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Coating Raw Materials
Coil Coatings
Coil coating is a highly automated process for coating metal before fabrication. During a continuous process, a coil of metal is unwound as it is fed into a machine. Then, both the top and bottom sides of the metal are cleaned, chemically treated, primed, oven cured, topcoated, oven cured again, and rewound for shipment. This coated metal is then fabricated into numerous everyday applications such as washing machines, dryers, refrigerators, exterior building panels, can coatings and automotive parts. Manufacturers utilize coil coatings because it is more cost effective than coating each machine or part that they produce.
A variety of coating technologies can be used in the coil coating
process including one-component (1K) polyurethanes. Polyurethane coating
technology, using Bayer raw materials, offers numerous advantages
over other technologies including:
- Excellent weatherability, including protection from UV rays and acid rain
- High gloss
- Resistance to embrittlement upon aging
- Excellent flexibility and impact resistance
- Superior environmental etch protection
- Fast curing
- Adhesion to a variety of substrates
Coil coating is extremely versatile. This process allows customized treatments, such as organic and inorganic pigments, fluorocarbons, lubricants, rust treatments, and various primer combinations, to be applied during the continuous process. In addition, prepainted coils can be printed, striped and embossed to create special visual effects for the finished product.
The finished coils are also extremely versatile. Coils can be rewound or drawn, formed, bent or blanked to just about any shape required. Coils also can be fastened with bolts, screws, rivets, and similar devices as well as lockseamed, adhesive bonded, and welded.
Recommended products include those sold under the Desmophen
and Desmodur
BL tradenames. For information about Bayer coating raw materials,
contact us.
Metal and Plastic Coatings
From toys to tools, consumers demand longevity from their products.
Many manufacturers are meeting this need with polyurethane coatings
containing raw materials from Bayer. Polyurethane coatings provide
protection and keep products looking new longer.
Whether you're coating metal or plastic, polyurethane coatings offer
versatility that meet varying specifications of a wide marketplace.
For example, general metal applications include tools, metal doors,
lawn and garden furniture, engines, and agricultural equipment. general
plastics applications include toys, tools, TV cabinets, computer housings,
business machines, EMI shielding, and lawn and garden furniture. So
no matter what you're coating, polyurethane coatings dramatically
improve the quality and appearance of the product. In fact, the widespread
use of polyurethane coatings is due to their broad range of desirable
properties:
- Excellent weatherability, including protection from UV rays and acid rain
- High gloss and DOI (distinctness of image)
- Resistance to embrittlement upon aging
- Excellent flexibility, impact resistance
- Superior environmental etch protection
- Curable from room temperature to elevated baking conditions
- Adhesion to a variety of substrates
- Fast curing
Polyurethane coatings used for general metal and general plastic applications
use either one-component (1K) or two-component (2K) systems. These
systems are available as either solventborne or waterborne. Over the
past 30 years solventborne systems have been the predominant technology.
Bayer product lines used most often for solventborne technology are
Desmodur
N aliphatic polyisocyanates, Desmophen
polyesters, and Desmophen
acrylics.
Coatings based on these products offer VOC levels in the range of 2.8 lb./gal. to 3.5 lb./gal., and combine film properties of F-3H pencil and flexibility up to 160 in.-lb. reverse impact as well as chemical resistance.
If weatherability is required for your coatings system, aliphatic polyisocyanates offer superior UV protection compared to aromatic polyisocyanates. However, aromatic polyisocyanates cure faster contributing to increased production line throughput, and they are very suitable for interior use.
With heightened awareness of the environment, Bayer has introduced
higher solids
materials and waterborne
technology as real alternatives to help lower volatile organic
compound (VOC) levels. Higher solids materials have very low viscosity
that contributes to a VOC lower than 2.8 lb./gal. To achieve even
lower VOC levels, Bayer developed and introduced 2K waterborne polyurethane
technology. VOC levels can be as low as 1 lb./gal. and can approach
0 lb./gal. With minimum solvent emissions from these systems, coatings
manufacturers would be able to increase production without reaching
their emissions threshold.
Bayer product lines used most often for 2K waterborne technology are
Bayhydrol
and Bayhydur.
2K waterborne coatings maintain the high performance standards that
customers have come to expect from 2K solventborne systems. The greatest
advantages of 2K waterborne systems are extremely low VOC levels and
low solvent odor.
1K solventborne and waterborne systems are also suitable for use with
general metal and plastic products. 1K solventborne systems typically
use Bayer's Desmodur
E polyisocyanates that crosslinks with atmospheric moisture to
give insoluble higher molecular weight polyurethane/polyurea. Used
as a primer, this system offers good corrosion protection. However,
due to the systems reliance on atmospheric moisture to cure, dry times
may be longer and vary with weather conditions.
1K waterborne coatings are available through Bayer's Bayhydrol product line. These products are suitable for plastics and very flexible substrates. Plastic substrates typically using 1K waterborne coatings include polcarbonate, ABS, PET, Polystyrene, PVC and Polyurethane RIM.
For additional information about polyurethane coatings, contact your
local paint company. For information about polyurethane raw materials
for General Metal and Plastic coatings, contact
us.
Powder Coatings
Oftentimes referred to as "dry painting," powder
coatings are the fastest growing finishing technology in North
America. Thrust into the spotlight because of their environmental
advantages, they are here to stay due to their numerous benefits.
Powder coatings are now coating everything from automobiles to lawn
furniture.
The term "dry painting" refers to powder coatings' lack of liquid, solvent or water, in their formula. It is applied "dry" directly to a surface in a fine powder form. A powder coating is made of 4 key ingredients: resins, pigments, curing agents and additives. A powder coating manufacturer mixes these ingredients according to its formula. The mixture is then fed into an extruder which melts and crosslinks the materials. After it cools, the material is chipped and ground into a fine powder. The charged powder is spray applied to an electrically grounded surface. Finally, the coated piece is heated so that the powder coating is fused into a smooth finish.
Because they don't use solvents in their formula, powder coatings release little to zero volatile organic compounds (VOC) into the atmosphere. This not only helps our environment, but it also reduces costs for finishers because they no longer have to purchase and maintain expensive pollution control equipment. In addition, most powder coating overspray that does not adhere to the substrate can be reclaimed for future use. As a result, finishers utilize nearly 100% of their coating material leaving little waste and less cleanup.
As a leader in the coating industry, Bayer is dedicated to the powder
coating market and is committed to offering its customers the best
possible service. This includes a wide selection of coating materials
with the ease of utilizing one supplier. Bayer also has a worldwide
technical support network with agencies located in over 150 countries.
For additional information about polyurethane powder coatings, contact us
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