bar compositions are combined with a simple die without logo, the thinnest within the defined thickness range and the highest modulus elastomeric paint within the defined elastic modulus range achieve acceptable mold release. be able to. However, when a similar composition is combined with a die with a complex logo or a die that accepts a complex shape, an acceptable mold release can be achieved if the paint is close to the maximum thickness within the thickness range and the elastic modulus is relatively small. Achieved. Similarly, for bar compositions that are inherently difficult to stamp, acceptable release may be achieved if the elastomeric coating is closer to the maximum thickness within the thickness range and has a relatively low modulus of elasticity. Thus, while claiming the advantages of using thin paints in the manufacture of bar detergents, the present invention also takes into account varying paint thickness and modulus within defined ranges.

The device according to the invention can be used for stamping a bar detergent containing a surfactant, said bar detergent comprising substantially soap, a synthetic detergent or a mixture of soap and a synthetic detergent. The device is particularly applicable to the embossing of soft and / or sticky bar detergents, which include synthetic surfactants, fat contents, for example 63 to 78 of the total weight.
Included are translucent and transparent bar soaps reduced to the weight percent range, and bar detergents containing skin benefit agents such as wetting agents, polyols, oils, fatty acids and fatty alcohols.

According to another aspect of the present invention, i) forming an elastomeric coating having a thickness of less than 200 μm on at least one of the bar detergent stamping surfaces of the die; ii) applying the bar detergent composition to the die of step i). Iii) stamping the composition in the die to form a stamped bar, and iv) removing the surface-decorated bar from the die in an easily reproducible manner. A method of stamping a detergent bar comprising:

Preferably, the elastomeric coating is adhered to the die stamping surface by mechanical and / or chemical methods to increase the adhesion between the die and the coating.

The die surface may be subjected to some pretreatment before coating with an elastomeric material to improve the adhesion between the die surface and the paint. This pretreatment removes soft boundary layers, such as soft oxides, on metal surfaces, optimizes the degree of contact between the surface and the paint, and / or adheres to topography topography. The purpose is to change the area to increase and to protect the die surface before bonding. Suitable techniques can be divided into three main groups.

1 Mechanical abrasion-The techniques include wire brushing, abraded paper, blasting techniques (such as water blasting, grit blasting, sand blasting and glass bead blasting), polishing (diamond polishing) and spark erosion.

2 Chemical treatments-including solvent cleaning, acid treatment, surface etching (such as using acid), anodizing, and application of a primer or tacky adhesive (silane or silicone, or a combination thereof).

3. Energy surface pretreatment-widely used with non-metallic systems. The technology includes corona discharge, plasma, and laser technologies.

Advantageously, the elastomeric paint is applied not only to the die bar stamping surface of the die, but also to other parts of the stamping machine and other machines in the soap line. For example, a `` burr removal plate '' that separates a stamped bar and a bar composition excessively extruded, a back plate on which a die is installed,
It may also be applied to the non-molded surface of the die.

The present invention is further described with reference to the accompanying drawings and the non-limiting examples described below.

 FIG. 1 is a sectional view of a die containing a bar detergent.

FIG. 2 is a cross-sectional view of the die in a closed position with a bar detergent stamped between the die halves.

FIG. 3 is a cross-sectional view of the die in the open position after the stamping operation.

FIG. 4 is a plan view of a carbon steel die used in the following examples.

FIG. 5 shows the logo produced by the die half used in the examples below.

FIG. 6 is a cross-sectional view of the central portion of the bar detergent stamped with the die of FIG. 4 and having the logo shown in FIG.

The drawings are described in detail. FIG. 1 shows a die 1 including a split die half. The die forms each include a rigid member 2,3. Each die mold has its bar mold stamping surface 9, 12
Are provided with elastomer paints 5 and 6, respectively. The elastomeric paint is also applied to the die half surfaces 8, 10, 11 and 13. On one die, a logo 14 is engraved on the bar-formed surface of the rigid member 3 (in some cases, the logo is incorporated into the die half). The logo is also elastomer paint 6
Coated with.

