Method for automatically determining the electrical energy to be supplied to a furnace arranged upstream of a stretch blow molding machine for heating preforms
A predictive method using specific power-to-mass ratios and total draw ratios addresses the challenge of optimizing electrical energy distribution in stretch blow molding, ensuring uniform preform heating and reducing inefficiencies.
Patent Information
- Application Number
- JP2025512136
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-09-02
- Filing Date
- 2023-09-01
- Publication Date
- 2025-08-22
AI Technical Summary
Existing methods fail to predictively determine the optimal electrical energy required for preform heating in stretch blow molding processes, leading to inefficient heating and potential deformation of preforms due to suboptimal management of heating elements.
A predictive method using specific power-to-mass ratios and total draw ratios to calculate the electrical energy needed for each heating element, considering geometric and weight data of preforms and containers, along with hourly productivity, to ensure uniform heating and prevent deformation.
The method allows for fast and efficient determination of electrical energy distribution, reducing test time and improving the suitability of the industrial stretch-blow process, even with less experienced operators, by optimizing heating element activation and energy consumption.
Smart Images
Figure 2025527781000001_ABST
Abstract
Description
[Technical Field]
[0001] The present invention relates to a method for automatically determining the electrical energy (kWh) to be supplied to a furnace provided with a plurality of heating modules arranged in at least one workbench upstream of a stretch blow molding machine. [Background technology]
[0002] It is known that the stretch-blowing process must be preceded by a temperature conditioning step of the preform, in which the preform is heated to a predetermined temperature for inflation using a specific heating module that uses several heating elements, for example infrared lamps.
[0003] Typically, the heating modules are arranged symmetrically in two worktables connected by a curved stretch, with the heating elements in each module arranged along a plane substantially parallel to the plane containing the axis of the preform advancing along the worktable.
[0004] During the preform's passage through these modules, the neck of the preform must remain substantially cool, i.e., kept below the softening temperature, so that the subsequent blowing operation does not deform the preform.
[0005] Heating of the preform body is thermal radiation (convection) penetrating the thickness of the body of the preform; Contact with the surrounding air heated inside the furnace (conduction), Heat diffusion by conduction into the wall of the preform (stabilization / temperature reversal) It is also known that this is achieved by the combined effects of
[0006] It is also important to ventilate the interior of the heating module and the exterior of the preform within the heating module with a preset air flow rate to prevent the material on the exterior of the preform from reaching too high a temperature, which would cause the material placed inside the preform to crystallize while waiting to reach the blowing temperature. This ventilation allows the ambient temperature of the heating module to be kept at a desired level, removing excess heat caused by, for example, infrared radiation not captured by the preform, and moderate the temperature of the preform skin. This desired level of the interior temperature of the heating module is a level that allows the energy performance of the heating module to be optimized. It is well known that this energy performance is a function of the thickness of the preform. The air flow rate must be sufficient to perform this function, and it is desirable for the air flow rate to be well distributed within the heating module so that the entire surface of the preform wall that must be heated is uniformly treated.
[0007] In fact, it remains extremely complicated, especially for less experienced operators, to optimally manage the preform heating elements in the heating modules located upstream of the stretch blow molding machine according to the geometric and weight data of the preforms, the geometric data of the containers to be molded, and the hourly productivity of the stretch blow molding machine, expressed in containers per molding cavity per hour.
[0008] Known solutions exist that provide feedback regulation of the electrical energy (kWh) supplied to the heating elements of each module, said regulation being based on on-the-fly control of the container production process, but unfortunately the production process proceeds before this feedback regulation, resulting in preforms arriving at the stretch blow molding machine that are not fully heated.
[0009] In any case, no predictive type method is known that makes it possible to automatically determine the optimum electrical energy (kWh) to be supplied to the heating module according to a given hourly productivity of a molding machine for blow molding a specific container starting from a specific preform.
[0010] Therefore, a need is felt to provide an automated method of predictive type. Summary of the Invention [Problem to be solved by the invention]
[0011] It is an object of the present invention to provide a predictive method for automatically determining, using a computer, the optimum electrical energy (kWh) to be supplied to the heating module of a furnace located upstream of a stretch blow molding machine having a given hourly productivity of a specific container blown from a specific preform.
[0012] Another object of the present invention is to provide a predictive type method for managing the heating elements of the preforms in said heating module.
[0013] Another object of the present invention is to provide a method that can also automatically identify the number of heating elements that are activated within each heating module.
