Hot Gas Welding Machine
Particle-Free, Non-Contact Welding for High-Performance Engineering Plastics
Hot gas welding is a specialized plastic joining process requiring precise control of gas temperature, flow, nozzle geometry and joining parameters.
Heated Nitrogen · Non-Contact Heating · Particle-Free Welding · Complex 3D Joints · High-Performance Plastics
HG welding uses a non-contact heating method to join two components together. A hot air unit injects a directional jet of heated nitrogen gas through a row of eyelets into the welding rib of the upper and lower parts, heating and softens the plastic. The hot air unit stops the air supply and withdraws, and the upper and lower parts are pressed and cooled until they are bonded together.
HG welding produces no particles and does not degrade the material. 
Hot gas welding can be evaluated for a wide range of thermoplastics, including difficult-to-weld engineering plastics such as PA6, PA66, PBT, POM, PPO and PPS.. For many high-quality thermoplastics, It is particularly valuable when high weld strength, low particle generation and controlled thermal degradation are required.
Why Hot Gas Welding
Particle-Free Welding
No friction is required during heating.
Oxidation Control with Nitrogen
Inert nitrogen helps reduce oxidation and thermal degradation around the weld.
Non-Contact Heating
The heating tool does not touch the molten plastic surface.
High-Performance Plastics
Suitable for evaluation with materials such as PA, PBT, POM, PPO and PPS.
Complex 3D Weld Contours
Customized nozzles can follow irregular and three-dimensional joint geometries.
The left side of the figure below shows a part welded with nitrogen (1% oxygen content) and the right side shows a part welded with air (21% oxygen content). The weld of the part with nitrogen is oxidation-free and no degradation of the material.
Customized Hot Gas Nozzle System
The nozzle profile is engineered according to the weld contour so heated nitrogen can be distributed evenly along the required joining area.
Customized Contour · Uniform Gas Distribution · Complex 3D Geometry · Corrosion-Resistant Surface Treatment
Applications
It is widely used in higher temperature and higher welding strength requirements: such as air suspension.
The below parts are widely welded by hot gas welding machine.
High Temperature · High Pressure · High Strength · Clean Weld
Air Suspension Components
High-strength engineering plastic joints
Electric Water Pumps
Clean and pressure-resistant plastic assemblies
Fluid-System Components
Leak-tight and chemically resistant plastic housings
Pressure-Resistant Engineering Plastic Parts
Applications using PA, PBT, PPS and other high-performance thermoplastics
Choosing the Right Plastic Welding Process: Infrared-Preheated Vibration, Infrared or Hot-Gas Welding?
https://youtube.com/shorts/TSINdtzjMXw?si=8pczPCY7Fi7BE_4r
How It Works
→ 01 Part Positioning
→ 02 Heated Nitrogen Preheating
→ 03 Hot Gas Tool Retraction
→ 04 Joining Under Pressure
→ 05 Holding & Cooling
Hot Gas vs Infrared vs Hot Plate Welding
Hot Gas
Heated nitrogen, non-contact, particularly suited to high-performance engineering plastics.
Infrared
Radiant non-contact heating, suitable for clean and appearance-sensitive joints.
Hot Plate
Contact heating, mature and versatile for large thermoplastic assemblies.
5-Minute Automatic Tool Change
Automatic clamping and quick pneumatic/electrical connections reduce tooling changeover time and production downtime.