Method for heating preforms suitable for blow molding

Abstract

A method of heating preforms for blow molding is provided that includes inspecting the preforms upon entry into a system, heating the preforms, measuring the temperature of the preforms along their longitudinal axis and around their circumference, and optimizing the heating step responsive to a comparison of data from the inspection and measurement to optimize heating for subsequent preforms.

Description

[Technical Field]

[0001] The present technology relates to a system and process capable of subjecting preforms to a blow molding process to produce multiple preforms having multiple temperature profiles. [Background technology]

[0002] This section provides background information related to the present disclosure that is not necessarily prior art.

[0003] Various products are distributed in plastic containers, such as containers formed from one or more polymers. Common polymers used to form containers include polyesters such as polyethylene terephthalate (PET), high- and low-density polyethylene (PE), polypropylene (PP), polycarbonate (PC), etc. Plastic containers can be manufactured using various blow molding processes, including injection blow molding, hydraulic blow molding, and extrusion blow molding, which can use a preform that is expanded with a fluid to form the resulting container.

[0004] Injection blow molding can be used to form certain plastic containers in one or more stages, which may include the use of a stretch rod. In a two-stage injection stretch blow molding process, a polymer can first be formed into a preform using an injection molding process. The preform can include the neck and finish of the resulting container (which may include threads thereon) and a closed distal end. The preform can then be heated above the glass transition temperature of the polymer, optionally stretched longitudinally with a stretch rod, and blown into a mold-fitting container using high-pressure gas (e.g., air). As the preform expands, it stretches and assumes the shape of the mold cavity. The polymer solidifies upon contact with the cold surface of the mold, and the finished hollow container is then ejected from the mold.

[0005] Hydraulic blow molding can form and fill a container in a single operation. A liquid product can be used to mold a polymer preform in a mold and fill the resulting container, with the liquid product then remaining in the finished container. A heated preform, much like a preform used in injection blow molding, can be placed in a mold, optionally stretched, and then rapidly inflated or filled to form a container using a liquid product instead of a gas. The combination of the molding and filling processes can thus optimize the packaging of liquid products by eliminating the time requirements for transporting empty containers and subsequent filling operations.

[0006] Various types of preforms can be used in such blow molding processes. Particular embodiments of preforms include injection-molded, rotationally symmetric preforms with an elongated, cylindrical side body, a rounded, closed bottom, and a neck with an upper opening. Other preforms are rotationally asymmetric, with thicknesses varying along the elongated axis to facilitate material distribution to form asymmetric containers. In either case, there may be an external thread finish section located adjacent to the opening, which may be delimited toward its bottom by a collar or the like. The thread finish section may be preserved during blow molding of the preform; this finish may form, for example, threads for a screw cap on a finished beverage container. In contrast, the remainder of the preform may be deformed or stretched during the blow molding process. The preform may be heated to a predetermined temperature to enable blow molding in a desired manner. Heating may be accomplished by various means, including infrared radiation using an infrared oven, effectively providing defined and / or uniform temperature control of the preform.

[0007] In particular, the polymer material of the preform (e.g., PET) can be such that the polymer strain-hardens as it is stretched. Therefore, the molding temperature during the blow molding process can be a determining factor for the resulting container. The strain-hardening effect can be taken into account in the production of PET containers for the purpose of controlling and optimizing the wall thickness distribution. Depending on the manufacturing process, heat can be applied by infrared radiation so that the preform is heated according to a temperature profile. In this way, warmer parts of the preform can deform preferentially over other parts, as long as necessary so that the resistance to stretching resulting from strain hardening is greater than, for example, the resistance of adjacent cooler parts. The temperature profile can be uniformly distributed around the periphery of the preform or can vary process-dependently along the preform's longitudinal axis. Multiple heating zones, for example, up to nine or more zones, can be used to apply a desired temperature profile to the preform. Different heating zones can be individually controlled, allowing the selected settings to remain constant over longer periods of heating device operation.

