Apparatus and method to form hollow containers
12064914 ยท 2024-08-20
Assignee
Inventors
- Moreno MINGHETTI (Principality of Monaco, MC)
- Roberto MENTINI (Granarolo dell'Emilia, IT)
- Antonio MARTINA (Castel Maggiore, IT)
Cpc classification
B29C49/4823
PERFORMING OPERATIONS; TRANSPORTING
B29C49/46
PERFORMING OPERATIONS; TRANSPORTING
B29C49/4817
PERFORMING OPERATIONS; TRANSPORTING
B29C49/4802
PERFORMING OPERATIONS; TRANSPORTING
B29C49/4273
PERFORMING OPERATIONS; TRANSPORTING
B29C2049/4679
PERFORMING OPERATIONS; TRANSPORTING
B29C49/0412
PERFORMING OPERATIONS; TRANSPORTING
B29C2049/4805
PERFORMING OPERATIONS; TRANSPORTING
B29C49/42442
PERFORMING OPERATIONS; TRANSPORTING
International classification
B29C49/42
PERFORMING OPERATIONS; TRANSPORTING
Abstract
Apparatus for forming hollow containers (110), suitable to contain in particular one or more liquid or semi-liquid food products, starting from parisons (F) made of thermoplastic material. The apparatus comprises a matrix (11) defined by a pair of molds (12) cooperating with each other to define a cavity (13) shaped like the container (110) to be formed, and to define a support channel (14), configured to define an additional portion (112) of said container (110). The apparatus also comprises a forming punch (17), operatively mobile through said support channel (14) to enter into/exit from said cavity (13) so as to thrust and blow one of said parisons (F) against the walls of said cavity (13) to form at least said container (110).
Claims
1. Apparatus for forming hollow containers starting from parisons made of thermoplastic material, wherein the apparatus comprises a matrix defined by a pair of molds cooperating with each other to define a cavity shaped like the container to be formed, and a forming punch configured to thrust and blow a parisons to form said container within the pair of molds, said forming punch having a longitudinal extension along a longitudinal axis and being operatively mobile, in a direction parallel to said longitudinal axis, to enter into/exit from said cavity, said forming punch comprising a thrusting end portion configured to be introduced into said cavity and to contact said container during the formation thereof, so as to confer the container a desired shape, and a cutting portion, positioned opposite to said thrusting end portion to delimit said parison, wherein said pair of molds further comprises a support channel configured to form an additional portion intended to be removed from the container to allow said container to be filled, said support channel being connected to said cavity in correspondence with a connection zone disposed above a neck of the container, and being provided with an aperture, on the opposite side with respect to said cavity, in communication with outside, for entering and exiting of the forming punch, and wherein said forming punch further comprises an auxiliary portion, interposed between said thrusting end portion and said cutting portion, configured and dimensioned to be disposed along the support channel when the end portion of the forming punch reaches and contacts said connection zone during formation of the container.
2. Apparatus as in claim 1, wherein said auxiliary portion of said forming punch cooperates with said parison to define said additional portion provided with a first zone in correspondence with the connection zone of said support channel, and with a second zone in correspondence with said aperture of said support channel, wherein the part of said parison which defines said first zone has a compressive tension state, in a direction parallel to said longitudinal axis, greater than the compressive tension state, in a direction parallel to said longitudinal axis, of the part of said parison which defines said second zone.
3. Apparatus as in claim 1, wherein said connection zone comprises an annular calibration portion suitable to cooperate with said forming punch and with said parison so as to define at least one desired internal diameter size of the neck of said container.
4. Apparatus as in claim 3, wherein said annular calibration portion comprises a sealing segment substantially parallel to said longitudinal axis and having a height in the direction of said longitudinal axis comprised between about 1 mm and about 10 mm.
5. Apparatus as in claim 1, wherein said forming punch is configured to move from a first position, in which said forming punch is external to said matrix, to a second position, in which said forming punch cooperates with the matrix, wherein in said second position, said thrusting end portion is in contact with said container in the process of being formed, and wherein, at least in correspondence with said connection zone, said auxiliary portion is positioned to thrust and blow said parison against an internal wall of said support channel to form said additional portion above the neck of the container, and said cutting portion is positioned so as to delimit said parison in correspondence with said aperture.
6. Semi-finished product comprising a container formed with the apparatus of claim 1 and further comprising a body extending along a longitudinal axis, a neck and an additional portion which comprises a first zone connected to the neck of said container, and a second zone, opposite to the first zone, which is closed, wherein said first zone has a compressive tension state, in a direction parallel to said longitudinal axis, greater than the compressive tension state, in a direction parallel to said longitudinal axis, of said second zone.
