When looking
at he source of unwanted noise you will frequently find the "environment"
has a large part to play in the problem i.e. engines encased in housing which
cause noise to echo from bare surfaces. This is illustrated by considering how
noise is transmitted in an empty room, compared with the same room furnished with
carpets and curtains etc. which absorb sound considerably.
Bonding
We recommend affixing our engine insulating sheeting using Bostik
Fast-Tak Multipurpose Spray-On Adhesive Alternatively any strong adhesive
designed not to damage foam may be used. Mechanical fastenings can also be used
either in addition to or as an alternative to adhesives.
Ordering
Information
Nominal
Thickness
Facing
Box/Set
4 Sheets (900x600 approx)
14mm
Class 'O'
Foil
4911F1
All
the above types of sheeting are available in larger sheet sizes (120x100cm &
120x200cm) which are less expensive on a square metre basis. However they are
also more expensive to transport and are suggested therefore where the quantity
and order value is large enough to overcome the extra transport costs.
All
of the above types of sheeting include a single layer of polymeric barrier of
mass 5kg/m.sq, except the 45mm thick types which include double polymeric barrier,
and three layers of class 'O' foam.
Class
'O' Foam for Flame Resistance
There are many different types of foam in common use, and all are available to
special order. Class 'O' foams are recommended for marine applications because
of their superior flame resistance characteristics.
Our Acoustic/Insulation
Foams do not support combustion , melt or drip. When tested to B.S.476 Parts 6
& 7, Our Foams achieve class 'O' to the British Building Regulations.
The addition of a heavy layer of filled Polymer Barrier enhances the mass of the
product giving improved sound insulation properties. The thickness of the inner
and outer layers is adjustable and modifies both the overall mass and the absorption
& insulation performance.
Construction
/ How it Works Four layers are laminated together, this type of construction
reduces noise greatly.
Top
Layer A choice of facings is available to protect the foam. Tough and
flexible, and being 'transparent' allow noise to be absorbed. Unfaced foam sheets
become dirty quickly and are difficult to clean.
Barrier Layer
Our standard stock lines include a mineral loaded Polymeric Barrier, with a mass
of 5kg.m.sq, and fire rating BS4735:1971 self extinguishing. Mean sound reduction
index 22 dB to 150 R140 (Lead barriers are available to special order).
Isolation
Layer A this layer of foam stops noisetransmitting from the barrier layerto
the bulkhead.
Absorption Layer Class 'O' fire resistance foam
varying in thickness for different applications.
When looking
at he source of unwanted noise you will frequently find the "environment"
has a large part to play in the problem i.e. engines encased in housing which
cause noise to echo from bare surfaces. This is illustrated by considering how
noise is transmitted in an empty room, compared with the same room furnished with
carpets and curtains etc. which absorb sound considerably. 
