WO2009015731A2

WO2009015731A2 - Method and system for the production of containers in a drape-forming or blow-molding process

Info

Publication number: WO2009015731A2
Application number: PCT/EP2008/004881
Authority: WO
Inventors: Alois Monzel
Original assignee: Khs Ag
Priority date: 2007-07-31
Filing date: 2008-06-18
Publication date: 2009-02-05
Also published as: WO2009015731A3

Abstract

Disclosed are a method and a system (1) for producing bottles (2), kegs, or similar plastic containers in a drape-forming or blow-molding process using a pressurized process gas that is free or substantially free from oxygen.

Description

Method and plant for producing containers by stretch or blow molding

The invention relates to a method according to the preamble of claim 1 and to a system according to claim 12.

A method for producing bottles, KEGs or the like containers made of thermoplastic material, in particular PET by blow molding or stretch forming from preheated preforms using compressed air as blowing or process gas are known. The disadvantage here is, inter alia, that during blow-molding, air-oxygen diffuses into the wall of the container, which severely impairs the quality and / or the taste and / or the shelf life of such products, especially in the case of oxygen-sensitive products filled in such containers. It is also disadvantageous that the filling process contained in the containers, often directly following the blow molding process

Atmospheric oxygen must be removed by one or more rinses. For this purpose, expensive carbonic acid is used in practice.

"Oxygen-sensitive products" in the context of the invention are products of various kinds and different consistency, which are impaired or damaged by oxygen.

"Oxygen-free or substantially oxygen-free process gas" in the context of the invention is a gas which contains no oxygen (O2, O or O3) or at most only such a small, negligible proportion of oxygen, which does not affect or damage the in the container produced bottled product leads. The oxygen-free or substantially oxygen-free process gas then mainly contains nitrogen, possibly further constituents, such as a small amount of argon or carbon dioxide, and was preferably obtained by fractionation of ambient or atmospheric air.

Fractionation of ambient or atmospheric air in the sense of the invention means the separation of the ambient or atmospheric air in their gas and Steam components, in particular by using at least one gas filter, preferably by using at least one membrane filter.

The object of the invention is to provide a method and a system, with or in a rational manner a production of containers, such as bottles or KEGs by blowing or stretching without one or at least with a greatly reduced oxygen diffusion into the wall the container is possible. It is also an object of the present invention to at least reduce the rinsing operations preceding the filling. To solve this problem, a method according to claim 1 is formed. An installation for producing containers, for example bottles or KEGs by blow molding or stretch forming, is the subject of patent claim 12.

Further developments, advantages and applications of the invention will become apparent from the following description of exemplary embodiments and from the figures. In this case, all described and / or illustrated features alone or in any combination are fundamentally the subject of the invention, regardless of their summary in the claims or their dependency. Also, the content of the claims is made an integral part of the description.

The invention will be explained in more detail below with reference to the figure, which shows a simplified representation of a system for producing bottles or similar containers made of thermoplastic material by blow molding or stretch forming.

The plant generally designated 1 in the figure is used to produce bottles 2 from a thermoplastic, preferably PET bottles or PET drums by blow molding using preforms or preforms 3 of the thermoplastic material or PET. The plant 1 essentially comprises a preforming task 4, in which the preforms 3 are provided as a disordered quantity and from which they then hang in a predetermined orientation, namely on a conveyor 5 with its flange 3.1 forming the later mouth flange 2.1 of the bottles 2 Heating section 6 for heating to a temperature of, for example, about 135 ⁰ C. be supplied. The plant 1 further comprises a subsequent directly to the heating station 6 blowing machine 7, for example, in a manner known to those skilled in a circulating around a vertical machine axis rotor having a plurality of blow molds in which from the preheated preforms 3 by blowing or stretching the bottles 2 are formed. The finished bottles 2 are then fed from the blow molding machine 7, for example with their mouth flange 2.1 hanging on a conveyor to another use (arrow A).

A particularity of Appendix 1 is that the blowing of the bottles 2 in the blow molding machine 7 using an oxygen-free or substantially oxygen-free process gas, i. a substantially consisting of nitrogen process gas takes place, which in a plant 1 directly associated gas filter 9, i. obtained at the place of manufacture of the bottles 2 by fractionating ambient air, which is supplied to the gas filter 9 via a sterile filter 10 (arrow B). In a housing of the gas filter 9, at least one filter membrane 11 and / or at least one combination of filter membranes (11) is provided, which is arranged and selected in terms of their filtering effect such that the gas component of the air, namely nitrogen, which retains the process gas, is retained on it the remaining gas components of the ambient air, or at least the oxygen are forwarded, so that at the at least one filter membrane 11 associated output or the local line 12, the oxygen-free or substantially oxygen-free process gas is available and can be fed to a process gas supply 13 of the blow molding machine 7 in which the process gas is stored and / or compressed to the pressure required for blow molding (eg approx. 40 bar).

