Apparatus and method for optimizing injection molding parameters, formulations and mold structures

Abstract

Disclosed herein are methods and systems for determining mold design, polymer formulation, and process parameters for forming thermoplastic foams having a desired honeycomb structure as well as mechanical and physical properties. In one example, the system includes a trim mold and a plurality of interchangeable mold cavities including a pair of mold cavities for forming a solid polymer sample and two or more pairs of mold cavities for forming a thermoplastic foam sample. The mold cavity includes a plurality of sensors to determine pressure and temperature at different locations within the mold cavity. The samples are compared and decisions are made based on the comparison and an evaluation of data regarding the mold design, formulation and / or process parameters. Optionally, the methods and systems disclosed herein may use a venting system and a collection system to collect any output gas to determine the solubility of a particular polymer-gas combination to further determine mold design, formulation, and / or process parameters.

Description

TECHNICAL FIELD

[0001] The present disclosure relates generally to systems and methods for determining and optimizing various mold designs, polymer formulations, and process parameters for forming polymers having certain preferred physical characteristics and mechanical properties using an injection molded plaque mold testing device. More specifically, the present disclosure relates to systems and methods for using an injection molded plaque mold testing device having a plurality of interchangeable mold cavities, a plurality of sensors, and a process for collecting data to determine and optimize mold designs, polymer formulations, and process parameters for forming thermoplastic foams having certain preferred physical characteristics and mechanical properties. BACKGROUND

[0002] Thermoplastic foams, also known as cellular thermoplastics, are materials that provide useful properties in many applications. Thermoplastic foams are expanded polymers having two or more phases, typically a continuous solid polymer matrix phase and a distributed gas phase. This two-phase structure is formed from dispersed gas molecules in the form of bubbles during a molding process. The gas is incorporated into the molded component and forms voids after the polymer solidifies, thereby forming the two-phase structure. Thermoplastic foams provide useful properties and characteristics such as reduced density, reduced weight compared to typical molded polymer components; reduced heat and noise transmission; and impact and compression resistance.

[0003] The mechanical properties of thermoplastic foams are controlled by the cellular structure, which includes its cellular uniformity, average cell size, and cell density. These structural properties, in turn, are determined by the mold design, formulation, and process parameters of the molding process. As will be appreciated, current methods attempt to determine suitable mold design, formulation, and process parameters through a conventional trial-and-error approach. This trial-and-error approach includes forming multiple molds and conducting a large number of experiments, which results in a significant amount of time and cost to complete. What is needed is an apparatus and efficient and effective method for using such apparatus to facilitate determining and optimizing mold design, formulation, and process parameters for forming thermoplastic foams in a time and cost saving manner and obtaining thermoplastic foams having desired properties. The present disclosure describes and illustrates such an apparatus and efficient method for using such apparatus. SUMMARY

[0004] Disclosed herein is an apparatus for determining mold design, formulation, and process parameters for forming thermoplastic foams having desired cell structure, as well as mechanical and physical properties, and a method for using such apparatus.

[0005] In one example, the apparatus is a plaque mold assembly including multiple interchangeable mold cavities, including one pair of mold cavities for forming a solid polymer sample and two or more pairs of mold cavities for forming thermoplastic foam samples. The mold cavities include multiple sensors to determine pressure and / or temperature at different locations within the mold cavities during the molding process. Once the solid sample and two or more thermoplastic foam samples are molded, the data collected during the molding process and observations of the resulting samples can be compared and decisions made based on the comparison and evaluation of the data regarding optimization of mold design, formulation, and / or process parameters. Optionally, a venting system and collection tank can be used to collect any output gas. Once the output gas is collected, the solubility of the particular polymer-gas combination can be determined and used with the other data collected to determine and optimize mold design, formulation, and / or process parameters. Additional optional components include multiple inserts that modify the number and location of vent holes that affect outgassing venting during the molding process, and multiple gate and runner assemblies that modify the way molten polymer is injected into the cavities of the mold during the molding process. BRIEF DESCRIPTION OF DRAWINGS

[0006] In the drawings, which are not necessarily drawn to scale, like numerals describe similar components throughout the several views. Elements shown as single components can be replaced with multiple components. Elements shown as multiple components can be replaced with a single component. The drawings can not be drawn to scale. The proportions of certain elements may

[0007] Figure 1 A plaque mold is schematically illustrated with a pair of removable mold cavities in the plaque mold.

[0008] Figure 2 An exemplary sample for use with the methods described herein is schematically illustrated.

[0009] Figure 3 A pair of exemplary mold cavities are schematically illustrated with samples cut from a plaque formed during a molding process, where the mold cavities are designed to produce samples having a thickness of 3.2 mm.

[0010] Figure 4 A pair of exemplary mold cavities are schematically illustrated with samples cut from a plaque formed during a molding process, where the mold cavities are designed to produce samples having a thickness of 7.0 mm, and alternatively, samples having a thickness of 14.0 mm.

[0011] Figure 5 A mold plaque is schematically illustrated with mold cavities arranged to produce 3.2 mm solid samples.

[0012] Figure 6 A mold panel is shown schematically, with mold cavities arranged to produce 3.2 mm thermoplastic foam samples.

[0013] Figure 7 A mold panel is shown schematically, with mold cavities arranged to produce 7.0 mm thermoplastic foam samples.

[0014] Figure 8 A mold panel is shown schematically, with mold cavities arranged to produce 14.0 mm thermoplastic foam samples.

[0015] Figure 9 A mold panel is shown schematically, with mold cavities arranged to produce 25.4 mm thermoplastic foam samples.

[0016] Figure 10A A 3.2 mm panel produced by a panel mold is shown schematically.

[0017] Figure 10B A 7.0 mm panel produced by a panel mold is shown schematically.

[0018] Figure 10C A 14.0 mm panel produced by a panel mold is shown schematically.

[0019] Figure 10D A 25.4 mm panel produced by a panel mold is shown schematically.

[0020] Figure 11 A potential location of a sensor within a mold cavity is shown schematically.

[0021] Figure 12 A panel mold with two independent potential water circulation systems is shown schematically.

[0022] Figure 13 A perspective view of a panel mold with a collection tank is shown schematically.

[0023] Figure 14 Another perspective view of a panel mold with a collection tank is shown schematically.

[0024] Figure 15 A perspective view of a pair of collection cylinders for use with a panel mold system is shown schematically.

[0025] Figure 16 A perspective view of a panel mold with a pair of collection cylinders from Figure 15 is shown schematically.

[0026] Figure 17 A perspective view of three collection cylinders for use with a panel mold system is shown schematically.

[0027] Figure 18 Perspective view of a plaque mold with three collection cylinders from Figure 17 .

[0028] Figure 19 Comparison of pressure curves for different saturated polymer mixtures recorded by Figure 11 sensor number 1 in the 14 mm cavity.