[0014] Another object of the present invention is to provide a predictive type method for obtaining an optimal distribution of electrical energy (kWh) over the heating elements activated within each heating module. [Means for solving the problem]
[0015] The present invention achieves this object and at least one of the other objects that will become apparent in the light of this description by means of a method for automatically determining the electrical energy (kWh) to be supplied to a furnace provided with a plurality of heating modules arranged in at least one work table upstream of a stretch blow molding machine provided with a plurality of molding cavities for molding containers, each heating module being provided with a plurality of heating elements arranged along a plane substantially parallel to a plane containing the axes of preforms advancing along the work table, the method comprising the following steps: a) The following parameters are input: The hourly productivity of the molding machine, v, expressed as containers per molding cavity per hour; Geometric and weight data of the preform and preform neck, Geometric data of the container to be formed, Number of heating modules, The number of heating elements in each heating module providing a b) providing a first range of total draw ratios, a second range of total draw ratios including values greater than the first range, and a third range of total draw ratios including values greater than the second range; c) The first curve y = a × x -b , the second curve y=c× -d , and the third curve y=e×x -f where y is the specific power or power-to-mass ratio (W / g) that defines the power that the heating element must absorb per gram of net weight of the preform, said net weight of the preform being equal to the weight of the preform minus the weight of the preform neck, and x is the net weight of the preform in grams; d) calculating the total draw ratio by multiplying the axial draw ratio by the radial draw ratio; e) extracting the value W / g from a first curve if the total draw ratio calculated in step d) is within a first range, from a second curve if the total draw ratio is within a second range, or from a third curve if the total draw ratio is within a third range; f) calculating the electrical energy (kWh) required for said hourly productivity v; Includes:
[0016] In a preferred variant, said first range of total draw ratios includes values less than or equal to 8, said second range of total draw ratios includes values greater than 8 and less than 13.5, said third range of total draw ratios includes values less than or equal to 13.5, coefficient "a" has a value between 0.45 and 0.58, coefficient "b" has a value between -0.25 and -0.35, coefficient "c" has a value between 0.60 and 0.75, coefficient "d" has a value between -0.36 and -0.50, coefficient "e" has a value between 0.75 and 0.86 and coefficient "f" has a value between -0.54 and -0.60.
[0017] Advantageously, the method of the invention also allows for a fast and effective parameterization of the industrial stretch-blow process in a few minutes, with the aim of obtaining a product with 80% of the suitability of the industrial stretch-blow process.
[0018] By implementing this method, test time is significantly reduced even in the presence of less experienced operators, for whom it is statistically more complicated to perform the first part (80%) of an industrial stretch-blow process, but easier and more effective to complete the remaining 20% of the industrial process to final adjustment standards.
[0019] Other features and advantages of the present invention will become more apparent in light of the detailed description of illustrative, but non-exclusive, embodiments of the invention.
[0020] The dependent claims describe particular embodiments of the invention.
[0021] In describing the present invention, reference is made to the accompanying drawings, which are provided as non-limiting examples. [Brief explanation of the drawings]
[0022] [Figure 1] FIG. 1 is a schematic layout diagram of a heating module work table of a furnace located upstream of a molding machine. [Figure 2] FIG. 1 is a schematic cross-sectional view of a heating module traversed by a preform. [Figure 3] FIG. 10 is a diagram illustrating a schematic of the activation criteria for the heating element adjacent the bottom of the preform. [Figure 3a] FIG. 10 shows a variation showing the last and penultimate heating elements activated in the heating module. [Figure 4] FIG. 2 is a schematic cross-sectional view of a preform. [Figure 5] FIG. 5 is a schematic side view of a container inflated from the preform of FIG. 4. [Figure 6] 1 is a diagram with some input data for carrying out the method according to the invention; [Figure 7] FIG. 1 shows three trend curves of specific power W / g according to net weight of preform in grams. DETAILED DESCRIPTION OF THE INVENTION
[0023] Like reference numbers and letters in the figures identify like elements or components.
[0024] FIG. 1 shows a typical furnace, designated by the reference numeral 1, provided with a number of heating modules 2 arranged in a work table upstream of a stretch blow molding machine 3 provided with a number of molding cavities (not shown) for forming containers.
[0025] The arrow X indicates the direction of advance of the preforms 5 across the respective heating modules 2 .
[0026] Alternatively, the heating module 2 can be arranged in at least two work tables connected by a connecting stretch, for example a curved or serpentine stretch.
