Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N13/00—Investigating surface or boundary effects, e.g. wetting power; Investigating diffusion effects; Analysing materials by determining surface, boundary, or diffusion effects
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N13/00—Investigating surface or boundary effects, e.g. wetting power; Investigating diffusion effects; Analysing materials by determining surface, boundary, or diffusion effects
  • G01N13/02—Investigating surface tension of liquids
  • G01N2013/0241—Investigating surface tension of liquids bubble, pendant drop, sessile drop methods
  • G01N2013/025—Measuring foam stability

Definitions

• the invention relates to a device for foam generation and foam measurement in the case of surfactant-containing cosmetic personal cleansing agents, in particular shower and foam baths, in a friction vessel with an associated foam volume measuring chamber and a friction body arranged rotatably therein.
• the invention is directed to a method for foam generation and foam measurement in the case of surfactant-containing cosmetic body cleansing agents, in particular shower and foam baths, in which surfactant-containing body cleansing agent is foamed between two surfaces that move past each other and the foam is collected in a measuring chamber.
• cosmetic body cleansing agents such as toothpastes, foam and shower baths, shampoos or soaps, in addition to a good cleaning effect, and a characteristic "foam pattern" for the respective preparation.
• aspects such as stability of the foam as a function of time, fat resistance, rinsability, structure, compressibility, lubricity and other mechanical properties play a role.
• the friction between hands and hair is significantly reduced by foaming.
• the foam serves as an indicator of the presence of the last traces of surfactant.
• the dispersion of gas in a low-viscosity liquid is generally not stable. It is only surfactants that accumulate in the liquid lamellae that form stable foam. The function of the Surfactant consists in the formation of viscoelastic films on both sides of the liquid lamella.
• the foam When using cosmetic body cleansers, the foam is usually generated manually, generally with the hands or with a brush, mechanically by incorporating air into the aqueous surfactant phase.
• the amount of surfactant used, the texture of the skin and the washing movement are consumer-specific, so that so far there is no method and no device with which the foam formation in cosmetic body cleansing agents can be determined practically and reproducibly.
• a test method in which a test subject puts a defined amount of shower gel on one arm moistened with water and rubs it over with the moistened hand of the other arm, thus causing the preparation to foam.
• the foam quality is assessed visually on the basis of the foam formed.
• a quantitative measurement of the foam is not possible since the amount of foam is very small.
• the generation of the foam is very strongly influenced by the respective test person, since important test parameters, such as the expression and the relative speed between hand and arm and the nature of the skin (hair, pores) depend on the respective test person. This test accordingly delivers results that are very difficult to reproduce.
• a device and a method of the type described in the introduction is from the article by H. Wil smann "Foam determination of surfactants with a friction foam method" in FAS 55, 1964, p. 753 f. known. Foam is generated in a wire cylinder using a rotating plastic brush. This method is limited in use, however, because the high speed of the brush, even weakly foaming substances, already result in a relatively high and stable foam height. This makes differentiation at different surfactant concentrations difficult. In addition, this method is unsuitable for shower gels, since foam generation with the brush does not come very close to the shower process. Another test method is from Hilton, TB and Liss, RL in Soap. Chem. Specialties 36, No. 8, 50-4 (1960).
• a device is known from DE-PS-37 12 377 in which a liquid is foamed by a stirring propeller rotating therein. From DE-0S-25 51 260 it is known to foaming a liquid by stirring in gas. Furthermore, DE-OS-21 61 172 discloses foam formation by spraying liquid onto a network and / or an autoclave wall.
• the object of the invention is to create a solution with which the foam formation of surfactant-containing cosmetic cleaning agents can be investigated in a practical and appropriate manner and which can be used to obtain suitable and reproducible values quickly and easily for a qualitative and quantitative determination of the foam.
• this object is achieved according to the invention by a friction vessel with a conical inner surface and a rotating inner cone rubbing thereon, the friction vessel and inner cone being movable relative to one another in the axial direction, and with a foam volume measuring chamber arranged on the cover side and a water inlet on the bottom side and process.