[0029] Figure 20 Comparison of pressure curves for different saturated polymer mixtures recorded by Figure 11 sensor number 2 in the 14 mm cavity.

[0030] Figure 21 Comparison of pressure curves for different saturated polymer mixtures recorded by Figure 11 sensor number 3 in the 14 mm cavity.

[0031] Figure 22A to Figure 22D Schematic illustration of flow patterns of a polymer with developed flow characteristics at different time intervals.

[0032] Figure 23 are photographs of the flow behavior of a 14 mm general purpose polystyrene (GPPS) component and accompanying schematic model.

[0033] Figure 24 are photographs of the flow behavior of a 14 mm high impact polystyrene (HIPS) component and accompanying schematic model.

[0034] Figure 25 Comparison of temperature curves recorded by Figure 11 sensor number 1 in the 14 mm cavity.

[0035] Figure 26 Comparison of temperature curves recorded by Figure 11 sensor number 2 in the 14 mm cavity.

[0036] Figure 27 Comparison of temperature curves recorded by Figure 11 sensor number 3 in the 14 mm cavity.

[0037] Figure 28 are photographs of injection foam components of different formulations formed in a 14 mm mold cavity.

[0038] Figure 29 Comparison of pressure curves recorded by Figure 11 sensor numbers 1, 2, and 3 in the 14 mm cavity at an injection speed of 5 cubic inches per second.

[0039] Figure 30 A comparison of pressure curves recorded by Figure 11 No. 1, 2, and 3 sensors in a 14 mm cavity of the

[0040] Figure 31 A comparison of pressure curves recorded by Figure 11 No. 1, 2, and 3 sensors in a 14 mm cavity of the

[0041] Figure 32 A comparison of pressure curves recorded by Figure 11 No. 1, 2, and 3 sensors in a 14 mm cavity of the

[0042] Figure 33 A comparison of pressure curves recorded by Figure 11 No. 1, 2, and 3 sensors in a 14 mm cavity of the

[0043] Figure 34 A comparison of pressure curves recorded by Figure 11 No. 1, 2, and 3 sensors in a 14 mm cavity of the

[0044] Figure 35 A comparison of pressure curves recorded by Figure 11 No. 1, 2, and 3 sensors in a 14 mm cavity of the DETAILED DESCRIPTION

[0045] The devices, systems, arrangements, and methods disclosed in this document are described in detail by way of example and with reference to the drawings. It will be appreciated that modifications to disclosed and described examples, arrangements, configurations, components, elements, devices, methods, materials, etc. can be made and can be desired for particular applications. Any identification of specific technology, arrangements, methods, etc. are neither intended to nor should be Figures 1 to 35 A selected example of a device and method of using such a device for testing and determining mold design, formulation, and process parameters to form thermoplastic foams having certain preferred physical characteristics and mechanical properties is disclosed and described in detail.

[0046] Disclosed herein are apparatuses and methods of using such apparatuses for determining and optimizing mold design, formulation, and process parameters for injection molding thermoplastic foams having a preferred cellular structure that provides specific mechanical and physical properties. With respect to determining and optimizing mold design, examples of such mold design features that can be investigated and optimized using the apparatuses disclosed herein include, but are not limited to, the number and location of vents, and the design of gates and runners for injecting polymer into the mold cavity. With respect to optimizing formulation, examples of ingredients that can be investigated and optimized using the apparatuses disclosed herein include, but are not limited to, the type of molten polymer; if two or more polymers are used, the mixture of these polymers; the type and amount of blowing agent; and the type and amount of nucleating agent. With respect to process parameters, examples of such parameters that can be investigated and optimized using the apparatuses disclosed herein include, but are not limited to, the injection speed and temperature in the barrel and / or the mold cavity. It will be appreciated that the above examples are merely exemplary, and that the apparatuses and methods disclosed herein can be used to investigate and optimize other aspects of mold design, formulation, and process parameters for injection molding.

[0047] Generally, to injection mold a foamed polymer component, a polymer formulation requires one or more polymers, a blowing agent, and a nucleating agent. The formulation is processed in an injection barrel to reach molten conditions, and then injected into a mold cavity using certain process parameters, such as injection speed, injection pressure, and specific temperatures in the injection barrel and mold cavity. The mold also includes certain features to facilitate filling of the mold in a desired manner.

[0048] A suitable formulation of ingredients is critical to achieving a uniform and desired cellular structure, as well as desired physical and mechanical properties of the resulting molded component. Based on the intended application of the resulting thermoplastic foam, the formulation can be selected to optimize specific properties, such as physical, mechanical, thermal, insulating, and / or electrical properties. Such properties are controlled by the cellular structure specification of the thermoplastic foam, which is highly dependent on the formulation.

[0049] With respect to mold design, important factors include the design of gates and runners. A suitable pressure drop rate is important to produce an appropriate number and distribution of successful nuclei to result in a uniform cellular structure. During the injection molding process, the number and angle, shape, and diameter of gates, as well as the design and placement of runners, are important to achieve a desired result. Another important feature is the placement of vents within the mold cavity. Prior to injection of molten polymer into the mold cavity, the mold cavity is filled with ambient air that is displaced by the injected polymer. If the number and placement of vents is such that this ambient air becomes trapped between the walls of the mold cavity and the polymer flowing into the cavity, as will be further described herein, it can have a detrimental effect on the flow of the molten polymer.

[0050] Measuring the pressure throughout the mold cavity during the molding process can provide important insights to the designer regarding the mold design and process parameters. As will be further discussed herein, maintaining a relatively equal peak pressure throughout the mold cavity during the molding process can result in a more uniform and consistent distribution and size of "bubbles" (i.e., pockets of gas within the molten polymer that result in voids within the polymer matrix after the polymer solidifies) within the molten polymer, resulting in a consistent physical structure of the solidified polymer component resulting from the molding process.

[0051] Another important parameter that can be measured and quantified by the apparatus and methods disclosed herein is the gas saturation during the foaming process prior to and during the injection of the polymer into the mold cavity. Higher gas solubility results in higher gas saturation levels, which produces higher melt pressures. Molten polymers with higher gas pressure levels have higher thermodynamic instability and higher potential for pressure drop, which can result in higher expansion rates and reduced density (i.e., a lighter weight component compared to a solid polymer component of equivalent size) of the component produced from the injection molding process. Therefore, it is useful to measure the gas solubility during the molding process. One advantage of using the apparatus disclosed herein is that it provides a monomer shape that controls the gas phase of the injection molded component. By controlling the monomer shape of the cellular structure, the mechanical properties of the resulting thermoplastic foam component can be controlled.

