Introduction
Wax emulsions are one kind of formulated additives which are made up of refined and stabilized wax particles and are diluted in water. Another type of this additive is wax dispersions. Both the forms are liquid in nature and can be used for coating and ink formulations simply by mixing it. The major difference between wax emulsions and wax dispersions is that wax emulsions are < 1µm in size and have a minimum effect on the coating gloss while wax dispersions are 1-2µm in size and can be used with water easily. Wax emulsions can also be stabilized using 2 methods which are non-iconic emulsifiers (steric mechanism) and iconic emulsifiers (electrostatic mechanism). Mixing both of these emulsifiers can offer a great stability to the wax particles and increase the flexibility of the formulations.
Factors to be Considered While Formulating Wax Emulsions
Wax emulsions are advanced and ready-to-use which can be incorporated in the formulation by mixing it. Below are some of the factors that should be considered in the formulation of wax emulsions:
- Melting Point: The melting point of the wax should be low as compared to the melting point of curing temperatures in curing situations. If the melting point of wax is correct, it can melt easily and leads to the creation of a continuous film.
- Thickness Layer: The density of the dried wax on the film surface should be at highest to get the best possible result from the wax’s effect. The particle size of wax emulsionshould be as close as possible to the thickness of the coating layer to derive the desirable result.
- PH: The pH value of the wax should be under a unit of the system. This pH value can also be adjusted using aqueous ammonia and acetic acid during difficult situations.
- Type of Surface: Along with the other components, type of surface also matters while formulating the wax emulsion. Thus, the emulsion charge should match with the coating charge to improve stability of the wax.
- Order of Components: The order of adding components plays a crucial role in water-based formulation in maintaining the stability. Situations such as agglomeration can be avoided by adding the wax emulsion at the end. Chances of shock can be reduced if the wax emulsion is diluted more with soft or demineralized water.
- Regulatory Aspects: The regulatory aspects should be considered in both wax and other additives when the wax is used in the food industry such as for coating or packaging. The wax and additives should be formulated by abiding the rules and regulations of those regulatory organizations.
Types of Wax Emulsions
Following are some of the common types of wax and their specializations:
- Carnauba Wax: This wax is obtained from natural vegetable carnauba and offers advantages such as slip, lubricity, anti-blocking and mar resistance. The synthetic form of this wax can be PP (polypropylene), PE (polyethylene) and PTFE (polytetrafluorethylene).
- Paraffin Wax: This wax is obtained from paraffin mineral and its synthetic is Fischer-Tropsch. The advantages of this wax are anti-blocking, water repellence, slip and lubricity.
- PE: Polyethylene (PE) is a synthetic byproduct of carnauba wax. The advantages of this wax are slip, abrasion resistance and anti-blocking.
- PP: Polypropylene (PP) is also a byproduct of carnauba wax. It offers advantages such as anti-slip, anti-blocking and abrasion resistance.
- PTFE: Polytetrafluorethylene (PTFE) is a byproduct of Carnauba vegetable wax and Shellac animal wax. It offers advantages such as slip, lubricity, anti-blocking and abrasion resistance.
Coating Industries that Use Wax Emulsions
Wax emulsions are used widely in various coating industries due to the above stated advantages they offer. Some of the industries that use wax emulsions widely are as follows:
- Wooden Coatings: Wood stains and sealers require surface modifiers to improve the weather resistance capacity of exterior parts such as decks, rails, stairs, etc. Using wax emulsion in these parts protects the costly damages and increase their aesthetic value. Proper use of those modifiers can help in protecting wood floor coatings from traffic and wear. It also fulfils the VOC requirements by reducing scratching, scuffing and gloss loss.
- Concrete Coatings: Residential and Commercial coatings tend to damage over time due to various factors such as weather, vehicles and equipment. Surface modifiers and sealer formulations are used in these coatings to improve resistance of factors such as water, abrasion, graffiti, etc.
- Metal Coatings: Metal coating is used for various industrial products such as beverage cans, furniture, bridges, etc. Coating of surface modifiers helps those fixed structures to sustain for a longer period of time. Those products demand properties such as water repellence and mar protection from the coating.
- Architectural Coatings: Surface modifiers are used both in interior and exterior architectural coatings. It helps in providing water resistance to exterior appliances whereas in interior appliances, it is used to provide cleanliness and anti-blocking.
- Plastic Coatings: Surface modifiers are used in plastic coatings for 3 main reasons i.e., aesthetic, touch and wear resistance. These modifiers help the appliances in scratch and mar resistance and are used in various common products such as oils and coffee containers.
- Floor Polish Coatings: Wax surface modifiers fulfil the demands of polished floor coatings. Its proper selection can help in minimizing foot marks and offer slip control. It also helps in mar, scratch and abrasion resistance and extend the durability of the polish.
Take Away
This is the brief explanation about wax emulsions, its types and aspects while choosing the correct type. There is also a list of coating industries that use wax emulsions. We hope this information will be effective for you. Please let us know through your valuable feedback and the suggestion in the drop box.