• a friction vessel with a conical inner surface and a rotating inner cone rubbing thereon, the friction vessel and inner cone being movable relative to one another in the axial direction, and with a foam volume measuring chamber arranged on the cover side and a water inlet on the bottom side and process.
• the cosmetic body cleanser is easy to apply to the outer surface of the inner cone.
• the foam is produced by rotating the inner cone and rubbing the outer surface of the inner cone and the inner surface of the friction vessel. After a certain test period, the inner cone and the friction vessel can be moved relative to one another, so that there is a gap between the surfaces rubbing against one another. The foam formed can then be washed into the measuring chamber through the water inlet on the bottom and the foam volume that has formed can be measured here.
• a simple measure is the height of the foam carpet floating on the water.
• a particularly practical and almost identical foam formation for use on human skin is achieved according to a further development of the invention in that the surface of the inner cone made of cellulose with closed pores, preferably made of natural rubber, and the inner surface of the friction vessel made of a knob Material, preferably a knob rubber made of a Buna / natural rubber mixture.
• the device in a structurally simple manner, can be realized in that the inner cone is arranged in a stationary and positionally stable manner on a motor-driven stirrer shaft with a torque measuring device and the friction vessel can be moved vertically by means of a lifting device for pressing the surfaces of the friction vessel and inner cone against each other . Due to the motor drive, one is reproducible certain rotational speed of the measuring inner cone can be adjusted and by means of the torque measuring device it can be achieved that the friction housing or the receptacle and the inner cone are guided past each other with the same contact pressure in each experiment.
• a particularly gentle for the foam formed and for the floating in and out of the measuring chamber helpful exit from the friction vessel is achieved according to a further embodiment of the invention in that the friction vessel ver ⁇ above its conical inner area with a funnel-shaped cover with a transition into the measuring chamber is closed.
• the invention provides in a further embodiment that the measuring chamber opens into an overflow vessel. After the experiment has been carried out, water can thus be flushed into the friction vessel through the water inlet on the bottom and from there through the measuring chamber, which flushes the foam into the overflow vessel, from which it can then drain.
• the rinsing water remaining in the grater can run out of the grater from the bottom water outlet.
• the measuring chamber is cylindrical and consists of transparent material.
• the measuring chamber preferably also has a measuring scale.
• the simple construction of the device according to the invention additionally contributes to the fact that the agitator shaft is guided through the measuring chamber.
• the drive motor can be arranged above the device and the agitator shaft can be fed directly axially centrally to the conical inner surface of the friction vessel.
• the invention provides for the test water to be supplied by means of a metering pump.
• the friction vessel is designed to be heatable.
• the invention provides in a further development that the surfactant-containing body cleaning agent can be applied to the inner cone by means of a cannula-like line. In this way, it is possible to bring the friction vessel and inner cone into the experimentally set and desired friction connection before the body cleansing agent is applied.
• the inner cone has an opening angle of 10-15 °, preferably 12 °.
• the friction surface has a size of 70-100 cm 2 , preferably 85-90 cm 2 .
• the object is achieved according to the invention in that the surfactant-containing body cleaning agent is applied to the moistened outer surface of an inner cone, which is rubbed against a conical inner surface of a friction vessel and the resulting foam is then separated ⁇ the inner cone and the friction vessel are washed into the measuring chamber by the incoming water.
• the foaming of surfactant-containing personal cleansing agents can be determined in a reproducible and objectively comparable manner. It has been found that the foam volume formed without Destruction from the friction vessel is to be transported into the measuring chamber if, after moving the inner cone and the friction vessel apart, the foam formed is washed into the measuring chamber by the water flowing in.
• the method according to the invention provides that the foam volume formed in the friction vessel during a test period of 60 seconds and with a quantity of detergent of 1 ml (milliliters) is measured as a measure of the foam formation.
• the invention is advantageously characterized by the use of a device according to one of the device claims for foam generation and foam measurement in the case of cosmetic body cleansers containing surfactants, in particular shower and foam baths.