[0052] The apparatus and methods described herein can be used to study the formation of foam components having a "dual-cellular" structure. For purposes of this disclosure, a "dual-cellular" structure means that a first portion of the resulting foam component (e.g., a top layer or a left portion) has a first distribution of voids (i.e., size and density of voids in the polymer matrix), and a second portion of the resulting foam component (e.g., a bottom layer or a right portion) has a second distribution of voids. Using two different but complementary portions, a dual-cellular structure in a thermoplastic foam can play an important role in improving the performance of the molded component. For example, the forming polymer can be molded to have improved impact resistance while maintaining other desirable properties. Based on the use of the apparatus to apply the methods described herein, specific conditions for forming such dual-cellular structures for components having a desirable combination of properties can be developed, particularly with strict control over the two or more cooling processes incorporated into the mold cavity.

[0053] Figures 1 to 12 An exemplary apparatus for determining and optimizing mold design, formulation, and process parameters for injection molded thermoplastic foams is shown in FIGS. 1-3. These figures show a plaque mold having a plurality of interchangeable mold cavities. The interchangeable mold cavities include a number of pressure sensors to record pressure at different locations of the mold cavity, and a number of temperature sensors to record temperature at different locations of the mold cavity. The mold includes two independent water circulation systems, which can be used to study and develop different cellular structures, including dual-cellular structures, for injection molded thermoplastic foams.

[0054] Figure 1 An exemplary trim panel mold 10 is shown. The trim panel mold 10 includes an A-side 20 and a B-side 30. The A-side 20 includes a first portion 40 of the mold cavity and the B-side 30 includes a second portion 50 of the mold cavity. The first portion 40 and the second portion 50 combine together to form a mold cavity that facilitates the formation of a polymeric assembly, including a thermoplastic foam assembly. As will be appreciated, each mold cavity is selectively removable and replaceable with other mold cavities depending on the type of assembly to be formed.

[0055] The apparatus described herein includes the manufacture of multiple sets of injection molded inserts for the manufacture of one solid assembly and two or more different dimensioned thermoplastic foam assemblies, each molded in a different mold cavity pair to study the effects of different parameters on the flow and foaming behavior of different polymer formulations. In the embodiment shown herein, five sets of injection molded assemblies are included - one set for forming a solid assembly and four sets for forming foam assemblies of different dimensions. While this embodiment shows the use of five sets of injection molded inserts, it will be appreciated that more or less than five sets of injection molded inserts can be used to achieve useful results.

[0056] All mold cavity produced assemblies have the same top and bottom surface area, but the thickness of the resulting assemblies is different. In this embodiment, the length of this area is designed based on the length required for the largest dog bone or rectangular sample to test mechanical properties under the ASTM D 638-02a standard, i.e., 24.60 cm, for convenience. Figure 2 A schematic illustration of such a sample is shown in FIG. 1. The width of this area is set to 18.50 cm so that at least five test specimens can be accommodated at each mold cavity. Figure 3 and Figure 4 A matching mold cavity pair for use with the methods described herein is shown schematically. Figure 3 includes five samples cut from a trim panel formed from the mold cavity, where the mold cavity is designed to produce samples having a thickness of 3.2 mm. Figure 4 includes five samples cut from a trim panel formed from the mold cavity, where the mold cavity is designed to produce samples having a thickness of 7.0 mm. Additional trim panels can be formed to produce samples having a thickness of 14.0 mm and 25.4 mm. The samples shown herein facilitate the testing and comparison of material properties of samples of various thicknesses as well as the polymer formulations and process parameters used to form such samples. For example, once formed, such samples can be subjected to tensile, impact, three-point bend, and other similar tests to quantify and subsequently compare the mechanical properties of different samples.

[0057] The following is an explanation of the mold cavity and trim panel mold arrangement for producing five different thickness samples. Figure 5A mold cavity in a plaque mold producing a solid sample (i.e., no systematic monomer or void pattern in the polymer matrix) of thickness 3.2 mm is shown. This solid sample is used as a control sample for evaluating subsequent thermoplastic foam samples produced using the described methods. The setup is equipped with three in-cavity pressure sensors and an additional pressure sensor at the bleed location. The pressure sensors can be general purpose pressure sensors, or can be specialized low pressure sensors or high pressure sensors. In one example, the low pressure sensors can detect pressures from 0 bar (0 psi) to 10 bar (about 145 psi) and the high pressure sensors can detect pressures from 0 bar (0 psi) to 50 bar (about 725 psi). In Figure 5 In an example, the three in-cavity pressure sensors can be high pressure sensors and the additional pressure sensor at the bleed location can be a high pressure sensor or a low pressure sensor, depending on the desired data to be collected.

[0058] Figure 6 A mold cavity in a plaque mold producing a thermoplastic foam sample of thickness 3.2 mm is shown. In one example, the setup is equipped with three in-cavity low pressure sensors and a low or high pressure sensor at the bleed location. The 3.2 mm thermoplastic foam sample can be compared to the 3.2 mm solid sample for in-depth understanding of various parameters.

[0059] Figure 7 A mold cavity in a plaque mold producing a thermoplastic foam sample of thickness 7.0 mm is shown. In one example, the setup is equipped with three in-cavity low pressure sensors and a low or high pressure sensor at the bleed location. The thermoplastic foam sample of thickness 7.0 mm is compared to the solid and thermoplastic foam samples of thickness 3.2 mm for in-depth understanding of various parameters. In particular, the resulting cellular structure and weight reduction of the thermoplastic foam samples are compared.

[0060] Figure 8 A mold cavity in a plaque mold producing a thermoplastic foam sample of thickness 14.0 mm is shown. In one example, the setup is equipped with three in-cavity low pressure sensors and a low or high pressure sensor at the bleed location. The thermoplastic foam sample of thickness 14.0 mm is compared to the thermoplastic foam samples of thickness 3.2 mm and 7.0 mm for in-depth understanding of various parameters. In particular, the resulting cellular structure and weight reduction of the various thermoplastic foam samples are compared.

[0061] Figure 9The mold cavity in the plaque mold producing thermoplastic foam samples with a thickness of 25.4 mm is shown. In one example, the arrangement is equipped with three in-cavity low pressure sensors and a low pressure sensor at the location of the vent. Thermoplastic foam samples with a thickness of 25.4 mm are compared to thermoplastic foam samples with a thickness of 3.2 mm, 7.0 mm, and 14.0 mm to gain insight into various parameters. In particular, the resulting cellular structure and weight reduction of the various thermoplastic foam samples are compared. Further, this thickness is the standard thickness for which thermal conductivity testing is performed.

[0062] Figures 10A to 10D Various thickness plaque mold samples produced from a plaque mold having multiple interchangeable mold inserts are shown. Figure 10A A 3.2 mm plaque assembly having a total volume (which includes the cavity, gate, sprue, and runners) of 159.86 cm 3 is shown. Figure 10B A 7.0 mm plaque assembly having a total volume of 337.54 cm 3 is shown. Figure 10C A 14.0 mm plaque assembly having a total volume of 663.93 cm 3 is shown. Figure 10D A 25.4 mm plaque assembly having a total volume of 1169.67 cm 3 is shown.

