WO2019069149A1

WO2019069149A1 - Apparatus for heating plastic preforms in blowing machine

Info

Publication number: WO2019069149A1
Application number: PCT/IB2018/055936
Authority: WO
Inventors: Samir V. KHAKHARIA
Original assignee: Individual
Current assignee: Individual
Priority date: 2017-10-04
Filing date: 2018-08-07
Publication date: 2019-04-11
Anticipated expiration: 2020-04-04

Abstract

The present disclosure pertains to an apparatus for heating one or more preforms (104) that are conveyed to blowing section of a blowing machine to produce products having desired shape and size. The apparatus comprises a conveying mechanism (102) to convey the preforms (104) along a conveying path, said conveying path comprising at least one forward path and at least one return path along which the preforms (104) move, at least one heating module (106) having a plurality of heating elements arranged along the conveying path, wherein the at least one heating module (106) is positioned in between the at least one forward path and at least one return path such that heat radiated by the plurality of heating elements is simultaneously transferred to the preforms (104) moving along both the at least one forward path and the at least one return path.

Description

APPARATUS FOR HEATING PLASTIC PREFORMS IN BLOWING MACHINE

TECHNICAL FIELD

[001] The present disclosure relates to the field of blow molding. In particular, the present disclosure relates to heating of preforms in a two stage blow molding process.

BACKGROUND

[002] Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.

[003] Hollow Plastic containers such as bottles, jars, flasks, or similar objects are produced by stretching a plastic preform (also known as parison in the related art) using metal rods, and blowing pressurized air inside the preform while the preform is held in a mold. The preform making and blowing can be done either on same equipment, as in single stage blowing, or preforms can be made on a different equipment, then brought to a blowing machine (also known as stretch blow molding machine in the related art), as in two stage blowing. In two stage blowing process, when preforms are brought to a blowing machine, preforms are first heated (popularly known as re-heating process, because the material is already heated previously during manufacture of the preform), before being placed into the mold, for stretching and blowing to the required shape to form the hollow plastic container.

[004] One of the important processes in two stage blowing process is to re-heat preforms and achieve required accurate temperature that is specific along the length of preform. As temperature varies along the length of preform (known as temperature profile, or heating profile), it is important to maintain the same temperature profile in all preforms, so as to achieve uniform quality in all blown containers. This temperature profile is required to facilitate optimum and uniform material distribution during stretching and blowing processes.

[005] In conventional blowing machines, preforms travel on a singular path on one side of a heating lamp, and because of movement of the preforms in a singular path, temperature profile can be maintained consistent and accurate for all preforms. However, while processing a large number of preforms, overall length of such blowing machines increases, thereby increasing requirement of floor area. [006] Some blowing machines employ two or more heater banks placed side by side, and preforms that are placed on one side of a heater bank, move along multiple travel paths that adequately reduces the required floor area. Additionally or alternatively, some blowing machines use a heater module that emits radiation on both sides, and preforms travel on both sides of the heater module, thereby increasing heating efficiency of the machine by allowing more number of preforms to get exposure of the radiation. However, in such blowing machines, the preforms traveling on different paths are inconsistently heated that engenders variation in heating profile of the preforms and hinders consistency of quality of blown products.

[007] There is therefore a need for improvement in the art and provide method and apparatus for heating preforms in a blowing machine that reduces floor area required by the machine and maintains a requisite temperature profile of all the preforms passing through the apparatus. Further, there exists a need to provide method and apparatus for heating preforms in a blowing machine that increases heating efficiency of the machine without preform-to- preform variation in temperature profile of the preforms.

[008] All publications herein are incorporated by reference to the same extent as if each individual publication or patent application were specifically and individually indicated to be incorporated by reference. Where a definition or use of a term in an incorporated reference is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of that term in the reference does not apply.

