Low Pressure Melamine
Low Pressure Melamine (LPM) surfaced panels are the most
wear resistant of the range of pre-finished boards. They
are manufactured by most producers of Particleboard and Medium
Density Fibreboard.
Papers impregnated with a melamine based thermosetting resin are
applied to each side of the substrate in a short cycle hot press.
Heat and pressure cause the melamine to flow into the board surface
to give a hard plastic finish that is an integral part of the surface.
As the paper is coloured or printed before impregnation the textured,
coloured or printed appearance also becomes an integral part of
the board surface protected by the hard wearing melamine resin.
All substrates used for the manufacture of LPM surfaced products
comply with the specification detailed above. They include Particleboard
and Medium Density Fibreboard (both standard and MR types) with
a thickness range from 9 mm to 33 mm.
Decorative LPM products cover a wide range of solid colours, wood
grains and abstract patterns available together with a variety
of surface textures. Those readily available include satin, velvet
and various wood grain textures. The manufacturers' literature
should be consulted for the complete range. Low Pressure Melamine
products have a wide use in furniture manufacture, shop fittings,
built-in units and kitchen cabinets. Although they are not recommended
for kitchen work benches, the standard product is suitable for
shelving and vertical surfaces. Melamine surfaced products for
commercial applications such as computer work stations and toilet
partitions may require better wear characteristics than standard
products. Panels overlaid with thicker, more wear-resistant surfaces
are termed Structural Grade and should be selected where tougher
service conditions apply.
There is an industry - accepted standard for visual grading of
board surfaces. This standard permits minor imperfections on one
face of the overlaid panel. Specifiers should enquire about details
of grades and grading standards from individual manufacturers,
so that any special requirements can be negotiated well in advance
of product supply. The principles of Quality Control detailed above
are also applied to LPM products. In addition to the visual grading
of the surface quality, there are several physical tests carried
out on products to ensure that the impregnating resin has been
cured in the manner necessary to give the required properties.
These tests are based on Australian Standards AS/NZS 4266.
They include:
WEAR RESISTANCE - A standard abrasive test ensures that the melamine
impregnated finish retains its integrity, pattern and/or colour
under normally expected wear.
SURFACE STAIN RESISTANCE - LPM surfaced boards must have the ability
to withstand the effects of common materials used in the home or
office. Stain resistance is tested for about 25 substances.
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