KRELUS infrared heaters
Efficient, responsive, modular, economic

leister.com

We know how.

Leister’s KRELUS infrared heaters emit medium
wave infrared radiation. This is particularly wellabsorbed by plastics, paper, wood and water.
Special metal foils are used as emitters to ensure
homogeneous energy distribution and highefficiency.
Intensities of up to 60 kW/m² are achieved.

Characteristics
very short reaction time very good controllability
 high efficiency
 low heating of the rear side of the heater
 robust construction
In addition to modular heaters, Leister also manufactures customer-specific heaters. The associatedcontrols, which ensure safe and efficient operation,
are also part of the product range.

The outstanding properties apply both to modularheaters, which can be individually combined
into heater fields, and to specific heaters, which arecustom-made.

Heating and coolingbehavior

In addition to the high level of efficiency, the very
fast reaction of the metal foil emitters is a majoradvantage for customers. The heating foils glow
after only a few seconds and emit the full powerof the infrared radiation. After switching off,the heater cools down just as quickly. This meansthat the emitter can also be switched off during
short production interruptions, which saves energy
and costs. Furthermore, material that remains
under the heater during production interruptions
will not be damaged.
KRELUS Infrared heaters
Quartz heaters
Ceramic heaters

Custom-made heaters – profile heaters

Typical heating diagram

Typical cooling diagram

Temp °C

Temp °C

900

900

800

800

700

700

600

600

500

500

400

400

300

300

200

200

100

1000t [sec]0100200300

400

500

600

700

8000t [sec]0100200

300

400

500

600700800

The Module-heaters
The KRELUS Module-Heaters can be used as
single sources or individually combined to heaterfields.
All Module-heaters have a short reaction time andare continuously controllable. In order to achievea homogeneous temperature distribution with large
heater fields, individual zones can be controlled
separately.
Heater field, combined of different
modular infrared heaters

Thanks to the modular design, single heaters can beexchanged easy and quickly.

Technical Data
KRELUS-Module-heater – standard voltage

TypeMINI
G14-25 M

MINI
G7-50 M

MINI-MINI
G14-25 MMMINI-MINI
G9-40 MM

Dimensions mm (l × w × h)

248 × 248 × 65

496 × 123 × 65

248 × 123 × 65

398 × 79 × 65

Power kW

1.3 / 1.7 / 2.0 / 2.5 / 3.1 / 3.6 1.3 / 1.7 / 2.0 / 2.5 / 3.1 / 3.6 1.0

1.0Voltage V

200  – 240

200  – 240

200  – 240

200  – 240

KRELUS-Module-heater – special voltage

TypeSUPER-MINI
G11-12 SMSUPER-MINI
G5-25 SM

MICRO
G3-12

MICRO
G3-6

Dimensions mm (l × w × h)

123 × 123 × 50

248 × 61 × 50

123 × 37 × 36

61 × 37 × 36

Power kW

0.54 / 0.96

0.54 / 0.96

0.26

0.13

Voltage V777721

10.5

Radiation heating

The infrared radiation is a part of the electromagnetic spectra and lies between the visible
light and the microwave radiation in the wavelength
range of ~1 – 1000 µm. The technically relevant
range for heating is typically given as 1 – 10 µm.
A wavelength under 1.4 µm is referred to as shortwave, between 1.4 µm and 3 µm as medium wave
and over 3 µm it is called long wave radiation.
When the radiation interacts with material, absorption, transmission and reflection occur. Absorption
is decisive for heating. Many materials, e.g. allplastics, paper and water, absorb medium wave
infrared radiation particularly well (see graph).

Emission spectra of infrared heaters
Relative intensity
1.01750 °C

0.9
0.8
0.7

1550 °C

0.61200 °C

0.5

850 °C KRELUS

0.40.3

The KRELUS infrared heaters are made of metal foils
that reach a temperature of about 850 °C at maximum power. This temperature corresponds to apeak wavelength of 2.5 µm. The heaters therefore
emit primarily in the medium wave infrared range,
where the absorption of many materials is mostefficient.

0.2
0.1
00 0.5 1

1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 7.5

8Wavelength[µm]

Absorbing properties of various materials
Polyester
Polyamide
Polycarbonate
Acrylic
PVC
AcetatePolystyrene
ABS
Polyolefine PE/PP
Polyacetal POM
Water
Paper (white)
0 0.5 1

1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5

7 7.5

8

Wavelength[µm]

Applications

Homogeneous heating of an organo sheet
Source: Fraunhofer IPTKRELUS infrared heaters are used in many ways.
Wherever flat material has to be heated precisely
and efficiently, KRELUS infrared heaters from
Leister are the first choice.
Industries
plastics processing
 automotive
 packaging industry
 food industry
 paper manufacturing
 printing machinesApplications
textile, paper and film coating
 predrying and preheating
 embossing, laminating and concealing thermoforming
 composite processingIn all these applications the unique characteristics
of KRELUS infrared heaters are highly beneficial.

KRELUS infrared preheating for embossing machines
Source: Kampf LSF GmbH, Laussig, Germany

Characteristics
responsive precise powerful efficient custom-made economicComposite Components – Hybrid Injection Molding

With the KRELUS infrared heaters, Leister has
expanded its portfolio in the infrared range withindustrially usable, high-performance infrared
heaters.

leister.com

Get in touch

Benelux
Leister Technologies Benelux BV
3991 CE Houten / Nederland+31 (0)30 2199888
info@leister.nl

India
Leister Technologies India Pvt
600 041 Chennai / India+91 44 2454 3436
info@leister.inSingapore
Leister Tech Asia Pte. Ltd.
Singapore+65 9787 8712
info.sg@leister.com

China
Leister Technologies Ltd. Shanghai
201 109 / PRC+86 21 6442 2398
leister@leister.cn

Italy
Leister Technologies Italia s.r.l.
20054 Segrate / Italia+39 02 2137647
sales@leister.it

USA
Leister Technologies LLC
Itasca, IL 60143 / USA+1 855 534 7837
info.usa@leister.com

Germany
Leister Technologies
Deutschland GmbH
42103 Wuppertal / Germany+49 (202) 87006-0
info.de@leister.com

Japan
Leister Technologies KK
Yokohama 222-0033 / Japan+81 45 477 3637
sales-japan@leister.com

International Distribution
Leister International AG+41 41 662 74 74
leister@leister.com© Leister 05.2023 / DEKRELUS heaters have been convincing customers
for more than 40 years with demand-orientedsolutions.