Improved retention of stick preparations

Abstract

The base plate (A) of a stick applicator for the application of masses that are dimensionally stable in the temperature range of -10°C to +50°C has been modified with regard to its dimensioning, resulting in improved anchoring of the mass on the base plate (A).

Description

[0001] Improved support for embroidery designs

[0002] The invention is a base plate of a stick applicator for the application of masses that are dimensionally stable in the temperature range of -10°C to +50°C, and a stick applicator comprising such a specific base plate.

[0003] In cosmetics, various application forms of solid preparations are offered.

[0004] So-called stick preparations, such as deodorant sticks, are well-known. The stick mass is solid at room temperature and is distributed on the skin by rubbing.

[0005] These embroidery preparations are applied to surfaces, such as human skin, via embroidery applicator containers and are characterized by the following features.

[0006] The applicator tube has at least one opening through which the stick preparation can be transferred to the skin, for example, by abrasion. The applicator has a mechanism by which the preparation can be moved out of the opening. Such an applicator has the advantage that, after the top layer of the preparation has been abrasioned, it can be extended further out of the opening, allowing for further application. Applicator containers of this type are widely known in the prior art for lip balms or deodorant sticks, e.g., Nivea Dry Comfort Stick, Rexona Cotton Dry, Axe Leather & Cookies, Old Spice.

[0007] The preparation, primarily cosmetic stick preparation, is stored in the application container on a closed or partially open platform, also called a base plate, which can move the cosmetic preparation in the application container towards the opening via a screw thread.

[0008] These dispensing pens contain a centrally located spindle rod within the pen housing, extending to the dispensing area of ​​the dispensing material. The stick preparations are attached to a lower base plate within the sleeve, which engages with a spindle. The stick material rests on the base plate, which features segmented ribs, stiffening elements, and / or grids that secure the stick material to the plate or allow the stick material to enclose the base plate, forming a bond.

[0009] The spindle rod carries the base plate, also called the piston or slide, which is moved vertically when the spindle rod is rotated, thereby conveying the dispensing compound upwards or downwards depending on the direction of rotation. Due to its central position within the dispensing pin housing, the spindle rod is also centered within the dispensing compound. To apply the dispensing compound, the spindle rod is turned using a handwheel located at the bottom of the sleeve. This action raises the base plate, with the compound resting, anchored, or connected to it, out of the outlet(s) of the head and onto the application surface.

[0010] The embroidery materials are dimensionally stable at room temperature, advantageously firm, and can be rotated or pushed out of the sleeve via the spindle.

[0011] The stroke of the piston, the distance it moves up and down with each revolution of the spindle, can be varied by adjusting the pitch of the spindle threads. This allows the dispensing quantity of material per spindle revolution to be selectively adjusted.

[0012] After use, the preparation mixture can be moved back into the sleeve using the spindle.

[0013] As the sticky mixture moves up and down along the inner wall of the casing, friction occurs between the mixture and the casing's inner wall. To minimize friction, the inner casing has a smooth, continuous surface, at least in the area where the mixture is held.

[0014] The preparation or its components can also help to keep friction as low as possible, for example through oils or fats, which in turn can influence the properties and feel of the preparation to be applied.

[0015] To be used as a stick, the stick formulation ideally has a dimensionally stable consistency in the temperature range of -10°C to +50°C.

[0016] This means the preparation should not flow within this temperature range. The yield point is the lowest shear stress above which a plastic material behaves rheologically like a liquid (DIN 1342-1: 1983-10). The yield point is determined by recording a flow curve (based on DIN 53019: 1980-05; DIN 53214: 1982-02). Preparations according to the invention therefore have a yield point above this temperature range. Ideally, the preparations are dimensionally stable, preferably solid, within this temperature range.

[0017] The problem is that with the dimensionally stable, solid preparation forms, the mixture often tears or breaks off the base plate when being removed and especially when being screwed back in.

[0018] Surprisingly, a geometry of the base plate according to the invention significantly improved the anchoring of the stick-type material to the base plate. The invention is a base plate for stick applicators for the application of materials that are dimensionally stable in the temperature range of -10°C to +50°C and are supported on and against the base plate. The materials are applied to surfaces, particularly human skin, primarily by abrasion. The base plate is characterized by a thickness D in the range of 2–15 mm, particularly in the range of 5–10 mm, preferably 8–9.5 mm. The base plate has grid-shaped ribs, the ribs having a depth T in the range of 1–20 mm, particularly 2–8 mm, and the holes formed by the ribs are through-holes in the base plate.

[0019] D is the outer thickness or height (in mm) of the base plate. T is the depth or height (in mm) of the inner webs of the base plate.

