Saturday, 4 July 2015

Paint and Related Coating Standard Testing and Certification





Over 12,000 ASTM standards operate globally. Defined and set by us, they improve the lives of millions every day. Combined with our innovative business services, ASTM standards enhance performance and help everyone have confidence in the things they buy and use – from the toy in a child’s hand to the aircraft overhead.

 Working across borders, disciplines and industries we harness the expertise of over 30,000 members to create consensus and improve performance in manufacturing and materials, products and processes, systems and services.

Understanding commercial needs and consumer priorities, we touch every part of everyday life: helping our world work better. ASTM's paint and related coating standards are instrumental in specifying and evaluating the physical and chemical properties of various paints and coatings that are applied to certain bulk materials to improve their surface properties. 

Guides are also provided for the proper methods of applying these coatings, which also include enamels, varnishes, electroplating, pigments, and solvents. These paint and related coating standards help paint manufacturers and end-users in the appropriate testing and application procedures for the coating of their concern.

List of paint standards and related coating standards developed by ASTM - http://www.astm.org/Standards/paint-and-related-coating-standards.html

 Standard conditions for temperature and pressure

A standard sets of conditions for experimental measurements established to allow comparisons to be made between different sets of data. The most used standards are those of the International Union of Pure and Applied Chemistry (IUPAC) and the National Institute of Standards and Technology (NIST), although these are not universally accepted standards. Other organizations have established a variety of alternative definitions for their standard reference conditions.

In chemistry, IUPAC established standard temperature and pressure (informally abbreviated as STP) as a temperature of 273.15 K (0 °C, 32 °F) and an absolute pressure of exactly 100,000 Pa (1 bar, 14.5 psi, 0.9869 Atmospheric pressure). An unofficial, but commonly used standard is standard ambient temperature and pressure (SATP) as a temperature of 298.15 K (25 °C, 77 °F).

NIST uses a temperature of 20 °C (293.15 K, 68 °F) and an absolute pressure of 101.325 kPa (14.696 psi, 1 atm). The International Standard Metric Conditions for natural gas and similar fluids are 288.15 K (15.00 °C; 59.00 °F) and 101.325 kPa.
Based upon the American Society for Testing Materials (ASTM) - Testing of Automotive Coating

·         Scratch Resistance
The scratch resistance was determined in accordance with AS 1580 Method 403.1
A tungsten carbide needle is slid over the surface. The load required for the needle to penetrate through to the substrate is used to indicate the scratch resistance.

·         Chemical Resistance
The chemical resistance of the coating was determined in accordance with ASTM D1308-02
Concentrated Hydrochloric acid, Phosphoric acid, and Ethanol were applied to the surface of the coating, covered and allowed to be in contact with the surface for one hour. The surface was then washed with distilled water, allowed to dry and then inspected.

·         Resistance to ultra violet radiation
UV resistance was determined in accordance with ASTM G155
Using Xenon Arc Light allows reproduction of the weathering effects occurring when materials are exposed to sunlight (either direct or through window glass) and moisture. Test for colour fastness and accelerated life testing to long term UV exposure. Find out if the coating will withstand years’ worth of UV weathering.

·         Pencil Hardness (no AMST)
Make a line about 1/2-inch long. If the pencil you start with scratches the surface of the coating, then go down the pencil grades until you come to the first pencil that doesn't scratch the coating. Redo the test, and if you get the same results, you have determined the 'Pencil Hardness' of the coating you are testing.
 
Certification

Certification Testing is one step above Compliance Testing. Certification has a legal connotation signifying that a third party organization has put its stamp of approval on the outcome and has, in a sense, guaranteed that the products meet the conditions of the test.

Testing and Product Certification Program should be carried out in accordance with ISO / IEC 17065 by a member of the American Association for Laboratory Accreditation (A2LA) 

Basic 3- Step Leather Care



Basic 3- Step Leather Care
1.        Clean
2.        Hydrated
3.        Protected

Finished Leather

Correct information regarding the care of leather is scarce, often contradictory, misleading, or simply wrong. Misinformation can lead to inadvertent damage to your vehicles leather upholstery; my goal is to present clear, concise, accurate information.

There is a great deal of conflicting information on leather care  being put out by leather experts themselves who recommend the same products and techniques be used regardless of the leathers finish or use baffling pseudo-scientific techno speak as another marketing ploy, 

Furniture, Motorcycle, Equestrian and Automobile leather are all different type of leather finishes and require different care. You do need to understand some of the basic chemistry behind the tanning and finishes applied to automotive leather to understand how to renovate, clean or care for it.

