WO2023001731A1 - Device for producing containers from preforms made of thermoplastic material - Google Patents

Abstract

The invention relates to a device (10) for producing containers from preforms (44) made of thermoplastic material, the device having at least one heating zone (20) for thermally conditioning preforms (44), which zone has at least one heat-radiating element (34), wherein: the device (10) comprises at least one transport device (36) for moving preforms (44) along the heating zone (20), which transport device has at least one transport mandrel (40) for holding a preform (44); the transport mandrel (40) comprises a plug-in element (42) that has an end face (58) which, in a transport position in which the plug-in element (42) is at least partially plugged into an open region (46) of a preform (44), is situated in the preform (44); the plug-in element (42) has at least one opening (52), which is situated outside the preform (44) when in the transport position, at least one cooling channel (56) situated on the end face (58) and at least one connection channel (54), which fluid-communicatingly connects the at least one cooling channel (56) to the opening (52). A device (10) for producing containers from preforms made of thermoplastic material is thus provided, in which heating of the open region (46) of preforms (44) is further reduced without a large amount of effort.

Description

Device for manufacturing containers from preforms made of thermoplastic material

The invention relates to a device for producing containers from preforms made of thermoplastic material with at least one heating section for thermal conditioning of preforms.

For the manufacture of containers, preforms made of thermoplastic material can be used, which are formed into the containers. The shaping takes place by stretching the preform. To do this, the thermoplastic material of the preform is heated to the temperature required for reshaping. For heating, the preform can be fastened with its mouth to a transport mandrel who transports the preform along a heating section at which thermal radiation is emitted onto the preform. The various areas of the preform which can be heated to different temperatures. The transport mandrel can heat up as a result of the heating radiation and can transfer this additional thermal energy primarily to the mouth area of the preform. The mouth of the preform must therefore be protected from excessive heating in the heating section in order to avoid undesirable deformation, such as ovality at the mouth, or other errors in the manufacture of the container.

For this purpose it is known to carry out the transport mandrels with highly reflective upper surfaces in order to reduce the heating of the transport mandrels by the radiant heat. Furthermore, the transport mandrels or the openings of the preforms can also be blown with cooling air from the outside.

WO 2006/047260 A1 discloses a transport mandrel which has cooling channels at its tip in order to control the temperature at the mouth of a preform. To do this, a cooled fluid is pumped through the cooling channels while the transport mandrel is in contact with the preform ling for thermal conditioning of the preform is moved by a heating device.

The object of the invention is to provide a device for producing containers from preforms made of thermoplastic material, in which the heating of the mouth of preforms is further reduced without great effort.

The object is solved by the features of the independent claims. Advantageous developments are the subject of the dependent claims and the following description.

In a device for producing containers from preforms made of thermoplastic material with at least one heating section for thermal conditioning of preforms, which has at least one radiant heating element, the device having at least one transport device for moving preforms along the heating section with at least one transport mandrel for holding a preform, wherein the transport mandrel comprises a plug-in element with an end face which is arranged in the preform in a transport position, in which the plug-in element is at least partially inserted into a mouth of a preform, it is provided according to the invention that the plug-in element has at least one Opening, which is arranged outside of the preform in the transport position, has at least one cooling channel arranged on the end face and at least one channel which connects the at least one cooling channel to the at least one opening in a fluid-communicating manner t.

With the invention, a transport mandrel is thus provided in a device for the production of containers, in which externally supplied gas can be conducted into the plug-in element. In the heating section, gas that is blown from the outside onto the transport mandrel and the mouth area of the preform is guided inside the plug element to an end face of the transport mandrel, which is arranged in the preform's mouth when the preform is being transported along the heating section. For this purpose, the plug-in element has at least one cooling nal, which is arranged on the end face of the plug-in element.

The at least one cooling channel is connected via the at least one connection channel to the at least one opening, which is arranged on a surface of the plug-in element or the transport mandrel and has a fluid-communicating connection with the environment of the transport mandrel. Through the at least one opening, for example, gas provided from the outside can be introduced via the connecting channel into the cooling channel in order to cool the end face of the plug element, which is arranged inside the preform in the transport position. The at least one cooling channel can, for. B. be formed as an annular gap or as a cavity or chamber which extends around a longitudinal axis of the transport mandrel. The end face of the plug-in element can thus be cooled without great effort. In this case, only a small additional outlay in terms of cooling capacity is required if gas is used which is already used for cooling the outer surfaces of the transport mandrel and the mouth area of the preform. Furthermore, no additional cooling device is required to conduct a cooling fluid through the transport mandrel to its end face. This further reduces heating of the mouth of preforms without great effort.