[0008] Preforms of different configurations may require different heating regimens or methods in preparation for blow molding into the resulting container. For example, preforms formed with or containing different sizes, shapes, thicknesses, different polymers or polymer combinations, layers, etc., can each have a predetermined temperature profile optimized for a particular blow molding process. A specific example includes different heating regimens to produce different temperature profiles for PET preforms versus PP preforms. Another example includes different heating regimens to produce the same temperature profile, although preforms may have different characteristics (e.g., preforms formed from the same material but with different thicknesses) that require different regimens to achieve the same temperature profile. Accordingly, various heating parameters can be tailored to a particular preform, including the number of heating zones, the temperature of a particular heating zone, the exposure time to a particular heating zone, etc.

[0009] Blow molding systems often include a preform heating means adjacent to the system, allowing the heated preform to be delivered to the mold and molded into the resulting container within a short time before the preform's desired temperature profile changes. For example, the preform's path of travel through an infrared oven can be adjusted to generate a predetermined temperature profile for a given preform. However, if the conditions of the blow molding system and / or process change, it may be necessary to modify the preform path or heating means to accommodate the new temperature profile for a given preform. Changing blow molding conditions may involve using a different preform type, changing the mold, changing blow molding parameters, etc. Therefore, it can be difficult to adapt a blow molding system and / or process to changing conditions that require a change in the preform temperature profile while maintaining continuous or high-throughput production of containers. To accommodate preforms with different properties, a blow molding system often needs to change one or more settings, reach one or more new equilibria, or adapt one or more physical parameters. Summary of the Invention [Problem to be solved by the invention]

[0010] Without proper temperature control, heated preforms may have improper material distribution and / or expansion during the blow molding operation, and the resulting containers may rupture (or "blow out") or fail cosmetic inspection. In refined gas blow molding processes, approximately 1,500 to 2,500 containers per million gas-blown containers are expected to suffer blowouts. Blowouts from liquid-blown containers are expected to be roughly the same. With liquid blow molding, blowouts result in leakage and waste of the liquid product filling the container, more than air leakage. When the blow molding liquid is water, blowouts may result in wasted water and minimal downtime for the blow molding equipment to dry. When the blow molding liquid is, for example, a petroleum product, pharmaceutical, or cosmetic, blowout can result in significant time due to cleaning procedures required to make the blow molding equipment usable again, and can result in wasted or unusable product, each of which alone may have a significant economic impact on the blow molding process and product cost, and the combination of these may make the liquid blow molding process for packaging products economically unviable. It would be desirable to develop a blow molding method that reduces the expected blowouts in a blow molding operation (liquid or gas) to about 25 blowouts per million containers molded.

[0011] In consideration of these issues, the present technique provides a method for determining an acceptable temperature profile for a preform prior to a blow molding operation that minimizes blowouts and allows the resulting blow molding operation to be maintained at a continuous or high throughput. [Means for solving the problem]

[0012] Consistent with and consistent with the present invention, a method has surprisingly been discovered for determining an acceptable temperature profile for a preform prior to a blow molding operation to minimize blowouts.

[0013] In one embodiment of the present invention, a method of heating preforms comprises the steps of providing a plurality of preforms suitable for blow molding, inspecting each preform to identify at least the material from which the preform is formed, heating the preforms, measuring the temperature of at least a portion of each preform along its longitudinal axis and around its circumference, and based on a comparison of the measuring and inspecting steps, determining whether each preform has been heated to an acceptable temperature and optimizing the heating steps for subsequent preforms such that the heating steps are optimized for blow molding to prevent preform blowout.

[0014] In another embodiment of the present invention, a method of heating preforms comprises the steps of providing a plurality of preforms suitable for blow molding; inspecting each preform to identify at least the material forming the preform; heating each preform; measuring the temperature of at least a portion of each preform along a longitudinal axis of each preform and around its circumference; aggregating the measured temperatures of at least a portion of each preform; converting the aggregated measured temperatures into a three-dimensional thermal image representative of the measured temperatures of at least a portion of the preform; and determining whether each preform has been heated to an acceptable temperature based on a comparison of the three-dimensional thermal image to the inspecting step, and optimizing the heating step for subsequent preforms such that the heating step is optimized for blow molding to prevent preform blowout.

