Since the early 1970 s, powder coatings, powder coatings for
entirely without solvent, all can be converted to coating, coating
of high efficiency and comprehensive protection and decorative
performance is good wait for an advantage, extensive attention all
over the world, so as to obtain rapid development. Metal profile in
the hope of excellent durability, decorative and the
characteristics of processing formability, widely used in all
aspects of the building. The aluminum because of its good
processing properties, the characteristics of light weight,
consumption accounts for more than 80% of metal material. The
application of powder coatings in the field of aluminum has been
growing rapidly. At present, the powder coating on aluminium
profile application has expanded from Europe to the americas,
Australia, far east, the Middle East and Africa.
At present, the aluminum surface treatment generally exist in
anodic oxidation, electrophoresis painting and powder coating
processing mode of three kinds of every kind of way has its
advantages, occupies considerable market share. In aluminum
coating, powder coating of representative varieties are epoxy,
polyester, acrylic and silicone resin powder coatings, etc., as an
application, such as part of the aluminum frame, door window,
balcony, corridor, partition panel contour anticorrosive aluminium
profile, most use polyester, acrylic powder coating, in addition,
because of the epoxy resin powder coating with excellent adhesion
and anti corrosion, but the weather is bad, so commonly used in
indoor or used as a primer.
The type and performance of the aluminum profile powder coating
Has often used in powder coating of aluminum of weather resistant
polyester powder coatings, powder coatings with mostly saturated
polyester resin type, we usually according to its basic structure
can be divided into two categories, end carboxyl and end hydroxyl
groups.
The number of the ends of the carboxylic acid group is between 2000
and 8000, and the acid value is from 20 to 100 mgKOH/g. Among them,
the medium and high acid value (45-85) is commonly used in
epoxy/polyester blended powder coating, in the low acid value
(20-45) with three different melamine urea acid polyester glycidyl
ester (TGIC), hydroxy amide as curing agent for the preparation of
permanent excellence of pure polyester powder coating.
The polyester/TGIC powder coating can be classified according to
the Florida natural exposure test results, which can be divided
into three types:
1) standard resistant powder coating (available in Florida for 1 to
2 years)
2) improved resistant powder coatings (available in Florida for 2
to 3 years)
3) super resistant type resistant powder coating (available for
more than 5 years in Florida)
