Why Use a Vacuum Mixer?
Vacuum mixers prevent air bubbles and thoroughly homogenize ingredients. They also dry materials faster and make more efficient use of energy.
This 5L electric vacuum mixing equipment is programmable in speed, time and rotation direction, implements water cold stainless steel tank to ensure high efficiency in mixing. It is ideal for preparing LiCoO3, LiFePO4, Phosphors and various ceramic slurries without gas bubble which will lead to better dispersion and uniformity of processed materials.
Mixing Goals
Mixing under vacuum is useful for a number of applications. It accomplishes a variety of mixing goals, such as improved aesthetics (imagine a smooth cream or clear gel with no air bubbles) and removal of oxygen to prolong shelf-life, prevent decomposition of sensitive ingredients, or thwart unwanted chemical reactions or microbial growth.
Vacuum mixing eliminates the formation of air bubbles in the product, resulting in more uniformly textured mixtures with higher consistency and superior performance. It can vacuum mixer also help reduce product degradation due to oxidation. This can be especially important in the case of two-part materials such as silicones, urethanes and epoxies.
Manufacturers of cosmetic and pharmaceutical products often face challenges with air bubbles in their finished goods. These bubbles can cause a range of problems, including foaming, air pockets in the final product, or fouling in heat exchangers.
To achieve the best results, it is crucial to use a high-quality mixer that is specifically designed for the application at hand. Vacuum-powered mixers can be used to mix liquids, powders, pastes, ingredients and doughs. They can also be used to remove volatile contaminants from cured polymeric systems, such as composites or adhesives. This helps to ensure the highest quality and compliance with regulatory agencies. It also enables the process to be performed faster, helping manufacturers to produce their products in less time and improve productivity.
Blades
The type of blades used in a vacuum mixer are essential for the success of your mixing process. A single-shaft mixer with cowles mixing geometry can be adequate for low viscosity applications, but may not provide enough agitation for high viscosity materials. The use of a scaper blade helps to ensure adequate movement of material across the dispersing zone.
A single shaft mixer can also be designed with a scraper blade that contacts the tank wall, literally scraping material off the surface of the container and into the dispersing zone. These are typically made of PTFE (Teflon) due to its chemical compatibility and lower rigidity which allows them to move easily against the side of the container.
A rotary disperser utilizes the rotor and stator to create the shear forces needed to dissolve, emulsify and disperse ingredients and achieve a homogenous product. The rotor is rotated at a very high tip speed (the speed of the blade at its outer edge) which creates high levels of energy transfer and intense shear to break up solids and emulsify liquids. The high shear force minimizes the mixing time, thus minimizing the amount of air that is incorporated into the mix. This is especially important for sensitive materials such as stabilizers and aspartame powders. A vacuum mixer with a programmable mixing time is ideal for these materials.
Vacuum Pump
Mixing materials under vacuum helps reduce oxidation and makes the resulting slurry much more uniform. The mixer’s built-in pump is capable of pumping out the volume of air in the mixing container to create a low pressure vacuum condition inside the mixer.
These pumps are designed to handle a wide variety of applications and process conditions. Their main goal is to get the vacuum mixer manufacturer down to a point where the slurry can be mixed without forming bubbles. Several different types of pumps are used to achieve this, including rotary vane and liquid rings.
The rotary vane pump has rotating multibladed rotors and static stator that alternate. As each rotor rotates, the gas molecules are hit by the angled blades and knocked forward or downward. This causes them to be pulled toward the base of the rotor by the centrifugal force generated. Eventually the molecule is pulled into a gap between rotors and is exhausted out of the pump.
Often these pumps operate under oil for sealing and lubrication. The escaping oil mist is unpleasant to breathe and deposits an oil film on surfaces near the exhaust. In most cases the escaping oil carries a small amount of potential toxic constituents, so it is important that the pump be properly filtered and that the exhaust is vented outside of buildings, away from windows.
Safety
Mixing under vacuum reduces air inclusion and eliminates bubble formation, which improves the quality of the finished product. It also reduces oxidation, which is an important consideration when working with dental materials that can deteriorate over time.
When mixing under a vacuum, the emulsifying process occurs more quickly and efficiently. This makes the resulting product smoother, easier to apply and more easily penetrated by the skin. It is also more fluid and less viscous, so it may require a smaller amount of material to achieve the same results as an atmospheric mixture.
While some products can be mixed without the aid of a vacuum, the majority require the use of a vacuum mixer in order to limit excess air and ensure a bubble-free result. Some liquid products such as serums or milks do not need a vacuum mixer as they are already under low atmospheric pressure, so the elimination of air bubbles is naturally done throughout the entire manufacturing process.
Other products that benefit from a vacuum mixer include silicones, adhesives and conductive pastes. THINKY’s ARV-501 is a mid-sized mixer that can be used under vacuum or in non-vacuum mode. The cup holder vacuum design minimizes the volume of the resulting vacuum, which significantly cuts down on the time needed to achieve full vacuum and restore atmospheric pressure after the mixing cycle has completed.