[0027] The forming machine 3 can be a linear or rotary machine.
[0028] As better shown in FIG. 2, each heating module 2 is provided with a plurality of heating elements 6 arranged along a plane substantially parallel to a plane containing the axis of a preform 5 advancing along a work table, for example on a transfer line 4 provided with a chuck.
[0029] The method of the present invention is a predictive method that automatically determines the optimum electrical energy (kWh) for a given hourly productivity of a particular container blown from a particular preform.
[0030] Such a method advantageously comprises the following steps: a) The following parameters are input: The hourly productivity of the molding machine, v, expressed as the number of containers per molding cavity per hour (containers / cavity per hour); Geometric and weight data of the preform and preform neck, Geometric data of the container to be formed, Number of heating modules 2, The number of heating elements in each heating module 2 providing a b) providing a first range of total draw ratios, a second range of total draw ratios including values greater than the first range, and a third range of total draw ratios including values greater than the second range; c) The first curve y = a × x -b , the second curve y=c×x -d , and the third curve y=e×x -f where y is the specific power or power-to-mass ratio (W / g) that defines the power that the heating element must absorb per gram of net weight of the preform, said net weight of the preform being equal to the weight of the preform minus the weight of the preform neck, and x is the net weight of the preform in grams; d) calculating the total draw ratio by multiplying the axial draw ratio by the radial draw ratio; e) extracting the value W / g from a first curve if the total draw ratio calculated in step d) is within a first range, from a second curve if said total draw ratio is within a second range, or from a third curve if said total draw ratio is within a third range; f) calculating the electrical energy (kWh) required for said hourly productivity v; Includes:
[0031] In step f), the electrical energy (kWh) required for the hourly productivity v is (W / g × net weight of preform × v × number of molding cavities) / 1000 is equal to where W / g is the value extracted in step e).
[0032] Surprisingly, after lengthy and complex technical investigations, the inventors have found that by using a predetermined range of total draw ratios and predetermined ranges of the three coefficients of the three curves of step c) in combination with one another, the technical effect of automatically predicting the optimum electrical energy (kWh) for a given hourly productivity of a specific container blown from a specific preform is reached in a simple, fast and highly efficient way, with a significant reduction in consumption. This prediction is then also useful for automatically identifying the number of heating elements to be activated in each heating module.
[0033] In a preferred, but not exclusive, variation, a first range of total draw ratios includes values less than or equal to 8, a second range of total draw ratios includes values greater than 8 and less than 13.5, and a third range of total draw ratios includes values greater than or equal to 13.5, coefficient "a" has a value of from 0.45 to 0.58, coefficient "b" has a value of from -0.25 to -0.35, coefficient "c" has a value of from 0.60 to 0.75, coefficient "d" has a value of from -0.36 to -0.50, coefficient "e" has a value of from 0.75 to 0.86, and coefficient "f" has a value of from -0.54 to -0.60.
[0034] In another variant of the invention, the coefficient "a" has a value between 0.45 and 0.55, the coefficient "b" has a value between -0.27 and -0.35, the coefficient "c" has a value between 0.60 and 0.72, the coefficient "d" has a value between -0.40 and -0.48, the coefficient "e" has a value between 0.78 and 0.86, and the coefficient "f" has a value between -0.54 and -0.60.
[0035] Preferably, the method of the present invention allows the number of heating elements to be activated in each heating module to be automatically identified.
[0036] To achieve this result, after step f), the following steps are carried out: g) identifying the number of heating elements to be activated in each heating module (FIG. 3), always including all heating elements 6 lying on a horizontal plane intersecting the body of the advancing preform, and, taking into account the center-to-center distance between the last of said heating elements 6 lying on a horizontal plane intersecting the body of the preform and the next heating element 6' located proximal to it, including the next heating element 6' lying on a horizontal plane not intersecting the body of the preform only if a height Y corresponding to half the center-to-center distance of said center-to-center distance intersects the bottom of the preform; h) in each heating module 2, activating the heating elements identified in step g) by distributing the electrical energy (kWh) over said identified heating elements; is provided.
[0037] The last of the heating elements 6 lying on a horizontal plane intersecting the body of the preform is the heating element most distal from the neck of the advancing preform.
[0038] Another subsequent heating element 6' on the horizontal plane that does not intersect with the body of the preform is positioned below the last of the heating elements 6 on the horizontal plane that intersects with the body of the preform when the transfer line is configured to advance the preform with the neck opening facing upward, as shown in Figures 2 and 3.