[0063] Sensors can be strategically placed within the mold cavity to collect data that aids the method, such as the pressure and temperature of the saturated molten polymer. Figure 11 Four potential locations for in-cavity sensors to collect precise data during the molding process are shown. The sensor labeled 1 is located at the centerline of the mold cavity and at the beginning of the polymer flow into the mold cavity. The sensor labeled 2 is located at the centerline of the mold cavity and at the end of the flow through the mold cavity. The sensor labeled 3 is located at one corner of the mold cavity and at the end of the flow through the mold cavity. The sensor labeled 4 is located at the vent area. Figure 11 The sensor arrangement shown in FIG. 20 is just one example of a sensor arrangement. It will be appreciated that any number of sensor arrangements can be useful for the devices and methods disclosed herein.

[0064] As previously mentioned, the plaque mold can include two independent water circulation systems. Figure 12Such embodiments are shown in FIG. 6. Two independent water circulation systems can be used to produce a dual honeycomb structure sample. For example, the resulting assembly can include a first honeycomb structure throughout a first portion of the sample and a different second honeycomb structure throughout a second portion of the sample. In one embodiment, the upper half of the sample includes the first honeycomb structure and the lower half of the sample includes the second honeycomb structure. Such a dual honeycomb structure can be formed by applying two different cooling cycles to the first and second portions of the plaque mold. By varying the cooling cycles in a set of experiments, the apparatus disclosed herein can facilitate a quick and efficient study of the effects of different cooling cycles on the resulting sample structure.

[0065] Another data point useful in evaluating mold design, polymer formulation, and process settings is measuring the amount of gas introduced into the molding process and the amount of gas that does not incorporate into the thermoplastic foam (i.e., the output gas). Gas can be introduced into the molding process in several ways. For example, ambient gas is present in the mold cavity prior to molding, and gas can be injected into the mold cavity during the molding process to facilitate physical foaming. In another example, chemical blowing additives can be used in the polymer formulation to facilitate incorporation of gas. Such additives react within the barrel of the injection mechanism or within the mold cavity during assembly formation to produce gas, thereby facilitating chemical foaming. Evaluation of this data point can help determine the gas solubility of a particular polymer-gas combination. One way to measure the output gas is to capture all of the escaping gas in a collection canister.

[0066] Figure 13 and Figure 14 Two different perspective views, a plaque mold 100 and a collection canister 110, are shown with a hose 120 connecting the plaque mold 100 to the collection canister 110. To accurately collect all of the output gas, all of the vent holes from the mold cavity are connected at a vent bleed at the back end of the plaque mold 100. The output gas flows from all sides of the plaque mold 100 and is collected at a bleed end point located at the end of the plaque mold. The vent bleed end point is connected to the collection canister 110 using a high pressure hose 120 to transport all of the gas, including trapped air, to the collection canister 110, and the collected gas can be measured. The mold cavity can be equipped with O-rings or other sealing devices between the A-side and B-side of the mold cavity to prevent any gas from escaping through the interface between the A-side and B-side of the mold cavity.

[0067] Once fully collected and measured, the volume of the output gas can be determined and compared to the volume of ambient gas, injected gas, and / or the collected volume of generated gas, as well as the volume of gas collected from a control sample. The output gas captured and measured from the forming of the solid sample can be used as a control measurement to compare to subsequent measurements obtained from the forming of thermoplastic foam samples. In one embodiment, the collection tank can have a large volume compared to the amount of gas expected to be collected. In such an arrangement, the collection tank can be at very low pressure during the collection phase so as not to affect the flow of output gas into the collection tank. Once the gas is collected, the volume of the collection tank can be reduced so as to pressurize the collected output gas, and a pressure sensor located within the tank can be used to accurately determine the amount of output gas. It is useful to use moles to calculate the gas.

[0068] The gas collection system can be arranged such that the volume of the collection vessel for capturing the output gas can be changed to accommodate various sized mold cavities. It will be appreciated that if the mold cavity is larger, it is likely that a larger volume of output gas will need to be collected. Thus, it is possible to change the size of the collection vessel, thereby providing a gas collection system that can accommodate multiple sizes of mold cavities. Figure 15 and Figure 16 Such a gas collection system 200 is shown schematically. The gas collection system 200 includes two collection cylinders (210, 220), each having a movable piston (230, 240) located within the collection cylinder (210, 220). The two collection cylinders (210, 220) and the high pressure hose 250 leading to the panel mold 100 are connected by a series of tubes or pipes 260. The pipes 260 include valves 270 that can selectively open the fluid path between the hose 250 and one or both of the collection cylinders (210, 220). In addition, the valves 270 can selectively close the fluid path between the hose 250 and both of the collection cylinders (210, 220). Each of the collection cylinders (210, 220) also includes a one-way valve at the interface of the pipe 260 and the collection cylinder (210, 220) to minimize the chance of any gas escaping from the collection cylinder (210, 220) once gas has been collected.

[0069] The volume of the collection cylinders (210, 220) in selective fluid communication with the plaque mold 100 can be varied in two ways. First, the valve 270 can be set to open the fluid path to one collection cylinder (210, 220) or both collection cylinders (210, 220). Second, the pistons (230, 240) can be adjusted to independently vary the volume within each collection cylinder (210, 220). In one example, for a relatively small plaque mold, the valve 270 can be set to open the fluid path to only one collection cylinder 210, and the corresponding piston 230 can be lowered so that the volume of the collection cylinder 210 is relatively small to match the mold cavity within the plaque mold 100. If the plaque mold 100 is relatively large, the valve 270 can be set to open the fluid path to both collection cylinders (210, 220), and the corresponding pistons (230, 240) can be raised so that the volume of the collection cylinders (210, 220) is relatively large to match the mold cavity within the plaque mold 100.

[0070] The pistons (230, 240) can also assist in determining the volume of the collected gas in the collection cylinders (210, 220). Once the molding process is complete, and all of the output gas is collected, the pistons (230, 240) can be lowered to compress the collected gas and raise the pressure within the collection cylinders (210, 220). Pressure sensors located within each collection cylinder (210, 220) can measure and record the internal pressure of the collection cylinders (210, 220). This reading, along with the known volume during the measurement, can be used to determine the volume of the outgas collected at atmospheric pressure. Thus, the number of gas molecules incorporated into the molding assembly (i.e., the number of moles of gas) can be calculated, and can be used to determine the gas solubility of the polymer or polymer mixture.

