Apparatus and method for heating plastic preforms with controllable heating power

Patent metadata

Field	Value
Publication number	US-11260571-B2
Application number	US-201816642550-A
Country	US
Kind code	B2
Filing date	Sep 7, 2018
Priority date	Sep 7, 2017
Publication date	Mar 1, 2022
Grant date	Mar 1, 2022

Abstract

Provided is an apparatus for heating plastic preforms, with a transport device which transports the plastic preforms along a predefined transport path, wherein this transport device has a plurality of holding elements for holding the plastic preform, and with at least one first heating section which is arranged along the transport path, and at least one second heating section which is arranged along the transport path downstream of the first heating section, wherein the heating sections each include a plurality of independently controllable heating elements which allow heating of the plastic preforms in several heating zones, lying above each other in the longitudinal direction of the plastic preforms, with a temperature profile which changes in the longitudinal direction of the plastic preforms, wherein the apparatus includes a control device for controlling these heating sections.

First claim

The invention claimed is:

1. An apparatus for heating plastic preforms, with a transport device which transports the plastic preforms along a predefined transport path, wherein this transport device has a plurality of holding elements for holding the plastic preforms, and with at least one first heating section which is arranged along the transport path, and at least one second heating section which is arranged along the transport path downstream of the first heating section, wherein the heating sections each include a plurality of independently controllable heating elements which allow heating of the plastic preforms in several heating zones, lying above each other in the longitudinal direction of the plastic preforms, with a temperature profile which changes in the longitudinal direction of the plastic preforms, wherein the apparatus comprises a control device for controlling these heating sections, wherein the apparatus has an input device via which a user can predefine a set value for the individual heating zones, and a control device is provided which automatically actuates the individual heating elements taking account of a set value of at least one of the lamp power and a set value which is characteristic of the lamp power, and wherein a processor device automatically calculates whether and how many heating elements must be activated in which heating zone in response to an applied temperature specification by the user.

2. The apparatus according to claim 1 , wherein the predefinable set values are absolute or relative percentage zone power levels.

3. The apparatus according to claim 1 , wherein the predefinable set values are the energy levels introduced into at least one of the preform per zone and the preform temperatures to be achieved per zone.

4. The apparatus according to claim 1 , wherein the processor device is suitable and intended for determining the optimal set values of the individual heating elements for achieving a maximally long service life of the lamps.

5. The apparatus according to claim 1 , wherein at least one of the processor device and an algorithm determines the set values of the individual heating elements which are optimal for the most energy-efficient heating profile.

6. The apparatus according to claim 1 , wherein the input device allows the input of a plurality of set values for the individual heating zones.

7. The apparatus according to claim 1 , wherein the apparatus has a plurality of heating elements which are arranged successively along the transport path of the plastic preforms.

8. The apparatus according to claim 7 , wherein the heating elements of each heating section can be controlled independently of each other.

9. The apparatus according to claim 1 , wherein the apparatus has a first temperature measuring device which measures an actual temperature of the plastic preforms.

10. The apparatus according to claim 1 , wherein the control device controls a power of the heating elements between at least two limit values.

11. The apparatus according to claim 1 , wherein the apparatus comprises a second temperature measuring device for measuring a temperature of the plastic preforms.

12. The apparatus according to claim 1 , wherein heating elements or groups of heating elements to be activated can be selected.

13. A method for heating plastic preforms, wherein a transport device transports the plastic preforms along a predefined transport path, wherein this transport device has a plurality of holding elements for holding the plastic preforms, and wherein at least one first heating section, which is arranged along the transport path, and at least one second heating section, which is arranged along the transport path downstream of the first heating section, heat the plastic preforms, wherein the heating sections each comprise a plurality of independently controllable heating elements which allow heating of the plastic preforms in several heating zones, lying above each other in the longitudinal direction of the plastic preforms, with a temperature profile which changes in the longitudinal direction of the plastic preforms, wherein a control device controls these heating elements, comprising the steps of: providing the apparatus with an input device via which the user can predefine a set value for a heating process, and with a processor device actuating the individual heating elements taking account of the set value, and actuating the individual heating elements taking into account a set value of at least one of the lamp power and a set value which is characteristic of the lamp power, and wherein a processor device automatically calculates whether and how many heating elements must be activated in which heating zone in response to an applied temperature specification by the user.

14. The method according to claim 13 , wherein a temperature of the plastic preforms is measured for at least part of the time.

15. The apparatus according to claim 4 , wherein the processor device has an algorithm which performs corresponding calculations.

16. The apparatus according to claim 1 , wherein the processor device and/or the control device allows a change in transport speed of the plastic preforms.

17. The apparatus according to claim 1 , wherein the heating sections are arranged stationarily and the plastic preforms are transported past these heating sections or heating elements.

18. The apparatus according to claim 1 , wherein the apparatus has a temperature measuring device which measures the actual temperature of the plastic preforms and the processor device controls the heating of the plastic preforms on the basis of this measured temperature.

19. The apparatus according to claim 1 , wherein an algorithm is provided which takes account of the fact that the lamp power lies in a specific range, so that the individual heating elements or lamps are operated under optimal operating conditions and a lower and/or an upper limit value is established for operating temperatures, and a lamp power is configured such that a lamp temperature moves inside this range.

Assignees

• Krones Ag

Inventors

• Kitzinger Thomas
• Finger Dieter

Classifications

• B29C49/123

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• B29C2049/7882

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• B29C49/786

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• B29C49/06 Primary

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