IT202100033200A1 - PERFECTED DOUBLE WALL ASSEMBLED PREFORM AND PROCEDURE FOR THE CREATION OF THE SAME - Google Patents

Description

INDUSTRIAL INVENTION entitled:

?PERFECTED DOUBLE WALL ASSEMBLED PREFORM, AND PROCEDURE FOR MANUFACTURING THE SAME?

DESCRIPTION

The present invention refers to a double-walled preform for the production of double-walled containers following the blowing of said preform and, more? precisely, to an assembled preform which is consisting of two concentric preforms in which a first internal preform is fixedly inserted inside a second external preform. The object of the present invention is also the manufacturing process of the aforementioned double-walled preform.

The present invention finds application in all fields in which a container intended to contain liquids requires adequate barrier protections that a double-walled container can? give in order to preserve the properties over time? characteristics of the product contained.

State of the art

As ? known, the containers obtained by blowing PET preforms or similar material are intended to contain liquids in various product sectors: beverage, chemical, pharmaceutical, food, etc.

For certain uses and applications? It is necessary to create blown containers in PET or similar material which containers have a double wall. More? precisely, the system of the two concentric preforms? used when? it is necessary to improve and enhance some characteristics that cannot be obtained using the single preform. The construction solution of the container equipped with a double wall? particularly suitable for containers intended to contain liquids which require adequate protection in order to preserve their properties? characteristics, preserving them from contact with the air or other environments that can alter the chemical composition of the product.

For example, typical ? the case of a traditional container which, when? partially emptied, sees the increase in head space with an ever-increasing amount? of air in contact as the product comes out of the container. One of these conditions arises for beer kegs. In fact, in traditional containers, beer is dispensed by blowing CO2. As the beer is dispensed, the headspace is enriched with CO2, altering the balance between the liquid phase and the gaseous phase of the beer contained in the keg.

In the construction solution in which a double-walled container is provided,? For its realization, the blowing of two preforms in PET or similar material is envisaged, in which a first preform is inserted coaxially inside the second.

According to this implementation solution, ? It is possible to give the two individual preforms different mechanical characteristics depending on the final use of the container and the liquid it will contain.

For example, ? It is possible to obtain a container, through the blowing process of two preforms, in which the external preform will have? the function of mechanically protecting the internal container, while the internal preform, which is the one destined to receive the liquid, will have? all the characteristics and treatments necessary to preserve the properties? of the liquid contained (for example, O2 barrier, CO2 barrier, UV barrier, etc.).

This construction solution has the disadvantage of the fact that for the production process of the double preform? provided that the phase of inserting the internal preform into the external preform is normally carried out upstream of the blowing line. This assembly operation is carried out by sending the two preforms separately to an expensive automation system which inserts the two preforms into one another, conveying them to the subsequent blowing phase for the production of the container.

On the other hand, according to an alternative production process to the one indicated above, the internal and external preform are assembled downstream of their production. The disadvantage that this alternative construction solution presents consists in the fact that the fixing of the assembly is achieved through an expensive welding system so to prevent the two preforms from slipping out while moving them.

The present invention aims to resolve the aforementioned disadvantages by providing an improvement to an assembled double-walled preform and its manufacturing process in which ? the assembly of the two preforms (internal and external) is foreseen in a permanent, simple and effective way.

Thanks to the technical solution of the present invention, the double-walled container is what? obtained by blowing a preform already? assembled which contains a first and a second preform inserted coaxially into the first in a locked manner.

So the purpose of the present invention? that of providing two preforms of such geometry as to allow a fixed and permanent assembly of one preform inside the other, in such a way as to guarantee that during the manipulations necessary both for the transport of the preforms and for their processing up to the blowing of the same, stability is not compromised? of the assembly.

