Claims:We claim:
1. A process for forming a multilayer article (300), the process comprising:
positioning, a shell (201) of an article (200) within a support structure (106), wherein, the shell (201) is in solid phase and is adapted to form an outer layer of the article (200);
placing, a preform (100) inside the shell (201), wherein the preform (100) is pre-heated; and
inflating the preform (100) inside the shell (201) to form one or more inner layers (301) of the article (200).
2. The process as claimed in claim 1, wherein the shell (201) is pre-moulded to define the outer layer of the article (200).

3. The process as claimed in claim 1, wherein the shell (201) is of a single layer.

4. The process as claimed in claim 1, wherein the support structure (106) is a mould, and the mould is configured to confirm to a configuration of the shell (201).

5. The process as claimed in claim 1, wherein the preform (100) is in semi-solid state.

6. The process as claimed in claim 1, wherein the inflating of the preform (100) is performed by stretch blow moulding process.

7. The process as claimed in claim 6, wherein the one or more inner layers (301) adheres to an inner surface of the shell (201) during the stretch blow moulding process.

8. The process as claimed in claim 1, wherein two or more preforms (100) are inflated sequentially inside the inner layer (301) to form a plurality of the inner layers.

9. The process as claimed in claim 1, wherein the preform (100) is at least one of monolayer preform or a multilayer preform.

10. The process as claimed in claim 9, wherein the multilayer preform (502) is formed in solid phase by inserting one or more preforms inside or outside a receiving preform.

11. The process as claimed in claim 10, wherein the receiving preform (501) forms at least one layer of the multi-layer preform.

12. The process as claimed in claim 10, wherein the one or more preforms are receivable by the receiving preform (501) by a transition fit.

13. The process as claimed in claim 1, wherein the preform (100) is made of a Poly-Ethylene Terephthalate (PET) material.

14. A multilayer article (300) formed by a process as claimed in claim 1.
, Description:TECHNICAL FIELD
The present disclosure generally relates to a field of manufacturing engineering. Particularly but not exclusively, the present disclosure relates to a process for forming articles. Further embodiments of the disclosure disclose a process for forming multilayer article in solid phase.

BACKGROUND OF THE DISCLOSURE

Over the years, use of articles such as containers, bottles, tumblers, cans, carriers, and the like has been increasing. Such articles, may be commonly used for storing and holding various commodities such as beverages, food stuffs, liquids and the like. The articles may be made of materials such as plastic, metal, glass and the like. In the recent years, in packaging sector, glass or metal articles have been rapidly replaced by plastic or polymer articles because of its advantages such as lighter weight, flexibility in handling, break-resistance and moreover potentially lower costs. Conventionally, various methods were adapted such as compression moulding, rotational moulding, structural foam moulding, thermoforming and the like to form plastic containers, which involved complex machineries and tedious processes.

With the increase in demand and affinity towards plastic containers, new machine tools and efficient manufacturing processes have been evolved which enables to produce such articles at a faster rate and with improved quality. Further, these modern processes adapt food grade plastics, which meet food contact material regulations and offer safety to food packed in the container. One such advanced process adapted in recent time to manufacture containers is, a stretch blow moulding process.

The stretch blow moulding is a manufacturing process by which wide variety of hollow plastic articles are formed. As an example, the hollow articles may be bottles, tumblers, wide mouth containers and the like, whose purpose is for storing food, beverages, and liquid items like detergents, edible oils, and the like. The stretch blow moulding process employs a preform, which resembles the shape of a test tube with or without a threaded neck. The preform may be composed of one or more layers. Preforms are placed inside a mould and inflated with compressed air or liquid to obtain article of desired shape.

Further, with many added advantages of the plastic containers, its area of applicability is widened/expanded, to areas such as but not limiting to pharma, chemical and other commercial sectors, which demands for rigid and easy adaptable plastic containers. To meet the requirement of high rigid containers, multilayer containers are developed, which possess enhanced barrier properties. Conventionally, multilayer containers are formed by using multilayer preform. The multilayer preform may be formed by injection moulding process, which involves stacking different chemically compatible materials in layers using appropriate techniques.. Later, the multilayer preform may be inflated with the aid of compressed air or liquid to form a multilayer article.

However, adopting multilayer preforms of desired configuration to form multilayer articles limits the choice of materials and their miscible characteristics. Additionally, adapting this technique to form containers restricts their field of applicability and any rejection of the formed article leads to wastage of material. Moreover, with the increase in the thickness of the preform, inflating the preform may become cumbersome and cannot be adopted for forming complex geometrical structures. Lastly, the closely stacked layers in the article, hinders easy separation of the layers, which may lead to difficulties in recycling the article.