[0015] In another embodiment of the present invention, a method of heating preforms comprises the steps of providing a plurality of preforms suitable for blow molding; inspecting each preform to identify at least the material forming the preform; heating each preform; measuring a temperature of at least a portion of each preform along a longitudinal axis of each preform and around a periphery of each preform; aggregating the measured temperatures of at least a portion of each preform; converting the aggregated measured temperatures into a three-dimensional thermal image representative of the measured temperatures of at least a portion of the preform; converting the three-dimensional thermal image into a two-dimensional thermal image representative of the portion of the preform measured along the longitudinal axis of the preform and around a periphery of the preform; and determining whether each preform has been heated to an acceptable temperature based on a comparison of the two-dimensional thermal image to the inspecting step, and optimizing the heating step for subsequent preforms such that the heating step is optimized for blow molding to prevent preform blowout.

[0016] These and other advantages of the present invention will become readily apparent to those skilled in the art from the following detailed description of the preferred embodiments when considered in light of the accompanying drawings. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a plan view showing a schematic of an oven for heat treatment and thermal imaging of preforms. [Figure 2] 2 is a cross-sectional view including one of the heating means of FIG. 1 and a preform heated thereby. [Figure 3] 1 is an exemplary three-dimensional thermal image of a heated preform and the corresponding two-dimensional thermal image obtained therefrom. [Figure 4] Selective dissection of the images in Figure 3 is shown. [Figure 5] A side-by-side comparison of the two-dimensional thermal image of Figure 3 with a graphical representation of the thermal data used to generate the image. DETAILED DESCRIPTION OF THE INVENTION

[0018] The following description of the technology is merely exemplary in nature of the subject matter, manufacture, and use of one or more inventions and is not intended to limit the scope, application, or use of any particular invention claimed in this application, or in any other application that may claim priority to this application, or in any patent issued therefrom. With regard to the disclosed methods, the order of the steps presented is exemplary in nature; therefore, the order of the steps may be varied in various embodiments, including cases where certain steps may be performed simultaneously. As used herein, "A" and "an" indicate the presence of "at least one" of an element, and where possible, multiple instances of such elements may be present. Unless otherwise expressly stated, all numerical quantities herein are understood to be modified by the term "about," and in describing the broadest scope of the technology, all geometric and spatial descriptions are understood to be modified by the term "substantially." When applied to a numerical value, "about" indicates that the calculation or measurement allows for some imprecision in the value (with some approach to the precision of the value; approximately or reasonably close to the value; approximately). Instead, if for any reason the imprecision provided by "about" and / or "substantially" is not understood in the art in its ordinary sense, then "about" and / or "substantially" as used herein will indicate at least the variation that might result from ordinary methods of measuring or using such parameters.

[0019] All documents cited in this detailed description, including patents, patent applications, and scientific literature, are incorporated herein by reference unless expressly stated otherwise. In the event that a conflict or ambiguity may exist between a document incorporated by reference and this detailed description, the detailed description will control.

[0020] Although the open-ended term "comprising" is used herein to describe and claim embodiments of the present technology as synonymous with non-limiting terms such as including, containing, and having, embodiments can alternatively be described using more restrictive terms such as "consisting of" or "consisting essentially of." Thus, for any given embodiment reciting a material, component, or process step, the present technology also specifically includes embodiments consisting of, or consisting essentially of, such material, component, or process step, excluding (if consisting of), or excluding (if consisting essentially of), additional materials, components, or steps that affect a critical characteristic of the embodiment, even if such additional materials, components, or steps are not explicitly recited herein. For example, a description of a component or process reciting elements A, B, and C specifically contemplates embodiments consisting of, and consisting essentially of, A, B, and C, excluding element D, as may be described in the art, even if element D is not explicitly recited herein as excluded.

[0021] As referred to herein, the disclosure of ranges includes endpoints, unless otherwise specified, and includes all explicit values ​​and further divided ranges throughout the range. Thus, for example, a range "from A to B" or "from about A to about B" includes A and B. The disclosure of values ​​and ranges of values ​​for a particular parameter (amount, weight percent, etc.) does not exclude other values ​​and ranges of values ​​useful herein. It is contemplated that two or more specific exemplified values ​​for a given parameter may define the endpoints of a range of values ​​that can be claimed for that parameter. Similarly, the disclosure of two or more ranges of values ​​for a parameter (whether such ranges are nested, overlapping, or separate) is contemplated to encompass all possible combinations of the ranges of values ​​that can be claimed using the endpoints of the disclosed ranges. For example, if a parameter X is exemplified herein as having a value in the range of 1-10, or 2-9, or 3-8, it is also contemplated that parameter X may have other ranges of values, including 1-9, 1-8, 1-3, 1-2, 2-10, 2-8, 2-3, 3-10, 3-9, etc.