BRIEF DESCRIPTION OF THE INVENTION

The object of the present invention is a process for the production of a double-wall assembled concentric preform which includes a first internal preform inserted coaxially into a second external preform, and in which the two concentric preforms are mechanically assembled in an irreversible manner in such a way as to constitute a single indivisible body.

According to one aspect of the present invention, the two concentric preforms are irreversibly coupled and can be moved and processed as if they were a single preform.

According to another aspect of the present invention, the two preforms are produced individually, with materials that can be homogeneous or non-homogeneous.

The object of the present invention is also the double-wall assembled concentric preform obtained through the aforementioned process.

Thus, the present invention provides a method for making a double-walled preform, and a preform thus assembled? obtained substantially according to the attached claims.

DETAILED DESCRIPTION OF THE INVENTION

Will he come? Now provided is a detailed description of two preferred forms of manufacturing a double-walled preform and the related assembly process according to the present invention, given by way of example and not by way of limitation, making reference to the attached figures, in which:

Figure 1 illustrates a longitudinal sectional view of a double-walled preform assembled according to the state of the art;

Figure 2? a partially sectional and detailed view of a part of the assembled preform of figure 1;

Figure 3? a partial and longitudinal sectional view of a part of a preform assembled according to the state of the art;

Figure 4A ? a longitudinal sectional view of a first embodiment of an internal preform constituting part of the double-wall assembled preform of the present invention;

Figure 4B ? a longitudinal sectional view of a second embodiment of an internal preform constituting part of the double-wall assembled preform of the present invention;

Figure 5A ? an elevation and perspective view of an assembled preform of the present invention;

Figure 5B ? a perspective and longitudinal sectional view of the assembled preform of Figure 5A according to the present invention; and Figure 6 ? a perspective and partially longitudinal sectional view of the neck region of a blown container obtained with the assembled preform of the present invention.

With reference now to figures 1, 2 and 3, a preform assembled with a double wall according to the state of the art is illustrated.

As ? can be seen in figure 1, ? an assembled preform 1 is provided consisting of a first external preform 10 and a second internal preform 11 inserted into the first external preform 10, both the external 10 and internal 11 preforms typically having a cylindrical profile.

The external preform 10 has a neck region 2 which includes a substantially smooth internal surface 3, and an external surface 4 which constitutes the thread 5 for coupling with a relative cap (not shown in the figures) in the manner per se already? Note.

On the other hand, the internal preform 11 can be completely included/contained in the external preform 10 or surmount it for a short distance (as illustrated in figures 1 and 2).

Similarly to the external preform 10, the internal preform 11 also has a neck region 12 which has an internal surface normally of a cylindrical or slightly truncated cone shape, and an external surface which typically presents two contact regions 13 and 14 to interface on the surface 3 of the respective neck region 2 of the external preform 10 (better illustrated below).

As ? It is possible to notice in the figure, the two external preforms 10 and internal 11 once assembled generate a cavity space 6 between the external preform 10 and the internal preform 11, the space 6 being suitable for generating a volume of gas which is functional for the functioning of the container once blown (better illustrated below).

Referring now to figure 2, ? provided that, once the two internal 11 and external 10 preforms have been assembled, the contact region 13 in the external surface of the neck region 12 of the internal preform 11 interfaces with interference on the internal surface 3 of the neck region 2 of the external preform 10, and in such a way as to achieve one or more? interference points which allow the two preforms 10 and 11 to be solidly and permanently locked one inside the other once assembled.

Similarly and how already? illustrated in figure 1, when the internal preform 11? housed in the external preform 10, the contact region 14 present on the external surface of the neck region 12 of the internal preform 11 interfaces with interference on the internal surface 3 of the neck region 2 of the external preform 10, creating an interference point that allows solidly and permanently lock the two preforms 10 and 11 one inside the other once assembled.

Furthermore, and how? As can be seen in figure 2, at least one pair of holes 15 are provided on the surface of the neck region 12 (only one of which is shown in the figure). Once the two external 10 and internal 11 preforms have been assembled, the holes 15 are designed to put the internal volume 6 in pneumatic communication with the external environment in order to make the gas flow/flow from/to said internal volume 6.