• FIG. 1 shows a schematic diagram of the device according to the invention
• Figure 2 is a sectional view of the inner cone and the friction vessel with measuring chamber and overflow and in
• Figure 3 shows a section of the grater with an inserted inner cone.
• the device designated overall by 1 in FIG. 1 consists of a friction vessel 2 with a frustoconical inner surface 3.
• the friction vessel 2 is arranged on a lifting device 4, with which it can be moved up and down in the vertical direction (arrow 5) and to be adjusted to a desired height.
• the friction vessel 2 is closed with a funnel-shaped cover 8.
• the lid and the friction vessel 2 are connected to one another by means of a quick-release fastener 9.
• the outlet of the funnel-shaped cover 8 opens into a measuring chamber 10.
• the measuring chamber 10 opens into an overflow 12.
• a stirrer shaft 14 extends from the stirrer 13 and is guided centrally through the measuring chamber 10 along the longitudinal axis of the measuring chamber 10 and establishes a drive connection between the stirrer 13 and an inner cone 15.
• the inner cone 15 is inside of the friction vessel 2 is arranged below the funnel-shaped cover 8 and has a frustoconical configuration which makes it possible to bring the outer surface of the inner cone 15 into full contact with the frustoconical inner surface of the friction vessel 2.
• the outer surface of the inner cone and the inner surface of the friction vessel can be brought into frictional contact with one another by axially displacing the friction vessel.
• the friction vessel 2 is moved vertically upwards from the position shown in FIG. 1 by means of the lifting device 4 until the outer surface of the inner cone 15 and the inner surface 3 of the friction vessel 2 abut one another.
• the experiments for foam generation are carried out in this juxtaposition of the surfaces.
• the agitator 13 has a speed control and a torque measuring device, so that the tests can be carried out at a defined speed and a defined contact pressure.
• test water or normal tap water as so-called rinsing water can be fed to this water inlet 17 by means of a line 18 either from a storage vessel 19.
• the line 18 is connected to the reservoir 19 by means of a line 20, a valve 21 being installed in the line 20 to interrupt this connection.
• the line 18 is connected by a line 22 to the municipal water network, for example, a valve 23 also being arranged in the line 22 here to shut off the line water supply.
• the friction vessel 2 has a water outlet 24 on the bottom, from which a line 26, which can be shut off by means of a valve 25, leads into a drain.
• a line 27 leads from the overflow 12 into the drain.
• the entire device has a height of 1 m and occupies a footprint of 0.6 x 0.6 m.
• the capacity of the grater is 258 ml up to the overflow 12.
• the device or parts of the device shown in FIGS. 1-3 can be supplemented in a manner not shown in that the friction vessel 2 has a heating device. Furthermore, it is possible to additionally provide a metering pump in line 18, in order in particular to be able to supply the rinsing water from line 22 in a metered manner. Furthermore, it is possible to provide a cannula-like line opening on the inner surface 3 of the friction vessel or the outer surface of the inner cone 15, with which a surfactant-containing body cleaning agent, the foaming behavior of which is to be examined with the device, is applied to the outer surface of the inner cone 15 or the latter is to be fed.
• FIG. 2 also shows the relative assignment of the inner cone 15 and the friction vessel 2 in the position that generates the foam to be measured. In this position, the outer surface of the inner cone 15 and the inner surface 3 of the friction vessel 2 rub against each other and the inner cone 15, driven by the stirrer shaft 14, rotates in the direction of the arrow 28.
• the outer surface of the inner cone 15 is made of a material having a knob, especially a knob rubber 29 made of a Buna / natural rubber mixture. This is glued to the body of the friction vessel 2, which is preferably made of PVC.
• the surface of the inner cone consists of a cellular rubber 30, preferably of natural rubber, with closed pores, which is also glued to the surface of the body of the inner cone 15, which is preferably made of PVC. The best test results were achieved with these materials. However, it is also possible to produce the surfaces of the inner cone 15 and the friction vessel 2 in a row from other plastics or nonwovens.
• the opening angle ß 12 °.
• ⁇ 10-15 °
• the foam formed in the experiments can be washed into the measuring chamber 10 without being destroyed.
• a minimum amount of foam must be formed during the experiment. This is very much influenced by the size of the friction surfaces.
• the abutting friction surfaces of the inner cone 15 and the friction vessel 2 have a size of 90 cm 2 in the exemplary embodiment, which has proven to be particularly advantageous.
