Installation Guide

14
ACRYLIC SELECTION
SHEET THICKNESS
Determining proper sheet thickness is based on
the long dimension of the sign and the specified
maximum wind load in pounds per square feet (PSF)
(See Fig. 23). The sign is required to meet a speci-
fied wind load determined by building codes of your
area. Approximate wind loads in relation to wind
velocity can be seen in Table 1.
SHEET SIZE
Contraction and expansion allowances must
be taken into consideration when fabricating signs
for outdoor applications. PLASKOLITE’s sign grade
acrylic must be allowed to move freely within a
sign’s channels to prevent bowing or dislodging.
The coefficient of linear expansion is 0.00004-°F, or
.000072-°C
Calculate expansion by taking:
Measurement between channels (inches) X (maxi-
mum sign temperature* (°F) - room temperature
(°F)) X 0.00004.
Calculate contraction by taking:
Measurement between channels (inches) X (room
temperature (°F) - minimum temperature (°F)) X
0.00004.
A simple calculation is to allow 1/16” per linear
foot for expansion and contraction.
Note: * Maximum sign temperature must remain
below acrylic deflection temperature (See physical
property tables, pages 4 & 5).
IMPACT RESISTANCE
PLASKOLITE’S sign grade acrylic sheet can be
obtained with a choice of impact resistance. From
OPTIX SG, a general purpose acrylic, to DURAPLEX
SG10 that incorporates the most modifier, PLAS-
KOLITE acrylic sheet can meet the requirements to
minimize potential breakage (See physical property
tables, pages 4 & 5).
SIGN ASSEMBLY
ATTACHING ACRYLIC TO SIGN CABINETS
Typical sign cabinets use aluminum extrusions to
engage the edge of the acrylic sign face (See Fig. 24).
A hanger bar along the top edge of the acrylic
should be used to correct any sagging or bowing of
the sign face. This technique is commonly used in
warmer climates and with large signs where it is nec-
essary to prevent the weight of the sign from resting
on the lower portion of the sign frame, reducing the
possibility of sign deformation due to high tempera-
ture (See Fig. 25).
170
160
150
140
130
120
110
100
90
80
70
60
50
40
30
20
LONG DIMENSION (inches)
0 5 10 15 20 25 30 35 40 45
UNIFORM LOAD - PSF
.118
.177
.236
Figure 23
UNIFORM
LOAD
20 PSF
30 PSF
40 PSF
50 PSF
APPROXIMATE
WIND VELOCITY
75 MPH
90 MPH
100 MPH
130 MPH
Table 1
Figure 24