[0039] Alternatively, if the transfer line is configured to advance the preform with the neck opening facing downwards, it is not excluded that another subsequent heating element 6' is positioned above the last heating element 6.
[0040] Figure 3 shows the criteria for identifying the heating elements that are activated according to the length of the preform (step g). The term "ON" indicates a heating element that is activated, while the term "OFF" indicates a heating element that remains turned off.
[0041] In all embodiments of the invention, the heating elements 6, 6' may be infrared lamps arranged along a plane substantially parallel to the plane containing the axis of the preform across the heating module. As an alternative to infrared lamps, LED, NIR or laser lamps or other suitable heating elements may be used.
[0042] 4 and 5 show examples of preforms and containers obtained by stretch blow molding, respectively. These figures are illustrative of the geometric data of the molded preforms and containers used by the method of the present invention, namely: H p = height of the preform, h p_n = preform neck height, h p_ur = height of the area under the neck ring of the preform, d out_max = maximum outer diameter of the preform, t max = maximum thickness of the preform, H c = height of the container, h c_n = vessel neck height, h c_ur = height of the area below the neck ring of the vessel, D out_max = Maximum outer diameter of the container Shows.
[0043] As known in the art, the term "area under neck ring" means the area immediately below the support ring 7 where the thicker portion of the container remains due to unstretched material after blowing.
[0044] Taking these geometrical data into consideration, the radial stretch ratio is determined as follows: D out_max / (d out_max -t max ) It is calculated as The axial stretch ratio is the ratio: (H c -h c_n -h c_ur ) / (H p -h p_n -h p_ur ) It is calculated as follows.
[0045] The other input data is the center-to-center distance of the heating elements, preferably equal within each heating module; Maximum power of the heating elements, preferably equal within each heating module It may further include:
[0046] Preferably, in step h), the distribution of the electric energy (kWh) on the identified heating elements 6, 6' is carried out according to a first profile also when another heating element 6' in that horizontal plane that does not intersect the body of the preform is activated, or according to a second profile also when said another heating element 6' is not activated. The term "profile" means the tendency of the distribution of the electric energy (kWh) on the identified heating elements 6, 6' along a direction parallel to the axis of the preform 5 advancing along the work table.
[0047] More specifically, in a transfer line configured to advance preforms with the neck openings facing upwards as shown in Figures 2 to 3a, the optimal and automated distribution of electrical energy (kWh) on the identified heating elements 6, 6', even when said other heating element 6' is activated, is determined in the following way: A is defined as the electrical energy (kWh) calculated in step f) divided by the number of identified heating elements 6, 6′ in all the plurality of heating modules 2; n is defined as the number of identified heating elements 6, 6′ in each heating module 2; Within each heating module 2 For the upper identified heating element located closest to the support ring 7 of the advancing preform, the electrical energy supplied is: A1=A+x×A is equal to However, the coefficient x varies from 1 / 9 to 3 / 4, For the remaining identified heating elements, the electrical energy supplied is: A i =[(A×n)-A1] / (n-1) is equal to.
[0048] Instead, even if said other heating element 6' is not activated, the optimal and automated distribution of electrical energy (kWh) on the identified heating element 6 is determined in the following way: A is defined as the electrical energy (kWh) calculated in step f) divided by the number of identified heating elements 6 in all the plurality of heating modules 2; n is defined as the number of identified heating elements 6 in each heating module 2; Within each heating module 2, For the upper identified heating element located closest to the support ring 7 of the advancing preform, the electrical energy supplied is: A1=A+x×A is equal to However, the coefficient x varies from 1 / 9 to 3 / 4, In the case of an identified heating element located at an intermediate position between the upper identified heating element and the penultimate identified heating element 6″ below (FIG. 3a), the supplied electrical energy is: A i =[(A×n)-A1] / (n-1) is equal to In the case of the penultimate identified heating element 6 ″, the electrical energy supplied is: A n-1 =A i +x×A i is equal to For the last identified heating element 6''' located adjacent the bottom of the advancing preform, or a lower identified heating element, the electrical energy supplied is: A n-1 =A i -x×A i is equal to.