[0071] Figure 17 and Figure 18Another gas collection system 300 is schematically illustrated. The gas collection system 300 includes three collection cylinders (310, 320, 330), each having a movable piston (340, 350, 360) located within the collection cylinder (310, 320, 330). The collection cylinders (310, 320, 330) are connected to the panel mold 100 by a pipe 370 and a high pressure hose 380. The pipe 370 includes a pair of valves (390, 395) that can be selectively positioned to open a fluid path between the hose 380 and one or more of the collection cylinders (310, 320, 330). In addition, the pair of valves (390, 395) can be selectively positioned to close the fluid path between the hose 380 and the collection cylinders (310, 320, 330). Each of the collection cylinders (310, 320, 330) also includes a one-way valve at the interface of the pipe 370 and the collection cylinder (310, 320, 330) to minimize the chance of any gas escaping from the collection cylinder (310, 320, 330) once gas has been collected.

[0072] Operation of the gas collection system 300 is similar to that described for the two collection cylinder gas collection system 200. It will be appreciated that, Figures 17 to 18 The gas collection system 300 provides more flexibility in that the user selects between one and three collection cylinders (310, 320, 330) and the volume of each of the collection cylinders (310, 320, 330) is independently variable. While the examples of gas collection systems provided herein include a single tank, two collection cylinders, and three collection cylinders, it will be appreciated that any number of collection vessels can be used to collect gas to determine the gas solubility of a polymer. For example, if the volume of gas injected into the mold cavity is significantly increased, it can be necessary to add additional collection cylinders to the gas collection system 300 illustrated in FIG. 3. Figures 17 to 18 The gas collection system 300 illustrated in FIG. 3 can be augmented with additional collection cylinders. The gas collection systems described and illustrated herein are arranged to provide the user with the flexibility needed to adjust for variations in mold cavity size and other variables.

[0073] Experiments were performed to confirm the operation and accuracy of the gas collection system described herein. In one set of exemplary experiments, two polymers were foam injection molded under two different conditions - the first using a GPPS / HIPS mixture with process conditions expected to result in good gas solubility, and the second using polypropylene (PP) with process conditions expected to result in poor gas solubility. For the PP foam injection molding experiments, it is known that foaming of PP is very temperature sensitive, and the process temperature range in which PP successfully foams during injection molding is narrow. Therefore, process temperatures outside of this foaming narrow temperature range were used in the experiments, which were expected to result in poor gas solubility for the resulting molded samples. For the GPPS / HIPS mixture, which typically has good gas solubility performance, process parameters were chosen that resulted in successful foaming of the polymer mixture, which was expected to result in good gas solubility for the resulting molded samples. After these complementary experiments were performed, the amount of outgassing collected by the gas collection system was quantified and compared. The results indicated that the gas collection system collected over 5 times the number of moles of outgassing for the PP foam molded samples compared to the GPPS / HIPS mixed foam injection molded samples. When the foam molded samples have poor gas solubility, the amount of outgassing will be relatively high, and when the foam molded samples have good gas solubility, the amount of outgassing collected will be relatively low. Therefore, the results of the complementary experiments were consistent with expectations. The experiments described herein confirm the operation of the gas collection system. In addition, experiments were performed using PP and process parameters within the narrow temperature range for foaming PP. The outgassing collected for this molded sample was significantly lower than the outgassing for injection molded PP samples outside of the narrow temperature range for foaming PP. These additional experiments further confirm the operation of the gas collection system.

[0074] The outgassing collected by the gas collection system can be quantified by any number of methods. However, in one embodiment, a relative scale of gas solubility can be developed. As will be appreciated, while it is useful for the person selecting the polymer and process parameters and designing the foam injection molding mold to calculate the exact amount of outgassing for an injection molded sample, it is most important to be able to efficiently and effectively compare a plurality of sets of polymers, process parameters, and mold designs in determining which is most desirable. The relative scale can achieve this goal without worrying about the exact number of moles of outgassing for each injection molded sample. Such a relative scale can also standardize any outgassing not collected during the experiment and other such factors. Under such a relative scale, the polymer (or polymer mixture), process conditions, and mold design parameters used to mold each sample are assigned a relative number on a predetermined scale. Such a number can be used to quickly compare to other experiments using different polymers, process conditions, and mold design parameters to determine which experiment provides superior gas solubility results. This provides an efficient method for quickly evaluating various conditions.

[0075] Accordingly, the collection and / or calculation of the outgassing can be useful for optimizing several factors in injection molding. For example, the gas solubility of various polymers and polymer mixtures, the effect of blowing agents and nucleating agents on gas solubility, the effect of injection speed on gas solubility, the effect of temperature on gas solubility, and the effect of mold design parameters on gas solubility.

[0076] The foregoing disclosure generally describes the arrangement of devices and use of such devices in the study of mold design, polymer formulation, and process parameters for forming polymers, specifically foam polymers. The following disclosure should describe specific examples of methods for using the devices to study and optimize mold design, polymer formulation, and process parameters for molding polymers.

[0077] The following example is a detailed description of using the plaque mold system described herein to study chemical formulations, specifically to evaluate the foaming behavior of different polymers and polymer mixtures. In this example, two different polymers were used - general purpose polystyrene (GPPS) and high impact polystyrene (HIPS). Four separate experiments were conducted based on different mixtures of the two polymers - 100% GPPS, 100% HIPS, 70% / 30% GPPS / HIPS mixture, and 50% / 50% GPPS / HIPS mixture, respectively. GPPS is a rigid polymer, while HIPS is a styrene polymer that includes butadiene rubber chains, which increases the toughness of the polymer. These polymers are compatible with each other and can be mixed in different proportions. However, because the polymers have different chain mobility and melt strength, each polymer exhibits different foaming behavior when processed independently under the same molding parameters. All formulations used herein were processed under the same process conditions with the same concentration of blowing agent. Pressure sensors were placed at three different locations in the mold cavity and pressure measurements were taken at these three different locations. The first location, referred to as the “start of fill” (“SOF”), is identified as Sensor 1 in Figure 11 . The second location, referred to as the “end of fill center” (“EOF center”), is identified as Sensor 2 in Figure 11 . The third location, referred to as the “end of fill corner” (“EOF corner”), is identified as Sensor 3 in Figure 11 .

