• Categories:IR Lamp Technologies & News
• Author:E-DEN Lighting
• Origin:E-DEN IR Lighting
• Time of issue:2025-03-10
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(Summary description)Preheating and Drying Effects of Infrared Heating Technology in Industrial Processing

Infrared heating achieves energy savings, quality improvement, and cost reduction in preheating and drying processes through wavelength matching with the heated object's absorption, non-contact radiation heat transfer, and efficient energy conversion. This technology is particularly irreplaceable in moisture drying applications.

 

1.1. Food Processing

Rapid and Uniform Heating: Infrared radiation directly penetrates the food's surface, enabling simultaneous internal and external heating, reducing preheating time (e.g., baking, meat thawing), and minimizing nutrient loss.

 

Surface Sterilization: Short-wave infrared (0.76-2μm) can instantly eliminate surface microorganisms, enhancing the safety of bottled and canned foods. Mid-wave infrared (2-4μm) is effective for killing insect eggs in fruits or drying moisture in chili peppers, vegetables, tea leaves, and traditional Chinese herbs.

 

1.2. Coating Curing

Precise Temperature Control: Infrared wavelengths can be tailored to match the absorption spectra of coatings (e.g., mid-wave infrared 2-4μm is suitable for polymer resins), preventing excessive heating of the substrate.

 

Gradient Heating and Modular Design: Adjusting the number of infrared heaters in different zones, combined with precise temperature control (±1°C), accommodates substrates with irregular shapes. Zone-specific radiation intensity control facilitates gradient curing from the surface inward, reducing defects like bubbles and orange peel.

 

1.3. Textile Printing

Non-Contact Heating: Many printing equipment rollers have insufficient heating or prolonged preheating times. Infrared heating, designed for curved surfaces, achieves uniform temperature elevation, avoids mechanical damage to flexible materials, and shortens drying time, making it suitable for high-precision textile printing pre-drying.

 

1.4. Wood Coating Preheating

The efficiency of infrared heating is utilized in the preheating and drying stages of coating equipment. Specifically, infrared preheating before spraying paint on wood raises the wood's surface temperature, ensuring uniform paint adhesion and consistent thickness.

 

1.5. Electronics Industry

Localized Heating: Focusing infrared radiation allows precise preheating of solder joints or encapsulants, preventing thermal damage to components from overall heating.

 

Fast Response: Infrared systems have rapid start-stop times (milliseconds), suitable for high-precision semiconductor packaging processes.

 

Comparison of Infrared Heating with Traditional Heating Methods

Infrared heating technology offers distinct advantages over traditional heating methods such as hot air convection and microwave drying. The following table summarizes the key performance indicators of these heating methods:

 





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Infrared Drying


Hot Air Convection Drying


Microwave Drying




Heat Transfer Efficiency


Direct radiation (60-80%)


Indirect transfer (30-50%)


Volume heating (50-70%)




Drying Uniformity


High (requires wavelength matching)


Low (prone to temperature gradients)


Prone to hotspots (requires uniform field design)




Energy Consumption Cost


Low (no medium heating loss)


High (requires substantial air circulation)


Medium to high (electrical energy conversion loss)




Equipment Complexity


Simple (no fans/duct systems)


Complex (requires hot air circulation system)


Complex (magnetron/waveguide design)



Infrared Drying

Tea Leaf Infrared Drying: Infrared drying has been shown to increase the content of tea polyphenols by 10%～15%, enhancing the quality of the dried tea leaves.

Automotive Coating Infrared Curing: Utilizing infrared curing has reduced drying times around 40% and decreased volatile organic compound (VOC) emissions more than 30%, contributing to both efficiency and environmental sustainability.

PCB Board Pre-Baking: Implementing infrared pre-baking has cut half processing times , streamlining production without compromising quality.