7. Machine to produce a semi-finished product, wherein said semi-finished product comprises a container formed with the apparatus of claim 1 and an additional portion which comprises a first zone connected to said container, and a second zone, opposite said first zone, which is closed, wherein said first zone has a compressive tension state, in a direction parallel to said longitudinal axis, greater than the compressive tension state, in a direction parallel to said longitudinal axis, of said second zone, said machine comprising at least a forming station to form said semi-finished product, and a sealing station to seal said semi-finished product at the second zone of the additional portion.
8. Machine as in claim 7, wherein said sealing station comprises a welding assembly configured to seal said second end of said additional portion, following extraction of said container with the additional portion from said matrix.
9. Method to form hollow containers starting from parisons made of thermoplastic material, wherein said method comprises: a step of positioning one of said parisons in a matrix defined by a pair of molds cooperating with each other to define a cavity, shaped like the container to be made, and a support channel, configured to define an additional portion of said container intended to be removed to allow said container to be filled, said support channel being connected to said cavity in correspondence with a connection zone disposed above a neck of the container and being provided with an aperture, on the opposite side with respect to said cavity, in communication with the outside; a step of introducing a forming punch, in a direction parallel to a longitudinal axis, through said aperture of the support channel, into said cavity, to thrust and blow said parison against an internal wall of said cavity to form said container, and against the internal wall of said support channel to form said additional portion, said forming punch having an extension along said longitudinal axis and being provided with a thrusting end portion which is introduced into said cavity; wherein at the end of said introduction step, said thrusting end portion contacts said container within the cavity, a cutting portion of said forming punch, positioned opposite said thrusting end portion, delimits said parison in correspondence with said aperture, and an auxiliary portion of said forming punch which is interposed between said thrusting end portion and said cutting portion, reaches and contacts said connection zone; and a step of extracting said forming punch from said cavity through said support channel in a direction parallel to said longitudinal axis, when the forming of said container and of said additional portion is completed.
10. Method as in claim 9, wherein during said introduction step, said auxiliary portion of said forming punch cooperates with said parison to define said additional portion provided with a first zone in correspondence with the connection zone of said support channel and with a second zone in correspondence with said aperture of said support channel, wherein the part of said parison which defines said first zone has a compressive tension state, in a direction parallel to said longitudinal axis, greater than the compressive tension state, in a direction parallel to said longitudinal axis, of the part of said parison that defines said second zone.
11. Apparatus as in claim 1, wherein, in correspondence with said connection zone, said auxiliary portion of the forming punch compresses said parison in a radial direction, which is substantially orthogonal to said longitudinal axis.
12. Apparatus as in claim 4, wherein the sealing segment defines a sealing rim of the container, which is configured to cooperates with a corresponding sealing ring of a closing element.
Description
DESCRIPTION OF THE DRAWINGS
(1) These and other aspects, characteristics and advantages of the present invention will become apparent from the following description of some embodiments, given as a non-restrictive example with reference to the attached drawings wherein:
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(8) To facilitate comprehension, the same reference numbers have been used, where possible, to identify identical common elements in the drawings. It is understood that elements and characteristics of one embodiment can conveniently be incorporated into other embodiments without further clarifications.
DESCRIPTION OF EMBODIMENTS
(9) We will now refer in detail to the various embodiments of the invention, of which one or more examples are shown in the attached drawings. Each example is supplied by way of illustration of the invention and shall not be understood as a limitation thereof. For example, the characteristics shown or described insomuch as they are part of one embodiment can be adopted on, or in association with, other embodiments to produce another embodiment. It is understood that the present invention shall include all such modifications and variants.
(10) Before describing these embodiments, we must also clarify that the present description is not limited in its application to details of the construction and disposition of the components as described in the following description using the attached drawings. The present description can provide other embodiments and can be obtained or executed in various other ways. We must also clarify that the phraseology and terminology used here is for the purposes of description only, and cannot be considered as limitative.
(11) Embodiments described using the attached drawings concern an apparatus for forming hollow containers intended to contain liquid or semi-liquid food products, indicated as a whole with reference number 10 in the attached drawings.
(12) The apparatus for forming hollow containers, hereafter referred to as apparatus 10 for simplicity, is particularly suitable to form containers 110 starting from an extruded tube F, hereafter called parison F, made of thermoplastic material, by means of the widespread extrusion-blow molding technology.
(13) Here and hereafter in the description, with the term parison we mean a hollow tube made of thermoplastic material obtained by extrusion. The parison has no thread and has approximately the same length as the finished product, or a slightly longer length than that of the finished product, in this case approximately the same height as the container to be made. Since the parison has approximately the same length as the container to be made, during the blow-molding step, which will be described in detail below, the parison undergoes an enlargement mainly in the radial direction.
