Despatch Stackable LCC/LCD-4 - Manual (Page 33)

Stackable LCC/LCD Oven Owner’s Manual A SSEMBLY & S ETUP
Version 1.1 33
Copyright © 2012 by Despatch Industries.
All rights reserved. No part of the contents of this manual may be reproduced, copied or transmitted in any form or by any
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retrieval systems without the written permission of Despatch Industries, unless for purchaser's personal use.
4.3.1. HEPA Filter Burn-Off
4.3.1.1. HEPA Filter Burn-Off Process
The burn-off process takes place in any equipment where a new HEPA filter is used at
temperatures above 180°C / 356°F. Expect smoke, possibly a pungent odor and a light residue on
interior surfaces. This results from oxidation of the binder. Most of the binder will leave the filter
after running at a temperature of 260°C/500°F for 48 hours. Check the oven for particles or the
exhaust for smoke and odor to determine that the process is finished.

While the High-temperature filter has undergone tempering
treatment at the factory, smells and/or fumes may be released
during the first use at temperature.
4.3.1.2. Location of HEPA Filter Burn-Off Process
Select a location for the burn-off process where generated smoke and odor will be ventilated with
the least amount of interruption and inconvenience. Ideally this will be in the final location for the
oven. However, it may be a receiving dock, some well ventilated space or even outside if the
weather is acceptable. If this location is a very clean area, pay special attention to an exhaust
hook-up that fully captures the smoke and odor produced. The post-Burn-off cleaning (that is,
oven wipe down) may also generate dust. So take care if in a clean room.
4.3.1.3. Recommended HEPA Filter Burn-Off Process
1. Locate the equipment exhaust opening where chamber air is being expelled.
a. If the oven filter is burned off in a clean area, be sure to handle the equipment exhaust
appropriately.
b. If the equipment is large and the exhaust stack is a permanent service connection, connect
the equipment and exhaust stack before the burn-off process.
c. If the equipment is small with no permanent exhaust duct required, arrange a temporary
connection out of the clean area that will handle the maximum temperature of the
equipment. Direct the smoke and odor outside, or to a highly ventilated area.
2. Set the temperature control at the maximum process temperature.
a. Silicone: Ramp at 1.25°C/min to 260°C and soak for 48 hours.
b. Media Pack: Ramp at 1.25°C/min to 260°C and soak for 48 hours.
c. High-temperature (
Figure 14 ):
i. Option 1: Ramp at 1.7°C/min (or up to 5°C/min) to 350°C and soak for 48 hours.
ii. Option 2: Ramp to process temperature and soak for three consecutive three - hour
segments over 48 hours.

LCC oven chamber temperature transitions must not exceed
1.5°C/minute to maintain class 100 chamber conditions. For ramp
rates greater than 1.5°C/minute and up to 5°C/minute, the LCD model
will maintain class 100 chamber conditions.