All of which makes it difficult to find a definitive, unbiased answer. Using the correct product is important in order to protect your car’s interior. If you keep your cars’ interior clean, you can easily save your car for a good couple of years and it can stay in a ‘like-new’ condition, and maintain a better re-sale value. Cleanliness is one of the major things buyers look for when purchasing a vehicle. There are several finished leather upholstery cleaners available, which need to be used in accordance to the type of finished leather used in for your vehicles upholstery.

That is why it is imperative, that if you are concerned about the results you wish to achieve, you must perform a bit of research into finding the products suitable for your requirements.
After various meetings and discussions with leather tanners, their research and development teams, chemists and fat liquoring formulators and many leather care product manufacturers I’ve gained an understanding of this versatile material on both a practical and scientific level.

It had always confounded me that such a simple subject has been made into something so complicated. I have always thought that the more facts and information you have at hand the easier it is to judge what information you are being given. After all, how can you fully understand and properly use any product unless you have all the facts? In the final analysis; it’s your vehicle, your hard earned money and your choice

Always keep in mind that you’re dealing with the finished coating on the leather not with the leather hide itself

The use of oils, replacement of fat liquor, oil-based conditioning, proteins or the adjustment of pH levels is totally unnecessary; the surface is a urethane that contains pigmentation (colour) it neither needs or benefits from any of the above

Unless a Premium Leather option was purchased Isocyanate based ethyl carbamate (urethane) finished leather upholstery is used by 95% as OEM in modern automobiles. It comprises a multi stratum acrylic and polyurethane resin binder system covering over the leather hide; the top strata are the surface pigmentation (colour) and an abrasion resistant urethane is used to improve flexibility, fastness and adhesion to the leather, together with a clear top coat provides a very durable surface finish

Modern automotive leather upholstery use a completely different tanning  processes and finishing system, utilizing advanced polymers and chemicals (urethane doesn’t require conditioning or rejuvenation) and as a consequence  they do not need to be treated with aftercare products containing oils or proteins.

Premium leather has a recognizable fragrance that is missing from polyurethane and plastic; simple cleaning, hydration and protection are the steps that will prolong the life of finished leather.  
Simple cleaning, hydration and protection are the three steps that will prolong the life of Micro pigment finished leather. Always pre-test the product on a hidden area. Shake the foam container thoroughly. Spray the product at a distance of 12 inches from the leather to one section at a time, and allow product to remain in place for approximately 15 to 30 seconds.  

Finished leather doesn’t require conditioning or rejuvenation; always keep in mind that you’re dealing with the finished coating on the leather and not with the leather hide itself

Leather Care

Finished Leather
There is a great deal of conflicting information on leather care being put out by leather experts themselves who use baffling pseudo scientific techno speak as another marketing ploy, which makes it difficult to find a definitive, commercially unbiased answer. Having devoted many hours to this particular material and spending a lot of time with both leather tanners and their formulating chemists I have gained some insight  and it amazes me that such a simple subject has been made into something so complicated.

Here is one definitive truth –you are dealing with the leathers finish, not the hide itself. The use of oils, replacement of fat liquor, oil-based conditioning, proteins or the adjustment of pH levels is totally unnecessary; the surface is a urethane that contains pigmentation (colour) it neither needs or benefits from any of the above

Unless a Premium Leather option was purchased Isocyanate based ethyl carbamate (urethane) finished leather upholstery is used by 95% as OEM in modern automobiles. It comprises a multi stratum acrylic and polyurethane resin binder system covering over the leather hide; the top strata are the surface pigmentation (colour) and an abrasion resistant urethane is used to improve flexibility, fastness and adhesion to the leather, together with a clear top coat provides a very durable surface finish

Modern automotive leather upholstery use a completely different tanning  processes and finishing system, utilizing advanced polymers and chemicals (urethane doesn’t require conditioning or rejuvenation) and as a consequence  they do not need to be treated with aftercare products containing oils or proteins.

Premium leather has a recognizable fragrance that is missing from polyurethane and plastic; simple cleaning, hydration and protection are the steps that will prolong the life of finished leather.  
Simple cleaning, hydration and protection are the three steps that will prolong the life of Micro pigment finished leather. Always pre-test the product on a hidden area. Shake the foam container thoroughly. Spray the product at a distance of 12 inches from the leather to one section at a time, and allow product to remain in place for approximately 15 to 30 seconds.  