[0020] Figures 1 and 2 show and explain the preferred sizes and dimensions of the base plate.

[0021] The invention also includes a stick applicator for the application of masses that are dimensionally stable in the temperature range of -10°C to +50°C, comprising an applicator shell containing the mass, and at least one base plate according to the invention that is movable in the applicator shell and on which the mass is mounted.

[0022] The base plate is dimensioned according to the applicator housing in order to move smoothly within it and has a thickness D in the range of 2 - 15 mm, in particular in the range of 5 to 10 mm, preferably 8 to 9.5 mm, and grid-shaped ribs, wherein the ribs have a depth T in the range of 1 to 20 mm, in particular 2 - 8 mm, and the holes formed by the ribs in the base plate are continuous.

[0023] If the applicator housing is round in top view, the base plate should also be able to move smoothly around the circumference within the housing. Ideally, the applicator housing, and therefore also the base plate, should be oval, as shown in Figure 1.

[0024] Preferably, the length of the major major axis a of the elliptical shape of the base plate is selected to be in the range of 10 to 100 mm, in particular 20 to 60 mm, and the length of the minor axis b is selected to be in the range of 5 to 40 mm, preferably 10 to 30 mm.

[0025] The largest diameter of an ellipse is also called the major axis a, with half of it (a / 2) being called the semi-major axis.

[0026] The minor semi-axis (b / 2) is half the shortest diameter, the minor axis b, and is at an angle of exactly 90° to the major semi-axis.

[0027] The base plate is preferably curved in the side view (see Figure 1, section AA). The stick applicators according to the invention are constructed from known packaging materials, such as polyvinyl chloride (PVC), polyethylene (PE), polypropylene (PP), or polybutene (PB). The base plate is advantageously made of such materials, preferably polypropylene (PP).

[0028] The surface finish of the base plate, especially the ribs, at the contact surfaces with the nitrogen mass can be smooth or roughened, preferably roughened.

[0029] The mean roughness value Ra is a measure of the roughness of a technical surface. The standardized roughness values, surface roughness values, are given in Ra [pm].

[0030] Ra 0 - 0.7 : Polished to slightly polished

[0031] Ra 0.8-1.0: Fine matt

[0032] Ra 1.0 - 2.8: Matte surface

[0033] Ra 3.2-18: Rough surface

[0034] The surface roughness of the surface of the base plate according to the invention, in particular the surfaces that are in contact with the nitrogen mass, is preferably in the range of Ra 1.0 to 20, preferably 3.2 - 18.

[0035] The comparative experiments clearly showed that a higher holding force is generated with a surface roughness of up to 18 Ra than with a surface roughness below 3 Ra. This means that, according to the invention, higher and therefore improved adhesion forces develop between the nitrogen mass and the base plate.

[0036] The vertical surfaces of the ribs in the base plate, which are parallel to the direction of movement and have a depth T of up to 20 mm, increase the adhesion area between the pin material and the base plate, thereby achieving improved retention and anchoring of the pin material to the base plate.

[0037] The depth T of the webs can be equal to, greater than or less than the thickness D of the base plate, as illustrated in Figures 1 to 3.

[0038] Figure 1 shows a preferred base plate according to the invention. The length of the main axis a of the ellipsoidal base plate shape is advantageously 53.45 mm and the length of the secondary axis b is advantageously 22.08 mm.

[0039] The grid-like arrangement of the ribs in the base plate according to the invention is preferably designed such that the spacing of the ribs is selected to be between 3 and 10 mm. The ribs are advantageously straight, i.e., not curved, and preferably arranged parallel or perpendicular to each other. In another embodiment, the ribs can also be wavy or curved.

[0040] Figure 2 shows a base plate A according to the invention with ribs 1 and the holes or recesses 2 formed by them. In the middle is the thread 3 through which the base plate can be moved in the applicator housing by means of a spindle.

[0041] The applicator advantageously comprises, in addition to the casing, a rotating unit mounted on the base, a mechanism with which the base plate can be moved vertically within the casing, such as a thumbscrew. Using this rotating unit, the base plate can be moved within the casing, for example, via a spindle. The base plate includes a centrally located opening that engages with the spindle, for example, by means of a thread.

[0042] In another embodiment, the applicator can be equipped at the bottom with a simple, so-called push-up system, which makes it possible to simply push the base plate, along with the stick attached to it, upwards.

[0043] The upper opening of the applicator is equipped with a closure, for example with a removable lid.

[0044] Furthermore, the stick applicator according to the invention is basically constructed like known applicators for masses that are solid at room temperature, such as deodorant sticks.

[0045] In various comparative tests, the anchoring strength of different adhesive masses on different base plates was investigated using tensile tests.