[009] In some embodiments, the numbers expressing quantities of ingredients, properties such as concentration, reaction conditions, and so forth, used to describe and claim certain embodiments of the invention are to be understood as being modified in some instances by the term "about." Accordingly, in some embodiments, the numerical parameters set forth in the written description and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by a particular embodiment. In some embodiments, the numerical parameters should be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of some embodiments of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as practicable. The numerical values presented in some embodiments of the invention may contain certain errors necessarily resulting from the standard deviation found in their respective testing measurements. [0010] As used in the description herein and throughout the claims that follow, the meaning of "a," "an," and "the" includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of "in" includes "in" and "on" unless the context clearly dictates otherwise.

[0011] The recitation of ranges of values herein is merely intended to serve as a shorthand method of referring individually to each separate value falling within the range. Unless otherwise indicated herein, each individual value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g. "such as") provided with respect to certain embodiments herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention.

[0012] Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member can be referred to and claimed individually or in any combination with other members of the group or other elements found herein. One or more members of a group can be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is herein deemed to contain the group as modified thus fulfilling the written description of all groups used in the appended claims.

OBJECTS OF THE INVENTION

[0013] A general object of the present disclosure is to provide a preform heating apparatus for efficiently heating plastic preforms.

[0014] Another object of the present disclosure is to provide a preform heating apparatus that provides accurate and consistent temperature profile to all preforms passing through it.

[0015] Another object of the present disclosure is to provide a preform heating apparatus that requires less number of heating modules.

[0016] Another object of the present disclosure is to provide a preform heating apparatus that provides a long heating path to the plastic preforms.

[0017] Another object of the present disclosure is to provide a preform heating apparatus that has reduced length as compared to conventional preform heating apparatuses. [0018] Another object of the present disclosure is to provide a preform heating apparatus that requires less floor space.

[0019] These and other objects of the present invention will become readily apparent from the following detailed description taken in conjunction with the accompanying drawings.

SUMMARY

[0020] The present disclosure relates to heating of one or more preforms in a two stage blow molding process. Aspects of the present disclosure pertains to an apparatus for heating one or more preforms that are conveyed to a blowing section of a blowing machine to produce products having a desired shape and size.

[0021] In an aspect, the apparatus for heating one or more preforms (also referred to as "preform heating apparatus" and "preform re-heating apparatus" hereinafter) may include a conveying mechanism to convey one or more preforms along a conveying path. The conveying path includes at least one forward path and at least one return path along which the one or more preforms move. The preform heating apparatus may further include at least one heating module having a plurality of heating elements arranged along the conveying path to effect heating the one or more preforms.

[0022] In an aspect, the at least one heating module is positioned in between the at least one forward path and at least one return path such that heat radiated by the plurality of heating elements is simultaneously transferred to the one or more preforms moving along both the at least one forward path and the at least one return path.

[0023] In an embodiment, the conveying path is a singular path such that the at least one heating module maintains a consistent temperature profile for the one or more preforms when the one or more preforms move along the conveying path.

[0024] In an embodiment, the conveying mechanism includes a preform carrier to firmly hold and convey the one or more preforms along the conveying path. In an embodiment, the conveying mechanism includes a neck protection unit to protect neck sections of the one or more preforms.

[0025] In an embodiment, the conveying mechanism includes a reflector to reflect surplus heat supplied by the plurality of heating elements to the one or more preforms to increase intensity of heat provided to the one or more preforms. [0026] In an embodiment, the conveying mechanism further includes a plurality of interconnected conveyors to accommodate the one or more preforms. In an embodiment, the proposed preform heating apparatus further includes a driving means to enable movement of the plurality of interconnected conveyors along the conveying path. In an embodiment, the driving means assists tensioning of the plurality of interconnected conveyors such that tensile load of each of the plurality of interconnected conveyors is evenly distributed.

[0027] In an embodiment, the one or more preforms are configurable with the conveying mechanism in any of an upright position or an inverted position of the one or more preforms.

[0028] In an embodiment, the at least one forward path is extended to the at least one return path such that the at least one forward path is substantially parallel to the at least one return path.

[0029] In an embodiment, each of said plurality of heating elements are adapted to radiate heat in direction of the at least one forward path and the at least one return path to allow simultaneous heating of the one or more preforms moving along the at least one forward path and the at least one return path.