[0022] When an element or layer is referred to as "on," "engaged to," "connected to," or "coupled to" another element or layer, it can be directly on, engaged with, connected to, or coupled to the other element or layer, or intervening elements or layers can be present. In contrast, when an element is referred to as "directly on," "directly engaged to," "directly connected to," or "directly coupled to" another element or layer, there can be no intervening elements or layers. Other words used to describe relationships between elements should be interpreted similarly (e.g., "between" vs. "directly between," "adjacent" vs. "directly adjacent," etc.). As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed elements.

[0023] Terms such as "first," "second," and "third" may be used herein to describe various elements, components, regions, layers, and / or sections; however, these elements, components, regions, layers, and / or sections should not be limited by these terms. These terms are used solely to distinguish one element, component, region, layer, or section from another region, layer, or section. As used herein, terms such as "first," "second," and other numerical terms do not imply a sequence or order unless clearly indicated by context. Thus, a first element, component, region, layer, or section described below could be referred to as a second element, component, region, layer, or section without departing from the teachings of the exemplary embodiments.

[0024] Spatially relative terms such as "inside," "outside," "below," "belower," "lower," "above," and "upper" may be used herein for ease of description to describe the relationship of one element or feature to another element(s) or feature(s), as shown in the figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the illustrated device were turned over, elements described as "below" or "below" the other element or feature would be oriented "above" the other element or feature. Thus, the illustrative term "below" can encompass both an orientation of above and below. The device may also be otherwise oriented (rotated 90 degrees or at other orientations), and the spatially relative descriptions used herein would be interpreted accordingly.

[0025] 1, the present technology is depicted in a method of thermal imaging using a heating system 10 and a method of optimizing the temperature profile of a preform, and in particular a method of using such a system in blow molding a container (not shown) from a thermoplastic preform 12. The system 10, which will be described in more detail herein, generally includes a first camera 14, a second camera 16, and a heating means 18.

[0026] With respect to the preform 12, FIG. 2 illustrates an exemplary preform 12 having a longitudinal axis O and an overall shape resembling a test tube. The preform 12 has a neck 20, a shoulder 22, a body 24, and a closed-off bottom 26. Typically, the neck 20 and shoulder 22 are each formed and in their final shape upon entry into the system 10 and do not need to be heated or thermally imaged as contemplated herein. Thus, typically, only the body 24 and bottom 26 are thermally treated and thermally imaged by the system 10, although the entire preform 12 may be heated if desired. The tubular body 24 of the preform 12 includes a neck 20 closed at its upper end by a hemispherical bottom 26 and a lower end already in the defined shape of the neck 20 of a container, with a radially outwardly extending annular shoulder 22 roughly defining the unheated portion of the preform 12 from its heated portion. Preforms 12 can be formed from polyester materials such as polyethylene terephthalate (PET) and other polyesters, polypropylene, acrylonitrile acid esters, vinyl chloride, polyolefins, polyamides, and derivatives, blends, and copolymers thereof. As shown, preforms 12 have a shape well known to those skilled in the art similar to a test tube, with a generally cylindrical cross-section and a length that is typically about 50% of the resulting container height; alternatively, preforms 12 may have any shape, length, and be formed from any material as desired. As described herein, the heat treatment performed in system 10 is intended to prepare preforms 12 for conversion by blowing with a gas or liquid to form each preform 12 into a container.

[0027] In system 10, each preform 12 is provided at an infeed station entrance E via a magnetic levitation track, rail, or other transport mechanism (not shown). Preforms 12 are then individually loaded onto a conveyor 28, which transports the preforms 12 through system 10 and ultimately to an exit S of system 10 for further processing steps 30, as described in more detail below. Further processing steps 30 may include transporting the preforms 12 for re-entry at one of entrances E for additional heating, rejection, and recycling, or transporting the preforms 12 to a blow mold loading station (not shown) for forming the preforms 12 into containers.