FIG. 2 shows the die in the closed position, wherein the bar detergent 4 is stamped with a logo.

FIG. 3 shows the die in the open position after stamping. Due to the elastomeric coating 5, the billet can easily be removed from the die 2. Due to the paint 6, the billet can be easily removed from the other die 3 as well.

FIG. 4 shows a die mold 15 having needle holes 17, 18 for aligning and fixing the die cavity 16 and the die mold on the stamp. The cavity is provided with an opening 19 in which an ejector for producing a logo is placed. Hole 20 represents a passage through which a vacuum can be applied during use of the die in a stamping operation.

FIG. 5 shows a die cavity 16 complete with an ejector producing a logo 21.

Example The launch used for the trial was Binacci USN100 (Binacchi U
SN 100).

A series of die molds were made of carbon steel. The surface erosion values (Ra) shown in the table were obtained by spark erosion. After degreased with acetone, treated with a primer and coated with a series of elastomeric materials.

The examples also used a series of brass die dies. These were also degreased with acetone, treated with a primer, and coated.

In the examples, the elastomeric paint was made of a polyurethane or silicone material.

 The polyurethane used was as follows.

PU-polyurethane-Belzona 2221 (MP Fluid Elastomer) is a binary product based on toluene diisocyanate (TDI) and a polyol / phenylmercury neodecanoate catalyst. Xylene was added to reduce the viscosity of the TDI component. The resulting mixture was mixed with a polyol and a catalyst and applied to a die. The coating was cured on the die surface at ambient temperature.

PUA-Belzona 2221 modified and adjusted with xylene as described above and further with the addition of polypropylene glycol to reduce the modulus of the paint, mixed with three components, TDI / xylene, polyol / catalyst and polypropylene glycol, resulting in The material was applied to the die surface and cured.

KE-Kemira Durelast is an integrated system consisting of a polyurethane prepolymer based on diphenylmethane 4,4 'diisocyanate (MDI), the tip of which is isocyanate. After exposure to atmospheric moisture at ambient temperature, the paint was applied to the die surface and cured.

The primer used for the polyurethane was Verzona 2921 (an elastomer based on MDI / dichloromethane solution)
GP conditioner).

The silicone-based materials used as the elastomeric coatings were as follows:

Liquid silicone rubber, Silastic 9050-50P Part A and Part B from Si-Dow Corning Co. The two parts were mixed at room temperature to produce this coating. The resulting mixture is brushed onto the die surface, 200
Cured at ° C.

HS-Silastic HS500, a peroxide-cured silicone elastomer manufactured by Dow Corning, Inc. A premixed silicone elastomer and peroxide were dissolved in white spirit and brushed onto the die surface. Next, heating was performed to accelerate the curing system.

Silicone elastomer (Dow Corning 3-6060)
95% methyl isobutyl ketone, 2% polysilicate, isopropoxybis (acetylacetonate)
A primer containing 1% titanium and 2% acetoxy-terminated dimethyl, methylvinylsiloxane was diluted with white spirit.

The bar composition used in this example was as follows.

Formula A weight% anhydrous tallow soap 52.3 anhydrous coconut oil soap 29.9 coconut oil fatty acid 5.2 water etc. Add to total weight% 100 Formula B weight% sodium cocosyl isethionate 27.00 cocoamidopropyl betaine 5.00 polyethylene glycol M.Wt 33.12 fatty acid 11.00 Filler 10.00 Sodium stearate 5.00 Water and others Add to total weight% 100 Formulation C Weight% Sodium kosyl isethionate 49.78 82/18 Soap 8.31 Sodium stearate 2.95 Alkylbenzene sulfonate 2.02 Stearic acid 20.15 Palm oil fatty acid 3.08 Sodium isethionate 4.68 Water and others Add 100% by weight.

For Examples 1-7, a carbon steel die was used.
In Example 8 and Comparative Examples 1 * and 2 *, a brass die was used. In 1 * and 2 *, no die coating was applied to the die surface.

