Injection molding system and method

Abstract

To provide an injection molding system and an injection molding method for forming an article containing a plurality of parts having different physical or functional characteristics.SOLUTION: A molding device is provided, including a first mold, a second mold above the first mold, and a mold cavity defined by the first and second molds. A first mixture is injected into the mold cavity through a first feed port. A first component is formed from the first mixture. A second mixture is injected into the mold cavity through a second feed port. A second component is formed from the second mixture. The second component is at least partially in contact with the first component, and the first and second components have different physical properties.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] (CROSS REFERENCE TO RELATED APPLICATIONS) This application claims priority to U.S. Provisional Patent Application No. 63 / 518,107, filed August 8, 2023, and U.S. Patent Application No. 18 / 664,326, filed May 15, 2024, both of which are incorporated by reference in their entireties.

[0002] FIELD OF THE DISCLOSURE This disclosure relates to injection molding systems and methods, and in particular to injection molding systems and methods for forming articles that include multiple portions having different physical or functional properties. [Background technology]

[0003] Foamed polymeric materials have many advantages, such as high strength, low weight, impact resistance, thermal insulation, etc. Foamed articles can be made by injection molding or extrusion molding. For example, a polymeric material is melted and mixed with a blowing agent to form a mixture, and then the mixture is injected or extruded into a mold cavity under application of force or pressure, causing the mixture to foam in the cavity, and cooled to form the foamed article.

[0004] However, there is a need to improve the properties of foam articles made by injection molding systems, such as having different properties in different portions of the foam article. Thus, there is a need to improve the structure of injection molding systems and methods for making foam articles. Summary of the Invention

[0005] The present disclosure discloses an injection molding system and method.

[0006] According to one embodiment of the present disclosure, there is provided an injection molding method, comprising the steps of: providing a molding apparatus including a first mold, a second mold above the first mold, and a mold cavity defined by the first and second molds, injecting a first mixture into the mold cavity through a first feed port, forming a first component from the first mixture, injecting a second mixture into the mold cavity through a second feed port, and forming a second component from the second mixture, the second component being in at least partial contact with the first component, and the first and second components having different physical properties.

[0007] According to one embodiment of the present disclosure, there is provided an injection molding method, comprising the steps of: providing a molding apparatus including a first mold, a second mold above the first mold, and a mold cavity defined by the first and second molds, injecting a first mixture into the mold cavity through a first feed port, forming a first component from the first mixture, injecting a second mixture into the mold cavity through a second feed port, and forming a second component from the second mixture, the second component being separated from the first component, and the first and second components having different physical properties.

[0008] According to one embodiment of the present disclosure, there is provided an assembly of polymer components, the assembly including a first polymer component having a first skin layer and a second polymer component having a second skin layer in contact with the first skin layer, the first skin layer having a greater density than a central portion of the first polymer component, the second skin layer having a greater density than a central portion of the second polymer component, and a visible boundary line being between the first skin layer and the second skin layer. [Brief description of the drawings]

[0009] Aspects of the present disclosure are best understood from the following detailed description when read in conjunction with the accompanying drawings. It should be noted that, according to standard practice in the industry, various features have not been drawn to scale. In fact, dimensions of various features may be arbitrarily expanded or reduced for clarity of discussion.