[0028] Each preform 12 enters the system 10 (which is at ambient temperature) placed on a spindle 24 (as shown in FIG. 2 ), with a spindle 30 allowing 360° rotation as the preform 12 passes through the system 10. At the entrance E, each preform 12 is inspected and measured by a first camera 14. While the camera 14 is a visual inspection camera, the camera 14 may be an infrared camera or any other camera capable of measuring the desired characteristics described herein of each preform 12. For example, the camera 14 is configured to inspect, measure, transmit, and / or collect data about the preform 12, including, but not limited to, the starting (often ambient) temperature of the preform 12, the material from which the preform 12 is formed, the material state (i.e., amorphous vs. crystalline) of the preform 12, any inclusions (i.e., foreign matter) within the preform 12, a desired resolution image of the preform 12, and the physical dimensions (e.g., height, width, diameter) of the preform 12. The cameras are in electronic communication with a computer 34, and / or a process controller (not shown), and / or other data processor (not shown), which can process and / or aggregate images and data from the first camera 14.

[0029] After inspection and measurement by the camera 14, each preform 12 is transported through the system 10 by a conveyor 28 and passes through a series of heating means 18. The heating means 18 may be, for example, an infrared oven or any other suitable heating means known to those skilled in the art of blow molding. Direct and / or indirect (e.g., reflected) heat energy may be applied by the heating means 16. Multidirectional application of heat energy may be used, as may the preform 12 itself, where it is moved, spun, or rotated relative to various heat radiation sources in the various heating means 18. While any number of heating means 18 may be utilized as desired, as shown in FIG. 1, the system 10 includes three (3) heating means 18. As best shown in FIG. 2, each heating means 18 includes five heating elements 36 to facilitate heating of each preform 12 at different heights of the preform 12 along the longitudinal axis O. It will be understood that the number of heating means 18 and the heating elements 36 present in the heating means 18, or their operation during a given process, may vary based on the size or specifications of each preform 12, the material properties of each preform 12, etc. The heating means 18 are spaced longitudinally along the conveyor 28 through the system 10 to impart a desired temperature profile to the preforms 12 that enables optimization of the distribution of the plastic material during the remaining steps in the pre-stretching and blow-molding process. The temperature profile may vary or define a gradient along the longitudinal axis O of each preform 12. Alternatively, the temperature profile may be constant across the length of the preform 12. Furthermore, the temperature profile may vary across the thickness of the preform 12, for example, so that the material on the outside of the preform 12 is at a higher temperature than the material on the inside of the preform 12. The actual temperature profile will depend on the specific design of the preform 12, including its shape and material composition, material distribution, and the design of the resulting container being formed. As each preform 12 passes the heating means 18 , it is rotated on its spindle 32 so that it is heated by the heating means 18 until it reaches the camera 14 .

[0030] As shown in FIG. 1 , camera 16 is an infrared camera adapted to inspect and measure the temperature of each preform 12 along its longitudinal axis O and throughout its circumference. Camera 16 measures the temperature of preform 12 along axis O and the entire circumference of preform 12 at a predetermined and desired number of data points and / or at a desired resolution (constrained by camera 16). For example, data points correspond to the height of each heating element 36 and / or the portion of preform 12 between them along each angle of the circumference of preform 12 and / or the area between them. Camera 16 is in electronic communication with a computer 34 and / or process controller and / or other data processor (not shown) that can process and / or compile the thermal property data measured by camera 16. For example, computer 34 converts the thermal property data of each preform 12 into a three-dimensional thermal image 38 of each preform 12, as best shown in FIG. 3 . Computer 34 can then convert the three-dimensional thermal image 38 into a two-dimensional thermal image 40 (also known as a heat map). Alternatively, computer 34 may convert the thermal property data directly into a two-dimensional thermal image 40. Viewed from left to right, image 40 is a representation of temperature measurements of preform 12 taken from about 0° to about 359° as preform 12 rotates on spindle 30. In this manner, the temperature profile of three-dimensional preform 12 can be viewed in two dimensions. Furthermore, the temperature profile of preform 12 can be viewed overall or at desired discrete pixels or regions along a longitudinal region 42, as shown, for example, in FIG. 4 . By way of example, and as best shown in FIG. 4 , three-dimensional thermal image 38 can be divided into a desired number of longitudinal regions, such as 359 longitudinal regions corresponding to each angle of preform 12 rotated about its axis O from about 0° to about 359°. In this manner, specific longitudinal regions 42 of three-dimensional thermal image 38 and preform 12 itself can be more easily and readily observed on two-dimensional thermal image 40 without having to access and / or rotate three-dimensional thermal image 38.

