|
|
 |
Contents
Electric Infra Red Drying of Water-Based Adhesives on Envelopes
A key operation in the highly automated process of envelope production is the drying of the water-based adhesive strip
on the flap for sealing the envelope. This is normally achieved by a number of 5.5kW hot air blowers.
A critical examination of the process established the disadavantages of the existing drying method:
| • |
Very energy intensive. |
| • |
A limiting factor in setting the machine operating speed (bottleneck). |
| • |
Inconsistent drying. |
| • |
Hot and dusty working environment. |
Consequently, 22kW of hot air blowers were replaced by a 9kW thyristor controlled infra red heater enclosure.
Because of the high drying efficiency of infra red, the heater enclosure operates at only 3.5kW giving an
immediate 84% reduction in energy consumption over the original drying
system.
The controller includes an interlock, which cuts the power to the heaters the instant the conveyor is stopped
for any reason. This, coupled with the low thermal mass of the emitter, has
eliminated the need for the complex pneumatic retraction system associated
with the previous drying system.
The efficient transfer of infra red energy between heat source and product removed the previous bottleneck and
allowed machine speed to be increased by as much as 50%.
Because of the controllability, reliability and rapid response of the infra red system,
consistent drying has been achieved.
|
|
 |
| 9kW Thyristor controlled infra red heater enclosure |
| |
 |
| 9kW Thyristor controlled infra red heater enclosure |
|
|
|
|
|
|