Referring now to figure 3, the internal preform has protruding annular elements 18 arranged along the entire circumference of its external wall, the arrangement ? such that once the two external 10 and internal 11 preforms have been assembled, the protruding annular elements 18 abut the internal wall of the external preform 10. This construction solution allows to make more? the blocked connection between the external preform 10 and the internal preform 11 is rigid.

Furthermore, in order to allow pneumatic communication between the holes 15 and the internal volume 6 and with the external environment to make the gas flow/flow from/to said internal volume 6 during use of the blown container, a series of of longitudinal grooves 17 obtained on the internal wall of the external preform 10 in correspondence with the contact region of the annular elements 18.

With reference now to figures 4A and 4B, two embodiments of the internal preform made according to the present invention are respectively illustrated in perspective from above.

For illustrative clarity equal parts will have equal numbers and their detailed description will come omitted here since? already? provided previously.

With reference to figure 4A, according to the first embodiment of the present invention, ? an internal preform 11 is provided which presents, in correspondence with the neck region 12, a series of longitudinal grooves 15 which, once the internal preform 11 has been assembled in the external preform 10, allow pneumatic communication of the internal volume 6 with the outside (as already It is described above and better illustrated below).

Furthermore, the external wall of the preform 11 has a protruding surface 18 along the entire perimeter of the external wall. The protruding surface 18 has a multiplicity of of longitudinal grooves 180.

With reference now to figure 4B, according to the second embodiment of the present invention, ? an internal preform 11 is provided which has at least one hole 15 in correspondence with the neck region 12 which, once the internal preform 11 has been assembled in the external preform 10, allows pneumatic communication of the internal volume 6 with the outside (as already described above and better illustrated below).

Furthermore, the external wall of the preform 11 has a series of protruding longitudinal surface elements 18 arranged in an alternating manner along the entire perimeter of the external wall. The arrangement of the protruding surface elements 18? such as to create a series of separation grooves 180 between a first protruding surface element 18 and a second protruding surface element 18 adjacent to the first.

Furthermore, according to this alternative embodiment, ? expected one or more? regions 110 of the external surface of the preform 11 which do not have protruding elements 18, and these regions 110 are sandwiched between two series of protruding elements 18 (only one region 110 is illustrated in the figure).

Referring now to figures 5A and 5B, there is illustrated an assembled preform 1 according to the first embodiment of the present invention.

For illustrative clarity equal parts will have equal numbers and their detailed description will come omitted here since? already? provided previously.

As ? can be seen in the figures, ? a preform assembled according to the present invention is provided, which consists of a first external preform 10 which houses inside it and in a fixed manner a second internal preform 11 (the latter made according to the present invention as previously illustrated).

As appears evident in figure 5B, once the preform of the present invention has been assembled, the series of protruding elements 18 allow locking by interference on the respective walls of the internal preform 11 in the external preform 10. In this arrangement, the grooves 180 (not illustrated in the figure) allow pneumatic communication between the internal volume 6 between the two preforms and the external environment, passing circuitally through the series of grooves 15 present on the neck region 12 of the internal preform 11.

? It is worth specifying here that, according to the present invention, similarly to the first embodiment of the internal preform 11 (as previously illustrated in figure 4A), also in the second embodiment of the internal preform 11 (as illustrated in figure 4B) and once once the preform 1 has been assembled, the regions 110 of the external wall of the preform 11 being free from protruding elements 18, allow pneumatic communication between the internal volume 6 between the two preforms and the external environment, passing circuitally through the holes 15 present on the neck region 12 of the internal preform 11.

With reference now to figure 6, the neck region of a blown container obtained with the assembled preform of the present invention is illustrated in perspective and partially in longitudinal section, and in which the preferential flow channel of the gas coming from the volume is indicated from the inside outwards during the operation/emptying of the blown container obtained with the preform of the present invention.

