BEHAVIOUR IN A FIRE
Establishing the behavior of metal panels insulated with extruded polyurethane in a fire has always been difficult.
Additionally, the complexities of the various National Standards do not the help matters.
This applies particularly to the “Reaction to the fire” and “Resistance to fire” concepts, which define the behaviour of materials.
REACTION TO FIRE
Reaction to fire is the degree to which a material resists combustion.
With regard to this, materials are assigned a class (0, 1, 2, 3, 4, 5): the higher the class, the higher the degree of combustion.
The fire reaction class is established through tests of small sized samples, which are carried out by following extremely strict standards, which vary from country to country.
For this reason, except for Class 0, which is an ISO standard, it is difficult to make any correlation between the classifications accepted by the various national standards.
The non-combustibility test to assign Class 0 is carried out to the ISO-DIS 1182.2 standard, which envisages to a very small sample material to 750 C and checking the following.
- Formation of flames
- Increase in temperature
- Loss of weight
- In Italy, when the material passes this test, it is assigned Class 0, which in Germany is called A1 and in France MO.
No organic substances achieve Class 0, so they must be classified with other methods. For the Italian laws, they are:
- CSE RF 1/75/A – Suspended materials attacked by flames on both sides
- CSE RF 2/75A – Materials attacked by flames on one side
- CSE RF 3/75A – Materials subject to one flame and radiant heating
- Methods CSE RF 1/75A or CSE RF 2/75A are used according to the type of material.
- The Fire Reaction Class of the product is established by combining these categories.
- The other European countries classify the fire reaction in a different way.
SOUND INSULATION – SOUND ABSORPTION
The sound level is measured in decibels (dB), which are established by a given sound intensity and pressure, calculated in a logarithmic scale. When the sound is increased (reduced) by twofold the sound level increases (or decreases) by 10 dB.
Examples of sound pressure
1–Light leaf rustling20 dB2–Sound level in a reading room 30 dB3–Low-noise humming 40 dB4–Background noise at home 50 dB5–Standard conversation at the distance of 1 m60 dB6–Background noise of computing machines 70 dB7–Compact sized car at 80 km/h 80 dB8–Automatic lathe 90 dB9–Turboprop engineered airplane (inside)100 dB10–Car Hooter 110 dB11–Pneumatic hammer 120 dB12–Hydraulic press 130 dB13–4-engine airplane (take-off)140 dB 14–Launching rocket 200 dB