Edge
Engagement, Thermal Expansion.
Edge Engagement
To ensure optimum security under load it is imperative that at least
one vertical rib of the sheet is engaged and securely clamped in
the glazing system. This is most easily achieved when sheets have
closed edges. Where open edge sheets are used the sheet must be
cut as closely as possible to the rib thus minimising the unsupported
top and bottom faces. Glazing systems of adequate width to provide
sufficient engagement must be selected.
|
|
Thermal
Expansion
Accommodating the thermal expansion of Marlon ST Longlife sheet
cannot be over emphasised as this is generally greater than that
of other popular glazing materials and affects both length and
width. Installing without sufficient allowance for thermal movement
will result in thermal stress and bowing of the sheet.
The table below
compares the linear thermal expansion of Marlon ST Longlife with
other common materials
|
| |
Linear
thermal expansion |
| Marlon
ST Longlife |
6.7 x 10-5
m/m0C |
| PVC |
6.8 x 10-5
m/m0C |
| Acrylic |
7.0 x 10-5
m/m0C |
| Aluminium |
2.3 x 10-5
m/m0C |
| Steel |
12 x 10-5
m/m0C |
| Glass |
0.85 x
10-5 m/m0C |
Thermal
Expansion Calculator
In practical terms it is necessary to allow 3.5mm/metre length or
width for thermal expansion. The Calculator below gives the amount
of thermal expansion allowance which must be made for given lengths
or widths of sheet. |
|
IMPORTANT
NOTICE
This information and software is believed by Brett Martin Limited
to be accurate and reliable as of October 2001. However, since
this
information and software furnished by Brett Martin Limited is
provided without charge, and since use conditions are not within
Brett Martin Limited's control, Brett Martin Limited assumes
no obligation or liability for such information, software or
use of either; no warranty, express or implied, is given nor
is freedom from any patent,copyright, trademark or trade secret
owned by Brett Martin Limited or others to be inferred.
Brett Martin Limited does grant, to the extent it is able, the
right to user to use the software and the software's results.
It is the users responsibility to determine whether this information
and software is appropriate for user's purpose. |
|
| |
Thermal
expansion allowance - E |
| Glazing
length |
L1 = L2
- E |
| Glazing
width |
W1 = W2
- 2 (E/2) |
|
