Thermal joining of plastic objects by means of heating means having low curie temperature

An arrangement, comprising:

• a first inner object, which has a first plastic material having a first melting temperature;
• a second outer object, which surrounds the first inner object at least partially, and which has a second plastic material having a second melting temperature;
• a heating means, which is located between the first inner object and the second outer object, wherein the heating means has a ribbon-type structure and an adhesion changing layer, which is attached to, or formed at, at least one surface of the ribbon-type structure, wherein the adhesion changing layer effects a flow behavior of molten-on plastic material,
• wherein the ribbon-type structure has a ferromagnetic material, which is inductively heatable, and has a predetermined Curie temperature, which is higher than the first melting temperature and/or the second melting temperature,
• a plurality of openings is formed in the ribbon-type structure, in which openings a solidified plastic material is located, which connects the first inner object to the second outer object, and
• a first temperature difference between the predetermined Curie temperature and the first melting temperature and/or a second temperature difference between the predetermined Curie temperature and the second melting temperature is in the range between 5 K and 100 K.

A system, comprising:

• a first inner object which has a first plastic material with a first melting temperature;
• a second outer object, which surrounds the first inner object at least partially, and which has a second plastic material with a second melting temperature;
• a heating means located between the first inner object and the second outer object, wherein the heating means has a ribbon-type structure and an adhesion changing layer, which is attached to, or formed at, at least one surface of the ribbon-type structure, wherein the adhesion changing layer effects a flow behavior of molten-on plastic material,
• wherein the ribbon-type structure has a ferromagnetic material, which is inductively heatable, and has a predetermined Curie temperature, which is higher than the first melting temperature and/or the second melting temperature,
• a plurality of openings formed in the ribbon-type structure, in which openings a solidified plastic material is located, which connects the first inner object to the second outer object, and
• a first temperature difference between the predetermined Curie temperature and the first melting temperature and/or a second temperature difference between the predetermined Curie temperature and the second melting temperature is in the range between 5 K and 100 K;
• and
• a generator for generating an electromagnetic field, which inductively couples a primary coil of the generator to the heating means.

A method for thermally connecting two objects each having a plastic material, the method comprising:

• laying a heating means alongside to a first inner object or to a second outer object, wherein the heating means has a ribbon-type structure having a plurality of openings and a ferromagnetic material and an adhesion changing layer, which is attached to, or formed at, at least one surface of the ribbon-type structure, wherein the adhesion changing layer effects a flow behavior of molten-on plastic material;
• arranging the second outer object relative to the first inner object, such that the first inner object is surrounded at least partially by the second outer object and the heating means is located between the first inner object and the second outer object;
• inductively heating the heating means such that plastic material of the first inner object and/or plastic material of the second outer object melts on;
• intruding molten-on plastic material of the first inner object and/or of molten-on plastic material of the second outer object into the openings, such that the two plastic materials come in contact with each other, and/or melting-on of plastic material, which is already located in the openings;
• reducing a power, which is inductively transmitted to the heating means as a consequence of an approaching of the temperature of the ferromagnetic material to a Curie temperature of the ferromagnetic material;
• and
• cooling down the molten-on plastic material of the first inner object and/or of the molten-on plastic material of the second outer object and/or of the plastic material located in the openings, such that the two objects are mechanically connected to each other.