[0030] In an embodiment, when the one or more preforms are heated up to a specific temperature, the one or more heated preforms are conveyed to a blowing section of a blowing machine.

[0031] Those skilled in the art will further appreciate the advantages and superior features of the disclosure together with other important aspects thereof on reading the detailed description that follows in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The accompanying drawings are included to provide a further understanding of the present disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0033] FIGs. 1A and IB illustrate exemplary representations of preforms in neck-up and neck-down configurations respectively with proposed preform heating apparatus in accordance with embodiments of the present disclosure.

[0034] FIG. 2 illustrates an exemplary representation of movement of preforms along forward and return path of the proposed preform heating apparatus in accordance with embodiments of the present disclosure. [0035] FIG. 3A illustrates an exemplary representation of movement of preforms along two forward and return paths in accordance with embodiments of the present disclosure.

[0036] FIG. 3B illustrates an exemplary representation of movement of preforms along four forward and return paths in accordance with embodiments of the present disclosure.

[0037] FIG. 4 illustrates an exemplary representation of blow molding process of the preform heated by the proposed preform heating apparatus in accordance with embodiments of the present disclosure.

DETAILED DESCRIPTION

[0038] The following is a detailed description of embodiments of the disclosure depicted in the accompanying drawings. The embodiments are in such detail as to clearly communicate the disclosure. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure as defined by the appended claims.

[0039] Each of the appended claims defines a separate invention, which for infringement purposes is recognized as including equivalents to the various elements or limitations specified in the claims. Depending on the context, all references below to the "invention" may in some cases refer to certain specific embodiments only. In other cases it will be recognized that references to the "invention" will refer to subject matter recited in one or more, but not necessarily all, of the claims.

[0040] Various terms are used herein. To the extent a term used in a claim is not defined below, it should be given the broadest definition persons in the pertinent art have given that term as reflected in printed publications and issued patents at the time of filing.

[0041] The present disclosure relates to heating of one or more preforms in a two stage blow molding process. Aspects of the present disclosure pertains to an apparatus for heating one or more preforms that are conveyed to a blowing section of a blowing machine to produce products having a desired shape and size.

[0042] In an aspect, the apparatus for heating one or more preforms (also referred to as "preform heating apparatus" and "preform re-heating apparatus" hereinafter) may include a conveying mechanism to convey one or more preforms along a conveying path. The conveying path includes at least one forward path and at least one return path along which the one or more preforms move. The preform heating apparatus may further include at least one heating module having a plurality of heating elements arranged along the conveying path to effect heating the one or more preforms.

[0043] In an aspect, the at least one heating module is positioned in between the at least one forward path and at least one return path such that heat radiated by the plurality of heating elements is simultaneously transferred to the one or more preforms moving along both the at least one forward path and the at least one return path.

[0044] In an embodiment, the conveying path is a singular path such that the at least one heating module maintains a consistent temperature profile for the one or more preforms when the one or more preforms move along the conveying path.

[0045] In an embodiment, the conveying mechanism includes a preform carrier to firmly hold and convey the one or more preforms along the conveying path. In an embodiment, the conveying mechanism includes a neck protection unit to protect neck sections of the one or more preforms.

[0046] In an embodiment, the conveying mechanism includes a reflector to reflect surplus heat supplied by the plurality of heating elements to the one or more preforms to increase intensity of heat provided to the one or more preforms.

[0047] In an embodiment, the conveying mechanism further includes a plurality of interconnected conveyors to accommodate the one or more preforms. In an embodiment, the proposed preform heating apparatus further includes a driving means to enable movement of the plurality of interconnected conveyors along the conveying path. In an embodiment, the driving means assists tensioning of the plurality of interconnected conveyors such that tensile load of each of the plurality of interconnected conveyors is evenly distributed.

[0048] In an embodiment, the one or more preforms are configurable with the conveying mechanism in any of an upright position or an inverted position of the one or more preforms.

[0049] In an embodiment, the at least one forward path is extended to the at least one return path such that the at least one forward path is substantially parallel to the at least one return path.

