The Many Uses of a Vacuum Mixer
Vacuum mixers remove atmospheric oxygen from a mixture during mixing, thus preventing the decomposition of air-sensitive compounds. This is particularly important for thicker materials like pastes and gels.
This model features a powerful 3 horsepower motor and large capacity mixing pot capable of eliminating air during the matrix blending process for void-free cast solid surface materials. It also eliminates air during the drying process for faster processing.
Preparation of cements and amalgams
A vacuum mixer is an effective tool for preparing cements and amalgams. Unlike conventional mixing methods, the vacuum mixer can reduce air bubbles and improve the quality of the final Vacuum Emulsifying Mixer product. In addition, it is safer to use than traditional equipment and can save energy. It can also increase productivity and reduce the cost of production.
The present invention relates to a cartridge mixer for transferring monomer to a two component bone cement, in particular a meth)acrylate polymeric material. The monomer is preferably contained within an ampoule containing the liquid component of the bone cement. The cartridge mixer is provided with a diaphragm layer 55, e.g. made of a plastic such as polyethylene, that is air-impermeable. This diaphragm is disposed across the first end 19 of the cartridge body member 9, and is bowed at 57 as shown in FIG. 5. This releasable hermetic seal allows the monomer to be transferred from the ampoule to the cartridge mixer without a need for personnel to closely monitor this transfer with a needle or stopcock as is required with conventional syringe techniques or conventional stopcocks.
The device comprises a cartridge mixer incorporating the above-described hermetic seal and a glass ampoule for storing the monomer to be transferred to the cartridge mixer. The cartridge mixer is further provided with a polyethylene ball 89 which can be inserted in the ampoule prior to insertion of the monomer into the cartridge mixer so as to provide a positive sealing action to prevent air ingress into the cartridge mixer upon transfer of the monomer thereto.
Impregnation of filler pellets
Some products must be mixed under vacuum to avoid the formation of air bubbles in their formulation. These include gels and pastes that are used in syringe filling, printing and similar applications. Vacuum mixing also helps dry heat-sensitive materials without risk of thermal degradation. In some cases, the use of vacuum even eliminates the need for a separate post-mixing deaeration step, thus speeding up processing times.
To achieve this, a vacuum mixer is essentially a double-planetary blender with blades that rotate around a central assembly and churn the product thoroughly. The central assembly is fitted with a special casing that creates vacuum conditions. The level of vacuum can be adjusted depending on the specific application.
The process disclosed in the US patent involves a composite pellet that has a core consisting of talc and glass fibers surrounded by a sheath made of a thermoplastic polymer. The sheath can be formed either by a coating or by impregnating the fibers with the polymer. The resulting pellets can be used in injection molding processes to form the finished article. A higher stiffness of the final article can be achieved by raising the amount of glass fibers in the sheath. However, this increases the weight of the final article and may not be desirable in some applications.
By using a vacuum mixer to prepare the above-described composition, it is possible to obtain pellets with high isotropic E-modulus and favorable tensile strength and elongation at break. These can be used in a manufacturing process where the long glass fibers are embedded into the sheath or supplied as a masterbatch.
Dispersal of powdered active ingredients in liquids
A vacuum mixer can be used to disperse powdered active ingredients in liquids for a variety of reasons. For some applications, the void-free mixture is essential to the performance of molded composites, coatings, personal care products and more. In other cases, vacuum can prevent oxidation of sensitive chemicals or thwart unwanted chemical reactions and microbial growth. In all these situations, mixing in vacuum conditions achieves many goals at once.
In some cases, dispersing powdered additives mixer supplier in a liquid requires agitation at high intensities for long periods of time. This can lead to powder agglomeration in the liquid and inconsistent distribution of the product. In these situations, a vacuum mixer can provide a significant increase in mixing energy and shorten processing times.
Vacuum mixers can be used for batch mixing or in-line mixing over one or more hydration tanks. In either case, a vacuum is pulled on the powdered additive and sucked into a circulating liquid for dispersal and homogenization. In some systems, the rotor/stator assembly itself generates the main shear to ensure consistent, repeatable, and superior results.
The Ross Solids/Liquid Injection Manifold (SLIM) provides a new twist on the vacuum mixer concept by generating its own power to pull in powders under shear conditions. This allows the operator to inject the powders at a controlled rate and ensures that they are exposed to the liquid phase where shear is strongest.
Mixing of powdered active ingredients in liquids
In the production of nutritional powders containing proteins, vitamins, minerals and sweeteners, mixing and dispersing active ingredients is an important step. For example, the protein sources such as whey or casein must be mixed with sweeteners, flavors and other additives. The resulting mixture must be free of air, which can be an important factor in the product’s shelf life and flow properties.
Mixing under vacuum conditions significantly reduces the oxidation rate and increases the product quality. It also prevents foaming of the product due to aeration caused by mixers with whipping action and helps stabilize formulations. This method of mixing is particularly suitable for products containing air-sensitive ingredients, such as cosmetics and personal care products. It also prevents the decomposition of air-sensitive active ingredients and thwarts unwanted chemical reactions and microbial growth.
Another benefit of mixing under vacuum is the elimination of lumps when adding large quantities of powders to liquids. A lump-free, homogeneous mixture has better viscosity and can be handled more easily in downstream processing. It also reduces the number of required batches.
A wide range of batch mixers can be used for mixing under vacuum. These can include single-shaft devices such as high speed saw-tooth dispersers or rotor/stator mixers for low viscosity formulations to double planetary mixers for batching high-density compounds. Vacuum mixers are available with or without built-in pumps and with different levels of vacuum pressure.