Category of polymers which contain the ester functional group in their main chain is a Polyester. The reaction of dibasic organic acids and polyhydric alcohols forms Unsaturated Polyester Resins.
COMPONENTS-
Pigments
The material is composed of pigments that are very similar to those used in other pavement
markings. The pigments are used to impart color, hiding and other desirable properties, like all
other markings. However, these pigments are pre-ground prior to being blended into the resin.
Resins
The marking has polyester resin that is mixed with a reactive solvent, a styrene compound.
Normally, solvents are expected to evaporate and not participate in the setting up process. In
addition to acting as a solvent, the styrene participates in the polymerization process. In order for
this material to begin to react, a catalyst must be added to initiate the reaction.
Additives
Driers are added to assist in the curing process.
Reflective Beads
Beads are uniformly applied across the entire width of the marking by either a gravity or pressurized
bead applicator located immediately behind the polyester spray gun. Beads are generally applied
at a rate of 8 lb/gal.
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Advantages
• Essentially two components in one container
• Long lasting and durable
• Does not discolor badly
• Relatively inexpensive
• Works well on concrete
Disadvantages
• Peroxide catalyst is a very reactive oxidizer
• Requires placarding as a hazardous material
• Requires commercial drivers license
• Flush solvent is flammable and a hazardous waste
• Moisture in surface a major factor and detriment
• HMA paving oils are a detriment
• Set up time depends on type of resin (usually 3-20 minutes)
• Difficult to determine whether mixed properly
Applications-
Polyester resins are used in sheet moulding compound, bulk moulding
compound and the toner of laser printers. Wall panels fabricated from
polyester resins reinforced with fiberglass so-called fiberglass
reinforced plastic (FRP) are typically used in restaurants, kitchens,
restrooms and other areas that require washable low-maintenance walls.
Market Trends & Forecast-
Unsaturated Polyester Resin (UPR) Market Consumption Share, By Geography, 2013
In the year 2013, global UPR demand is estimated to
be worth $6.5 billion and is expected to reach $9.5 billion by 2018,
growing at a CAGR of 6.8% from 2013 to 2018. Asia-Pacific region
dominates the unsaturated polyester resin market and its value is
expected to grow at nearly 8.0% CAGR in the next five years. North
America and Europe are growing at a steady CAGR compare to
Asia-Pacific.
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