Polyrhyn is generically identified as a 100% solid, elastomeric polyurethane coating. It is a thermosetting material which, due to its rapid polymerization, is applied at virtually any thickness in a single coat
Polyrhyn represents the maximum expression of the trend towards the reduction of harmful V.O.C’s by eliminating solvents altogether. Previously unheard of performance in the control of severe corrosion abrasion and impact is possible with this coating.
Polyrhyn eliminates the inherent porosity of traditional coating caused by solvent evaporation. As the solvents evaporate, the traditional coating shrinks to a thickness relative to its solids content, with the detrimental effect of leaving evaporation trails and pores that greatly reduce adhesion and allow corrosive elements to reach the surface being protected.
Polyrhyn will achieve its full cure immediately exposed or submerged in compatible solutions. Very cold ambient temperatures will only retard but not affect performance once it has cured.
Polyrhyn provides unequalled chemical resistance to many dilute acids and alkalis, sea water, brine, crude and fuel oils, wastewater and many more corrosive substances. Its elastomeric flexibility and resilience produces an extremely tough sealant coating, highly resistant to impact and abrasion and at the same time, provides a low friction surface which will greatly improve fluids and solids flow.
Polyrhyn was designed for ease and speed of application. Its low viscosity components provide excellent spray ability in shop or field. The Material is applied with the most efficient plural component spray rig available.
Polyrhyn is competitive in it’s initial price with many other "High Performance" coatings, but when its longevity and superior performance are considered, it may well be the most cost effective corrosion and abrasion control available today.
Rhino Linings manufactures chemicals and equipment to spray the high quality, solvent free polyurethane linings.
The Rhino Linings coating protects the surface from both corrosive and abrasive wear. It forms a permanent air and watertight bond directly to the prepared surface, ensuring that the area remains rust free.
Rhino Linings are resistant to most chemicals including solvents such as oil, grease, gasoline and other acids. Even cement and glue will power-spray right off the liner with no harm to it.
Rhino Linings has many more applications other than truck and van beds. Commercial industrial vehicles road sweepers, acid and water tanks, commercial tankers, horse and boat trailers, boat decking, building materials and most anywhere one can find water and corrosion.
The Chemistry of TUFF STUFF
P0LYURETHANE, a very versatile member of the plastics family, may be found as flexible or rigid products in solid or cellular form. Great scope exists for the formulator.
The TUFF STUFF Technology is centred around the polymerization of isocyanates, or ISO’s, and polyol hydroxyls, or RESINS. Isocianate is a substance whose nucleus is made from the chemical group nitrogen, carbon, and oxygen. A polyol hydroxyl is a substance that contains active hydrogen-rich materials. Combined a certain way, the polymer that is created becomes a urethane. A group of urethane molecules link together to form polyurethane. TUFF STUFF is a polyurethane.
Practical Features of TUFF STUFF
TUFF STUFF is a 100% solids, polyether-based urethane elastomer coating system which can be sprayed onto a variety of surfaces to provide abrasion-resistant protective linings which have good resistance to water and corrosive chemicals, and moderate resistance to oils.
In addition, the practical features of using urethanes are:
The selection of hydrogen donors, diisocyanates and catalysts are made according to the properties required from the final elastomer. Consideration must be given to the conditions under which the urethane will be sprayed.
The thickness of elastomer to be applied to a vertical or horizontal surface greatly influences the catalyst levels used. Certain catalysts, with their fast gel characteristics, are highly suitable for formulations that will be applied to vertical surfaces. This type of fast gel formulation will show little tendency to sag or run.
On the other hand, if a gel time is made too fast, the possibility exists of restriction in the mixing sector of the spray gun. This is particularly true of guns employing impeller and static mixing heads. Over-catalyzing will also lead to very high exothermic reaction temperatures.
It has been known for elastomers to be destroyed within moments due to excessive exothermic temperatures being attained.
Good flow-out for mirror like finishes when sprayed onto horizontal surfaces is obtained by using less active catalysts. The level must, however, not be kept too low, or the full cure may be extended beyond practical limits. If this happens, polymer growth within the elastomer becomes slower than NCO/H2O reaction with consequent foaming. A good balance of catalysts is therefore necessary.
The viscosity of the two components should also receive considerable attention. While a minority of the types of spray equipment are capable of mixing materials of differing viscosities, it is considered safe practice to formulate the two components to within 100 cycles per second of each other. This ensures adequate mixing in all types of equipment.
Diisocyanate + Hydroxyl = Urethane, forms the basis of urethane chemistry, and may be selectively induced by varying the conditions under which the components are reacted or the use of specific catalysts.
Traditionally, the above compounds are combined together in liquid form, via two means… the "one shot" method whereby, the ingredients are telescoped together simultaneously or where a prepolymer is manufactured under controlled conditions, utilising a polyol and isocianate, and terminated with an excess of isocianate groups. These terminal groups are later reacted with a polyol or diamine, to form the urethane polymer.