[0050] In an embodiment, each of said plurality of heating elements are adapted to radiate heat in direction of the at least one forward path and the at least one return path to allow simultaneous heating of the one or more preforms moving along the at least one forward path and the at least one return path. [0051] In an embodiment, when the one or more preforms are heated up to a specific temperature, the one or more heated preforms are conveyed to a blowing section of a blowing machine.

[0052] FIGs. 1A and IB illustrate exemplary representations of preforms in neck-up and neck-down configurations respectively with proposed preform heating apparatus in accordance with embodiments of the present disclosure. In an aspect, the disclosed preform heating apparatus can include a conveying mechanism 102 to pass one or more preforms 104 along a path, and at least one heating module 106 to enable heating of the one or more preforms 104 in either of the neck-up and neck-down orientations.

[0053] In an exemplary embodiment, the conveying mechanism 102 can include a neck protection unit 108 to protect neck section of the preform 102, a preform carrier 112 to firmly hold and convey preform 102, a reflector 110 to reflect surplus heat supplied by the heating module 106 to the preform 104 so as to increase the intensity of heat provided to the preform 104. In an exemplary embodiment, the conveying mechanism 102 can be configured as a single assembly that can transfer one or more preforms 104 from one place to another along a conveying path, or it can include a plurality of conveyors or chain/block mechanism that can hold the preforms 104 and transfer them from one place to another along the conveying path. In an exemplary embodiment, the conveying mechanism 102 can include a plurality of mandrels 112 that can interact with the preforms 104 and can allow firm holding of the preforms 104 so as to enable proper transfer of the preforms 104 from one place to another along the conveying path.

[0054] In an exemplary embodiment, the heating module 106 can include a plurality of heating elements 106-1, 106-2, 106-3 and so forth (collectively referred to as 106) such as heating lamps, polymer PTC heating elements, ceramic heating elements, composite heating elements, infrared heaters and the likes to enable transfer of heat to the preforms 104 through convection or radiation. The heating elements of the heating module 106 can be arranged along the conveying path, and they can convect or radiate heat in more than one direction. For instance, heating elements of the heating module 106 can radiate heat in two directions, more specifically in a front direction and a rear direction so as to allow heating of preforms 104 available in the front as well as rear directions of the heating elements.

[0055] In an exemplary embodiment, a preform/parison 104 is a hollow tube having preliminary shape and size of a molded product. A preform 104 is formed to a shape which is to be molded to a specific shape and thereafter blown to a bottle, flask, jar and the likes in a blowing machine. In an exemplary aspect, the preforms 104 can be configured with the conveying mechanism 102 in either a neck-up configuration or a neck-down configuration, wherein in the neck-up configuration, the preform 104 is placed on the conveying mechanism 102 in an upright position, and in the neck-down configuration, the preform 104 is placed on the conveying mechanism 102 in an inverted position.

[0056] In an exemplary aspect, the preform re-heating apparatus can further include a plurality of driving means such as motors to allow movement of the conveying mechanism 102 along the conveying path and to ensure that tensile load along the conveying mechanism 102 is evenly distributed. The driving means can be coupled with multiple driving mechanisms configured to control movement of the conveying mechanism 102.

[0057] FIG. 2 illustrates an exemplary representation of movement of preforms along forward and return path of the proposed preform re-heating apparatus in accordance with embodiments of the present disclosure. In an exemplary aspect, the conveying path on which the preforms 104 travel is a singular path such that an accurate and consistent temperature profile can be maintained for all the preforms 104.

[0058] In an exemplary aspect, the conveying path can include a forward path on which the preforms 104 travel on one side (front side) of the heating module 106, and the forward path can be extended to a return path positioned along the other side (rear side) of the heating module 106 such that the forward path is substantially parallel to the return path and both are in turn parallel to the row of heating module 106. Thus, the preforms 104 travel on both sides of the heating module 106, the heating module 106 being in between the forward path and the return path. Further, because all preforms 104 travel on the same path, they achieve same thermal conditions, and thus, a specific temperature profile can be maintained for all the preforms 104. Additionally, exposure of the preform 104 on two sides of heating module 106 allows use of radiation directed both sides of the heating module 104, thereby increasing heating efficiency of the apparatus.