[0031] As described above, the temperature of the preform 12 is compiled by the computer 34. The measured temperatures are then plotted against the measurement location on the preform 12, as shown in graph 44 of Figure 5. As shown in graph 44, the temperature of the preform 12 at each temperature measurement (x-axis) taken by the camera 14 is plotted against the location of that measurement (x-axis) on the preform 12. In this way, graph 44, which is a numeric / graphical representation of the temperature measurements, can be easily compared and directly correlated with the two-dimensional thermal image 40, which is a color-based heat map.

[0032] By creating a two-dimensional thermal image 40, temperature measurements of each heated preform 12 can be easily and readily confirmed before the preform 12 is transferred to the blow molding station and formed into a final container. In some cases, the thermal images 38, 40 and / or graph 44 may indicate that the preform 12 has "cold areas" 46 or "warm areas" 48. Such areas 48, 48 may result in blowouts during blow molding and thus require remedial action during heating of the preform 12. The exact location of such areas 46, 48 can be precisely located by observing and analyzing the thermal images 38, 40 and / or graph 44, so that remedial action can be taken to ensure proper heating of the preform 12 to minimize blowouts during blow molding into a container. Remedial action can include one or more adjustments to the processing parameters and settings of the system 10, including adjustments to the heating means 16 or particular heating elements 36 to increase or decrease the temperature of any portion of the preform 12 (e.g., regions 46, 48), as desired, so that subsequent preforms have different, acceptable temperature profiles to minimize blowouts during blow molding. Additional remedial action can be, for example, adjusting upward or downward the spin speed of the spindle 32 on which each preform 12 is placed, or increasing or decreasing the residence time of the preforms 12 in the system 10 (or the speed of the conveyor 28), and / or increasing or decreasing the cooling airflow within the system 10.

[0033] During use, images and / or information acquired from the first camera 14 are processed by the computer 34 to determine the appropriate heat treatment for each preform 12 receiving from the heating means 18. For example, the first camera 14 can identify individual preforms formed from different materials or having different sizes corresponding to resulting containers with different volumes. In this manner, each preform 12 can require its own specific heat treatment from the heating means 18, and / or the first camera 14 can detect an unacceptable number of inclusions or other unacceptable issues with a particular preform and signal the system 10 via the computer 34 or process controller to reject the preform and remove it for recycling or disposal. As each preform 12 receives its heat treatment from the heating means 18, data about each preform 12 is collected by the second camera 16. The computer 34 compares the data received for each preform 12 from the first camera 14 with the data received from the second camera 16 to determine whether the heat treatment was appropriate and acceptable for the given specifications (e.g., dimensions and / or material) of the preform 12.

[0034] The computer 34 or process controller can adjust the system 10 so that subsequent preforms 12 of similar specifications receive the appropriate heat treatment, for example, by increasing or decreasing the intensity of the heating means 18, adjusting the spin speed of the spindle 32 on which each preform 12 is positioned, increasing or decreasing the residence time of the preforms 12 within the system 10 (i.e., the speed of the conveyor 28), and / or increasing or decreasing the cooling air flow within the system 10. The computer 34 and / or process controller makes adjustments to the system 10, as necessary, based on images from the cameras 14, 16 and / or a comparison of data from the cameras 14, 16 for each preform 12. By ensuring that each preform 12 receives an appropriate and acceptable heat treatment before it is subjected to the blow molding operation (i.e., further processing steps 30), blowouts of the preform(s) 12 are minimized and cost savings can be realized.

[0035] The exemplary embodiments are provided so that this disclosure will be thorough and will fully convey its scope to those skilled in the art. Numerous specific details are set forth, such as examples of specific components, devices, and methods, to provide a thorough understanding of the embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, and that the exemplary embodiments may be embodied in many different forms, and neither should be construed to limit the scope of the present disclosure. In some exemplary embodiments, well-known processes, well-known device structures, and well-known techniques are not described in detail. Equivalent changes, modifications, and variations of some embodiments, materials, compositions, and methods can be made within the scope of the present technology with substantially similar results.