Finished leather doesn’t require conditioning or rejuvenation; always keep in mind that you’re dealing with the finished coating on the leather and not with the leather hide itself

1. Clean - there are two cleaning-related factors that can cause your leather to wear prematurely.  The first is dirt, and the second is oil, combined they become very abrasive, as dirt / grit and subsequent friction cause the finish to wear

Remove surface dirt and dust, cleaning the seams periodically is important as dirt / grit will abrade the stitching causing them to fail, prise them apart, then use a soft brush, vacuum and then use a foam cleaner, one section at a time, and then finally wipe off with a clean, damp 100% cotton micro fibre towel

The advantage of foam over liquid is the minimum amount of moisture, very important for cleaning absorbent, perforated and moisture sensitive leathers.

 Use foam cleaner, which should be given dwell time and then gentle agitation with a medium stiff bristled brush to get the product into the materials surface, the low moisture content of foam can then be easily rinsed and the surface dried. Remove excess product and debris with a clean, damp 100% cotton micro fibre towel. If the foam is allowed to dry the soil will be re-deposited to the surface. Check the results and repeat process as necessary

For heavily soiled areas use a foam cleaner (Leather Master™ Foam Cleaner) that contains a surfactant that will lift dirt and soil, allow react time to do its work and then use a soft brush to agitate and loosen the dirt (Swissvax Leather Brush) especially on light coloured leathers; this enables the cleaning of the micro pores and creases and lifts the dirt out and reveal any further work that needs doing (dye transfer, stains, etc)

Sauna Towel Method

If your leather is really grubby the hot sauna terry weave towel method is extremely effective at lifting dirt.
1.        Using a damp terry weave towel, fold and place in a microwave suitable container
2.        Remove when towel becomes steaming hot
3.        Using tongs remove towel and place over soiled area(s)
4.        Allow to cool
5.        Wipe surface(s) with a damp towel


6.        Once surfaces are treated use a suitable 1z einszett Vinyl Deep Cleaner (Plastik Reiniger) an intensive, non-corrosive, non-acidic two-phase deep cleaner for that removes build-up thoroughly and effortlessly, these chemicals restore the original texture, tactile feel and resiliency or Leather Master™ Strong Cleaner, using very little applied pressure

For extremely soiled finished leather - use a Griot's 3- inch (speed # 4-5) an Interior Brush for Orbital Polisher ( Porter Cable 7424, Griot's Random Orbital Polishers (3 inch and 6 inch) as well as the Cyclo )  The brush has a connector which screw directly into listed orbital polishers. For extremely soiled finished leather - use a Griot's 3- inch (speed # 4-5) an Interior Brush for Orbital Polisher ( Porter Cable 7424, Griot's Random Orbital Polishers (3 inch and 6 inch) as well as the Cyclo x 2 )  The brush has a connector which screw directly into listed orbital polishers.

Use with 1z einszett Vinyl Deep Cleaner (Plastik Reiniger) an intensive, non-corrosive, non-acidic two-phase deep cleaner for that removes build-up thoroughly and effortlessly, these chemicals restore the original texture, tactile feel and resiliency or Leather Master™ Strong Cleaner, using very little applied pressure

2. Hydrated – when leather tanner’s talk about conditioning leather they are referring to its moisture content, re-hydration is used to restore or maintain fluid balance (transpiration and evaporation of moisture); not the replenishment or replacement of the fat liquoring, oils and / or waxes.

Moisture balance is a sine qua non (an indispensable and essential action) in leather care.  Leather naturally absorbs and retains moisture vapour, meaning it’s also susceptible to losing the moisture necessary to keep it pliant and soft. One of major attribute is its ability for transpiration (allowing the movement of moisture back and forth (evaporation and hydration), which it does even better than wool.

Repetitive heat cycling causes the leather to lose moisture, resulting in the formation of creasing or surface cracks, which may lead to the leather contracting; however the urethane remains stable, which may lead to it delaminating.

A regular wipe down with a damp towel on a regular basis is all you need to condition and / or hydrate finished leather, and  by using aqueous (water- based) products that do not contain oils and/or waxes, check the label if they do then don't use them. Leather should be hydrated on a regular basis and is somewhat climate dependent.