[0059] In an exemplary aspect, the conveying mechanism 102 can be configured such that it is bendable at its ends in both directions (i.e., clockwise as well as anti-clockwise directions when looking from top). In another exemplary aspect, forward path can be extended to return path by forming a U-bend or a similar configuration. However, extension of forward path to return path by forming a U-loop configuration does not limit the scope of the present disclosure in any manner, and any other form of extension of forward path to the return path is well within the scope of the present disclosure. [0060] FIG. 3A illustrates an exemplary representation of movement of preforms along two forward and return paths in accordance with embodiments of the present disclosure. FIG. 3B illustrates an exemplary representation of movement of preforms along four forward and return paths in accordance with embodiments of the present disclosure. In an exemplary implementation, the conveying path can be multiplied for as many times are required, which can increase width of the apparatus marginally, and substantially reduce its length. This helps in reducing foot print and accordingly floor area required by the blowing machine. Hence, multiple conveying paths can be used in conjunction one after the other to achieve objective of a reduction in length of the apparatus. In an exemplary aspect, the proposed apparatus also accounts for reduction in number of heating modules 106 along with reduction in overall length of the apparatus.

[0061] In an exemplary aspect, FIG. 3A illustrates two interconnected forward-return paths and FIG. 3B illustrates four interconnected forward-return paths. It is to be appreciated that multiple conveying paths can be interconnected to reduce floor space required by the blowing machine, and to enable accurate and consistent heating of the preforms 104 passing through the apparatus along the conveying paths so as to, maintain a specific temperature profile for the preforms 104. Further, implementation of the conveying mechanism 102 in multiple conveying paths substantially reduces number of heating modules 106 and thus, reduces overall costs associated with the apparatus. Additionally, exposure of the preform 104 on two sides of heating module 106 allows use of radiation on both sides of the heating module 104, thereby reducing power consumption, and therefore increasing heating efficiency of the apparatus.

[0062] FIG. 4 illustrates an exemplary representation of blow molding process of the preform heated by the proposed preform re-heating apparatus in accordance with embodiments of the present disclosure. In an aspect, after re-heating of the preforms 104 by the preform re-heating apparatus, the heated preforms 104 can be automatically transferred to blowing section of the blowing machine. In an exemplary aspect, the blowing machine incorporates a provision of automatically conveying heated preforms 104 directly to the blowing section after successful heating of the preforms 104 by the proposed preform reheating apparatus. In an exemplary aspect, the blowing machine further incorporates a provision of manually conveying heated preforms 104 directly to the blowing section after successful heating of the preforms 104 by the proposed preform re-heating apparatus. [0063] In an exemplary aspect, blowing section of the blowing machine can include a mold 402 separated into two or more parts in order to create a cavity of specific shape and size that construes desired shape and size of the product to be blown. A base mold 404 of a specific shape and size is provided at bottom of the blowing section that incorporates an inverted shape of bottom section of the product to be blown.

[0064] In an exemplary implementation, heated preforms 104 can be sequentially placed into the blowing section. A heated preform 104 can be supported by two or more parts of the mold 402, and a stretch rod 406 is allowed to enter the preform 104 through an opening of its neck section. Compressed air is passed around the stretch rod and / or through the stretch rod 406 into the heated preform 104 that enables expansion of the preform 104 into the cavity of the mold 402. The preform 104 expands in the cavity of the mold 402 and bottom mold 404, such that it takes shape of the cavity. Thereafter, the compressed air is exhausted and stretch rod 406 is taken out of the preform 104 and the final blown product is taken out of the blowing section. It would be appreciated that instead of using compressed air, any other blowing means such as a pressurized fluid, for example, pressurized water, pressurized gas and any other pressurized fluid may be used to blow the preform 104 into a container, and any such modification/alteration is well within the scope of the present disclosure.

[0065] It is to be appreciated that processes involving transfer of preforms from the preform re-heating apparatus to blowing section of the blowing machine is automated using suitable automation mechanisms. In addition, ejection of final blown product from the blowing machine is also automated using suitable automation mechanisms.