[0078] Figure 19A comparison of pressure curves from four different experiments—100% GPPS, 70% / 30% GPPS / HIPS mixtures, 50% / 50% GPPS / HIPS mixtures, and 100% HIPS mixture—was plotted, recorded by an SOF sensor in a 14 mm mold cavity. The curves represent the average of seven to ten different iterations for each of the four experiments. Based on Figure 19 The graphs show that the peak pressure of the saturated melt decreases as the proportion of HIPS increases. Higher peak pressures generally indicate more gas molecules trapped within the polymer during the foaming process. These graphs confirm that GPPS retains more gas molecules during the foaming process compared to HIPS, due to the higher melt strength of GPPS. In other words, for saturated HIPS, a greater percentage of gas molecules generated by the blown agent escapes compared to GPPS. Consequently, modules formed with HIPS exhibit lower monomer growth potential compared to modules formed with GPPS under the same process conditions and blown agent concentration. The weight loss of modules formed during these experiments is related to the... Figure 19 The conclusions drawn from the pressure curves are consistent. For GPPS, the component weight reduction was 39%, and for HIPS, it was 35%. Therefore, GPPS, exhibiting a higher pressure curve peak compared to HIPS, resulted in better foaming behavior and greater weight reduction. As expected, for the GPPS / HIPS blend, the weight reduction was approximately 37%, while the pressure curve peak fell between that of GPPS and HIPS. This experiment serves as an example of how this apparatus can be used to rapidly and efficiently investigate the properties of various polymer blends to optimize formulations for injection molding of such blended polymers.

[0079] Figure 20 The image depicts the data recorded at the EOF center sensor within a 14mm cavity, along with... Figure 19Comparison of pressure curves for the same saturated polymer mixture. Similar to the SOF, the pressure peak of the saturated melt at the EOF center location decreases as the HIPS proportion increases. Another interesting observation relates to the change in pressure peak versus fill time for the different mixtures. The pressure curve for HIPS is moving toward lower fill times compared to GPPS. In other words, the saturated HIPS is approaching the end of the fill center much faster than GPPS. As shown by the curves for 100% GPPS, 70% / 30% GPPS / HIPS mixture, 50% / 50% GPPS / HIPS mixture, and 100% HIPS, the pressure curve peak occurs fastest for 100% HIPS, slows down as the mixture increases, and is slowest for 100% GPPS. Based on the pressure curves, the peak for GPPS occurs at about 12 seconds, while the peak for HIPS occurs at about 6 seconds. Thus, the saturated melt of HIPS is reaching the EOF twice as fast as GPPS. This information is very useful to mold designers as well as personnel selecting formulations and process parameters.

[0080] Figure 21 A comparison of pressure curves for the same saturated polymer mixture recorded at the EOF corner in a 14 mm cavity is depicted. Similar to the SOF and EOF center pressure readings, the pressure peak of the saturated melt at the EOF corner also decreases as the HIPS proportion increases. In addition, HIPS shows a double foaming behavior at the EOF corner. As shown in the Figure 21 In some iterations based on the saturated HIPS melt, the pressure peak occurs at about 12 seconds, while others have a pressure peak at about 7 seconds. In other words, the saturated HIPS melt of some iterations is approaching the EOF corner sensor much faster than others. This behavior is observed randomly from injection to injection.

[0081] This behavior indicates that the apparatus disclosed herein can be used to determine whether certain polymers or polymer mixtures, as they are injected into a mold cavity, generate a "developing" flow pattern or a "random" flow pattern. For the purposes of this disclosure, a "developing" flow pattern means that as the polymer is injected into the cavity, the polymer symmetrically fills the cavity from the injection point to the farthest wall of the mold cavity in a "u-shaped flow front." Figures 22A to 22D The progression of this developing flow is schematically depicted, where Figure 22A The flow front early in the injection molding process is shown, and Figure 22DThe flow front at the end of the molding process is shown. The flow front first reaches the center of the distal wall of the cavity, then simultaneously fills the corners. For the purposes of this disclosure, "random" flow means that the flow does not follow a symmetric or proportional path. The polymer fills the cavity in a manner where the flow front reaches the distal wall of the cavity at random locations. That is, from shot to shot, the flow front can unpredictably reach the center of the distal wall first, the right corner first, or the left corner first. As described using the following experiments, the EOF center and EOF corner sensors can be used to determine whether a polymer or polymer mixture is experiencing developing flow or random flow under various conditions.

[0082] To understand the flow behavior of a polymer or polymer mixture, a short shot study was performed using a foam injection molding assembly based on two different systems, GPPS and HIPS. This study demonstrates the practical advantages of the trim mold system described herein. Figure 23 A photograph and accompanying schematic model depicting the flow behavior of the short shot study of the 14 mm GPPS assembly is depicted. As shown, the saturated GPPS melt exhibits a uniform and symmetric velocity flow profile with a u-shaped flow from the SOF towards the EOF until the cavity is filled. Once the short shot study was performed, the results of the short shot study were verified using the pressure readings at the EOF center sensor and the EOF corner sensor versus time. As will be appreciated, using this sensor eliminates the need to perform multiple short shot studies. The pressure readings from the EOF center sensor and the EOF corner sensor can be used to determine whether the polymer exhibits developing flow. Essentially, if the EOF center sensor always detects flow of the polymer at the EOF center sensor before the flow reaches the EOF corner sensor, the flow is developing. If the EOF corner sensor regularly detects flow of the polymer before the EOF center sensor detects flow of the polymer, the flow is random. While the method is described using one EOF corner sensor, it will be appreciated that two EOF corner sensors can be positioned in opposite corners to collect additional data, such as determining whether the flow of the polymer reaches each corner at about the same time or significantly different times.

[0083] Figure 24Photographs and an accompanying schematic model depict the flow behavior of a 14mm HIPS assembly in a short-shot study during the early stages of the foam injection molding process. As shown, for different injections, the polymer flow exhibits random filling and varying proximity to the corners of the mold cavity. As described above, in descriptions using pressure readings to determine the development of flow, pressure readings from the EOF corner sensor can be used to determine whether the flow is random without requiring multiple short-shot tests. For example, if the time taken for the EOF corner sensor to sense the polymer flow to that location is inconsistent across multiple injection molding experiments, the polymer flow is random. More specifically, if, for multiple experiments, the data on the time taken for the EOF corner sensor to sense the polymer flow to that location falls into two statistical groups, the polymer flow is random. Figure 24 As depicted, when comparing the images at the bottom left and bottom right, for random flow, a certain percentage of the time data taken for the polymer to reach the EOF corner sensor will be significantly shorter (as shown in the bottom right image), and a certain percentage of the time data taken for the polymer to reach the EOF corner sensor will be significantly longer (as shown in the bottom left image). Figure 24 In the illustrative example shown, a single EOF corner sensor is used. However, in other embodiments, two EOF corner sensors and / or an EOF center sensor can be used to increase the amount of data collected for analysis.

[0084] Figures 25 to 27 Depicting and Figures 19 to 21 A comparison of temperature profiles for the same saturated polymer mixture was performed at the SOF sensor, EOF center sensor, and EOF corner sensor. Based on the graph, as the HIPS proportion increases, the temperature peak of the saturated melt decreases at all three locations. This means that more gas molecules escape from the bulk of the saturated HIPS melt, which carries away more heat from the melt and lowers the temperature. Therefore, this finding confirms the pressure profile results and shows that, under the same process conditions and blown agent / gas molecule concentration, the potential for monomer growth in HIPS modules is lower than that in GPPS modules. Furthermore, as... Figure 26 As shown, HIPS based on saturated melt approaches the EOF center position faster than other formulations. Figure 27 Temperature profiles for different formulations at the EOF corner, double foaming behavior of the 100% HIPS formulation, and random filling behavior were depicted.