3. Protected - is essential as it will protect the surface finish, without hindering transpiration, while acting as a sacrificial layer; this way you are not actually cleaning the Leather's original surface, but cleaning from the surface of the protection. It also makes dirt easier to clean off

Leather Master™ - Protection Cream (a Scotchgard™ type product specifically formulated for lather) the polymers penetrate the surface of finished leather and cross-link to form a durable protective film that is breathable, allowing transpiration and keeps the leather supple. Being aqueous (water- based) it restores moisture to finished leather and provides a protective sacrificial barrier against all kinds of soiling, water, oil, alcohol-based stains and perspiration marks, so you are cleaning the protective layer
3a. Ultra violet (UV) protection - 303® Aerospace Protectant will provide invaluable ultra violet (UV) protection  against photo degradation (fading); especially in a roadster or convertible vehicle, steering wheel and dashboards

Is water-based and will provide invaluable ultra violet (UV) radiation protection against photo degradation (fading) protection; especially in a roadster or convertible vehicles. It doesn’t contain silicones, so it won't attract and capture dust. You should apply to a clean surface (it doesn’t contain any cleaning agents) 

It will not prevent finished leather hydration (transpiration and evaporation of moisture) as it’s water-based, although it coats the leather with a micro fine coating; it will not seal it per se.

Note: this product does NOT air dry.  Use a second dry cloth to finish the application process.  Extra buffing with at dry cloth increases bonding, repellence and durability

Patina(softness)  - used to improve and maintain the tactile feel and lustre  to ensure the leather remains soft and supple; apply Leather Master™ Soft Touch and allow to dry for approx. 20 minutes, finally using a clean dry 100% cotton micro fibre towel  buff to a matte sheen. This product is NOT a conditioner per se but is used to restore the softness to hard finished leather; place the car in a sunny location and roll down the windows. Allow the car to sit in the sun for one or two hours to warm the surfaces

Maintenance:
Monthly hydration of leather upholstery in most southern states; Florida, Texas and Arizona, and etc. especially during the summer months, would not be out of line

Always be willing to learn; because the more you learn, the more you’ll realize what you don’t know.
It is said that knowledge is power, with the caveat that it includes access to a reliable information sources. 

I would like to think that these articles become an asset to anyone who is new to detailing and to professional’s alike, as well as industry experts who seek to advance their knowledge.

I hope the article are informative. By having some understanding of the ‘What’ and ‘Why’ as well as the ‘How’ along with a little science to help you understand how the chemicals we use react, you can achieve the results you desire.

I would appreciate it if you would share these articles as it helps other detailers further their knowledge.

As always if you have questions, I’ll do my best to answer; bear in mind the only stupid questions is the one that was unasked. Questions and/ or constructive comments are always appreciated


Copyright © 2002 - 2015 TOGWT® (Established 1980) all rights reserved




The Science behind Coatings

Silicon dioxide (SiO2)

Probably the greatest impact has come from the use of micro technology coatings, which have completely changed the landscape of the detailing industry. Products like Zaino, Collinite, and etc. used to be the best protection available but micro technology products offer greatly extended durability, scratch resistance and protection from the elements that can be measured in seasons or years, as opposed to weeks or months.

A common element in a coating formula, Silicon dioxide (SiO2) also known as silica, is a chemical compound that is an oxide of silicon. Silica is most commonly found in nature as quartz.


Often misnamed as a glass coating. However glass is an amorphous (non-crystalline) solid material which is often transparent. Of the many silica-based glasses that exist, ordinary glazing and container glass is formed from a specific type called soda-lime glass, composed of approximately 75% silicon dioxide (SiO2), sodium oxide (Na2O) from sodium carbonate (Na2CO3), calcium oxide, (CaO), and several minor additives. 

What is Nanotechnology as it relates to Detailing?

The science of nanotechnology; the creation, organization, or manipulation of materials, devices, or systems at the nanometre level Nanotechnology, Nano particles or Nano structures, exactly what are they and how do they relate to detailing?

Most of these coatings are not true nanotube/tubule technology. This would cause a serious health concern for all of those - not to mention be ridiculously expensive. The context that “nano" (as related to detailing) is only as a relative size indicator merely to identify a micro sized particulate. They are sub-micron particles that form a clear thin film of tightly packed nano particles forming an extension of the surface. The particles are up to a 1000 times denser which makes for an ultra-durable hard wearing surface.

Technically most detailing product particulates are not nano metre in size, although they are extremely small, as the term ‘nano’ adequately describes. Single-component coatings interlace on a molecular basis and form an extremely durable protective layer on the paint surface provided they are applied properly.

The significance of a nano-coating is its micro sized particles that can form a very tight bond with the surface of most materials; including glass, paint, plastic, rubber, aluminium, chrome, stainless steel and fabrics. These materials will have surface imperfections i.e. peaks and valleys, micro-fissures when viewed under high magnification. 

These undulations allow a nano-coating polymer to form a tight molecular bond (much like a printer’s powdered ink when poured over paper that has writing indentations on it) with the surface it’s applied to. 