• the inner cone 15 thus has a height h of 100 mm and a diameter d of 18 m.
• the inner cone 15 is driven at a speed of 200 revolutions per minute.
• a defined contact pressure between the friction surface of the inner cone and the friction vessel can be set, the device also has a torque measuring device, not shown. Because the inner cone 15, which is fixedly connected to the stand 7 via the stirrer shaft 14 and the agitator 13, and the friction vessel 2, which can be moved vertically up and down by means of the lifting device 8, can be moved relative to one another, the contact pressure can be adjusted by adjusting the lifting device Direction 8 can be changed until the torque measuring device acting on the stirrer shaft 14 indicates the desired value.
• the surfactant-containing body cleansing agent to be examined in the device is applied directly to the outer surface of the inner cone 15 as long as the friction vessel 2 has not yet been closed with the lid 8 and the quick-release fastener 9. That is, Only after the surfactant-containing agent has been added is the friction vessel 2 closed and the corresponding surfaces of the inner cone 15 and the friction vessel 2 brought into the rubbing abutment. The foam that forms in the friction vessel during the test is washed into the measuring chamber 10 after the end of the test and measured there.
• the measuring chamber 10 is made of transparent material, preferably of glass or plexiglass, and has a scale.
• the inner cone 15 and the friction vessel 2 are first moved apart by relative movement to such an extent that a gap forms between the friction surfaces, as can be seen schematically in FIG. Subsequently, test water from the reservoir 19 is fed to the grater 2 through the water inlet 17. Due to the test water inflow on the bottom, the foam is slowly suspended with the water level. The foam rises through the funnel-shaped cover 8 into the preferably cylindrical measuring chamber 10. Here, the height difference between the upper and the lower one can now be measured using the measuring scale Foam interface, ie the height or thickness of the foam carpet washed into the measuring chamber 10 can be measured or read. The foam volume can be calculated from the measured foam height and the free cross-sectional area of the cylinder.
• the foam can be rinsed by further water supply, now preferably by supplying rinsing water through line 22 into the overflow 12, from where water and foam enter a drain or spout.
• the inner cone 15 and the friction vessel 2 are first moved into the relative position to one another shown in FIG.
• the friction surfaces are then moistened by supplying test water from the reservoir 19.
• the device 1 is filled with test water through the water inlet 17 until it emerges at the overflow 12.
• the valve 21 is then closed and the valve 25 is opened so that the test water can flow out of the device 1 again through the outlet 24.
• about 1 ml of the body cleansing agent containing tenides is applied to the outer surface of the inner cone 15.
• the friction vessel 2 is lowered again until the gap between the inner cone and the friction vessel, shown schematically in FIG. 1, is formed. Now the valve 21 is opened again so that further test water can flow into the friction vessel 2. Valves 23 and 25 are closed during this time. Test water now flows in until the foam formed has been completely washed into the measuring chamber 10 as a foam carpet floating on the water level. Now the valve 21 is closed. The height of the foam floating on the water level in the measuring chamber 10 is read off. Subsequently, the valve 23 is opened and tap water flows into the grating vessel 2 as rinsing water. With this rinsing water, the foam is rinsed into the overflow 12 and from there passes through the line 27 into a spout.
• valve 23 is closed and the valve 25 is opened, so that the remaining rinsing water in the friction vessel or in the device 1 can run off through the water outlet 24 and can be supplied to a spout.
• the valve 25 is then closed and the device 1 is available for a new experiment.

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• Physics & Mathematics (AREA)
• Health & Medical Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Chemical & Material Sciences (AREA)
• Analytical Chemistry (AREA)
• Biochemistry (AREA)
• General Health & Medical Sciences (AREA)
• General Physics & Mathematics (AREA)
• Immunology (AREA)
• Pathology (AREA)
• Cleaning By Liquid Or Steam (AREA)
• Detergent Compositions (AREA)

Applications Claiming Priority (2)

Publications (1)

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ID=6406232

Family Applications (1)

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Cited By (1)

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Citations (3)

• 1990
  • 1990-05-11 DE DE19904015229 patent/DE4015229A1/de active Granted
• 1991
  • 1991-05-02 WO PCT/EP1991/000834 patent/WO1991018275A1/de not_active Ceased

Patent Citations (3)

Non-Patent Citations (1)

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