[0066] Thus, the present disclosure provides an apparatus for heating one or more preforms that are conveyed to blowing section of a blowing machine to produce products having desired shape and size. The apparatus includes a conveying mechanism to convey the one or more preforms along a conveying path, said conveying path having at least one forward path and at least one return path along which the one or more preforms move, at least one heating module having a plurality of heating elements arranged along the conveying path, wherein the at least one heating module is positioned in between the at least one forward path and at least one return path such that heat radiated by the plurality of heating elements is simultaneously transferred to the one or more preforms moving along both the at least one forward path and the at least one return path. Once the one or more preforms are heated up to a specific temperature, the heated preforms are conveyed/transferred to the blowing section of the blowing machine to produce molded products having desired shapes and sizes. [0067] While the foregoing describes various embodiments of the invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof. The scope of the invention is determined by the claims that follow. The invention is not limited to the described embodiments, versions or examples, which are included to enable a person having ordinary skill in the art to make and use the invention when combined with information and knowledge available to the person having ordinary skill in the art.

ADVANTAGES OF THE INVENTION

[0068] The present disclosure provides a preform heating apparatus for efficiently heating plastic preforms.

[0069] The present disclosure provides a preform heating apparatus that provides accurate and consistent temperature profile to all preforms passing through it.

[0070] The present disclosure provides a preform heating apparatus that requires less number of heating modules.

[0071] The present disclosure provides a preform heating apparatus that provides a long heating path to the plastic preforms.

[0072] The present disclosure provides a preform heating apparatus that has reduced length as compared to conventional preform heating apparatuses.

[0073] The present disclosure provides a preform heating apparatus that requires less floor space.

Claims

I Claim:

1. An apparatus for heating one or more preforms, said apparatus comprising: a conveying mechanism to convey one or more preforms along a conveying path, said conveying path comprising at least one forward path and at least one return path along which the one or more preforms move; and at least one heating module comprising a plurality of heating elements arranged along the conveying path to heat the one or more preforms, wherein said at least one heating module is positioned in between the at least one forward path and at least one return path such that heat radiated by the plurality of heating elements is simultaneously transferred to the one or more preforms moving along both the at least one forward path and the at least one return path.

2. The apparatus as claimed in claim 1, wherein said conveying path is a singular path such that the at least one heating module maintains a consistent temperature profile for the one or more preforms when the one or more preforms move along the conveying path.

3. The apparatus as claimed in claim 1, wherein the conveying mechanism comprises a preform carrier to firmly hold and convey the one or more preforms along the conveying path, and wherein the conveying mechanism further comprises a neck protection unit to protect neck sections of the one or more preforms.

4. The apparatus as claimed in claim 1, wherein the conveying mechanism comprises a reflector to reflect surplus heat supplied by the plurality of heating elements to the one or more preforms to increase intensity of heat provided to the one or more preforms.

5. The apparatus as claimed in claim 1, wherein the conveying mechanism comprises a plurality of interconnected conveyors to accommodate the one or more preforms.

6. The apparatus as claimed in claim 5, further comprising a driving means to enable movement of the plurality of interconnected conveyors along the conveying path, and wherein the driving means assists tensioning of the plurality of interconnected conveyors such that tensile load of each of the plurality of interconnected conveyors is evenly distributed.

7. The apparatus as claimed in claim 1, wherein the one or more preforms are configured with the conveying mechanism in any of an upright position or an inverted position of the one or more preforms.

8. The apparatus as claimed in claim 1, wherein the at least one forward path is extended to the at least one return path such that the at least one forward path is substantially parallel to the at least one return path.

9. The apparatus as claimed in claim 1, wherein each of said plurality of heating elements are adapted to radiate heat in direction of the at least one forward path and the at least one return path to allow simultaneous heating of the one or more preforms moving along the at least one forward path and the at least one return path.

10. The apparatus as claimed in claim 1, wherein when the one or more preforms are heated up to a specific temperature, the one or more heated preforms are conveyed to a blowing section of a blowing machine.