The present disclosure is directed to overcome one or more limitations stated above.

The information disclosed in this background of the disclosure section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgment or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

SUMMARY OF THE DISCLOSURE

One or more shortcomings of conventional process are overcome and additional advantages are provided through the provision of process as claimed in the present disclosure. Additional features and advantages are realized through the techniques of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered a part of the claimed disclosure.

In a non-limiting embodiment of the disclosure, a process for forming a multilayer article is disclosed. The process comprises of positioning a shell of an article within a support structure, wherein the shell is in solid phase and is adapted to form an outer layer of the article. Further, the process involves, placing a pre-heated preform inside the shell, which is inflated to form one or more inner layers of the article.
In an embodiment, the shell a single layer and is pre-moulded to define the outer layer of the article.

In an embodiment, the support structure is a mould, and further the mould is configured to confirm to a configuration of the shell.

In an embodiment, a preform is inflated by stretch/un-stretch blow moulding process. Further, more layers formed during inflation of the preform, adheres to an inner surface of the shell. Additionally, two or more preforms is inflated inside the shell to form a plurality of inner layers of the article.

In an embodiment, the preform is at least one of a monolayer preform or a multilayer preform and is in semi-solid state. Further, the preform is made of a Poly-Ethylene Terephthalate or other materials which can meet blowing process.
In an embodiment, the multilayer preform is formed in solid phase by inserting one or more preforms inside or outside a receiving preform. The receiving preform forms at least one layer of the multi-layer preform.

In an embodiment, the one or more preforms are receivable by the receiving preform by a transition fit.

It is to be understood that the aspects and embodiments of the disclosure described above may be used in any combination with each other. Several of the aspects and embodiments may be combined together to form a further embodiment of the disclosure.

The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.

BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS

The novel features and characteristic of the disclosure are set forth in the appended claims. The disclosure itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings. One or more embodiments are now described, by way of example only, with reference to the accompanying drawings wherein like reference numerals represent like elements and in which:

Figure. 1 illustrates a schematic front view of a hollow article, in accordance with an exemplary embodiment of the present disclosure.

Figure. 2 illustrates a schematic front view of a preform, according to an exemplary embodiment of the present disclosure.

Figure. 3 illustrates sectional view of a support structure or a mould accommodating the article of figure. 1 in which a preform of Figure. 2 is placed, according to an embodiment of the present disclosure.

Figure. 4 illustrates a multilayer article formed by adapting the process of Figure.3, according to an embodiment of the present disclosure.

Figures 5A, 5B and 5C illustrates formation of multilayer preform in a solid phase, according to an exemplary embodiment of the present disclosure.

The figures depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.

DETAILED DESCRIPTION

While the embodiments in the disclosure are subject to various modifications and alternative forms, specific embodiment thereof has been shown by way of example in the figures and will be described below. It should be understood, however, that it is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternative falling within the scope of the disclosure.

It is to be noted that a person skilled in the art would be motivated from the present disclosure and modify various aspects of the process for forming multilayer articles. However, such modifications should be construed within the scope of the disclosure. Accordingly, the drawings show only those specific details that are pertinent to understand the embodiments of the present disclosure, so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having benefit of the description herein.

The terms “comprises”, “comprising”, or any other variations thereof used in the disclosure, are intended to cover a non-exclusive inclusion, such that a device, system, assembly that comprises a list of components does not include only those components but may include other components not expressly listed or inherent to such system, or assembly, or device. In other words, one or more elements in a system or device proceeded by “comprises… a” does not, without more constraints, preclude the existence of other elements or additional elements in the system or device.

Embodiments of the present disclosure disclose a process of forming a multilayer article, which may be used for any commercial purpose. Conventional process adopt the multilayer preform for forming the multilayer article. The multilayer preform may be formed by injection moulding process, which involves stacking different chemically compatible materials in layers. This process of forming the multi-layered articles involves high end machines, moulds and moreover, limited to simple geometrical shape and configurations. Further, the articles formed by this technique are irreparable, since the stacked multiple layers bond together to form a single structure and rupture to any of the layer in the article cannot be replaced by other layer as it is tedious to separate rigidly bonded layers. Additionally, the articles formed by the conventional process do not provide provision for easy separation of the layers, which leads to difficulties in recycling the article. Moreover, the articles formed by this process have limited mechanical features and do not provide flexibility over choice of materials as it requires only chemically compatible materials to achieve firm bonding. Also, the conventional process cannot be used for strengthening articles which are formed by other process by employing one or more inner layers. The present disclosure, aims at adapting a unique process to form a multilayer container overcoming the limitations stated above.