[0049] Alternatively, in a transfer line configured to advance the preforms with the neck openings facing downwards (solution not shown), the optimal and automated distribution of the electrical energy (kWh) on the identified heating elements 6, 6', even when said other heating element 6' is activated, is determined in the following way: A is defined as the electrical energy (kWh) calculated in step f) divided by the number of identified heating elements 6, 6′ in all the plurality of heating modules 2; n is defined as the number of identified heating elements 6, 6′ in each heating module 2; Within each heating module 2 For the lower identified heating element located in the position closest to the support ring 7 of the advancing preform, the electrical energy supplied is: A1=A+x×A is equal to However, the coefficient x varies from 1 / 9 to 3 / 4, For the remaining identified heating elements, the electrical energy supplied is: A i=[(A×n)-A1] / (n-1) is equal to.
[0050] Instead, even if said other heating element 6' is not activated, the optimal and automated distribution of electrical energy (kWh) on the identified heating element 6 is determined in the following way: A is defined as the electrical energy (kWh) calculated in step f) divided by the number of identified heating elements 6 in all the plurality of heating modules 2; n is defined as the number of identified heating elements 6 in each heating module 2; Within each heating module 2, For the lower identified heating element located in the position closest to the support ring 7 of the advancing preform, the electrical energy supplied is: A1=A+x×A is equal to However, the coefficient x varies from 1 / 9 to 3 / 4, In the case of an identified heating element located at an intermediate position between the lower identified heating element and the penultimate identified heating element 6″ above (FIG. 3a), the electrical energy supplied is: A i =[(A×n)-A1] / (n-1) is equal to In the case of the penultimate identified heating element 6 ″, the electrical energy supplied is: A n-1 =A i +x×A i is equal to For the last identified heating element 6''' located adjacent the bottom of the advancing preform, or for the upper identified heating element, the electrical energy supplied is: A n-1 =A i -x×A i is equal to.
[0051] The method according to the invention therefore makes it possible to quickly determine, even in an automated manner, the optimal distribution of electrical energy (kWh) over the identified heating elements that must be activated in each heating module 2.
Claims
1. A method for automatically determining the electrical energy (kWh) to be supplied to a furnace (1) provided with a plurality of heating modules (2) arranged in at least one work table upstream of a stretch blow molding machine (3) provided with a plurality of molding cavities for molding containers, each heating module (2) provided with a plurality of heating elements (6) arranged along a plane substantially parallel to a plane containing the axis of a preform (5) advancing along the work table, said method comprising the following steps: a) The following parameters are input: the hourly productivity (v) of the molding machine, expressed in containers per molding cavity per hour; geometric and weight data of said preform and preform neck; geometric data of the container to be formed; the number of said heating modules (2), The number of said heating elements (6) in each heating module (2) providing a b) providing a first range of total draw ratios, a second range of total draw ratios including values greater than the first range, and a third range of total draw ratios including values greater than the second range; c) First curve y = a x －ｂ , the second curve y=c× －ｄ , and the third curve y=e×x －ｆ where y is the specific power or power-to-mass ratio (W / g) that defines the power that the heating element (6) must absorb per gram of net weight of the preform, the net weight of the preform being equal to the weight of the preform minus the weight of the preform neck, and x is the net weight of the preform in grams; d) calculating the total draw ratio by multiplying the axial draw ratio by the radial draw ratio; e) extracting a value W / g from the first curve if the total draw ratio calculated in step d) is within the first range, from the second curve if the total draw ratio is within the second range, or from the third curve if the total draw ratio is within the third range; f) calculating the electrical energy (kWh) required for the hourly productivity (v); A method comprising:
2. the first range of total draw ratios includes values less than or equal to 8, the second range of total draw ratios includes values greater than 8 and less than 13.5, and the third range of total draw ratios includes values greater than or equal to 13.5; Coefficient "a" has a value between 0.45 and 0.58, coefficient "b" has a value between -0.25 and -0.35, coefficient "c" has a value between 0.60 and 0.75, coefficient "d" has a value between -0.36 and -0.50, coefficient "e" has a value between 0.75 and 0.86, and coefficient "f" has a value between -0.54 and -0.60; Preferably, the electrical energy (kWh) required for the hourly productivity (v) is: (W / g x net weight of the preform x v x number of molding cavities) / 1000 is equal to 2. The method of claim 1, wherein W / g is the value extracted in step e).