Claims

1. 1. A method of heating a preform, comprising: providing a plurality of preforms suitable for blow molding; inspecting each preform to identify at least the material from which said preform is made; heating each preform; measuring the temperature of at least a portion of each preform along a longitudinal axis of each preform and around a circumference of each preform; determining whether each preform has been heated to an acceptable temperature based on a comparison of the measuring step and the inspecting step, and optimizing the heating step of subsequent preforms so that the heating step is optimized for blow molding to prevent preform blowout; A method for providing the above.

2. The method of claim 1 , further comprising the step of aggregating the measured temperatures of the at least a portion of each preform.

3. The method of claim 2 further comprising converting the collected measured temperatures into a three-dimensional thermal image representative of the measured temperatures of the at least a portion of the preform.

4. 4. The method of claim 3, wherein in the converting step, the aggregated temperatures are converted into a two-dimensional thermal image representing a portion of the preform measured around the periphery of the preform along a longitudinal axis of the preform.

5. The method of claim 4 , wherein the two-dimensional thermal image is a heat map.

6. The method of claim 4 , wherein during the heating step, the preform is rotated at least 360° about its longitudinal axis.

7. 6. The method of claim 5, wherein the heat map represents measurements of the circumference of the preform from about 0° to about 359° of the at least part of the preform.

8. The method of claim 2 further comprising converting the aggregated temperatures into a graphical image representing the temperature of the at least a portion of the preform versus measurement location.

9. The method of claim 1 , wherein the inspecting step is performed with a first camera and the measuring step is performed with a second camera.

10. The method of claim 9 , wherein the second camera is an infrared camera.

11. The method of claim 9 , wherein the first camera is a visual inspection camera.

12. The method of claim 11 , wherein the first camera records an image of the preform with a desired pixilation.

13. The method of claim 1 , wherein the plurality of preforms are not all formed from the same material.

14. 14. The method of claim 13, wherein each preform is heated according to a desired heating profile depending on the material from which each preform is made based on the inspecting step.

15. The method of claim 1 , wherein during the inspecting step, at least one of a starting temperature of the preform, a material state of the preform, the presence of inclusions within the preform, and a physical dimension of the preform is detected.

16. 1. A method of heating a preform, comprising: providing a plurality of preforms suitable for blow molding; inspecting each preform to identify at least the material from which said preform is made; heating each preform; measuring the temperature of at least a portion of each preform along a longitudinal axis of each preform and around a circumference of each preform; aggregating the measured temperatures of the at least a portion of each preform; converting the collected measured temperatures into a three-dimensional thermal image representative of the measured temperatures of the at least a portion of the preform; determining whether each preform has been heated to an acceptable temperature based on a comparison of the three-dimensional thermal image with the inspecting step, and optimizing the heating step for subsequent preforms so that the heating step is optimized for blow molding to prevent preform blowout; A method for providing the above.

17. 17. The method of claim 16, wherein in the converting step prior to the optimizing step, the three-dimensional thermal image is converted into a two-dimensional thermal image representing a portion of the preform measured around the periphery of the preform along a longitudinal axis of the preform.

18. 18. The method of claim 17, wherein the inspecting step is performed with a first camera and the measuring step is performed with a second camera.

19. 1. A method of heating a preform, comprising: providing a plurality of preforms suitable for blow molding; inspecting each preform to identify at least the material from which said preform is made; heating each preform; measuring the temperature of at least a portion of each preform along a longitudinal axis of each preform and around a circumference of each preform; aggregating the measured temperatures of the at least a portion of each preform; converting the collected measured temperatures into a three-dimensional thermal image representative of the measured temperatures of the at least a portion of the preform; converting the three-dimensional thermal image into a two-dimensional thermal image representing a portion of the preform measured around the periphery of the preform along the longitudinal axis of the preform; determining whether each preform has been heated to an acceptable temperature based on a comparison of the two-dimensional thermal image with the inspecting step, and optimizing the heating step for subsequent preforms so that the heating step is optimized for blow molding to prevent preform blowout; A method for providing the above.

20. 20. The method of claim 19, wherein each preform is heated according to a desired heating profile depending on the material from which each preform is made based on the inspecting step.

Images