Protective Coatings Fact Sheet: Polyaspartics

An Introduction

Although polyaspartics are over a decade old with a proven record in harsh environments at this point, it has only recently reached a point of wider adoption in the protective coatings space. The name polyaspartic is becoming more recognisable among formulators, specifiers, and applicators in the coatings industry world wide, as a way to differentiate it from its cousins polyureas and polyurethanes.

Polyaspartic is a type of polyurea. Polyaspartic aliphatic polyurea, to use its full name. Polyureas are two component coating systems like those you are already familiar with. A resin is mixed with hardener/catalyst to create a reaction, hardening the material. Polyaspartic variants are based on the reaction of an aliphatic polyisocyante and a polyaspartic ester, which is an aliphatic diamine. Polyaspartics have typically filled different niches to polyureas, but the gap is closing. As polyaspartics advance and close in on the rapid cure times of polyureas, their thinner film thickness requirements means less product is required to achieve results. 

The application techniques which can be used for polyaspartics include: 

  • Plural component spray
  • Brush and/or roller
  • Airless spray
  • Conventional spray

As polyaspartics allow formulators to control the rate of reaction and cure, polyaspartics typically range from 5 minutes to 2 hours of pot life/working time. Polyaspartics tend to be applied much like their other cousin, 2 component aliphatic polyurethanes.

 The differences between polyaspartics and polyurethanes

  • Polyaspartics generally have a higher solids content. 70% to 100%
  • Polyaspartics can generally be applied at higher wet film thicknesses, up to 15mils (380 microns) in a single application. Thicker than this is not advised and thickness can slow the cure.
  • Polyaspartics cure faster and allow for return to service sooner than polyurethanes. Polyaspartics can achieve full cure in 1-2 hours.
  • Polyaspartics can cure and be applied at 0 degrees Celsius (30F) and up to 60 degrees Celsius (140F) 
  • They can also be applied in high humidity, often up to 95% 
  • Polyaspartics exhibit high flexibility and elongation properties. This means excellent tear strength for standing up to cuts, gouging and abrasion. Being flexible, it provides a almost bounce effect - softening the kinetic energy from impacts.
  • Polyaspartics are typically very low or 0 VOC
  • Low odour 
  • High gloss and colour due to complete UV stability.

What makes polyaspartics so unique? 

When fully cured polyaspartics exhibit exceptional properties in many desirable areas when it comes to coatings for asset protection, corrosion prevention and general longevity. 

When cured, polyaspartics can withstand temperatures up to 150 degrees Celsius, resists staining from acids, oils, fats, food, and other chemicals. While also being rapid curing, abrasion resistant, with high bonding properties to concrete, steel, ceramic tile, fibreglass, and other composites. 

With its superior elongation and gloss retention it is far less prone to damage and cracking than epoxy or urethanes whiles also being extremely easy to clean and graffiti resistant.  It can also be applied over coatings, such as epoxy, zinc, urethane, and polyureas, as a final top coat. 

Polyaspartic DTM after 11 years of full time service

The real world benefits of polyaspartics

Polyaspartic really shines when considering the lifetime cost savings it allows. Polyaspartics keep coating costs down significantly by decreasing the time and energy required for the curing process while also having increased durability. Cutting install time and increasing recoat intervals. Its wide range of desirable cured properties means it replaces many other coatings, and can perform in harsh and varying conditions.  

While the cost per litre of most polyaspartics may be higher than that of urethanes, epoxy, or polyurea. Once the application speed, generally less coats required, cure time, and longer life span are accounted for, it is far cheaper in the long run. 

Polyaspartic rail car after 11 years

Polyaspartic tips and tricks

Thinning:

Consult with the manufacturer, although thinning is not usually required certain environmental conditions and applications may call for it. Keeping any local VOC regualtions in mind, the most common solvents used to think poyaspartics are MEK, acetone, and xylene. 

Mixing:

Always follow manufacturer instructions when mixing. A genuine polyaspartic will always be 1:1 ratio by volume. Use an appropriate mechanical mixer, ensuring not to introduce air or moisture where possible. Plural spray equipment does away with manual mixing, blending the products either in a reactor or at the plural gun spray tip.

Recoat times: 

Dry to touch and curing times will be influenced by temperature, humidity, air flow, and film thickness. Lower temp, humidity, airflow, and thicker film thickness will slow curing. The opposites of which will speed curing, shortening recoat windows. Make sure to check with the manufacturer for min and max recoat intervals. 

Shelf life and storage:

Most polyaspartics will have a shelf life of 12 months in properly sealed un-opened containers. Store between 10 and 45 celcius when possible. Always ensure the product is not stored in freezing or over 55 degree temperatures. Most polyaspartics are solvent free and non-flammable, so no special storage considerations are required, unlike solvent based products. 

Health and safety:

With proper ventilation used in conjunction with personal safety equipment –including air purifying respirators, air scrubbers, and eye and skin protection – result in very low exposure to measurable levels of airborne isocyanates and polyaspartic esters.

Conclusion 

Polyaspartics are becoming a valuable and more accessible alternative to epoxies, urethanes, and conventional polyureas. With increased cure speed, easy mixing ratio, and many other user friendly attributes without sacrificing physical properties, polyaspartics provide productivity enhancements to a variety of coating and painting operations. 

From an application perspective, particularly by spray, polyaspartics are not 'too fast' in that they need specialised equipment or have to necessarily be sprayed with heating to be applied. Less expensive and complicated spray equipment as well as options to use brush or roller make polyaspartics easier to deploy than polyureas. The advantages of polyaspartic technology, compounded with the proven performance and health safety of these materials, makes polyaspartic coatings and excellent option for offering clients the next level in coatings application.

Industry sectors that can utilise polyaspartic coatings: 

  • Military Equipment and Vehicles
  • Bridge coatings
  • Deck coatings
  • Cold storage / low temperature application
  • Processing area floors and walls
  • Rail Cars
  • Pipelines
  • Wind Turbines
  • Airports and Airport Equipment
  • Amusement Parks and Water Parks
  • Pharmaceutical
  • Power
  • Industrial equipment
  • Industrial floors
  • Marine Chemical plants
  • Off-Shore Oil Platforms
  • Fertilizer Plants
  • Water & Wastewater
  • Pulp & Paper plants
  • Food & Beverage
  • Healthcare
  • Universities and Schools
  • Mass Transit
  • Garage floors
  • Retail floors
  • Stadiums
  • Automotive
  • OEM
  • Zoos & Veterinary Clinics
  • Aquariums
  • Tunnels

corrosion protection under bridge

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