Automotive Coating

[: any liquid, liquefiable, or mastic composition which after application to a substrate in a thin layer is converted to an opaque solid film]

Paint protection coatings have many similarities to automotive paint and share the same solids mechanics attributes. PPG CeramiClear™ is a product that Mercedes-Benz co-developed and introduced nearly 10 years ago, and at that time it was the first clear coat to utilize nanotechnology for higher scratch resistance and reduced paint fade.

Paint is a liquid, usually comprising 30 to 40% solids and 60 to 70% liquid. As it dries it becomes a solid and a gas (the solvent) that evaporates, leaving behind the solid. The three primary type of ingredients found in most paint type coatings are -

1.        Binder (film former)
2.        Carrier (solvent)
3.        Solutes (pigment)

The binder is the film-forming component of paint, it imparts properties such as gloss, durability, flexibility, and toughness.  Many binders are too thick to be applied and must be thinned.

The thinner is also called the carrier, because it makes it possible to transfer the binder to the surface.

The pigment provides the paint with colour. All paints consist of a solids portion, essentially comprised of the pigments and binder, and a liquid portion. After the liquid portion evaporates and a coating dries, it is the solids that remain on the surface. Some paints form by solvent evaporation only, but most rely on cross-linking processes


Surfactants are added to stabilize the paint so that it will not separate, settle or become too thick to use. They also keep pigments dispersed for maximum gloss and hiding; and they help “wet” the surface being painted so the paint won’t “crawl” when it is applied. Surfactants also provide compatibility between tinting colorants and bases so that the correct colour will be obtained.

Solid mechanics 

[: solids generally have three responses to force, depending on the amount of force and the type of material]

·         Elasticity - the ability to temporarily change shape, but return to the original shape when the pressure is removed.
·         Hardness (in the elastic range) -a small temporary change in shape for a given force, is known as stiffness in the case of a given object, or a high elastic modulus in the case of a material.
·         Plasticity - the ability to permanently change shape in response to the force, but remain in one piece.
·         Yield strength - is the point at which elastic deformation gives way to plastic deformation.

·         Deformation (in the plastic range) - is non-linear, and is described by a stress-strain curve. This response produces the observed properties of scratch and indentation hardness, as described and measured in materials science.

Some materials exhibit both elasticity and viscosity when undergoing plastic deformation; this is called viscoelasticity.

Paint Surfaces

Automotive paint surfaces contain microscopic peaks and valleys, much like the profile of a mountain range. These irregularities are known as capillary structures; there may be millions of these defects per square inch. Contaminants such as fine dirt, minerals, and pollutants are drawn into the voids where they are extremely hard to remove.

The filling of the capillary structures with micro particles produces a hydrophobic surface. (A hydrophobic surface is one that repels moisture.) In contrast, a hydrophilic surface is one that absorbs moisture. The potential of a surface to absorb or repel moisture is based on many factors, including: temperature, relative humidity, material homogeneity, and static electricity. Surface roughness is also a major factor; the rougher the surface, the higher the spreading rate or attraction for water. The smoother the surface, the more repellent it is to moisture (Lotus Effect).

The significance of a micro coating is its small particle size that  can form a very tight bond with the surface of most materials; including glass, paint, plastic, rubber, aluminium, chrome, stainless steel and  fabrics, will have surface imperfections i.e. micro-fissures when viewed under high magnification. These undulations allow a micro coatings to form a tight molecular bond (much like a printers ink when poured over paper that has writing indentations on it) with the surface it’s applied to This level surface also improves paint surface clarity and reduce light scattering, providing improved light reflectance (LRV)

Sealing a surface with micro particles means applying a micro structure onto the surface, these treated surfaces become hydrophobic and resists road dirt, grime and etc. attaching to its surface by the ‘Lotus Effect’. It is therefore highly water repellent, which enables less effort during the cleaning stages and optimum protection to the paintwork, glass, alloys, fabric and trim.

Micro technology coatings form a very tight matrix chain-link a micro structure that comprises a clear thin film of tightly packed nano particles forming an extension of the surface. These very dense particles are both a very strong bond and one that is not easily breached by chemicals or detergents. They also improve paint surface clarity and reduce light scattering, providing improved light reflectance

Through self-organizing anti adhesion components, the micro structure forms an invisible barrier similar to glass. They form a bond by lodging themselves into the micro pores of the paint forming an anchored foundation and then this foundation is built upon to form the nano particle matrix. This is why a clean and dry, oil-free (micro pore) surface is so important. Only the micro structure remains on the sealed surfaces, while the water evaporates.