Accordingly, embodiments of the present disclosure disclose, a process for forming a multilayer article. Primarily, the process adapts solid phase to form multilayer articles. Solid phase refers to the state of matter of the article in which multiple inner layers are formed, without melting the polymer. As an example, the pre-moulded articles may be plastic containers, tumblers and the like which may be formed by any forming process. The process according to present disclosure involves, positioning a pre-moulded article rigidly within a support structure. In an embodiment, the support structure may be a blow mould comprising mould halves, which facilitates easy removal of the final formed article. Further, the process involves placing a pre-heated preform within the article positioned inside the support structure. The article in which the preform is placed may act as support structure or mould such that, upon inflating the preform by passing compressed air/liquid, forms an inner layer adjacent to the surface of the article. Additionally, the process may be repeated to form plurality of layers inside the article adjacent to the other layers to obtain a pre-determined number of layers and thickness based on the requirement.

Adopting the process of the present disclosure to form multi-layer articles does not limit over the choice of materials to form different layers. As an example, plastic or polymer layer may be formed over inner surfaces of a steel container and the like. Further, the process provides flexibility in achieving control over thickness of the layers formed inside the article, assists in smooth assimilation of the layers and may be easily extended to form multilayer articles involving complex geometrical shapes. Additionally, this process may eliminate the use of adhesives to bond the layers, since the layers may be stacked naturally due to pressure developed during inflating the preform inside the article. Moreover, the multilayer articles formed by this process exhibit enhanced mechanical properties and may withstand high impact force.

