Today, variety of polymers are manufactured and used for different coating applications. In the changing scenario of the coatings world, newer and versatile coatings are being used for decoration as well as protection applications. The need and awareness of floor coatings and heavy duty industrial coatings are increasing. Depending on the area of applications, substrates, surfaces, properties expectations, newer floor coatings have been introduced and commercially used.

Advantages & Need for Floor Coatings

In the olden days, flooring material was mainly confined to natural wood, and then this wooden flooring was coated and protected by using French polish or shellac polish. However, the use was very limited, since regular maintenance was required due to limited water resistance and abrasion resistance. However today, most of the floors are made up of cementitious surfaces & concrete structure. The correctly engineered and constructed concrete is one of the strongest construction materials, with long lasting properties. However, even properly cured concrete also cannot withstand atmosphere exposure and corrosive environment, in the long run.

Therefore, need arose for the development of protective floor coatings. Variety of polymers introduced for different substrates, surfaces mainly for getting long term advantages:

• Floor coating for protection and decoration
• For easier installation and maintenance
• Continuous membrane with non-permeability of water and moisture, with breathable and non-breathable properties
• Very high order of adhesion, pull off strength
• Outstanding impact and abrasion resistance
• Excellent contraction and expansion properties, with better tensile strength, crack-bridging properties and high order of elongation
• Superior compressive strength, shore A hardness
• Hygienic, dust free, tough surface
• Chemical resistance - Acid, Alkali, Solvent resistance
• Antiskid properties, fire resistance properties
• Carbon dioxide diffusion resistance, to protect cementitious surface and the concrete structure – rebar’s
• Chloride ion reduction and moisture vapour permeable coating to stop or prevent concrete floor deterioration
• Impermeable to liquid penetration

Factors affecting deterioration of concrete Floors:

• During formation of floorings: Laitance and Efflorescence formation, Dampness Alkalinity, Porosity, visible cracks, micro porosity.
• Mechanical damage: Abrasion, Friction, Impact, load bearing, scratches due to machine, man movements.
• Chemical damage: Oils, Fats, grease, detergent cleaning, high water jet cleaning, chloride ion attacks, petrol and fuel.
• Thermal shock: Vibration, contraction expansion movement, water Freezing, earth movements, storms.
• Biodegradation: Formation of bacteria, Algae, Fungi, Moulds. Due to coastal areas, damp surface concrete floor gets biodegraded.
• Weather climatic conditions: Temperature, salt, Humidity, Rain water, UV exposure, Atmospheric charges.

Trowelled floorings:

These are heavily filled compositions, which can be applied by trowel to a thickness of about 5-6 mm. They provide a combination of high mechanical strength, chemical resistance and thus suitable for heavy duty service e.g. in areas subjected to abrasion by vehicles, fork-lift trucks, drums etc. Where product spillage is also problem.

The choice and quantity of fillers used is very important to formulate goods quality floor. The addition of fillers provides the mechanical strength in the flooring. The epoxy resin binder, serves to bond these filler particles together and provides chemical resistance. It is essential, that all the filler particles are wetted by the binder resin, leaving no voids or porous surface. These requirements are achieved by using fillers with the suitable particle size grading and resin of appropriate viscosity and setting time.

The performance of the floor is also influenced by the filler: binder ratio and the type of filler, since the quality of filler vary in terms of hardness, abrasion resistance etc. As also the application properties of the flooring, its trowel ability, are dependent on the quality of fillers as well as on the quantity of fillers. These fillers should be free from water content, moisture content for better performance.

Since, the cost of the floor is very important and dependent on the quality, quantity and particle size, the widely used filler fort this purpose is Silica Sand with different particle size grading. The filler: binder ratio vary from the flooring properties expectations, which may be in the range of 5:1 to 6:1, affecting the mechanical properties like tensile strength, flexural strength, elongation and impact resistance. However, chemical resistance properties only can be achieved by decreasing the filler.

Preparation of Trowelling Mix:

The proper mixing of the binder and filler is essential to achieve good results. The resin binder and the curing agent, are supplied in separate packs, to be weighted in appropriate proportion, as recommended by the manufacturer. They are thoroughly mixed together and then this binder is mixed with the filler. Rotating drum mixers with fixed blades have been mixing, in specified working time, to be laid down on the floor.

Application of trowelling compound:

The application of a trowelling floor compound to a suitably prepared substrate involves number of stages,

• Primer coat-Resin binder plus curing agent
• Trowelling mix-Resin binder plus curing agent plus filler
• Sealer coat or Topcoat-Resin binder plus curing agent

The trowelled floors should be opened for use, only after seven days, after achieving optimum properties. Since during this period cross linking mechanism is nearby completed.

Self-levelling floorings:

The epoxy resins, self-levelling composition are recommended in the areas which are not subjected to a severe degree of mechanical wear. They can be formulated to provide a high level of chemical resistance; they can be also used for highly decorative appearance.

• Self-levelling flooring are relatively lightly filled and normally applied in film thickness of about 2 mm.
• The all-round, easy to clean, self-levelling epoxy flooring system with a wide range of design options in terms of colour and surface structure.
• System thickness: approx. 2 to 4 mm

Self-levelling floorings:

The building and construction activities have been increased to a great extent, as also High-rise towers, shopping malls, supermarkets, car show rooms, hospital complexes are coming up everywhere. Self-levelling flooring can be used mainly in following areas.

• Underground car parking of housing complexes
• High-rise building car parking
• Deck and ramp in car parking areas
• Factories and Industrial workshops
• Pharmaceutical Industries
• Swimming pool areas
• Hospitals, massage parlours, Hotels
• Shopping complexes, super malls, walking areas
• Cold storages, warehouses, store rooms, play grounds etc