Micro technology offers superior durability, hydrophobicity, surface hardness and scratch resistance, resistance to environmental contaminants, works like a clear coat in providing ultra violet (UV) and heat radiation protection without colour change (yellowing) or oxidation and easier maintenance, simply rinsing with plain water results in a clean surface without loss of gloss; these products are having a profound impact and radically change auto detailing

Paint sealants compared to Coatings

Paint sealants are synthetic products designed for long-term paint protection and easy application. They are composed mainly of amino functional polymers, which last longer than any natural wax and are highly resistant to the elements. Synthetic liquid waxes are another way of describing paint sealants. The main benefit of a paint sealant is their durability compared to a wax, polymer-based sealants will last anywhere from 3 to 6 months.

A coating is applied to a clean surface and are capable of  a micro structure 'film build', that is to say a measurable thickness, that surface takes on properties that are virtually identical to hardened glass. It is chemically inert and will not react with the base material. In other words, dirt will not bond to the treated surface, thereby reducing soiling and organic staining. Acid rain and other chemical compounds easily wash off, significantly reducing the hydroscopic nature of surfaces exposed to industrial or environmental pollution.

Does paint density (hardness) affect its scratch resistance?

Many coating products claim an obtained surface (Pencil) hardness of 9H but this has little if anything to do with scratch resistance. Scratch resistance can be related to higher cross-link density and elasticity of the coating network.

Some Nanotechnology Coating products

·         AQuartz is an inorganic silica / silicon dioxide
·         DuPont's SupraShield™, PPG's Optech™ and CeramiClear™ are all inorganic silica coating
·         Gtechniq is an inorganic silicate crystallization compound
·         Modesta is an inorganic Silicon dioxide (SiO2)
·         Nanolex is an inorganic, solvent-based nanostructure coating
·         Opti-Coating Pro is a silicon carbide (SiC) grains of silicon carbide are bonded together by sintering to form a very hard ceramic



Hydrophobic surface [: The requirements for a self-cleaning hydrophobic surface are a very high static water contact angle θ, the condition often quoted is θ>160°, and a very low roll-off angle, i.e. the minimum inclination angle necessary for a droplet to roll off the surface] [1] 



The lotus effect [: refers to self-cleaning properties that are a result of very high water repellence (super- hydrophobicity), as exhibited by the leaves of the lotus flower] Dirt particles are picked up by water droplets due to the micro architecture on the surface, which minimizes the droplet's adhesion to that surface

Hydrophobicity

Definition of both Water repellence (hydrophobicity) and Roll-off

Hydrophobic surface [: The requirements for a self-cleaning hydrophobic surface are a very high static water contact angle θ, the condition often quoted is θ>160°, and a very low roll-off angle, i.e. the minimum inclination angle necessary for a droplet to roll off the surface] [1]

Hydrophobicity [: the property of being water-repellent; tending to repel and not absorb water is determined by the contact angle]

A hydrophobic surface is one that repels moisture. In contrast, a hydrophilic surface is one that absorbs moisture. The potential of a surface to absorb or repel moisture is based on many factors, including: temperature, relative humidity, material homogeneity, and static electricity. Surface roughness is also a major factor; the rougher the surface, the higher the spreading rate or attraction for water. The smoother the surface, the more repellent it is to moisture. 




Contact angle

The contact angle [: is the angle measured through the liquid, where a liquid/vapour interface meets a solid surface. It quantifies the wettability of a solid surface by a liquid via the Young equation]

Contact angle measurement provides a simple way to determine the level of surface protection. The formation of large, closely spaced water droplets demonstrates that moisture is effectively prevented from being absorbed (a hydrophobic surface) into the surface profile. The classification of water droplets on a hard surface is known in industry as a “water break test” or ASTM F-22. This test is used extensively in the industry to check surface cleanliness.

The size, shape, and height of the water droplets are measured by their contact angle. Contact angle is figured by a straight line that starts at the base of the droplet and travels along its outer surface to the break-off point. The measurement between this line and the surface determines the contact angle

Surfaces with a contact angle A 90° are referred to as hydrophilic and those with an angle A90° as hydrophobic. Some plants show contact angles up to 160° and are called super-hydrophobic meaning that only 2-3% of a drop's surface is in contact. Plants with a double structured surface like the lotus can reach a contact angle of 170° whereas a droplet’s actual contact area is only 0.6%. All this leads to a self-cleaning effect.