According to one example, the end face can have a reflector surface for reflecting heating radiation that is emitted by the at least one radiant heating element, with the at least one cooling channel adjoining the reflector surface.

The reflector surface is designed to reflect heating radiation that hits the end face when passing through the heating section. For this purpose, the reflector surface can cover almost the entire end face and shield it from the heating radiation. Furthermore, the reflector surface can be designed to be highly reflective. Despite the reflective properties of the reflector surface, part of the heating radiation is absorbed, so that the reflector surface heats up. In particular with large mouth diameters of the preforms, increased heating of the reflector surface occurs, with the end face or the reflector surface changing when the mouth is doubled. fourfold. Gas can be conducted to the reflector surface through the at least one cooling channel on the end face. The at least one cooling channel can extend along the reflector surface, so that gas sweeps along the reflector surface. The at least one cooling channel can be arranged on the end face, for example, on a side of the reflector surface pointing away from the end face. Furthermore, the at least one cooling channel can be arranged, for example, between the plug-in element and the reflector surface.

It is also conceivable that the device has, for example, a cooling element for generating a gas flow for cooling the transport mandrel on the heating section, with the plug-in element being arranged in the transport position in the gas flow. The gas stream includes gas, e.g. B. air, for cooling the preform and the transport mandrel.

The cooling element can have an outlet opening for the gas flow, which is arranged on the heating section. The gas flow can have ambient temperature or be cooled. Since the plug-in element is arranged in the gas flow in the transport position, the plug-in element can be at least partially cooled by the gas flow. Since with a heating of the end face can also be reduced.

The at least one opening can also be arranged at least temporarily in the gas flow, for example in the transport position.

The gas stream can then flow through the opening into the cooling channel via the connecting channel. In the cooling channel, heat can be exchanged between the end face or a reflector surface and the gas flow, so that the heating of the end face or the plug-in element can be further reduced.

According to a further example, the plug-in element can have at least two openings which are connected to the at least one cooling channel in a fluid-communicating manner, with at least one of the at least two openings being arranged outside of the gas flow if at least at least one other of the at least two openings is arranged in the gas stream.

The transport mandrel can perform a rotation around its own longitudinal axis with the preform in order to optimize the thermal conditioning of the preform. The openings can then be arranged radially laterally on the plug-in element at different positions on the circumference. With each rotation, a first opening is rotated at least temporarily into the gas flow, so that the gas flow can flow into the opening. At the same time, a second opening can then be screwed out of the gas flow, so that the gas flow cannot flow directly into the other opening. The first opening can serve as an inlet and the second opening can serve as an outlet for the cooling channel. Gas can then flow out of the outlet through the inlet via the cooling channel.

It is also conceivable that the plug-in element can have a large number of openings, which are distributed in a star shape around a longitudinal axis extending from the end face.

In this way, a directionally fixed gas flow can be introduced into the cooling channel in every rotational position of the transport mandrel. All openings can then alternately serve as an inlet for one part of the revolution and as an outlet for the cooling channel for another part of the revolution. Even if the transport mandrel is not rotating, at least one inlet and at least one outlet can be provided via the large number of openings.

The transport device can have, for example, a large number of transport mandrels and a chain of mandrels connecting the transport mandrels for moving and rotating the transport mandrels along the heating section.

The invention further relates to a transport mandrel for moving a preform along a heating section, the transport mandrel having a plug-in element with an end face which is in a transport _Position in which the plug-in element is inserted into an opening of a preform, in which the preform is arranged, the plug-in element having at least one opening which is arranged outside of the preform in the transport position, the plug-in element having at least one cooling channel arranged on the end face and at least one channel fluidly connecting the at least one cooling channel to the at least one opening.

The transport mandrel can be further developed according to the device according to the previous description.

Advantages and effects as well as further developments of the transport mandrel result from the advantages and effects as well as further developments of the device described above. In order to avoid repetition, reference is therefore made to the previous description in this regard.

The invention is described below using an exemplary embodiment with the accompanying drawing. Show it:

FIG. 1 shows a schematic representation of a device;

Figure 2a, b is a schematic cross-sectional view of a

heating section with cooling element; and

FIG. 3 shows a schematic representation of a plug-in element.

The device for manufacturing containers from preforms made of thermoplastic material is hereinafter denoted in its entirety by the reference numeral 10, as illustrated in FIG.