[0085] Figure 28A series of photographs showing injection foam components based on different formulations are depicted. In the component based on 100% GPPS (the left-most component), a uniform and symmetric flow path can be observed. Furthermore, as the HIPS content is added from left to right, the random flow path becomes more evident, with the maximum random flow seen in the 100% HIPS component (the right-most component).

[0086] In the above example, the benefits of various mixtures of GPPS and HIPS were evaluated. GPPS provides good surface finish to the final product, but GPPS is brittle, which can be an undesirable trait. HIPS provides toughness and high impact resistance, but has an undesirable surface finish. Mixing GPPS and HIPS can provide the best performance of both polymers; however, to optimize the precise mixing percentage and process parameters, typically a lot of trial and error is required. Using the plaque mold system described herein, various properties of two different polymers and mixtures of polymers can be quickly evaluated. For example, is the flow of the polymer and mixture of polymers within the mold cavity developed or random. Using the pressure and temperature profiles, the formulation can be tailored to control the filling behavior of the polymer mixture in a particular mold design. The formulation can be further developed to achieve target weight reduction by using the plaque mold system. It will be appreciated that designing a formulation with the optimal blowing agent concentration can optimize the gas molecule content, resulting in better foaming behavior. This goal can be achieved by using the plaque mold system, which provides an evaluation of the compatibility of different gas molecules in the polymer or mixture of polymers to achieve reduced output gas and higher expansion ratio, resulting in greater weight reduction.

[0087] The following example describes a method for optimizing process conditions, specifically injection speed. Injection speed can affect the cellular structure of the foamed polymer, which in turn can affect the mechanical properties of the final molded component. Therefore, it is important to understand the effect of injection speed for the design of an optimized molding process. The method described uses data collected by three pressure sensors - a pressure sensor at the SOF, a pressure sensor at the center of the EOF, and a pressure sensor at the corner of the EOF. In a particular experiment, two different grades of nylon 66 were used to study the optimal injection speed. The first grade of nylon 66 has a relatively high viscosity and a relatively low melt flow rate, and will be referred to herein as N66-HV. The second grade of nylon 66 has a relatively low viscosity and a relatively high melt flow rate, and will be referred to herein as N66-LV. A 14 mm mold cavity was used to form sample components of each grade of nylon 66 at three different injection speeds - 5 cubic inches per second, 10 cubic inches per second, and 20 cubic inches per second. Pressure data was measured and captured during the molding process, and a pressure-time plot was plotted for each of the three sensors.

[0088] For N66-LV, Figure 29 is a pressure-time plot for the three sensors at an injection speed of 5 cubic inches per second. Figure 30 is a pressure-time plot for the three sensors at an injection speed of 10 cubic inches per second. Figure 31 is a pressure-time plot for the three sensors at an injection speed of 20 cubic inches per second. For a consistent cellular structure, it is expected that the peak pressure readings between the SOF sensor and the EOF sensor will be approximately equal. If the peak pressure throughout the mold cavity is approximately equal, then the monomer initiation and growth throughout the molded sample should be consistent. As shown, Figures 29 to 31 for the EOF sensor, the peak pressure for an injection speed of 5 cubic inches per second is significantly higher than the SOF sensor, and for the EOF sensor, the peak pressure for an injection speed of 20 cubic inches per second is significantly lower than the SOF sensor. This pressure difference is likely to result in an inconsistent cellular structure. However, the peak pressure for an injection speed of 10 cubic inches per second results in consistent peak pressures across the EOF and SOF sensors. Thus, the testing indicates that an injection speed of 10 cubic inches per second optimizes the consistency of the cellular structure of a foamed component injection molded using N66-LV. A morphological study was conducted by cutting open the samples and observing the internal cellular structure, and it was confirmed that an injection speed of 10 cubic inches per second optimizes the consistency of the cellular structure of N66-LV.

[0089] For N66-HV, Figure 32 is a pressure-time plot for the three sensors at an injection speed of 5 cubic inches per second, Figure 33 is a pressure-time plot for the three sensors at an injection speed of 10 cubic inches per second, and Figure 34 is a pressure-time plot for the three sensors at an injection speed of 20 cubic inches per second. For the N66-HV experiment, the SOF sensor experienced injection noise (indicated by the dotted circle) early in the injection cycle. For an injection speed of 5 cubic inches per second, the peak pressure for the SOF sensor was determined at the inflection point of the downward curve following the initial injection noise. As shown, Figures 32 to 34 for the SOF sensor, the peak pressures for injection speeds of 10 cubic inches per second and 20 cubic inches per second are significantly higher than the EOF sensor. However, the peak pressure for an injection speed of 5 cubic inches per second results in consistent peak pressures across the EOF and SOF sensors. Thus, the testing indicates that an injection speed of 5 cubic inches per second optimizes the consistency of the cellular structure of a foamed component injection molded using N66-HV. A morphological study was conducted by cutting open the samples and observing the internal cellular structure, and it was confirmed that an injection speed of 5 cubic inches per second optimizes the consistency of the cellular structure of N66-HV.

[0090] The pressure measurements collected by the SOF and EOF sensors for the above experiment can also be informative not only of the uniformity of the cellular structure, but also of the void size in the absence of the polymer matrix. The lower the pressure, the greater the bubble growth during the molding process, which results in larger voids. In other embodiments of the method used with the devices described herein, multiple tests can be performed to find, for example: (i) process parameters that result in a low uniform peak pressure across the mold cavity to promote a uniform cellular structure with large voids; (ii) process parameters that result in a high uniform peak pressure across the mold cavity to promote a uniform cellular structure with small voids; or (iii) process conditions that result in a pressure differential between the SOF and EOF to promote a gradient cellular structure across the resulting molded component.

[0091] The following example describes a method for optimizing a component in a formulation, specifically the concentration of blowing agent. Optimizing the blowing agent concentration of a formulation for foam injection molding can increase the uniformity of the cellular structure of the resulting molded component, decrease the density, reduce shrinkage, and reduce weld lines. In this experiment, the base polymer used was polyvinyl chloride (PVC) and was mixed with blowing agent at different concentrations of 1.0%, 1.25%, and 1.5%. The blowing agent was present to enhance the foaming process. A 14 mm mold cavity was used. Pressure readings were measured and recorded at three locations (SOF, EOF center, and EOF corner). As Figure 35 The data collected from the pressure sensors is plotted against time as depicted in FIG. 5. The SOF sensor detected the injection noise at the beginning of the cycle (identified using a dashed circle) and the inflection point of the downward curve after the noise is the peak pressure at the SOF sensor. For the formulation with a 1.5% blowing agent concentration, the peak pressure at the EOF is closest to the peak pressure at the SOF sensor. Therefore, of the three blowing agent concentrations, the 1.5% concentration produced the most uniform cellular structure. Morphological studies confirmed this result.

