Shrinking process for producing solid, transportable and printable containers and a device for carrying out a shrinking process of this type
The invention relates to a shrinking process for producing solid, transportable and printable containers by wrapping the articles to be packaged with a film in such a manner as to produce an overlapping section of the film ends on the base area, heating by heat exchange or convection in order to seal the free ends in the area of overlap, and finally heating in a shrinking oven, the container so produced being stabilized by the shrinking process. The method comprises first locally limiting the incoming hot air to the base area of the container to form a peripheral shell in the area of the bottle bottoms, the shape of the container being stabilized thereby, while the container is continuously transported during stabilization and the hot air directed onto the base area of the container in a bundle of discretely distributed gas jets is thereby discharged and guided back after a locally limited heat transfer with the film, and more hot gas is directed laterally against the continuously transported container at an increased lateral blow speed in order to complete the shrinking process. The invention further relates to a device for carrying out the shrinking process.
1. A shrinking process for producing, transportable and printable containers for articles which are taller than they are wide and which include base surfaces and contain heat-sensitive filling substances, comprising:
covering the articles to be packaged with a film such that the film ends overlap in the area of the base surfaces of the articles;
heat sealing by heat transfer or convection overlapping ends in the area of overlap, and then heat shrinking the container in a shrinking oven, the container so produced being stabilized by the shrinking process;
wherein incoming hot air is first locally limited to a base area of the container to form a peripheral shell in an area of the article bottoms, the shape of the container being stabilized thereby, and the container being continuously transported during stabilization, the hot air being directed onto the base area of the container in a bundle of discretely distributed gas jets from a gas circulation system and guided back to the gas circulation system after the locally limited heat transfer with the film, with additional hot gas being directed laterally against the container as it is continuously transported at an increased lateral blow speed in the shrinking oven in order to complete the shrinking process.
2. A shrinking process according claim 1 , wherein the film is sealed to form a container base and at the same time is shrunk and a positive formation of the base area of the container is thereby produced.
3. A shrinking process according claim 2 , wherein the container is moved on a conveyor device during the sealing operation, wherein the hot air flowing in is suctioned after the heat transfer and is controlled thereby such that the sealing is limited on the area of overlap or a partial area of the base.
4. A shrinking process according claim 1 , wherein the container is moved on a conveyor device during the sealing operation, wherein the hot air flowing in is suctioned after the heat transfer and is controlled thereby such that the sealing is limited on the area of overlap or a partial area of the base.
5. A shrinking process according claim 1 , wherein local impingement is carried out by activating discretely distributed outflow units and outlet air units that are controlled mechanically, hydraulically or electrically.
6. A shrinking process according claim 5 , wherein a vacuum is formed in the outlet air units sufficient to accelerate the hot air out of the outflow units in the area of overlap and to guide it at increased speed over the film ends to be sealed.
7. A shrinking process according claim 5 , wherein the control of the inlet air units and outlet air units is carried out by transverse and longitudinal sliders, wherein individual units from the discretely distributed inlet air units and outlet air units are activated according to the local impingement of the film ends in the area of overlap.