Cream cosmetics are emulsion that mainly consist of oil, fat, wax, water, emulsifiers and etc. It can form a protective film which supplies appropriate moisture, oil or nutrients to the skin, thus protecting the skin from external unfavorable factors, as well as delaying aging and maintaining skin health. The viscosity of cream emulsion is relatively high, and it is necessary to fully mix and disperse the oil phase and water phase to produce nano-sized emulsion for better absorption.
For different cosmetics, different dispersion solutions are applicable. The following are several application cases of homogenziers in the cream cosmetics industry.
Case I: Dispersion of Liposomes by TRILOS Ultra-high Pressure Nano Homogenizer
1. Case Description:
The primary emulsion sample of a well-known domestic cosmetics company was dispersed at 1000 bar using a certain German imported high pressure homogenizer, but the stability and dispersibility of the obtained liposomes were poor. To improve the effect, a better solution is urgently needed.
2. Application Solution:
TRILOS Ultra-high Pressure Nano Homogenizer (hereinafter referred to as "Nano Homogenizer") adopts the high pressure homogenization technique, which can generate huge shear force, collision force and cavitation force in a short time, hence a large amount of energy is concentrated on the material, making the components of the material exist in a completely homogeneous state and dramatically enhancing the efficiency.
Nano Homogenizer doesn’t clog or leak. The touchscreen can monitor the pressure curve in real time. Its maximum pressure can reach 4000 bar.
Figure 1. Schematic diagram of Nano Homogenizer
Figure 2.TRILOS Ultra-high Pressure Nano Homogenizer
3. Experimental Description:
First , the primary emulsion sample is pre-processed by a mixer; and then Nano Homogenizer is used to manufacture NLC liposomes; Last, Lisco dispersion and homogenization analyzer is used to test the dispersion stability of the sample.
4. Dispersion Experimental Process:
The primary emulsion pre-processed by a mixer is placed in the Nano Homogenizer and homogenized 5 times at 1000 bar to obtain NLC liposomes (Figure 3).
Figure 3. Manufactured NLC liposomes
5. Dispersion Stability Experimental Results:
Good cosmetics should meet the requirements in terms of stability, functionality, usability and safety. All of requirements should be considered as designing the cosmetics formula. Essentially, dispersion stability is the basis of the other requirements. Therefore, the investigation of sample dispersion stability is an important part in the project development process.
Figure 4. Lisico dispersion and homogenization analyzer (nuclear magnetic resonance method)
We use the Lisico dispersion and homogenization analyzer to test the dispersion stability of the sample. The results are shown in Figure 5. NLC-0 is the primary emulsion among the samples. NLC-1 to NLC-5 are the NLC liposomes after being processed 1 to 5 times at 1000 bar, respectively. It can be seen from the figure that after homogenization once, the relaxation time of the sample decreases significantly, indicating that its dispersion stability is greatly improved. With the further increase of the homogenization times, the relaxation time of the sample increases slightly. After homogenization 5 times, the relaxation time of the NLC-5 sample reaches the minimum, and the dispersion stability is the best.
Figure 5 Relaxation time of each sample
Case II: Dispersion of Sleeping Masks, BB Creams and Liquid Foundations by Rotor-Stator mixers
The main working principle of the high-shear mixer is to force the mixed liquid to pass through a very narrow gap at a high speed through mechanical action. Under the hydrodynamic effects, a large shear effect is generated, so that the dispersed phase particles or droplets are broken to achieve the purpose of homogenization and emulsification. A relatively advanced high-shear homogenization and emulsification equipment is the rotor-stator mixer, which mainly consists of a stator and a concentric high-speed rotating rotor. The gap between the stator and the rotor is very small, and the rotation speed of the rotor is very fast.
Trilos high-quality, high-speed electric mixers are used for dispersion, homogenization, emulsification, shearing and crushing. They can be used handheld or fixed, are easy to operate and have excellent performance.
1. TRILOS D-9 High-Speed Overhead Mixer:
It is a digital brushless high-speed mixer that does not produce carbon powder, which avoids sample contamination. It has an ultra-wide speed range of 3,000 - 25,000 rpm and quiet operation. It can maintain a constant speed when processing samples with a large volume and increasing viscosity.
Volume range: 0.1-20000 ml
Speed range: 3000-25000 rpm
Speed adjustment: stepless speed control
Size of mixer main body (diameter × length): 92X183X177mm
Trilos D-9 Mixer is used to process the gel-like sleeping mask, and the required effect could be achieved after homogenizing for 2-3 minutes (Figure 6).
Figure 6 Processing of sleeping mask with Trilos D-9 Mixer
2.Trilos D27 High-end Mixer
2.1 BB Cream
BB cream is a kind of liquid cream. Since the liquid cream has fluidity, it is often difficult to maintain stability and is prone to stratification during storage. Therefore, its production process is more difficult than that of solid production. To maintain the stability of the liquid cream, BB cream has one more powder raw material than ordinary cream and one more color paste grinding process. In the production process, an inline high-efficiency emulsification equipment must be used to obtain even and fine emulsified particles and attain emulsification stability.
BB cream preparation process:
(1) Preparation of the oil phase: Add oil, fat, wax, emulsifiers and other oil-soluble components to the dispersion tank, turn on the inline continuous disperser D27, and make them fully even and ready to use. For a 2500 mL sample, at a rotation speed of 17000 rpm, it needs to be homogenized and emulsified for 30s to achieve the expected results.
(2) Preparation of the water phase: add deionized water to the jacketed dissolving tank, and add water-soluble components such as glycerol, propylene glycol, sorbitol and other moisturizers, alkalis, water-soluble emulsifiers, etc., then stir them.
(3) Emulsification: Slowly add the above water phase materials to the oil phase materials in the emulsification tank, and stir and emulsify for a certain period of time.
After emulsification, the emulsification system passes through the D27 emulsifier for thickening at one time, and the whole process is completed by passing through once, and the finished product is directly discharged. It passes through at 15000 rpm.
2.2 Liquid Foundation
Liquid foundation is a very popular type of foundation cosmetics nowadays, suitable for most skin types. It is an emulsion-like cosmetic with added powder. It is mainly made by taking advantage of the good compatibility between powdered pigments and glycerol and water.
Liquid foundation preparation process:
The liquid foundation sample pre-processed by the mixer is placed in the D27 emulsifier to process for several minutes, and the finished product is directly discharged. It passes through at 20000 rpm.
Figure 7 Processing of BB cream and liquid foundation with TRILOS D27 disperser
Advantages of the D27 Inline High-speed Dispersion System:
1. The D27 emulsification system adopts a German original 316L dispersion head. Under high-speed rotation, the product can obtain a very fine particle size and high uniformity, thus greatly improving the quality and stability of BB cream and liquid foundation. The product is fine and not prone to stratification.
2. The inline emulsification system rarely generates bubbles, and the paste is uniform and extremely fine.
3. It saves time. There is no need for long processing time, saving production time and avoiding the damage to the product caused by high temperature generated during long processing.
Conclusion:
The above experiments can prove that using our Nano Homogenizer can effectively solve the customer's demand for liposome dispersion after 5 treatments, and the stability reaches the best. In addition, the Trilos electric dispersers series have a good dispersion effect on sleeping masks, BB creams and liquid foundations, providing consumers with high-quality products as well as reducing production costs to a certain extent.
