A process for the welding of a first molding (11a) to a second molding (1b),
- where the first molding (1a) comprises a first lateral area (3a), a second lateral area (4a) and an end (2a), which comprises a first thermoplastic polymer, and
- where the second molding (1b) comprises a junction area (2b) which comprises a second thermoplastic polymer,
- comprising the steps of
- a) provision of the first molding (1a),
- b) provision of the second molding (1b),
- c) provision of an implement (5) which has a first external area (6a) and a second external area (6b),
- where the first external area (6a) comprises a duct (7a), and where the duct (7a) has a floor (10a), a first duct wall (8a) with a first highest point (12a) and a second duct wall (9a) with a second highest point (13a), where the floor (10a) comprises a means (11a) for the introduction of gas into the duct (7a), where a duct-entry plane (14a) runs through the first highest point (12a) parallel to the first external area (6a) and where the location of an exterior duct region (17a) is between a projection line (15a) from the first highest point (12a) along a direction running perpendicularly to the duct-entry plane (14a) and a projection line (16a) from the second highest point (13a) along a direction running perpendicularly to the duct-entry plane (14a),
- where the second external area (6b) comprises a duct (7b), and where the duct (7b) has a floor (10b), a first duct wall (8b) with a first highest point (12b) and a second duct wall (9b) with a second highest point (13b), where the floor (10b) comprises a means (11b) for the introduction of gas into the duct (7b), where a duct-entry plane (14b) runs through the first highest point (12b) parallel to the second external area (6b) and where the location of the exterior duct region (17b) is between a projection line (15b) from the first highest point (12b) along a direction running perpendicularly to the duct-entry plane (14b) and a projection line (16b) from the second highest point (13b) along a direction running perpendicularly to the duct-entry plane (14b),
- d) positioning of the first molding (1a), where
- a distance (Xa) of the end (2a) from the duct-entry plane (14a) in a direction running perpendicularly to the duct-entry plane (14a) is in the range from 3 mm outside the duct (7a) to 10 mm inside the duct (7a), where
- if the distance (Xa) is in the range from >0 mm to 3 mm outside the duct (7a), the location of the end (2a) is at least to some extent in the exterior duct region (17a),
- and if the distance (Xa) is in the range from 0 mm to 10 mm inside the duct (7a), a minimal distance (Y1a) of the first lateral area (3a) from the first duct wall (8a) is in the range from 0.2 to 5 mm, and a minimal distance (Y2a) of the second lateral area (4a) from the second duct wall (9a) is in the range from 0.2 to 5 mm,
- e) positioning of the second molding (1b), where
- a distance (Xb) of the junction area (2b) from the duct-entry plane (14b) in a direction running perpendicularly to the duct-entry plane (14b) is in the range from 3 mm outside the duct (7b) to 10 mm inside the duct (7b), where
- if the distance (Xb) is in the range from >0 mm to 3 mm outside the duct (7b), the junction area (2b) is at least to some extent in the exterior duct region (17b),
- and if the distance (Xb) is in the range from 0 mm to 10 mm inside the duct (7b), the second molding (1b) additionally has a first lateral area (3b) and a second lateral area (4b) and a minimal distance (Y1b) of the first lateral area (3b) from the first duct wall (8b) is in the range from 0.2 to 5 mm, and where a minimal distance (Y2b) of the second lateral area (4b) from the second duct wall (9b) is in the range from 0.2 to 5 mm,
- f) introduction of a hot gas via the means (11a) for the introduction of gas into the duct (7a), where the temperature of the end (2a) of the first molding (1a) increases to a temperature T1a and where the first thermoplastic polymer comprised in the end (2a) melts,
- g) introduction of a hot gas via the means (11b) for the introduction of gas into the duct (7b), where the temperature of the junction area (2b) of the second molding (1b) increases to a temperature T1b and where the second thermoplastic polymer comprised in the junction area (2b) melts,
- h) removal of the first molding (1a) from the position achieved in step d),
- i) removal of the second molding (1b) from the position achieved in step e),
- j) bringing of the heated end (2a) of the first molding (1a) into contact with the heated junction area (2b) of the second molding (1b) and cooling of the heated end (2a) of the first molding (1a) to a temperature T2a and of the heated junction area (2b) of the second molding (1b) to a temperature T2b while the heated end (2a) and the heated junction area (2b) are in contact with one another to form a weld between the first molding (1a) and the second molding (1b).