Full Product Manual

19
CEMENTING PLEXIGLAS
®
ACRYLIC SHEET
General Health and Safety Precautions
Care must be taken whenever heating any thermoplastic,
including Solarkote
®
capped film. When fabricating, use good
practices consistent with any operation that uses high speed saw
blades, bits or drills. The use of machine guards and hold down
bars is recommended whenever possible. To avoid burns during
thermoforming, the use of thermally protective gloves and
sleeves is recommended.
The heat of thermoforming, cutting, machining, finishing,
annealing, or otherwise processing Plexiglas
®
acrylic sheet may
result in the release of vapors, including methyl methacrylate
(MMA) monomer. In addition, cementing Plexiglas acrylic sheet
introduces other vapors relating to the formulation of adhesives.
Cutting Plexiglas acrylic sheet may also generate polymer dust.
Any dust produced is considered nuisance dust and should be
removed with adequate vacuum dust removal at the point of
generation. It is important to use adequate ventilation during any
processing of Plexiglas
®
acrylic sheet. High concentrations of
MMA vapors can cause eye and respiratory irritation, headache
and nausea. Preferably the ventilation should be as close to the
point of vapor generation as possible.
Flammability The ignition temperature of Plexiglas
®
acrylic
sheet is higher than that of most woods, but it will ignite readily.
Take precautions when flame polishing, laser cutting or any
operation that requires intense heat so that the Plexiglas
®
acrylic
sheet will not ignite. Plexiglas
®
acrylic burns vigorously and
generates heat rapidly. Burning Plexiglas
®
acrylic sheet does
not produce excessive quantities of smoke or gases more toxic
than those produced by wood or paper. The concentration of
carbon monoxide and/or carbon dioxide released by burning
Plexiglas
®
acrylic sheet depends on the quantity of Plexiglas
®
acrylic sheet involved and the condition of burning.
Storage & Handling Plexiglas
®
acrylic sheet is a combustible
thermoplastic material. In general the same fire precautions
that are observed in connection with the handling and use of
any ordinary combustible material should be observed when
handling and storing or using Plexiglas
®
acrylic sheet. Avoid
exposure to extreme heat or aromatic solvents.
General Joining Comments
Pieces fabricated from Plexiglas
®
acrylic sheet may be joined
using mechanical methods such as bolts, thermal methods such
as welding, or chemical methods such as cementing. The following
sections discuss the techniques commonly used to cement
Plexiglas
®
acrylic sheet to itself and to other materials.
Cementing Plexiglas
®
acrylic sheet is relatively easy, but proper
techniques must be practiced to avoid problems. The two most
common problems are crazing and poor joint strength.
Acrylic plastics will eventually craze when subjected to high
stresses for a long time. Crazing is a network of fine cracks running
on, or slightly under, the surface of plastics materials. The tendency
to craze is greatly increased when the stressed material is exposed
to a solvent or to solvent vapors. Most of the cements described
in this manual may craze Plexiglas
®
acrylic sheet if used improperly.