All examples were evaluated for die block / die release and logo reproducibility.

Die block / die breaks were evaluated visually and scored according to a certain scale. A rating of 1 indicates that the bar is free to detach from the die, and a rating of 5 indicates that the bar sticks to the die and does not separate.

Logo reproduction was visually evaluated with a bar detergent removed from the die, and scored according to a certain scale. Rating 1
Indicates that all details of the logo have been reproduced, and a score of 5 indicates that the details of the logo have been at least partially erased and the outline of the logo is not sharp.

It is clear from the results that thin paints can be used to stamp various product formulations and to obtain excellent die block / die release and logo reproducibility.
When no elastomeric paint was applied, the bar detergent did not come off the die.

Continued on the front page (72) Inventor Edmundson, Bryan United Kingdom, Cesier el 64.0 TA, South Wirral, Neston, Hampton Crescent 42 (72) Inventor Neuhof, Mario Peter Germany Country, Day 35644 Hohenard-Altenkirchen, Birkenbeek 11 (72) Inventor Story, Edward Ross United Kingdom, Merseyside El 605.5 Art D'Aubrille, Wirral, Hess Wall, Brian Drive Drive 19 (56) References JP-A-56-124237 (JP, A) JP-B-6-4879 (JP, B2)

Claims (14)

(57) [Claims] 1. A bar-shaped detergent stamping device including a die,
The die has at least one bar-shaped detergent stamping surface,
Apparatus characterized in that said bar-shaped detergent stamping surface comprises an elastomeric paint and the total thickness of the elastomeric paint is less than 200 μm. 2. Apparatus according to claim 1, wherein the elastomeric paint is the only elastomeric material on the bar detergent stamping surface. 3. The method of claim 1, wherein the die comprises a rigid material selected from metals and alloys thereof, thermosetting resins and thermoplastics, hard cast polyurethanes, ceramics, composites and laminates. Item 3. The apparatus according to Item 2. 4. An elastomer coating comprising an elastomer, rubber,
3. The device according to claim 1 or 2, wherein the device is selected from thermoplastic elastomers and their copolymers and mixtures. 5. An elastomer coating material having a thickness of 1 μm to 200 μm.
3. Apparatus according to claim 1 or claim 2 in the range of less than m. 6. The method according to claim 1, further comprising a deburring plate coated with at least one elastomer paint.
Item 3. The apparatus according to item 2 or 2. 7. The apparatus according to claim 1, further comprising a back plate to which a die is attached, wherein the back plate is coated with at least one elastomer paint. 8. An elastomer coating material having an elastic modulus of 0.1 to 50 MPa.
3. Apparatus according to claim 1 or claim 2 which is within the range. 9. A method for forming an elastomeric coating on a stick-type detergent stamping apparatus, comprising: i) pretreating the apparatus by a chemical and / or mechanical method to form an adhesive surface for the elastomeric coating. And ii) applying said elastomeric paint characterized in that the thickness is less than 200 μm. 10. The method according to claim 9, wherein the mechanical method is a surface cleaning method selected from wire brush, abrasive paper, blasting method, spark erosion, polishing and a treatment using a combination thereof. Method. 11. The method of claim 9 wherein the chemical method is selected from solvent washing, acid treatment, surface etching, use of a primer, use of a tacky adhesive, and combinations thereof. 12. A method of stamping a bar-like detergent using the apparatus according to claim 1 or 2. 13. The method of stamping a bar-like detergent according to claim 12, wherein: i) a thickness of at least one of the bar-like detergent stamping surfaces of the die is 20;
Forming an elastomeric coating of less than 0 μm; ii) sending the bar detergent composition to the die of step i); iii) stamping the composition in a die to form a stamped bar detergent; And iv) removing the bar detergent from the die so that the surface decoration can be applied in an easily reproducible manner. 14. The method according to claim 12, wherein the surface decoration is a logo, a trademark, or the like.