In the past, urethane polymers were formed by using one of the two methods already mentioned. After mixing, the compounds were cast, or dispersed into molds, where they were allowed to solidify, or "gel", before being de-molded, and subjected to a curing cycle. It can therefore be appreciated that urethanes were confined to being fabricated in the processor’s shop where molds and curing ovens were available.
As the use of urethanes spread, a demand was created for an alternate means of applying urethanes on a site which did not have these facilities, or to apply flexible protective urethane membranes to large objects such as tanks, which the normal curing ovens would not accommodate. Beside the above reasons, urethane in their own right hold a place among other organic protective membranes. The amazing abilities of urethanes have assured the growth potential of this versatile polymer… ability to be formulated in a range of shore hardness, from soft elastomers to hard elastomers to hard elastoplastics, resistance to abrasion, impact, chemicals, oils, retaining these properties across a wide range of temperatures.
The Selection of Properties and Conditions for TUFF STUFF
Polyurethane, a phenomenal material for the modern world, gave rise to the techniques developed by Rhino Linings in the application of protective coatings.
In adapting urethane chemistry to spray applications, Rhino Linings’ process considers the following conditions:
TUFF STUFF is a premium quality, 100% solid elastomer polyurethane coating system. The rugged product allows for elongation, withstands abrasion, has excellent resistance to many petroleum products, acid and alkali, has a high tear strength, and has excellent flexibility.
The features of TUFF STUFF combine many of the advantages of rigid plastics, metals and ceramics with the flexibility and resistance of rubber-like substances. It is versatile, cost-effective and dependable.
The Chemistry of TUFF STUFF
Chemically, TUFF STUFF is a polymer containing urethane groups (NH-CO-O), created by reacting isocianates with polyol blends and chain extenders. By using specialised blends of many other proprietary ingredients, Rhino Linings has achieved an exclusive blend of polyurethane which has proven itself to be extremely versatile, and able to meet a wide variety of uses.
This polyurethane coating has been tested over the years and has shown tough resistance to most salts, acids and alkali solutions, water immersion, Petro Chemical and Petroleum Products.
TUFF STUFF is applied with plural component spray equipment, using an approximate 1:2 ratio between isocianate and a polyol resin. The MK14, is a low pressure spraying system, is designed specially for commercial custom spraying and is available only from Rhino Linings. MK14 is ideal for coating small to medium size areas. Large areas are prepared using the HP101, the Rhino Linings high-pressure system. In both systems, the components are mixed at the gun, using a static mixer.
A selection of interchangeable spray tips allow for various spray widths, flow rates and spraying angles, and increases the versatility of TUFF STUFF to almost-universal applications and uses.
TUFF STUFF is applied continuously in multiple passes until the desired thickness is achieved. Good adhesion is generally achieved when subsequent coats are applied within 4 hours at 23° C (75° F). The coats are best applied without further preparation, as long as the surface has been kept clean and dry and the coats have not been subjected to higher temperatures.
Further surface preparation is required if the coating has aged more than 4 hours but less than 24 hours.
Roughening the coating with a wire brush or wheel or light sand blasting, followed by a thorough solvent wash such as acetone or MEK, helps to achieve excellent adhesion with the subsequent coating. If the coating has aged more than 24 hours, the addition of a primer will also be required. (See primer table in Substrate section)
CHARACTERISTICS OF TUFF STUFF
Overall, products coated with TUFF STUFF are stronger, and more durable than those coated with conventional elastomers and plastics. TUFF STUFF products exhibit a remarkable range of properties that allow them to outperform wood, metals, rubber or plastics in many applications:
TUFF STUFF often outperforms rubber, plastics, and metals, where severe wear is a problem. TUFF STUFF’s strong resistance to abrasion allows for the fabrication of many products using less material, making it a very cost effective production material. Other benefits include lighter weigh, longer life, and reduced costs of maintenance and replacement.
Hardness, Shore A 75 – 85 (ASTM D-2240)
Tensile Strength (psi) 1700 – 2000 (ASTM D-412)
Elongation (%) 250 – 300 (ASTM D-412)
Flexural Modulus (psi) 2400 – 2800 (ASTM D-790)
Taber Abrasion, mg of loss/1000 cycles (ASTM D-1044)
CS17 Wheel 0 - 2
H18 Wheel 13 - 24
Tear Resistance, Die C, pli 240 – 260 (ASTM D-624)
Ross Flex, % crack growth/50,000 cycles 0 (ASTM F1A-308)
Specific Gravity, grams/cc 1.08 - 1.10 (ASTM D-792)
Secant Modulus, in psi @ 100% Elongation 800 – 1000 (ASTM D-412)
@ 200% Elongation 600 - 800
Water Absorption, % < 1.6 (ASTM D-570)
Flammability Self-extinguishing (ASTM MVSS302)
Dialectic Strength, volts/mil 300 (ASTM D-149)
Volume Resistivity, ohm/inches 600 x 1012 (ASTM D-257)
Dialectic Constant, MHz 5.4 (ASTM D-150)
Dissipation Factor, MHz 0.0058 (ASTM D-150)
Cathodic Disbonding pass (ASTM G8)
Elcometer Adhesion Pull Test pass (ASTM D-4541)