Infrared Radiation Welding of Thermoplastics
Infrared radiation welding of thermoplastics is a non-contact welding process in which the surfaces to be joined are melted by infrared radiation and joined under pressure. This prevents material adhesion and guarantees contour-accurate weld zones.
Physical-Chemical Mechanism of Action
Infrared radiation is directed onto the thermoplastics to be joined. The surfaces absorb the energy and heat up until they reach the melting point. Under pressure, the molten materials are pressed together and bond to form a solid joint.
Metallurgical Relevance & Welding Risks
This process is especially suitable for plastics because it requires no contact heating. It prevents material from sticking to the heating element and enables contour-accurate joint zones. However, insufficient energy supply can lead to incomplete melting, which can result in poor bonds or cracks. Excessive energy can modify the material and impair its mechanical properties.
Workshop Practice & Instructions
• Energy Supply: Make sure the infrared radiation is sufficient to bring the thermoplastics to the melting point, but not too high to modify the material.
• Pressure: Apply constant pressure to the surfaces to be joined to ensure a clean and defined joint.
• Temperature Control: Continuously monitor the temperature of the surfaces to be joined to ensure they are in the optimal melting temperature range.
• Joint Zones: Ensure the joint zones are contour-accurate and clean to achieve high mechanical strength of the bond.