Shampoo is a mixture of surfactants, conditioning agents, and many other ingredients in an aqueous base. In addition to basic shampoos which simply clean the hair, there are products designed for specific hair types; “2-in-1” shampoos; products which offer properties such as treatment of dandruff; UV protection; some degree of coloring (although most hair colorants are based on conditioners rather than shampoos); and “medicated” products. Consequently formulations vary widely.
The Process of Shampoo Manufacturing
A typical shampoo manufacturing process would be as follows:
• Water is metered into the manufacturing vessel. This is often heated to around 55-60°C to aid dilution/hydration of other ingredients.
• The first ingredient added is normally the surfactant, as other additives, particularly those which affect viscosity, can make dilution of the surfactant more difficult.
• Conditioners and other ingredients are added.
• PH is adjusted to the required level.
• Sodium chloride or other viscosity modifiers are added last, along with color and fragrance.
The Problems of Traditional Shampoo Mixer
A number of problems can be encountered when using conventional shampoo making machine:
• Aeration must be avoided, as this can lead to clouding of clear shampoos and problems where packaging is filled by volume rather than weight.
• “High Active” products require special handling
• Silicones are immiscible with water and can be chemically incompatible with some surfactants, making them very difficult to emulsify or suspend.
• Agitators in traditional shampoo manufacturing machines do not produce sufficient shear to reduce silicones to the finest possible droplet size and obtain a stable emulsion/suspension. They will tend to vortex, increasing aeration.
• Many ingredients have a much higher viscosity than water. When blending these with an agitator, the higher viscosity material can form globules which are simply washed around without being diluted or dispersed.
• Thickening agents such as carbomers and cellulose or gum based products may require high shear mixing to be “activated”.
• The addition of sodium chloride becomes increasingly difficult as the viscosity rises.
• Vigorous agitation is required to overcome these problems, however, with conventional agitators this can lead to aeration.
The Solution of Shampoo Production
These problems can be overcome by the use of a Ginhong high shear mixer, typically an inline high shear mixer added to the existing process. Batch homogenizer and high speed dispersers can also be used. Operation is as follows:
The shampoo manufacturing equipment is charged with water. The in-tank agitator and inline mixer are started, and the surfactant and other ingredients are added in the order specified. The powerful suction created by the inline mixer draws the materials through the pipeline into the rotor stator homogenizer.
Centrifugal force drives the materials to the periphery of the work head where they are subjected to intense high shear in the gap between the rotor and stator.
The shampoo is forced out through the stator and circulated back to the process vessel as fresh material is drawn into the work head.
The Advantages of Ginhong Shampoo Making Equipment
• The high shear mixing action of a Ginhong homogenizer can rapidly blend liquids of widely differing viscosities
• The inline mixer, manufacturing vessel and piping form a closed shampoo production line, eliminating aeration
• Dramatic reduction in mixing times
• Significantly better yield of thickening agents than can be achieved by traditional methods
• Consistent shampoo quality and repeatability