The device 10 can have a feed device 12 which feeds the device 10 with preforms. In one example, the preforms can be transferred to a heating section 20 of the device 10 by means of a transport wheel 14 . In this case, the preforms on the heating section 20 are transported by transport mandrels of a transport device 36 recorded. The transport device 36 extends along the heating section 20 and can be guided through the heating section 20 via deflection wheels 38 . The heating section 20 also has at least one radiant heater element 34 for emitting radiant heat and at least one cooling element 32 for generating a gas flow. As they pass through the heating section 20, the preforms are thermally conditioned for later forming into containers.

After passing through the heating section 20, the thermally condi tioned preforms, z. B. by means of a transfer wheel 16, a forming device 24, z. B. a blow wheel are passed. In the molding device 24, the preforms are molded into containers.

After forming, the containers, e.g. B. by means of a further transfer wheel 18, are removed from the molding device 24. The containers produced can further, e.g. B. by means of one or more transport wheels 22, an output device (not illustrated provides) are passed to z. B. to a coating device and / or sterilization device and / or to a filling device (not shown) to be transported.

FIGS. 2a and 2b show a cross section through the heating section 20, the cross section running transversely to the transport direction. i.e. the preforms are moved out of the plane of the page or into the plane of the page.

A preform 44 which is fastened to a transport mandrel 40 is shown. The transport mandrel 40 is in turn attached to a chain of thorns of the transport device 36 . The transport device 36 can have a large number of transport mandrels 40 .

The radiant heater element 34 can emit radiant heat onto the preform 44 when the transport device 36 transports the preform 44 past the radiant heater element 34 . During transport, the transport mandrel 40 can rotate about its own longitudinal axis 50, so that the preform 44 is also rotated. This causes, that in the circumferential direction of the preform 44 not only a fixed sector of the preform 44 is exposed to the heating radiation, which is directed towards the heating element, but that the thermal energy from the heating radiation is distributed on all sides of the preform 44.

The transport mandrel 40 has a plug-in element 42 for fastening the preform 44 . The plug-in element 42 can be inserted or plugged into a mouth 46 of a preform 44 with a retaining section 68 in the transport position and fastened therein.

The cooling element 32 has an opening 48 which is arranged at the level of a portion 70 of the male element 42 . A gas flow that can flow from the cooling element 32 out of the opening 48 is therefore directed towards this section 70 of the plug element 42 . In this case, the plug-in element 42 has at least one opening 52 which is arranged in the section 70 from the plug-in element 42 .

The gas flow can be cooled by the cooling element 32 or have ambient temperature. Since the transport mandrel 40 has a temperature that is significantly above the ambient temperature as a result of the exposure to radiation from the radiant heating element 34, a gas flow at ambient temperature can generally bring about cooling.

The plug-in element 42 is explained in more detail below by means of FIG. 2b.

The male member 42 has an end surface 58 which is disposed within the preform 44 when the male member 42 is connected to a preform 44 . The end face 58 points into the preform 44 and can have a reflector surface 60 . The reflector surface 60 is designed to reflect at least part of the heating radiation impinging on the reflector surface 60. The non-reflected part of the heating radiation heats the reflector surface 60. For cooling the reflector surface 60, the plug-in element 42 comprises at least one cooling channel 56 on the end face 58, which is adjacent to the reflector surface 56. The cooling channel 56 can be formed annularly around the longitudinal axis 50 of the plug-in element 42 or of the transport mandrel 40 .

The cooling channel 56 is connected in fluid communication with the at least one opening 52 via a connecting channel 54 . A gas stream that flows into the at least one opening 52 is thus conducted via the connecting duct 54 to the cooling duct 56 . When flowing along the cooling channel 56, the gas flow sweeps over the back of the reflector surface 60, so that the reflector surface 60 can be cooled by the gas flow.

The cooling channel 56 can have an outlet through which the gas flow heated by the reflector surface 60 can be discharged.

The outlet can be formed by a further opening 52 which can be connected to the cooling channel 56 via a further connecting channel 54 . In Figure 2b, for example, this is the opening 52 on the left in the figure. The opening 52 on the right-hand side in the figure then acts as an inlet into the cooling channel 56.

By cooling the end face 58, heating of the mouth 46 of the preform 44 can be reduced.

FIG. 3 shows a transport mandrel 40 with a plug-in element 42 in a schematic three-dimensional view from the outside. The plug-in element 42 has a plurality of openings 42, in this case the game has six openings 42, which are arranged in a star shape about the longitudinal axis 50. The openings 52 are further arranged at a transition between a radial side wall 62 and an upper side 64 of the plug element 42 . In each case one connecting channel 52 connects an opening 42 in fluid communication with the cooling channel 56. All openings 42 are thus connected to one another in fluid communication via the cooling channel 56. The plug-in element 42 can furthermore also have a plurality of cooling channels 56 which are separate from one another.