[0092] Additional components can be used with the devices described herein to optimize the mold design. For example, inserts are used to selectively modify the location and size of the vent holes throughout the mold. Vent holes can play an important role in injection molding because the ambient air within the mold cavity must be considered when designing the mold cavity and molding process. Vent holes are a common method of managing and expelling ambient air during the molding process. Despite the conventional vent hole placement, it is common for ambient air within the mold cavity to be pushed to the back of the mold (such as in the EOF corner locations described herein) during the injection molding process. If not properly vented, this ambient air can collect in the EOF corners and make it impossible to completely fill the mold cavity or unnecessarily increase the pressure within the mold cavity portion.

[0093] To investigate solutions to this problem, a plurality of vent inserts can be formed, each having a different number of vent holes. Such vent inserts can be arranged to be interchangeably included into the mold cavity and used in a plurality of experiments to investigate the effect of different vent levels on the molding process. In one experiment, three different vent inserts having different numbers of vent holes are used and arranged to be placed in the two EOF corner locations. The three vent inserts are used to mold a plurality of components and pressure measurements are collected and recorded throughout the molding process at the two EOF corner locations and at the EOF center location. By analyzing the pressure data at the various locations during the molding process, the effect of ambient air and venting of ambient air can be determined. This determination can be used to optimize the vent holes of the final mold cavity for commercial production of the components.

[0094] In another example, a plurality of inserts for the injection gate and runner can be formed to investigate the effect of different gate and runner configurations. For example, single gate and dual gate inserts can be formed. In another example, gates having different diameters can be formed. In yet another example, gates at different angles to the mold cavity can be formed. Similarly, for the runner, the number of runners, the diameter of the runners, the location of the runners, and the angle of the runners can all be varied to produce any number of desired inserts to fully test their effect on the molding process. Similar to the above, a plurality of experiments can be conducted and measurements such as temperature and pressure can be collected and recorded during the molding process. This data can be used to optimize the style of gate and runner to be used with a particular mold cavity and / or molding process.

[0095] The foregoing description of the examples has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the description to the precise form disclosed. Many modifications and variations are possible in light of the above teaching. Some of those modifications and variations have been discussed and others will be understood by those skilled in the art. The examples were chosen and described in order to best illustrate the principles of various examples suitable for particular applications and the best implementation of these principles. Of course, the scope is not intended to be limited to the examples set forth herein, but rather other variants are intended to be within the scope of what's described herein.

Claims

1. A trim mold assembly for forming a polymer component, characterized by, The trim panel mold assembly includes: a plurality of interchangeable cavities, each cavity including at least one sensor; wherein one of the plurality of cavities is selectively used to form a polymer component; wherein the at least one sensor of the cavity used to form the polymer component is arranged to measure an environmental parameter during formation of the polymer component.

2. The trim panel mold assembly of claim 1, wherein, The plurality of interchangeable molds includes: a first cavity arranged to form at least one generally solid polymer component; a second cavity arranged to form at least one 3.2 mm thermoplastic foam component; a third cavity arranged to form at least one 7.0 mm thermoplastic foam component; a fourth cavity arranged to form at least one 14.0 mm thermoplastic foam component; and a fifth cavity arranged to form at least one 25.4 mm thermoplastic foam component.

3. The trim panel forming assembly of claim 2, wherein, Performance of the solid polymer component formed using the first cavity can be compared to performance of one or more thermoplastic foam components formed using the second, third, fourth, and / or fifth cavities to analyze variables.

4. The trim panel mold assembly of claim 3, wherein, Variables include mold design, polymer formulation, and process parameters.

5. The trim panel mold assembly of claim 3, wherein, The variables include mechanical properties, including tensile strength, impact resistance, and flexural strength.

6. The trim panel mold assembly of claim 1, wherein, Also included are: a first water circulation system; and a second water circulation system independent of the first water circulation system.

7. The trim panel mold assembly of claim 6, wherein, The first and second water circulation systems can be independently controlled such that the polymer component formed includes varying mechanical properties across different portions of the polymer component.

8. The trim panel mold assembly of claim 1, wherein, Also included are: a venting system arranged to provide a path for a gas not incorporated into the polymer component during formation to exit the cavity; a collection system to store the gas not incorporated into the polymer component during formation; and a hose connecting the venting system and the collection system.

9. The trim panel mold assembly of claim 8, wherein, A volume of the gas collected in the collection system during the formation process can be used to determine a gas solubility of the polymer component.

10. The trim panel mold assembly of claim 8, wherein, The collection system includes two cylinders in selective fluid communication with the venting system to store the gas not incorporated into the polymer component during formation.

11. The trim panel mold assembly of claim 10, wherein, Each cylinder includes an adjustable piston that can change a volume of the cylinder.

12. The trim panel mold system of claim 11, wherein, Each cylinder includes a pressure sensor to measure an internal pressure of the cylinder.

13. The trim panel mold system of claim 11, wherein, Each cylinder includes a temperature sensor to measure a temperature of the cylinder.

14. The trim panel mold assembly of claim 1, wherein, The at least one sensor is arranged to measure the environmental parameter at periodic intervals during formation of the polymer component.

15. The trim panel mold assembly of claim 1, wherein, The at least one sensor is a plurality of sensors distributed throughout the cavity.

16. The trim panel mold assembly of claim 15, wherein, At least one of the plurality of sensors is arranged to measure pressure or temperature.

17. A plaque mold assembly for forming a polymeric component and investigating the behavior of the polymer during the forming process, characterized by, The trim panel mold assembly includes: a plurality of interchangeable cavities, a plurality of sensors within each of the plurality of interchangeable cavities; wherein a first cavity is selectively used to form one or more polymer components; wherein the plurality of sensors includes a sensor in the first cavity.

18. The trim panel mold assembly of claim 17, wherein, The sensor measures temperature throughout the molding process, records the temperature measurements, and the temperature measurements are used to plot a temperature-time graph during the molding process.

19. The trim panel mold assembly of claim 17, wherein, The sensor measures pressure throughout the molding process, records the pressure measurements, and the pressure measurements are used to plot a temperature-time graph during the molding process.

20. The trim panel mold assembly of claim 17, wherein, The measurements captured by the sensor are used to assess flow behavior of the polymer used to form the one or more polymer components, process parameters used to form the one or more polymer components, or mold design features of the mold cavity used to form the one or more polymer components.

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