[0046] The primary objective of the tensile tests is to create a force-displacement diagram to define the holding force between the base plate and the nitrogen mass. By applying tensile forces to the prepared specimens in a tensile testing machine, the holding force is recorded until detachment from the base plate and graphically represented as a force-displacement diagram. This diagram shows how much force is exerted on the nitrogen mass and how far it moves. This provides important information about the strength and holding capacity of the nitrogen mass. The defined goal is therefore to gain precise insights into the holding force of the specimens through these tests and to assess the reliability of their maximum holding force before detachment.

[0047] Tables 1 and 2 show the results of the comparative tests.

[0048] The tests were carried out using a Zwick tensile testing machine with a newly developed holding device. Sixty runs were performed for each version. Holding the bar mass in the machine did not result in any damage or weakening of the respective masses.

[0049] As a result, a force-strain diagram was created. The diagrams show how the materials behave under increasing force. This allows conclusions to be drawn about the bond between the nitrogen mass and the mounting plate.

[0050] The parameters and the respective force-strain diagram are shown in the following tables and figures 6 to 11.

[0051] Tests Ref, V1 to V5 were carried out using an emulsion stick preparation of Example 1. Figure 4 shows the six different base plates tested.

[0052] Table 1:

[0053] The stability tests show an improved holding force for the base plate V4 according to the invention.

[0054] The force-strain diagrams (Figs. 6 to 11) show that only the base plate according to the invention enables a holding force of over 60 N before the mass detaches from the base plate or tears off. Further comparative investigations examined the influence of the roughness of the base plate walls and the inner surface of the webs.

[0055] These experiments were carried out using the emulsion stick preparation of Example 1.

[0056] In this test series, the holding power of only two base plates was tested against each other.

[0057] The reference base plate (Ref) was tested against the base plates M2 and M4 according to the invention, as well as the base plates M1 and M3. M1 and M2 have smooth web surfaces, while M3 and M4 each have roughened web surfaces with a Ra of 18.

[0058] Table 2 shows the test results:

[0059] Here too, the base plates (M2, M4) according to the invention, with both smooth and roughened web surfaces, show better holding forces than the comparison base plates.

[0060] Figure 5 shows the tested floor panels.

[0061] Below is an overview and examples 1 to 5 of possible embroidery masses. The figures refer to weight percentages of the total mass of the preparation. By means of the base plate according to the invention, these embroidery masses showed an improved hold on the base plate, which largely reduced or completely avoided breakage during use in the embroidery applicator.

[0062] The base plate according to the invention can therefore be used for improved anchoring of a dimensionally stable mass in the temperature range of -10°C to +50°C on the base plate of a stick applicator.

[0063] Likewise, the base plate according to the invention can be used in a stick applicator for the application of cosmetic deodorant preparations that are dimensionally stable in the temperature range of -10°C to +50°C.

Claims

Patent claims 1. Base plate of a stick applicator for the application of dimensionally stable masses in the temperature range of -10°C to +50°C to surfaces by abrasion, which are mounted on the base plate, characterized in that the base plate has a thickness D in the range of 2 - 15 mm, in particular in the range of 5 to 10 mm, preferably 8 to 9.5 mm, and grid-shaped ribs, wherein the ribs have a depth T in the range of 1 to 20 mm, in particular 2 - 8 mm, and the holes formed by the ribs are continuous in the base plate.

2. Base plate according to claim 1 characterized in that the base plate is oval in shape as an ellipse and the length of the major principal axis a of the ellipse shape is in the range of 10 to 50 mm, in particular 20 to 30 mm, and the length of the minor semi-axis b is in the range of 5 to 20 mm, preferably e to 13 mm.

3. Base plate according to claim 1 or 2 characterized in that the contact surfaces of the base plate with the nitrogen mass are roughened, in particular with a surface roughness of at least 1 Ra, preferably 1 to 20 Ra, in particular 3.2 to 18 Ra.

4. Base plate according to one of the preceding claims, characterized in that the The webs are arranged parallel or perpendicular to each other, and the spacing between the webs is chosen to be between 3 and 10 mm.

5. Stick applicator for the application of masses dimensionally stable in the temperature range of -10°C to +50°C comprising an applicator shell containing the mass, at least one base plate movable in the applicator shell according to one of the preceding claims.

6. Use of a base plate according to one of claims 1 to 4 for improved anchoring of a dimensionally stable mass in the temperature range of -10°C to +50°C on the base plate of a stick applicator.

7. Use of a base plate according to claim 6 in a stick applicator for the application of cosmetic deodorant preparations that are dimensionally stable in the temperature range of -10°C to +50°C.

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