1. Common characteristics of materials suitable for high-frequency embossing machines
Polar molecular structure
The efficiency of high-frequency heating depends on the dielectric loss factor (tanδ) of the material, and usually requires the material molecular chain to contain polar groups such as chlorine, oxygen, and nitrogen (such as chlorine atoms in PVC and ester groups in TPU). The friction heat generation rate of the molecular chain of this type of material under high-frequency electromagnetic fields can reach 10⁶-10⁹ times/second, and the energy conversion efficiency is much higher than that of non-polar materials (such as PP and PE).
Typical case: When embossing PU leather of car seats, the heating speed of PVC coating (tanδ=0.15) is 50 times faster than that of PP base cloth (tanδ=0.003), ensuring synchronous welding of composite materials.
Thermoplastic reversible deformation
The material needs to achieve segmental movement in the range from glass transition temperature (Tg) to melting point (Tm), and can quickly soften and retain the embossed shape after high-frequency heating. Crystalline materials (such as PET) need to control the heating temperature to 5-10℃ below Tm to avoid crystallization and shrinkage; amorphous materials (such as PVC) can be heated to the flow state (about 160-180℃) to achieve deep embossing.
Technical parameters: The power density of the high-frequency embossing machine is usually set to 2-6kW/cm², ensuring that the material reaches the process temperature within 0.3-1 second.
2. Application scenarios of high-frequency embossing machines in the automotive industry
Automotive interior field
Seat surface: emboss diamond patterns and air holes (depth 0.3-1.5mm) on the surface of genuine leather or artificial leather, and replace the adhesive process with high-frequency molecular welding to eliminate the risk of VOCs release;
Door panel decoration: emboss carbon fiber patterns after pre-coating PVC coating on PP/EPDM-TD20 substrate to achieve A-level surface effect, scratch resistance (5N load) > 100,000 times without damage;
Ceiling sound insulation: High-frequency pressing between PET non-woven fabric and EVA foam layer to form an acoustic damping layer with a thickness of 0.5mm, and the noise reduction performance is improved by 4dB (A).
3. Future trends of high-frequency embossing machine material technology
Intelligent process driven by material database
Establish a high-frequency embossing material performance database (covering 50+ parameters such as dielectric constant, thermal conductivity, shrinkage, etc.), and realize real-time optimization of process parameters (frequency, power, time) through AI algorithm. For example, after inputting the material type and target embossing depth, the system can automatically recommend the best process combination, shortening the development cycle by 70%.
Cross-scale molding technology
Develop a "macro embossing + micro structure" composite process to achieve nano-level surface modification while high-frequency embossing. For example, while embossing macro anti-slip patterns on the surface of a car seat, micron-level protrusions (5μm in diameter, 1μm in height) are generated on the pattern surface by regulating the high-frequency field strength, increasing the anti-slip coefficient by 40%.