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klaverlover
30-08-2008, 08:07 AM
My company has a little problem.

By the start up from a freezer, there raising bubbles on the outside from the insulated panels.

Some facts and usefull information

The freezer room is 35*20*6 and the sec freezer room is 10*10*4 ( and there there are no problems of bubbles on panels)
The insulated panels are 20cm of tickness. The panels are from isobar from Belgium.
The panels are south orientated and the day of start up the outside temp was approx 27C°
The start up procedure was was normal, and that is we brought the temp too 0C° in a slow tempo with a freezer door slightly open and fermod's working.

Now the question, What is the possible reason for the bubble forming on the panels.
Because everybody is blaiming each other.
Most freq called reason is too fast dropping of temp, but our plc prog shows a slow drop of temp/h till he came on setpoint of 0C°.
So not a exsessive temp drop, as they claim.

All idea's are welcome, so we can learn of them and can avoid them.

Thx in advance
Klaverlover

chemi-cool
30-08-2008, 10:03 AM
What sort of bubbles?

Can you post some pictures?

klaverlover
30-08-2008, 10:50 AM
It are bubbles 50*15cm horizontal on the panels on approx 4m height

The photos are mailed to the insurrence company.
No digital photo's for the moment. When i have digital photos, i will post them.

smpsmp45
05-09-2008, 06:57 AM
The Bubbles are formed due to air entrapped inside. Basically when the panel is molded, the air inside the sheets has to escape out. There are blow holes provided for this in the profile sections. Many a times the blow holes are blocked due to earlier panel production & the air being lighter in weight compared to PU chemicals gets to the surface. The only option left is to puncture the panels at various places using a pin holes. In case the delaminations are large enough, you shall have to use special PVC screws after putting up silicone inside. We had done this in many places & things later come out good. This essentially happens with discontinuous production of the panels. Though this is not a serious problem as such, the manufacturer has to check back on his facilities & the Al sections on which the Blow holes are provided.