For illustrative clarity, equal parts will have equal numbers and their detailed description will be given. omitted here since? already? provided previously.

As ? It is possible to notice in the figure, once the preform 1 has been assembled according to the previously described embodiments, it is blown according to an already industrial process. known in the state of the art, and with the aim of obtaining a double-walled blown container (only the top region of the neck region of the container being illustrated in the figure).

The blown container like this? obtained therefore presents a first container obtained by blowing the first preform 10 and a second container arranged inside the first container and obtained by blowing the internal preform 11, the second container being suitable for containing a liquid (the liquid typically being a gaseous drink or similar ). The second container is typically collapsible inside the first container. This arrangement provides a volume defined by the space 6 existing between the external preform 10 and the internal preform 11 once blown simultaneously, the volume 6 wrapping the wall of the internal container which wall? collapsible and therefore the internal volume 6? variable.

The neck of the container does not undergo plastic deformations during the forming (blowing) phase of the preform 1 and, therefore, retains the original structure of the assembled preform.

According to the present invention, the coupling at the contact regions 18 between the two preforms 10 and 11 is preferably chosen with an interference of around 0.2 mm, but it can? be included in the range from 0.02 mm to 0.5 mm depending on the applications and the volume of the double-walled container obtained after blowing the assembled preform.

Therefore, as illustrated in the figure and according to the present invention, the arrangement of the grooves 180 obtained on the external wall of the internal preform 11, and of the ports 15 on the neck region 12 of the internal preform 11? such that a preferential duct is created as illustrated with the arrows F, and in which it can? flow more? the gas contained in the volume of the interspace 6 between the external container 10 and the internal container 11 easily and quickly during the operation/emptying of the blown container (that is, both during the filling of the blown container, and during the emptying of the blown container, and during the container recycling operations).

The facilitated passage of the gas through the aforementioned grooves 180 and 15 makes it possible to guarantee the absence of overpressures inside the container which could compromise the safety of the operators.

Will he come? A description of the manufacturing process of the assembled preform 1 is now provided.

First, the external 10 and internal 11 preforms are formed separately, each by injection into a respective mold with the material that will constitute it. the same and which is chosen depending on the applications to which? is the double-walled container you will get intended for? following blowing of the aforementioned preform 1 once coupled.

Subsequently, the internal preform 11 is inserted inside the external preform 10 by bringing the neck part 12 of the internal preform 11 closer to the neck part 3 of the external preform 10.

Then, the internal preform 11 is pushed inside the external preform 10, forcing the coupling by interference at the mating surfaces 18 of the internal preform 11 on the respective surface region of the preform 10 and as illustrated previously in the figures.

In this condition, preform 1? irreversibly assembled and ? ready to be subjected to the subsequent production phases to obtain a double-walled blown container, and according to a production process such as ? already? known to the state of the art.

Advantages

The present invention has numerous advantages.

A first advantage? given by the fact that transport costs are halved since two separate preforms are not transported but only one preform stuck one inside the other.

A second advantage? given by the fact that the reduction of transport costs allows a notable expansion of the markets and a notable expansion of the fields of use of concentric preforms.

A third advantage? given by the fact that the preform stuck one inside the other can? be fed directly into the blow molding machine, eliminating the expensive automation system that inserts the two preforms into each other.

A fourth advantage? given the fact that anyone who owns a blow molder will be able to? use the preform without resorting to the automatic system which, in addition to being expensive, makes the system more complex, lowering its reliability.