3. After step f), the following steps are carried out to manage said heating element (6): g) identifying the number of heating elements to be activated in each heating module (2), always including all of the heating elements (6) that lie on a horizontal plane intersecting the body of the advancing preform, and, taking into account the center-to-center distance between the last of the heating elements (6) that lie on a horizontal plane intersecting the body of the preform and the next heating element (6') that is proximal to it, including the next heating element (6') that is on a horizontal plane that does not intersect the body of the preform only if a height (Y) corresponding to half the center-to-center distance of the center-to-center distance intersects the bottom of the preform; h) within each heating module (2), activating the heating elements identified in step g) by distributing the electrical energy (kWh) over the identified heating elements; The method of claim 1 or 2, wherein
4. 3. The method of claim 2, wherein coefficient "a" has a value between 0.45 and 0.55, coefficient "b" has a value between -0.27 and -0.35, coefficient "c" has a value between 0.60 and 0.72, coefficient "d" has a value between -0.40 and -0.48, coefficient "e" has a value between 0.78 and 0.86, and coefficient "f" has a value between -0.54 and -0.
60.
5. 4. The method of claim 3, wherein in step h) the distribution of the electrical energy (kWh) over the identified heating element is performed according to a first profile also when the other heating elements (6') located in that horizontal plane that does not intersect the body of the preform are activated, or according to a second profile also when the other heating elements (6') are not activated.
6. If the other heating element (6') is activated, the distribution of the electrical energy (kWh) over the identified heating element (6, 6') is also determined in the following way: A is defined as the electrical energy (kWh) divided by the number of identified heating elements (6, 6') in the plurality of heating modules (2); n is defined as the number of identified heating elements (6, 6') in each heating module (2); Within each heating module (2) For the identified heating element closest to the support ring (7) of the advancing preform, the electrical energy supplied is: A １ =A+x×A is equal to where the coefficient x varies from 1 / 9 to 3 / 4, For the remaining identified heating elements, the electrical energy supplied is: A ｉ =[(A×n)-A １ ] / (n-1) The method of claim 3 or 5, wherein the
7. If the other heating element (6') is not activated, the distribution of the electrical energy (kWh) over the identified heating element (6) is determined in the following way: A is defined as the electrical energy (kWh) divided by the number of identified heating elements (6) in the plurality of heating modules (2); n is defined as the number of identified heating elements (6) in each heating module (2); Within each heating module (2) For the identified heating element closest to the support ring (7) of the advancing preform, the electrical energy supplied is: A １ =A+x×A is equal to where the coefficient x varies from 1 / 9 to 3 / 4, For the identified heating element located at an intermediate position between the identified heating element closest to the support ring (7) and the penultimate identified heating element below or above, the electrical energy supplied is: A ｉ =[(A×n)-A １ ] / (n-1) is equal to For the penultimate identified heating element, the electrical energy supplied is: A ｎ－１ =A ｉ +x×A ｉ is equal to For the last identified heating element located closest to the bottom of the advancing preform, or a lower identified heating element or an upper identified heating element, the electrical energy supplied is: A ｎ－１ =A ｉ -x×A ｉ The method of claim 3 or 5, wherein the
8. The axial stretch ratio is: (H ｃ -h ｃ＿ｎ -h ｃ＿ｕｒ ) / (H ｐ -h ｐ＿ｎ -h ｐ＿ｕｒ ),however H ｃ = the height of the container, h ｃ＿ｎ = the height of the container neck, h ｃ＿ｕｒ = the height of the area under the neck ring of the container, H ｐ = the height of the preform, h ｐ＿ｎ = the height of the preform neck, h ｐ＿ｕｒ = height of the area under the neck ring of the preform It is calculated as The radial stretch ratio is: D ｏｕｔ＿ｍａｘ / (d ｏｕｔ＿ｍａｘ -t ｍａｘ ),however D ｏｕｔ＿ｍａｘ = the maximum outer diameter of the container, d ｏｕｔ＿ｍａｘ = the maximum outer diameter of the preform, t ｍａｘ = maximum thickness of the preform 8. The method according to claim 1, wherein the calculated value is:
9. 9. The method according to any one of claims 1 to 8, wherein the heating element in each heating module (2) is an infrared or NIR lamp or an LED or laser lamp.
10. The geometric data of the preform is the height of the preform; the height of the neck; the height of said area below the neck ring; maximum outer diameter, Maximum Thickness Including, The geometric data of the container to be formed is the height of the container; the height of the neck; The height of said area below the neck ring Maximum outer diameter 10. The method of any one of claims 1 to 9, comprising:
11. The input data is the center-to-center distance of said heating elements, preferably equal within each heating module; the maximum power of said heating elements, preferably equal within each heating module; 11. The method of claim 1, further comprising: