The joining of plastics is required because component geometries are severely restricted in conventional manufacturing processes such as injection molding or extrusion. In addition to established processes such as hot plate welding, infrared welding, or vibration welding, hot gas butt welding is becoming more and more important industrially due to its advantages. The main benefits are the contactless heating process, the suitability for glass fiber reinforced, and high-temperature plastics as well as complex component geometries. However, various degradation phenomena can occur during the heating process used for economic reasons, due to the presence of oxygen in the air and to the high gas temperatures. In addition, the current patent situation suggests that welding with an oxidizing gas is not permissible depending on the material. On the other hand, however, there is experience from extrusion welding, with which long-term resistant weld seams can be produced using air. Investigations have shown that the same weld seam properties can be achieved with polypropylene using either air or nitrogen as the process gas. Experimental investigations have now been carried out on the suitability of different gases with regard to the weld seam quality when welding polyamides, which are generally regarded as more prone to oxidation. The results show that weld strengths are higher when nitrogen is used as process gas. However, equal weld strengths can be achieved with air and nitrogen when the material contains heat stabilizers.

由于在传统的制造工艺（例如注塑或挤出）中会严重限制部件的几何形状，因此需要进行塑料连接。除了诸如热板焊接，红外焊接或振动焊接之类的既定过程之外，由于其优点，热气对接焊接在工业上也变得越来越重要。主要优点是非接触加热工艺，适用于玻璃纤维增​​强，高温塑料以及复杂几何形状的零件。但是，由于空气中氧气的存在和气体温度高，出于经济原因，在加热过程中可能会发生各种降解现象。另外，当前的专利状况表明，取决于材料，不允许使用氧化气体进行焊接。但是，另一方面，挤压焊接技术具有丰富的经验，利用该技术可以使用空气产生长期耐久的焊缝。研究表明，使用空气或氮气作为工艺气体的聚丙烯可以实现相同的焊缝性能。现在已经进行了关于在焊接聚酰胺时关于焊缝质量的不同气体的适用性的实验研究，这些聚酰胺通常被认为更易于氧化。结果表明，使用氮气作为工艺气体时，焊接强度更高。但是，当材料包含热稳定剂时，使用空气和氮气可以获得相同的焊接强度。研究表明，使用空气或氮气作为工艺气体的聚丙烯可以实现相同的焊缝性能。现在已经进行了关于在焊接聚酰胺时关于焊缝质量的不同气体的适用性的实验研究，这些聚酰胺通常被认为更易于氧化。结果表明，使用氮气作为工艺气体时，焊接强度更高。但是，当材料包含热稳定剂时，使用空气和氮气可以获得相同的焊接强度。研究表明，使用空气或氮气作为工艺气体的聚丙烯可以实现相同的焊缝性能。现在已经进行了关于在焊接聚酰胺时关于焊缝质量的不同气体的适用性的实验研究，这些聚酰胺通常被认为更易于氧化。结果表明，使用氮气作为工艺气体时，焊接强度更高。但是，当材料包含热稳定剂时，使用空气和氮气可以获得相同的焊接强度。通常被认为更容易氧化。结果表明，使用氮气作为工艺气体时，焊接强度更高。但是，当材料包含热稳定剂时，使用空气和氮气可以获得相同的焊接强度。通常被认为更容易氧化。结果表明，使用氮气作为工艺气体时，焊接强度更高。但是，当材料包含热稳定剂时，使用空气和氮气可以获得相同的焊接强度。