By using a nitrogen gas formed or substantially free of nitrogen and thus oxygen-free or substantially oxygen-free process gas during blow molding of the bottles 2, an in-diffusion of oxygen into the plastic of the bottles 2 is effectively prevented. In particular, if the system 1 is part of an overall system in which the bottles 2 are fed immediately after their preparation for filling with a product of a filling machine, by the use of nitrogen as the process gas also in advantageous Way achieved that the interior, but at least a majority of the interior of the filling machine supplied bottles 2 is still occupied by nitrogen and thus protected against ingress of air-oxygen. In particular, even when filling oxygen-sensitive products can therefore be dispensed with the usually partly repeated rinsing of the bottles 2 with an inert gas immediately before filling or this prior to the actual filling process prior rinsing can be significantly shortened or simplified. This has the advantage that the angular range of the rotary movement of the rotor required for flushing is shortened, and thus that for the actual filling process, especially in filling machines of a rotating design, in which the rinsing and filling of the bottles 2 takes place on a rotor driven peripherally about a vertical machine axis usable angular range of the rotational movement of the rotor is increased, so that with such an overall system much higher performance (number of bottles produced and filled 2 per unit time) are possible with the same rotor diameter.

The invention has been described above by means of an embodiment. It is understood that changes and modifications are possible without thereby departing from the inventive concept underlying the invention.

Thus, it was assumed above that with the plant 1 bottles 2, in particular PET bottles are manufactured. Of course, the invention is not limited to the production of bottles, but also includes the production of other containers by blow molding or stretch forming, in particular the production of KEGs and especially of PET-KEGs.

Furthermore, there is also the possibility of preheating the preforms 3 in an oxygen-free or substantially oxygen-free atmosphere, ie to carry out in the nitrogen atmosphere, so as to prevent this pre-heating an in-diffusion of air-oxygen in the bottle 2 forming plastic. For this purpose, the formed in a housing interior of the heating section 6 is then applied to the nitrogen obtained from the ambient air from the gas filter 9, as shown with the direction indicated in the figure by broken lines line 14. LIST OF REFERENCE NUMBERS

1 Plant for the production of bottles or containers by blow molding

2 bottle

2.1 mouth flange

3 preform (preform)

3.1 flange

4 preforming task

5 transporter

6 heating section

7 blowing machine

8 transporter

9 gas filters

10 sterile filters

11 filter membrane

12 output

13 nitrogen supply device

14 line

A conveying or process direction

B air flow

Claims

claims

1. A method for producing containers (2) from plastic by blow molding or stretch forming using a pressurized process gas, characterized in that the process gas is an oxygen-free or substantially oxygen-free process gas.

2. The method according to claim 1, characterized in that the process gas is formed by nitrogen or substantially nitrogen.

3. The method according to claim 2, characterized in that the process gas is obtained in at least one gas filter (9) by fractionating ambient air.

4. The method according to claim 3, characterized in that the process gas in situ, i. at or in the region of the place of manufacture in which at least one gas filter (9) is obtained.

5. The method according to claim 3 or 4, characterized in that the at least one gas filter is a membrane filter.

6. The method according to any one of claims 3 - 5, characterized in that the gas filter (9) supplied ambient air is treated before fractionation in at least one sterile filter (10) for the separation of foreign substances or particles and for the removal of germs or microorganisms.

7. The method according to any one of claims 3-6, characterized in that the process gas obtained by fractionating the ambient air is treated in at least one sterile filter for the removal of foreign substances or particles and for the removal of germs or microorganisms.

8. The method according to any one of the preceding claims, characterized in that the process gas obtained from the ambient air of a supply unit (13) of a blow molding machine (7) for storage and / or Generation of the pressure required for the blow molding is supplied.

9. The method according to any one of the preceding claims, characterized in that the blow molding using in at least one heating section or heating station (6) preheated preforms (3).

10. The method according to claim 9, characterized in that the preheating takes place in an atmosphere formed by the process gas.

11.Verfahren according to any one of the preceding claims, characterized in that the containers are KEGs or PET bottles.

12. Plant for producing bottles, KEGs or the like plastic container (2) in a blow molding machine (7) by blow molding or stretch forming using a pressurized process gas, characterized in that the process gas is an oxygen-free or substantially oxygen-free process gas ,

13. Plant according to claim 12, characterized in that the process gas is formed by nitrogen or substantially nitrogen.

14. Plant according to claim 12 or 13, characterized by at least one gas filter (9), with which the process gas is obtained by fractionating ambient air.

15. Plant according to claim 14, characterized in that the at least one gas filter (9) is part of the blowing machine (7) or the plant (1).

16. Plant according to claim 14 or 15, characterized in that the at least one gas filter (9) is a membrane filter.

17. Plant according to one of claims 14-16, characterized by at least one sterile filter (10), with which the at least one gas filter (9) supplied ambient air prior to fractionation for the separation of foreign substances and / or particles and for the removal of germs or microorganisms.

18. Plant according to one of claims 14 - 17, characterized by at least one sterile filter (10), with which the gas from the filter (9) supplied process gas for the separation of foreign matter and / or particles and for the removal of germs or microorganisms is treated.

19. Plant according to one of the preceding claims, characterized by a supply unit (13) for storing the process gas and / or generating a process gas pressure required for blow molding.

20. Plant according to one of the preceding claims, characterized by a heating section or heating station (6) for preheating the preforms (3) in an atmosphere formed by the process gas.