Alternatively or additionally, the at least one opening 52 can also be arranged at other positions on the plug-in element 42 as long as it is arranged outside of the mouth 46 or the preform 44 in section 70 when the plug-in element 42 is connected to the preform 44. Thus, the at least one opening 52 z. B. fully constantly on the top 64 or completely on the side wall 62 of the male element 42 may be arranged.

Below the openings 42 of the holding portion 68 of the element 42 Steckele is arranged, on which the holding elements 66 are attached. The holding elements 66 can be formed as balls, clamping jaws or the like, which can be moved at least partially out of the holding section 68 and at least partially into the holding section 68 . To insert the holding section 68 into a mouth 46 of a preform 44, the holding elements 66 are section 68 moved into the holding section. In order to fasten the preform 44 to the plug-in element 42, the holding elements 66 are moved out of the holding section 68 and press against the mouth 46 from the inside.

The example described above is in no way intended to limit the invention. Rather, the invention can be modified in many different ways. All of the features of the inventions described above can be essential to the invention alone or in combination with one another. Reference List

10 device for the production of containers

12 feeder

14 transport wheel

16 transfer wheel

18 transfer wheel

20 heating section

22 transport wheel

24 molding device

30 output device

32 cooling element

34 _radiant element

36 transport device

38 idler wheel

40 transport mandrel

42 male element

44 preform

46 estuary

48 opening

50 longitudinal axis

52 opening

54 connecting channel

56 cooling channel

58 face

60 reflector surface

62 side wall

64 top

66 holding element

68 holding section

70 section

Claims

Expectations 1. Device for the production of containers from preforms (44) made of thermoplastic material with at least one heating section (20) for the thermal conditioning of preforms (44), which has at least one radiant heating element (34), the device (10) having at least one transport device (36) for moving preforms (44 ) along the heating section (20) with at least one transport mandrel (40) for holding a preform (44), the transport mandrel (40) comprising a plug element (42) with an end face (58) which, in a transport position, in in which the plug-in element (42) is at least partially inserted into an opening (46) of a preform (44), is arranged in the preform (44), characterized in that the plug-in element (42) has at least one opening (52) which is arranged outside the preform (44) in the transport position, has at least one cooling channel (56) arranged on the end face (58) and at least one connecting channel (54) which connects the at least one cooling channel (56) to the at least one opening (52) connec det fluid-communicating. 2. Device according to claim 1, characterized in that the end face (58) has a reflector surface (60) for reflecting heating radiation, which is emitted by the at least one heating radiant element (34), the at least one cooling channel (56) on the reflector surface (60) is adjacent. 3. Device according to claim 1 or 2, characterized in that the device (10) has a cooling element (32) for generating a gas flow for cooling the transport mandrel (40) on the heating section (20), the plug-in element (42) is arranged in the transport position in the gas flow. 4. Device according to claim 3, characterized in that the at least one opening (52) is arranged at least temporarily in the gas flow in the transport position. 5. Device according to Claim 3 or 4, characterized in that the plug-in element (42) has at least two openings (52) which are connected in fluid communication with the at least one cooling channel (56), with at least one of the at least two openings (52 ) is arranged outside of the gas flow when at least one other of the at least two openings (52) is arranged in the gas flow. 6. Device according to one of claims 1 to 5, characterized in that the plug-in element (42) has a plurality of openings (52) which are distributed in a star shape around a longitudinal axis (50) extending from the end face (58). are. 7. Device according to one of claims 1 to 6, characterized in that the transport device (36) has a plurality of transport mandrels (40) and a mandrel chain connecting the transport mandrels (40) for moving and rotating the transport mandrels (40) along the heating section (20). 8. Transport mandrel for moving a preform (44) along a heating section (20), the transport mandrel (40) having a plug-in element (42) with an end face (58) which, in a transport position, in which the plug-in element (42) is in a mouth of a preform (44) is inserted, in which the preform (44) is arranged, characterized in that the plug-in element (42) has at least one opening (52) which is arranged outside of the preform (44) in the transport position wherein the plug-in element (42) comprises at least one cooling channel (56) arranged on the end face (58) and at least one connecting channel (54) which connects the at least one cooling channel (56) in fluid communication with the at least one opening (52). 9. Transport mandrel (40) according to claim 8, characterized in that the transport mandrel (40) is further developed according to one of claims 2 to 7.