(14) In particular, the containers 110 formed by the apparatus 10 are suitable to contain liquid or semi-liquid food productsfor example milk, wine, fruit juices, liquid or semi-liquid ready-made foodbut more generally any liquid or semi-liquid product whatsoever that requires an adequate degree of preservation and a shelf-life of an medium-lasting product, for example 2-3 weeks. According to a particular example of use, the apparatus 10 is particularly suitable to make bottles intended to receive pasteurized fresh milk with a shelf-life of 7 days, or microfiltered milk with a shelf-life of 21 days.
(15) In accordance with some embodiments, shown in
(16) The support channel 14 is connected to the cavity 13 in correspondence with a connection zone 15 and is provided with an aperture 16, opposite the cavity 13, in communication with the outside.
(17) The apparatus 10 also comprises a forming punch 17 that has an extension in the direction of a longitudinal axis Z and is operatively mobile, in a direction parallel to the longitudinal axis Z, through the support channel 14 in order to enter into/exit from the cavity 13.
(18) The forming punch 17 is provided with a thrusting end portion 18 configured to be introduced into the cavity 13 so as to thrust and blow a parison F against the walls of the cavity 13 to form at least the container 110.
(19) The thrusting end portion 18 of the forming punch 17 is also configured to contact the container 110, in the process of being formed, at least in correspondence with the connection zone 15 to give it a desired size (
(20) The forming punch 17 also comprises a cutting portion 19, positioned upstream of the thrusting end portion 18, and suitable to delimit the parison F in correspondence with the aperture 16.
(21) The forming punch 17 also comprises an auxiliary portion 21, interposed between the thrusting end portion 18 and the cutting portion 19, and configured to allow the thrusting portion 18 to reach and contact the parison F in correspondence with the connection zone 15 and to thrust and blow the parison F against the walls of the support channel 14 in order to form the additional portion 112 as above.
(22) According to some embodiments, better viewed in
(23) In accordance with some embodiments, the matrix 11 is defined by a pair of molds 12 facing each other and able to selectively couple in correspondence with a coupling plane passing through the longitudinal axis Z and, with particular reference to
(24) The molds 12 are reciprocally mobile away from/toward each other in order to allow the container 110 to be formed in the closed condition (molds 12 next to each other,
(25) Each mold 12 has a containing wall 22 which defines, in cooperation with the containing wall 22 of the other mold 12, the part of the cavity 13 intended to define the receptacle portion 113 of the container 110, and a coupling wall 24 which defines, in cooperation with the coupling wall 24 of the other mold 12, the part of the cavity 13 intended to define the coupling portion 114 of the container 110.
(26) In accordance with the embodiment shown in
(27) In accordance with other embodiments, the matrix 11 is defined by a pair of specular molds 12, one of which is shown in
(28) In accordance with some embodiments, the cavity 13 comprises, in correspondence with the connection zone 15, a calibration portion 20 suitable to cooperate with the forming punch 17 and with the parison F so as to define in a desired manner at least the internal diametral size of the mouth 116 (
(29) The calibration portion 20 is defined by a sealing segment 29 that has a height in a direction parallel to the longitudinal axis Z comprised between about 1 mm and about 10 mm, preferably between about 1.5 mm and about 4 mm. The sealing segment 29 is intended to define a sealing flap 117 of the mouth 116 of the container 110, which is ring-shaped. The sealing flap 117 cooperates, during use, with a sealing ring 118 of the closing mean 115,
(30) In accordance with some embodiments, shown in
(31) In accordance with some embodiments, shown in
(32) The first segment 31 is provided with expansion zones 33 substantially orthogonal to the longitudinal axis Z and configured to allow a homogeneous draw of the parison F by the forming punch 17. In particular, the expansion zones 33 can advantageously function as a unit for storing material during the forming process.
(33) The second segment 32 is substantially smooth and has a tubular shape that connects to the aperture 16.
(34) In accordance with some embodiments, shown in
(35) In accordance with some embodiments, the forming punch 17 has an axial-symmetrical and elongated shape in the direction of the longitudinal axis Z.
(36) The forming punch 17 is configured to pass from a first position, in which the forming punch 17 is outside the matrix 11 and does not cooperate with it, to a second position, in which the forming punch 17 cooperates with the matrix 11. In the second position the thrusting end portion 18 is in contact with the container 110, in the process of being formed, at least in correspondence with the connection edge 15, the auxiliary portion 21 is positioned to thrust and blow the parison F against the walls of the support channel 14 in order to form the additional portion 112, and the cutting portion 19 is positioned so as to delimit the parison F in correspondence with the aperture 16.
(37) In accordance with some embodiments, shown in
(38) The cutting portion 19 can comprise cutting and compression elements 23 protruding with respect to the auxiliary portion 21 in order to delimit the parison F in correspondence with the aperture 16.
