Lab Mixers

Laboratory mixers forms a very important category of laboratory equipment. When it comes to mixing, dissolving, emulsifying, disintegrating, homogenizing, and dissolving of samples no other equipment can match the efficiency of laboratory mixers. Laboratory mixers have proved its usefulness in all kinds of laboratory work. From routine lab work, to r&d labs mixers are needed everywhere. Coming to the industries where laboratory mixers are widely used include, chemicals, food and beverage, building materials, pharmaceuticals, personal care etc.

The basic function of the laboratory mixer is to make the samples uniform in size. Laboratory mixer range offers with it a broad variety of accessories and mixing tool options.

How does a Laboratory mixer work?
A basic functioning of a laboratory mixer is given here. For convenience it can be divided into four stages.

A) The laboratory mixer has a precision machined mixing workhead. The rotor blades within it moves with very high speed. The high speed of the rotor blades produces a powerful suction. This action draws the liquid and solids upwards to the centre of workhead from the bottom of the vessel.


B) By using centrifugal force, materials are driven to the periphery of the workhead. Here these materials are milled in the clearance between the inner wall of the stator and the end of the rotor blades.


C)In the next step, due to tremendous hydraulic shear the materials are forced out via the perforations at a high speed into the stator. Subsequently they get distributed into the main body of the mix.


D) Lastly, the materials after ejection from the head are projected radially towards the sides of mixing vessel. This action takes place at a very high speed. The mixing cycle continues uninterruptedly with fresh material getting drawn towards the workhead. The resultant mix is perfectly uniform and homogenized.

Features of Laboratory Mixer

• Laboratory mixers can operate at ambient temperatures
• They show excellent reproducibility on scaling up to full scale production
• They can operate on the principle of direct gear mechanisms, that means it can be manipulated to arrive at certain speed or velocity.
• Laboratory mixers add a high gloss to the products, for example to the tablets produced in pharmaceutical industries.
• Lab mixers adds smoothness to the final products
• They are designed to perform of widest possible range of mixing applications
• Under full-scale working conditions, lab mixers can accurately predict the performance of large machines.
• They ensure controlled mixing pattern so as to minimise the cause of aeration.

Laboratory Mixer Selection Guide
Selecting the appropriate mixer guide is not an easy task. It requires an elaborate analysis of the performance parameters. Some of the things to be considered are given below:

• Speed range and precision : These are generally measured in revolutions/ minute (rpm).
  
• Viscosity range : It is typically measured in cycles per second (cps).
  
• Capacity : Capacity denotes the actual size of the mixing vessel, whose unit is liters (L) or gallons (gal).
  
• Torque prerequisites : It refers to the rotational force needed for the mixer motor. Generally expressed in oz or lb
  
• Operating temperature/range : They get expressed in degrees Fahrenheit (F) / Celsius (C).
  
• Heating elements : Heating elements in a laboratory mixer are commonly made with ceramic materials. They are expressed in Watts(W). Generally laboratory mixers come with the facility of internal heating or cooling for control of temperature.
  
• Sample introduction methods : These are basically of two types. Continuous and batch mixers. As indicative of the names continuous mixers accept continuous flow, whereas there is acceptance of measured volume or flow in case of batch mixers
  
• Horsepower(hp) prerequisites : It is the efficiency that is needed of the mixer motor with regard to torque (oz) and rotation speed (rpm)
  
• Liquid Viscosity : Liquid exhibit different properties when force is applied. Based on this four common liquid behaviour can be identified that plays an important role in selection of laboratory mixer. They are:
  » Dilatant Liquids
  » Newtonian Liquids
  » Pseudoplastic Liquids
  » Thixotropic Liquids
• Duty cycle : Duty cycle refers to the different time intervals that can be attributed to a lab mixer that is not run continuously. The time intervals are starting, running, stopping, and lastly idling.

Types of Laboratory Mixers
As laboratory mixers differ with regard to user interface options, display types, or presence of special features there are an enormous range available. Some of which are given here.

Roller Mixer : Roller mixer is appropriate for mixing and blending of blood samples.



Vortex Mixer : A vortex mixer is a common device that finds application in most laboratories for mixing small vials of liquid.



Gradient Mixers : Gradient Mixer is used for manufacturing of saccharose or CsCl gradients as well as in the preparation of polyacrylamide gradient gels.



Double Planetary Mixer : A Double Planetary Mixer can provide intensive mixing, blending as well as homogenizing of liquids and solid products in the form of pastes.



General Purpose Mixer : General Purpose Mixer is used for routine, low-viscosity laboratory mixing and blending applications.



High Shear Mixer : High Shear Mixer is appropriate for laboratory applications involving particle size reduction, dispersion, emulsification, homogenization etc.

Laboratory Air Mixer : Laboratory Air Mixers are just right for mixing small quantities and are very effective for sampling in chemical or biological laboratories.