Roll-off

The lotus effect [: refers to self-cleaning properties that are a result of very high water repellence (super- hydrophobicity), as exhibited by the leaves of the lotus flower]

Repellant [: able to repel a particular thing; impervious to a particular substance]

Roll off of dirt particles with a reduced contact area are encapsulated by water droplets and are easily cleaned off the surface. If a water droplet rolls across such a contaminated surface the adhesion between the dirt particles and the water droplet is very much reduced and the dirt is easily removed from the surface

Coating Viability



Surface energy [: defined as the excess energy at the surface of a material compared to the bulk or the work per unit area done by the force that creates the new surface]

Interface energy) [: in the physics of solids, surfaces must be intrinsically less energetically favourable than the bulk of a material (the molecules on the surface have more energy compared with the molecules in the bulk of the material]

In order to successfully form a continuous coating, the liquid should be able to wet the surface of the material. Wettability depends on one specific property of the surface: surface energy. The surface energy of the solid substrate directly affects how well a liquid wets the surface. To achieve good wettability the surface energy of the substrate needs to exceed that of the surface tension of the liquid by around 2 - 10 mN/m (Dynes). The Dyne level reflects the surface wettability - the higher the Dyne level, the better the wettability/adhesion.

To obtain optimum adhesion, it is necessary to increase the surface energy of the substrate to just above that of the material to be applied. For optimum adhesion of a coating on various substrates, it is necessary to obtain a high surface energy. Determining the surface energy can be achieved by measuring contact angle or by use of Surface Energy Test Liquids or Pens (Dyne level testing).

This form of measurement is based on the ISO method for measuring the surface energy of polyethylene film. Surface energy may be defined as the excess energy at the surface of a material compared to the bulk.  Every solid surface has a specific and measurable surface energy.  The unit of measurement used is the Dyne/cm² or mN/m.



When the Dyne level test liquid is applied to the surface, the liquid will either form a continuous film on the surface or pull back into small droplets. If the Dyne test fluid remains as a film for 3 seconds, the substrate will have a minimum surface energy of that fluid value, expressed in N/m (Dynes). Should the Dyne test fluid reticulate or draw back into droplets in less than 1 second then the surface energy of the substrate is lower than that of the fluid itself. To test the viability of a coating requires measuring the surface energy (surface tension).

Using a Dyne Test Pen will measure the surface tension and identify whither the coating is still viable, which requires a surface tension of 38mN/m or higher.

Measure the surface energy by using slight pressure to draw the Dyne Quick Test Pen tip across the coated surface. If the ink lines shrink or bead within 1-2 seconds then the surface protection is degrading as the surface energy level has dropped to less than 38 Dynes. If the ink lines remain as marked and do not shrink then the test sample surface protection is still viable as the coating has a surface energy of 38 Dynes or higher.

Dyne Quick Test Pen - http://www.dynetechnology.co.uk/measurement-equipment/quick-test-pens/

Product Application

Be cognizant that for a coating product to reach its full potential; that is to say the correct contact angle, durability and optimum cross-linking it imperative that you provide a ‘clean’ surface. Prior to application both above and sub-surfaces should be decontaminates, polishing lubrication (oils, polymer (silicones) and wax) system should be removed

Use the appropriate personal protection equipment (PPE) an approved mask (Consult the current 3M Respiratory Selection Guide for additional information or call 1-800-243-4630 for 3M technical assistance) nitrile gloves and safety glasses as a minimum.

Due to the construction of micro fibre towels, they comprise a hydrophobic Polyester (a scrubbing fibre) which also gives the material strength and durability and a hydrophilic Polyamide (an absorbing fibre) that is tremendously absorbent and quick drying. This nylon hybrid is created during weaving to create microscopic loops, which form a network of tiny hooks, scrubbing away dirt and grime.  The nature of this yarn is that it is an absorbent; the reason polyester appears to absorb liquids is the many thousands of micro fibres that collectively encapsulate liquids.

1)       Dr Joe dedicated Lint-Free 100% Cotton Surgical Towels, that  have a lint free, tight cotton herringbone weave and a thread count of 170  per square inch,  which is ideal for hard surfaces as they have more ‘grip’ than micro fibre towels and helps to spread the coatings evenly.Fold the towel in half and then half again.

2)       The coating can also be applied with a lint-free and non-abrasive microfiber suede cloths (very low nap), which will evenly spread the coating as opposed to absorbing it. Edgeless optical grade suede weave Use a fresh cloth with an applicator block to help you lay down the perfect application of liquid coatings and other protection products. The Rag Company Detail Master™ Pro but the major disadvantage of this type of application is the coating dries and solidifies to glass, which means you need 5- 8 towels that will be discarded after use.

My preferred application method is to use base coating (P-01A) applied with a rotary machine polisher and apply the coating with a spray gun as I feel this gives a consistent thickness and coverage. The coating can be applied with a micro fibre towel but the major disadvantage of this type of application is the coating dries and solidifies to glass, which means you need 5- 8 towels that will be discarded after use.

