Roxul Industrial Insulation Process - Manual (Page 121)

2.2 Product properties & test methods
2.2.5 Water repellency
ASTM C1104 / 1104M
“Standard Test Method for Determining the Water
Vapor Sorption of Unfaced Mineral Fiber Insulation”
.
This standard covers the determination of the amount
of water vapor sorbed by mineral fiber insulation
exposed to a high-humidity atmosphere. The test
samples are first dried in an oven and then transferred
to an environmental chamber maintained at 120 °F
(49 °C) and 95 % relative humidity for 96 hours. The
water vapor sorption is calculated using the weight
difference before and after testing and is expressed in
weight percentage or volume percentage.
Caution with regard to paint shops
When using hydrophobically treated insulation
materials in spraying plants, also ensure that the
hydrophobic oil does not have any negative impact
– e.g. by means of paint wetting impairment
substances such as silicon oils – on the coating
process. ProRox
® insulation products are
hydrophobically treated without silicon oils or
silicon resins and therefore also fulfil the
guidelines of the automotive industry, such as
VW-Test 3.10.7. They may be used in paint shops.
2.2.6 Water vapor transmission
With installations constructed outdoors, the possibility
of moisture penetrating the insulation system or being
“built in” can never be ruled out. Therefore, it is
important that insulation exhibits a high degree of
water vapor permeability, which allows the water to
escape from the installation once it has been started
up started through diffusion or evaporation processes.
This will prevent a negative impact on the insulation
properties.
2.2.7 Air flow resistance
The resistance that an insulation material offers
against the flow of air is referred to as air flow
resistance. It depends on the apparent density, the
fiber dimensions, the fiber orientation and the
proportion of non-fibrous elements. It determines the
level of convection in the insulation and its acoustic-
technical properties. ASTM C522 "Standard test
method for air flow resistance of acoustic materials"
covers the determination of air flow resistivity, which is
a material property expressed in terms of mks rayls/m
(Pa.s/m
2 ) and describes the relationship between the
pressure difference and flow rate in an insulation
material of 3 1/3 ft (1 m) thickness.
One of the factors that influences convection in an
insulation material is its flow resistance. This is
important when insulation materials adjoin air spaces,
such as finned walls in boilers, and there are no
airtight roofs or intermediate layers (foils).
When such thermal insulation materials are
constructed vertically, the longitudinal flow resistance
should therefore measure at least 50 kPa s/m² in
accordance with EN 29053.
2.2.8 Compression resistance
The resistance that an insulation system offers to
external mechanical loads (wind loads, equipment,
people, cladding loads) is influenced by factors
including the pressure resistance of the insulation.
The compressive stress of mineral wool is preferably
specified at 10 % compression. The compressive
strength is the ratio of the strength under a
predetermined compression to the loaded surface of
the test sample, as identified during a compression
test in accordance with ASTM C165 "Standard Test
Method for Measuring Compressive Properties of
Thermal Insulation".
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