Existing metal tubular heaters were causing distortion and stress at the bend area.
Delayed Start Up
The existing metal tubular heaters took too long to reach operating temperature.
Heat Absorption Characteristics
Acrylic absorbs energy best at 1.15, 3.2 and 3.5 microns. The existing metal tubular heaters had a peak wavelength emittance of 3.4 microns and a negligible amount of energy at the 1.15 micron level.
Excessive Energy Consumption
When production stopped, the existing heat source continued to consume energy at in-production rates.
Solution
Heat
For acrylic thicknesses above .5 inch (13 mm), a Model 4185 Infrared Strip Heater was used to heat the acrylic from the top at the bend point. For acrylic thicknesses less than .5 inch (13 mm), a Model 5194 Infrared Line Heater was used to heat the acrylic from the top at the bend point. To decrease heat up time, additional heaters were added to heat the acrylic from below.
Power Control
A Model 664F Phase Angle SCR Power Controller controlled the power to the Infrared Strip Heaters and Infrared Line Heaters.
Instant On/Off
The Infrared Strip Heaters and Infrared Line Heaters heated up and cooled down instantly based upon signals received from the SCR Power Controller.
Peak Wavelength
Both heater types emitted peak energy at a wavelength of 1.15 microns and emitted high energy levels through 4.0 microns across the electromagnetic spectrum.
Both heater types emitted 76 watts of energy per linear inch, compared to 35 watts per linear inch for the metal tubular heaters.
Both heater types emitted 76 watts of energy per linear inch, compared to 35 watts per linear inch for the metal tubular heaters.
Benefits
Improved Energy Absorption
The acrylic was able to absorb more energy at the wavelengths provided by the Model 4185 Infrared Strip Heaters and Model 5194 Infrared Line Heaters, which greatly reduced heat up times.
Faster Heating
The Infrared Strip Heater brought the acrylic to forming temperature in approximately four minutes, less than one-third the time of previous heating cycles. The Infrared Line Heater brought the acrylic to forming temperature in approximately 15 seconds to three minutes, depending upon the thickness of the acrylic.
Improved Quality
The heating characteristics of the Infrared Strip Heaters and Infrared Line Heaters eliminated stress and distortion in the bend area.
Faster Start Up
The instant on capability of both heater types eliminated long delays in start up.
Reduced Energy Consumption
The instant off capability of both heater types drastically reduced energy consumption during production stoppage.