Drying / Curing

Use of infra-red lamps is highly recommended. Allow 24 hours in a moisture / dust free environment.
Curing – the product will be fully cured in (subject to environmental conditions experience)

Coating Maintenance

Many people have the incorrect impression that paint coatings are a “no maintenance required” type of product.  This is simply not true.  Routine washing is crucial.  As your coating becomes covered with dirt and contamination, you will notice a decrease in hydrophobic properties. It’s important to remove any surface contaminates on a regular basis with a car wash concentrate that will not leave gloss enhancers or surfactants behind due to a coatings ‘roll off’ washing and drying the paint surface is very easily accomplished

The normal car wash concentrates mostly contain surfactants and alkaline additives. They work by breaking down surface tension and wetting the surface to facilitate soil removal by flushing. With many of the newer coatings traditional car wash solutions, especially at their normal extreme dilutions.

Use a specially formulated product like Optimum ONR or Modesta H-05 Shampoo– specifically formulated for hydrophilic coatings. This special shampoo removes dirt and restores/prolongs the coating’s original hydrophobicity. This is an ideal coating maintenance shampoo

Dry surfaces with a waffle weave (pique) towels to ensure zero marring to the paint surface

Summary

Polish the paint surface to remove (without removing too much clear coat) any surface imperfections as this product cures to become optically clear and will highlight any surface defects. It has always puzzled me why people over-polish their car paint and cause the paint to fail prematurely; we all have seen examples of clear coat failure. A coating is the most effective way to avoid premature failure of clear coats.

Coatings offers superior durability, hydrophobicity, surface hardness and scratch resistance, resistance to environmental contaminants and works in a similar way to a clear coat in providing ultra violet (UV) and heat radiation protection without colour change (yellowing) or oxidation and easier maintenance, simply rinsing with plain water results in a clean surface without loss of gloss. I think these products will have a profound impact and radically change auto detailing

Bibliography

1.            Royal Society of Chemistry (RSC) Library & Information Centre
2.            Glossary of Chemical Terms - Faculty of Chemical Technology
3.            Basic Concepts of Nanotechnology, History of Nano-Technology, News, Materials and                        Potential Risks
4.            Lotus-inspired nanotechnology applications, B. Karthick1  and Ramesh Maheshwari
5.            SpecialChem4 Polymers
6.            PPG Coating Products
7.            Macromolecular Chemistry and Physics
8.            European Coatings Handbook 2nd Edition, by Brock, Groteklaes, Mischke
9.            Bayer Material Science, Automotive  eNewsletters (Coating, Adhesives and Specialties)

The information in this article is based on the current status of technical development as well as our experience with the products.

Foot Note:

I carried out extensive laboratory testing of coatings utilizing standard lab protocols, this entailed chemical analysis with a mass spectrometer, heat, acid and ultra violet radiation resistance, surface hardness and hydrophilic properties.

Based upon the American Society for Testing Materials (ASTM) - Testing of Clear Automotive Coating

·         Scratch Resistance
The scratch resistance was determined in accordance with AS 1580 Method 403.1
A tungsten carbide needle is slid over the surface. The load required for the needle to penetrate through to the substrate is used to indicate the scratch resistance.

·         Chemical Resistance
The chemical resistance of the coating was determined in accordance with ASTM D1308-02
Concentrated Hydrochloric acid, Phosphoric acid, and Ethanol were applied to the surface of the coating, covered and allowed to be in contact with the surface for one hour. The surface was then washed with distilled water, allowed to dry and then inspected.

·         Pencil Hardness (not part of an ASTM )
Make a line about 1/2-inch long. If the pencil you start with scratches the surface of the coating, then go down the pencil grades until you come to the first pencil that doesn't scratch the coating. Redo the test, and if you get the same results, you have determined the 'Pencil Hardness' of the coating you are testing.

·         Resistance to ultra violet radiation(UV)
UV resistance was determined in accordance with ASTM G155
Using Xenon Arc Light allows reproduction of the weathering effects occurring when materials are exposed to sunlight (either direct or through window glass) and moisture. Test for colour fastness and accelerated life testing to long term UV exposure. Find out if the coating will withstand years’ worth of UV weathering.

The mas spec analysis showed many similarities between some brands, which not surprisingly would suggest relabeled products.

The few, just let’s say unique, products although using completely different chemicals in their formulation exhibited outstanding results

Filing a patent on a chemical formulation is extremely difficult and would not solve the problem as changing just one component would make the patent void. Change is what R and D (development) is all about, and besides relabeled product in the final analysis results in more sales.



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