(39) According to some embodiments, not shown, the forming punch 17 can have on its external surface a plurality of holes suitable to allow the injection of a compressed gas, for example cooled air, in order to blow the parison F onto the walls of the cavity 13 and onto the walls of the support channel 14 to make respectively the container 110 and the additional portion 112, which is at least temporarily connected to the container 110. In the versions provided here, such holes, not shown, can be distributed homogeneously in the forming punch 17.
(40) In accordance with possible embodiments, shown in
(41) The parison F can be made with an extrusion process in a station upstream with respect to the one in which the blow molding of the container 110 occurs, and can be subsequently positioned between the molds 12, when the molds 12 are moved away from each other, in an open condition.
(42) The parison F can be made with a thermoplastic polymeric material, suitable for contact with food stuffs, chosen from a group comprising polyethylene, polypropylene, polyethylene terephthalate, polythene.
(43) Preferably, the parison F is made of polyethylene, advantageously with high density polyethylene.
(44) In accordance with one aspect of the present invention, the additional portion 112 of the container 110 comprises a first zone 112a in correspondence with the connection zone 15 of the support channel 14 and a second zone 112b in correspondence with the aperture 16 of the support channel 14 where the part of parison F which defines the first zone 112a has a compressive tension state, in a direction parallel to the longitudinal axis Z, greater than the compressive tension state, in a direction parallel to the longitudinal axis Z, of the part of parison F that defines said second zone 112b. In particular, the first zone 112a has a higher hardness than the second zone 112b.
(45) Embodiments described here, shown in
(46) In accordance with some embodiments, a machine to produce a semi-finished product 100 comprises at least a forming station in which the apparatus 10 is operatively provided, a station to seal the semi-finished product 100 positioned downstream of the forming station and, optionally, a station to cut the semi-finished product 100 positioned downstream of the sealing station.
(47) In particular, the cutting station is present if the machine to produce the semi-finished product 100 is directly connected with a plant for filling the containers 110 with a liquid or semi-liquid product. In this case, in fact, the additional portion 112 is separated from the container 110 in the cutting station so as to allow the container 110 to be filled with a liquid or semi-liquid product.
(48) Otherwise, if the containers 110 are filled in another production plant, the machine allows to produce closed semi-finished products 100 intended to be transported to the location of the filling plant and, immediately before it, the cutting station that separates the additional portion 112 from the receptacle portion 113 to allow the latter to be filled.
(49) In accordance with some embodiments, shown in
(50) The sealing station allows to increase the probability that, once the additional portion 112 has been sealed, the container 110, and in particular the receptacle portion 113, does not contain bacteria, which could contaminate the product with which the container 110 will be filled.
(51) In an example embodiment, the welding unit 210 comprises a welding gripper 211 (schematically shown by the rectangle of
(52) In accordance with some embodiments, shown in
(53) Embodiments described here also concern a method to form hollow containers suitable to contain one or more liquid or semi-liquid food products.
(54) The method comprises a step of positioning a parison F in the matrix 11 defined by the pair of molds 12 cooperating with each other to define the cavity 13, which has the shape of the container 110 to be made, and a support channel 14 configured to define the additional portion 112 of the container 110. Subsequently, the method provides a step of introducing the forming punch 17, in a direction parallel to the longitudinal axis Z, through the support channel 14 into the cavity 13, in order to thrust and blow the parison F against the walls of the cavity 13 so that the thrusting end portion 18 contacts the container 110, in the process of being formed, at least in correspondence with the connection edge 15 to confer a desired size on it. Finally, the forming method according to the present invention provides a step of extracting the forming punch 17 from the cavity 13 through the support channel 14 in a direction parallel to the longitudinal axis Z, when the forming of the container 110 and of the additional portion 112 is completed.
(55) According to some embodiments of the present invention, the method to form containers 110 can be executed within the context of a machine for producing semi-finished products 100, in accordance with the embodiments described above. In this case, a method is provided to produce semi-finished products in which after the method to form containers described above has been executed, a step of transferring the containers thus formed to a sealing station is provided, where these are sealed in the manner described above so as to produce such semi-finished products 100.
(56) It is clear that modifications and/or additions of parts or steps may be made to the apparatus for forming hollow containers and corresponding method to form hollow containers as described heretofore, without departing from the field and scope of the present invention.
(57) It is also clear that, although the present invention has been described with reference to some specific examples, a person of skill in the art shall certainly be able to achieve many other equivalent forms of apparatus for forming hollow containers and corresponding method to form hollow containers, having the characteristics as set forth in the claims and hence all coming within the field of protection defined thereby.
(58) In the following claims, the sole purpose of the references in brackets is to facilitate reading: they must not be considered as restrictive factors with regard to the field of protection claimed in the specific claims.