|
|
|
|
|
|
Panels and boards faced with Formica® decorative laminate nearly always require the reverse side to be faced with a similar material to counter-balance the effects of dimensional changes that may occur.
Optimum Flatness
Best results are obtained by using identical laminates simultaneously bonded to both face and back. This might appear unnecessarily expensive, but is justified when the extra cost is related to the degree of flatness required and to the final installed price of the panel. Always consider this method for large free standing panels such as screens, balustrades, cubicles, sliding doors, thin ceiling panels, shelving, etc.
BS 4965 Flatness Requirements
Most installations have somewhat less demanding flatness requirements and are usually satisfied by the criteria specified in BS 4965: 1mm maximum distortion over 600mm length.
Two important clauses about flatness limits are contained in BS 4965.
1. Because it is difficult to achieve flatness in thin panels, no tolerance is specified for boards or panels using substrates less than 12mm thick.
2. Many factors, including changes in temperature and relative humidity (such as can be encountered at building sites) can cause boards and panels to bow and twist irreversibly.
Therefore flatness to BS 4965 requirements can be guaranteed only at the time of delivery from the composite board manufacturer. This is particularly important if opposite sides of a panel are likely to be exposed to marked temperature and/or humidity differences.
Backing sheets should be of the same type and grade as, and of similar thickness to, the face laminates. Formica Limited offers a range of special backing boards for use with the main grades of laminate. Properly pre-conditioned with their decorative counterparts before bonding, they will enable the manufacturer to achieve BS 4965 flatness standard. Always use such boards where this standard is a requirement, such as in wall panelling and in all general casework including radiator covers.
Other Requirements
Linings to kitchen cabinets and the inside faces to cupboard doors need an attractive, easily cleaned surface. While the flatness of these components must be considered, their overall dimensions are relatively small; experience has shown that the Cabinet Liner products offered by Formica Limited in both White and Beige will satisfy both aesthetic and flatness requirements.
For certain installations, where the reverse side has to be backed to add stiffness or to seal the substrate but where flatness and appearance are not critical, Formica Limited offers a variety of backing boards. These are produced for maximum economy: when properly fabricated they generally provide an acceptable level of counter-balance, but no flatness guarantees can be given. They are suitable for use in applications such as curved panels, postformed worktops, window sill boards, and panels which will be fixed back to a stout framework.
Recommendations
Select backing laminates according to the following flatness demands.
|
|
Face Laminate Grade
|
Category A
Optimum Flatness
(Better than BS 4965 limit)
|
Category B
Flatness meeting
BS 4965 limit
|
Category C
Sealing purposes only:
flatness not guaranteed
|
|
HGS
|
Compensating laminate of same colour,
pattern and grade as face laminate
|
|
Any backing laminate, e.g. Universal
Backing Board; Production Backing
Board; DC White, etc.
|
|
VGS
|
|
|
HGP
|
|
|
VGP
|
|
|
VFP
|
|
|
LTP
|
|
|
Veneer Laminate
|
|
Any conventional laminate backing board
|
Metallic Laminate
Polished Chrome
|
|
Universal Backing Board
|
Metallic Laminate
Other Polished Finishes
|
|
Metallic Laminate
Matt and Brushed
|
|
Metallic Laminate
Embossed Aluminum
|
|
Metallic Laminate
Embossed Copper
|
|
Metallic Laminate
F2178 Stainless Steel
|
|
Metallic Laminate
F4109 Alu Cubic
|
|
Metallic Laminate
F4587 Birch Cubic
|
|
|
ColorCore Laminate
|
|
----------
|
* With Formica ColorCore multi-layer, use Category A compensating laminate.
Importance of Sheet Direction in Avoiding Bowing
1. To avoid bowing, always use face and back laminates cut from the same direction of the laminate sheet and never at right angles to each other.
2. Dimensional movement of the laminate in the lengthwise direction is less than half the movement in the transverse direction. So, whenever possible, and always if board flatness is a critical factor, cut the longest dimension of the laminate panel from its lengthwise direction (parallel with the direction of sanding).
|
|
|
|