The following paragraphs describe the present disclosure with reference to Figures. 1 to 4. In the Figures, the same element or elements which have similar functions are indicated by the same reference signs.
Referring to figure. 1, which is an exemplary embodiment of the present disclosure illustrating a hollow article (200) [hereinafter referred as container]. The container may be formed by any manufacturing process known in the state of art. In an embodiment, the manufacturing processes may be extrusion moulding, rotational moulding, structural foam moulding, thermoforming and the like. The container (200) may be formed of any material such as plastic, metal, polymer and the like. Generally, the container (200) formed by any of the manufacturing processes possess a shell (201), which defines the outer layer of the container (200). Further, the outer layer defines the shape, configuration and geometry of the container (200).
Figure. 2, is an exemplary embodiment of the present disclosure, which illustrates a front view of a preform (100). The preform (100) may be a polymeric pre-shaped part, which may be inflated inside the support structure or mould (106) to form articles of desired shape and configuration. In an embodiment, the preform (100) may be made of a Poly-Ethylene Terephthalate (PET) or any other material suitable for blowing. As an example, the preform (100) illustrated in figure. 2, may be a tube-like piece of plastic having generally a threaded neck portion (105), a cylindrical outer wall (101) connecting a closed end (102) and an open end (103). The preform (100) may have an opening (104) through which compressed high pressure fluid such as air may be passed to inflate the preform (100). In an embodiment, the preform (100) may be formed by injection moulding process. In an embodiment, the preform (100) may be a monolayer or a multilayer. Further, the preform (100) obtained by injection moulding process may be subsequently inflated by adapting stretch blow moulding technique until the latter takes the shape of the mould (106) to form articles of desired shape and configuration. It is to be noted that, configuration of the preform (100) illustrated in figure. 2 is an exemplary configuration, and is included for the purpose of simplicity. One should not consider the configuration of the preform (100) as limitation to the present disclosure.
Now referring to figure. 3, which is an exemplary embodiment of the present disclosure illustrates sectional view of support structure or mould (106) in which the container (200) and the preform (100) are placed, which in turn depicts a process for forming multiple layers. In an embodiment, the container (200) without a threaded neck portion [best seen in figure. 1] may be adapted to form multiple inner layers (301). Initially, shell (201) of the container (200), which is in solid phase defining the outer layer of the container (200) is positioned inside the mould (106) comprising mould halves (107) [best seen in figure. 3]. In an embodiment, the configuration of the mould (106) may be in conformity with the configuration of the shell (201) of the container (200) to achieve firm placement/engagement of the container (200) inside the mould (106).
Further, the preform (100) will be is placed inside the shell (201) of the container (200). The shell (201) of the container (200) acts as a mould for the preform (100). In an embodiment, the preform (100) may be pre-heated using suitable heating technique [not shown in figures], but not limiting to infrared ray heating, in order to transform solid phase of the preform (100) to a semi-solid phase. The semi-solid preform (100) may be then inflated by adapting a stretch or unstretch blow moulding process. The stretch blow moulding process which involves a stretching element [not shown in figure], which extends through the preform (100), thus stretching the preform (100) along the axis (A-A) in longitudinal direction and simultaneously compressed air is passed into the preform (100) through the opening (104) until the latter takes the shape of the container (200). Due to applied compressed air/liquid, and the preform (100) being in semi solid phase, it naturally adheres to the inner surface of the shell (201) without the aid of adhesives and thus forming an inner layer (301) adjacent to the surface of the shell (201) of the container (200) to form a multilayer container (300) [as seen in figure. 4] with enhanced strength, stiffness and other mechanical properties. In an embodiment, the adhesive may optionally added between the layers.
In an embodiment, the process may be repeated to form additional layers in the article adjacent to the already formed inner layers by inflating number of preforms to form a multilayer article. For forming the additional layers, the pre-heated preform may be placed inside the shell, and the blowing process may be repeated. For this stage, the layer already formed inside the shell acts as support or a secondary shell, and the process repeats. Each layer can be of same material or of different materials to suit desired structure of final container.
In an embodiment, the preform comprising a threaded neck may be inflated at the end of the process or at any stage during the process to form an article with neck portion on to which cap or lid may be fastened. As an example, if three layers has to be formed in the article, either the third preform or the preform inflated at any of the stages may possess a threaded neck portion.
In an embodiment, an article comprising a threaded neck portion may be multi-layered by inflating the preforms without threaded neck portion.
Referring to figures. 5A, 5B and 5C which are exemplary embodiments of the present disclosure illustrating a process for forming a multilayer preform (502) in solid phase. The multilayer preform as the name suggests may have two or more layers unlike a single layer preform. The multilayer preform (502) may be used where the article of three or more layers is to be produced by a method of the present disclosure. The multilayer preform according to embodiments of the present disclosure may be produced in a solid phase. The process for producing the multilayer preform may include, initially placing, a preform (501) without a threaded neck portion inside a support member [not shown in figure], such that it acts as a receiving preform. Then, the preform (500) with a threaded neck portion may be placed inside or outside the receivable preform (501), such that the receivable preform (501) may act as either outer layer or inner layer depending on the configuration. In an embodiment, for externally receiving the additional layer of preform, the outer diameter or perimeter of the receiving preform (501) may be made smaller than the inner diameter or perimeter of the additional layer of preform. For internally receiving the additional layer of preform, the outer diameter or perimeter of the receiving preform (501) may be made larger than the inner diameter or perimeter of the additional layer of preform. The receiving preform (501) forms a transition fit with the additional layer of preform, in order to achieve firm bonding between the adhering surfaces or layers upon inflating. In an embodiment, the receiving preform (501) and other preforms forming additional layer may be made of same or different materials. The multilayer preform (502) in solid phase may be heated, and then may be directly inflated inside the shell of the article to form the multilayer article at a single blowing process. It is to be noted that the Figure 5A-5C illustrates, preform with threaded neck placed inside the preform without threaded neck. However, one should not consider the same as limitation. Since, the preform without threaded neck may be receivable inside by the preform with threaded neck.
In an embodiment, the preform may not be inflated/deformed beyond the natural stretch ratio (NSR) to obtain final product with enhanced mechanical properties.
In an embodiment, the process is simple and can be performed without the aid of high end machines and complex moulds to form multilayer articles. Also, decorative patterns may be incorporated between the layers to enhance aesthetic appearance. Further, the multilayer articles formed by this process exhibit good mechanical and impact resistance. Since the process adapts solid phase, there may be no restriction on choice of materials and can be extended to articles with complex geometric shapes without deviating from the scope of the disclosure. Also, the process may be readily adapted to strengthen any article which may be formed of any process.

Equivalents:

With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity.
It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as "open" terms (e.g., the term "including" should be interpreted as "including but not limited to," the term "having" should be interpreted as "having at least," the term "includes" should be interpreted as "includes but is not limited to," etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases "at least one" and "one or more" to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles "a" or "an" limits any particular claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases "one or more" or "at least one" and indefinite articles such as "a" or "an" (e.g., "a" and/or "an" should typically be interpreted to mean "at least one" or "one or more"); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of "two recitations," without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to "at least one of A, B, and C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, and C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances, where a convention analogous to "at least one of A, B, or C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, or C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase "A or B" will be understood to include the possibilities of "A" or "B" or "A and B."

While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.

Referral Numerals:

Referral numeral Description
A-A Preform axis
100 Preform
101 Cylindrical outer wall of the preform
102 Closed end of the preform
103 Open end of the preform
104 Opening of the preform
105 Threaded neck of preform
106 Support structure or mould
107 Mould halves
200 Pre-moulded container
201 Shell of the container
300 Multilayer article or container
301 Inner layer of a multilayer container
500 Monolayer preform with a threaded neck portion
501 Preform without a threaded neck portion
502 Multilayer preform