Claims (10)

INDUSTRIAL INVENTION entitled: "PERFECTED DOUBLE-WALL ASSEMBLED PREFORM, AND PROCEDURE FOR THE CREATION OF THE SAME?" CLAIMS 1. Preform assembled (1) to obtain a double-walled blown container, comprising a first preform (10) which includes a neck part (2) which has an external region (4) which includes a threaded region (5) and an internal region (3), and a second preform (11) arranged inside said first preform (10), said second internal preform (11) presenting a neck region (12), and in which between said first preform ( 10) and said second preform (11) ? defined a volume (6) of interspace between the external preform (10) and the internal preform (11), said volume (6) being capable of containing a certain gas, characterized by the fact that said second preform (11) includes blocking means (18 ) on its external surface suitable to cooperate by blocking interference with a surface of said internal region (3) of said external preform (10) when said second preform (11) is inserted into said first preform (10). 2. Assembled preform (1) according to the previous claim, wherein said locking means comprise an annular protruding surface (18) which is obtained on a region of the external surface of said second preform (11) near of said neck region (12), the arrangement being such that said annular protruding surface (18) is adapted to cooperate by blocking interference with a respective surface region of said external preform (10) when the first is inserted inside the second. 3. Assembled preform (1) according to claim 2, wherein said protruding surface (18) further comprises a multiplicity of of longitudinal grooves (180) obtained integrally on said protruding surface (18). 4. Assembled preform (1) according to claim 1, wherein said locking means comprise a multiplicity of of protruding longitudinal elements (18) arranged annularly and alternately along the entire perimeter of the external wall of said preform (11) and in proximity to of said neck region (12), the arrangement being such that between a first and a second superficially protruding longitudinal element (18)? there is a separation groove (180). 5. Assembled preform (1) according to the previous claim, in which ? expected one or more? separation regions (110) on said external surface of said second preform (11), called one or more? separation regions (110) being arranged between a first and a second multiplicity? of protruding elements (18). 6. Assembled preform (1) according to any one of claims 2-5, wherein said locking interference between said protruding surface (18) of said second preform (11) and said surface region of said first preform (10) is ? choice in the range between 0.02 mm and 0.5 mm. 7. Assembled preform (1) according to the previous claim, wherein said locking interference is? around 0.1 mm. 8. Assembled preform (1) according to any of the previous claims, wherein at the edge part of said neck region (12) of said second internal preform (11)? obtained a multiplicity? of longitudinal grooves (15), the arrangement being such that said grooves (15) realize the pneumatic communication of said internal volume (6) with the external environment. 9. Assembled preform (1) according to any of the previous claims 1-7, wherein at the edge part of said neck region (12) of said second internal preform (11)? expected at least one or more? holes (15), the arrangement being such that at least one or more? holes (15) creates the pneumatic communication of said internal volume (6) with the external environment. 10. Process for the production of an assembled preform (1) for the production of a double-walled blown container, the preform (1) including a first preform (10) which includes a neck part (2) which has a region external (4) which includes a threaded region (5) and an internal region (3), and a second preform (11) arranged inside said first preform (10), said second internal preform (11) presenting a region of neck (12) adapted to cooperate in a locked manner with said neck region (3) of said first preform (10), and in which between said first preform (10) and said second preform (11)? defined a volume (6) of interspace between the external preform (10) and the internal preform (11), said volume (6) being capable of containing a given gas, and in which said neck region (12) of said second preform (11 ) includes locking means (18) suitable to cooperate by locking interference with said internal region (3) of the neck part (2) of said first external preform (10) when said second preform (11) ? inserted into said first preform (10), characterized by the fact that it includes the following phases: - Separate forming of said external preform (10) and said internal preform (11) via injection process into a mold for each preform; - Insertion of said internal preform (11) inside said external preform (10) until it touches the neck part (12) of the internal preform (11) on the neck part (3) of the external preform (10); - Exert a thrust force on the internal preform (11) inside the external preform (10) forcing by interference the coupling through said locking means (18) on said internal region (3) of the neck part (2) of said first external preform (10); - Obtaining a preform (1) assembled and irreversibly blocked; and - Sending said assembled preform (1) to the subsequent production phases to obtain a double-wall blown container.