[0010] [Figure 1] FIG. 1 is a schematic diagram of an injection molding system according to some embodiments of the present disclosure. [Diagram 2] 1 is a flowchart illustrating an injection molding method according to some embodiments of the present disclosure. [Diagram 3] FIG. 2 is a schematic diagram of the molding apparatus of FIG. 1 according to some embodiments of the present disclosure. [Figure 4] 3A-3C are schematic cross-sectional views illustrating exemplary stages of the injection molding method of FIG. 2 according to one embodiment of the present disclosure. [Diagram 5] 3A-3C are schematic cross-sectional views illustrating exemplary stages of the injection molding method of FIG. 2 according to one embodiment of the present disclosure. [Figure 6] 3A-3C are schematic cross-sectional views illustrating exemplary stages of the injection molding method of FIG. 2 according to one embodiment of the present disclosure. [Figure 7] 3A-3C are schematic cross-sectional views illustrating exemplary stages of the injection molding method of FIG. 2 according to one embodiment of the present disclosure. [Figure 8] 3A-3C are schematic cross-sectional views illustrating exemplary stages of the injection molding method of FIG. 2 according to one embodiment of the present disclosure. [Figure 9] 3A-3C are schematic cross-sectional views illustrating exemplary stages of the injection molding method of FIG. 2 according to one embodiment of the present disclosure. [Figure 10] 3A-3C are schematic cross-sectional views illustrating exemplary stages of the injection molding method of FIG. 2 according to one embodiment of the present disclosure. [Figure 11] 3A-3C are schematic cross-sectional views illustrating exemplary stages of the injection molding method of FIG. 2 according to one embodiment of the present disclosure. [Figure 12] 3A-3C are schematic cross-sectional views illustrating exemplary stages of the injection molding method of FIG. 2 according to one embodiment of the present disclosure. [Figure 13]3A-3C are schematic cross-sectional views illustrating exemplary stages of the injection molding method of FIG. 2 according to one embodiment of the present disclosure. [Figure 14] 3A-3C are schematic cross-sectional views illustrating exemplary stages of the injection molding method of FIG. 2 according to one embodiment of the present disclosure. [Figure 15] 3A-3C are schematic cross-sectional views illustrating exemplary stages of the injection molding method of FIG. 2 according to one embodiment of the present disclosure. [Figure 16] 3A-3C are schematic cross-sectional views illustrating exemplary stages of the injection molding method of FIG. 2 according to one embodiment of the present disclosure. [Figure 17] 3A-3C are schematic cross-sectional views illustrating exemplary stages of the injection molding method of FIG. 2 according to one embodiment of the present disclosure. [Figure 18] 3A-3C are schematic cross-sectional views illustrating exemplary stages of the injection molding method of FIG. 2 according to one embodiment of the present disclosure. [Figure 19] 3A-3C are schematic cross-sectional views illustrating exemplary stages of the injection molding method of FIG. 2 according to one embodiment of the present disclosure. [Figure 20] 3A-3C are schematic cross-sectional views illustrating exemplary stages of the injection molding method of FIG. 2 according to one embodiment of the present disclosure. [Figure 21] 3A-3C are schematic cross-sectional views illustrating exemplary stages of the injection molding method of FIG. 2 according to one embodiment of the present disclosure. [Figure 22] 3A-3C are schematic cross-sectional views illustrating exemplary stages of the injection molding method of FIG. 2 according to one embodiment of the present disclosure. [Figure 23] 3A-3C are schematic cross-sectional views illustrating exemplary stages of the injection molding method of FIG. 2 according to one embodiment of the present disclosure. [Figure 24] 3A-3C are schematic cross-sectional views illustrating exemplary stages of the injection molding method of FIG. 2 according to one embodiment of the present disclosure. [Diagram 25] 3A-3C are schematic cross-sectional views illustrating exemplary stages of the injection molding method of FIG. 2 according to one embodiment of the present disclosure. [Figure 26] 3A-3C are schematic cross-sectional views illustrating exemplary stages of the injection molding method of FIG. 2 according to one embodiment of the present disclosure. [Figure 27] 3A-3C are schematic cross-sectional views illustrating exemplary stages of the injection molding method of FIG. 2 according to one embodiment of the present disclosure. [Figure 28]3A-3C are schematic cross-sectional views illustrating exemplary stages of the injection molding method of FIG. 2 according to one embodiment of the present disclosure. [Figure 29] 3A-3C are schematic cross-sectional views illustrating exemplary stages of the injection molding method of FIG. 2 according to one embodiment of the present disclosure. [Diagram 30] 3A-3C are schematic cross-sectional views illustrating exemplary stages of the injection molding method of FIG. 2 according to one embodiment of the present disclosure. [Diagram 31] 3A-3C are schematic cross-sectional views illustrating exemplary stages of the injection molding method of FIG. 2 according to one embodiment of the present disclosure. [Diagram 32] 3A-3C are schematic cross-sectional views illustrating exemplary stages of the injection molding method of FIG. 2 according to one embodiment of the present disclosure. [Diagram 33] 3A-3C are schematic cross-sectional views illustrating exemplary stages of the injection molding method of FIG. 2 according to one embodiment of the present disclosure. [Diagram 34] 3A-3C are schematic cross-sectional views illustrating exemplary stages of the injection molding method of FIG. 2 according to one embodiment of the present disclosure. [Diagram 35] 3A-3C are schematic cross-sectional views illustrating exemplary stages of the injection molding method of FIG. 2 according to one embodiment of the present disclosure. [Diagram 36] 3A-3C are schematic cross-sectional views illustrating exemplary stages of the injection molding method of FIG. 2 according to one embodiment of the present disclosure. [Figure 37] 3A-3C are schematic cross-sectional views illustrating exemplary stages of the injection molding method of FIG. 2 according to one embodiment of the present disclosure. [Figure 38] 3A-3C are schematic cross-sectional views illustrating exemplary stages of the injection molding method of FIG. 2 according to one embodiment of the present disclosure. [Figure 39] 3A-3C are schematic cross-sectional views illustrating exemplary stages of the injection molding method of FIG. 2 according to one embodiment of the present disclosure. [Diagram 40] 3A-3C are schematic cross-sectional views illustrating exemplary stages of the injection molding method of FIG. 2 according to one embodiment of the present disclosure. [Diagram 41] 3A-3C are schematic cross-sectional views illustrating exemplary stages of the injection molding method of FIG. 2 according to one embodiment of the present disclosure. [Diagram 42] 3A-3C are schematic cross-sectional views illustrating exemplary stages of the injection molding method of FIG. 2 according to one embodiment of the present disclosure. [Diagram 43]3A-3C are schematic cross-sectional views illustrating exemplary stages of the injection molding method of FIG. 2 according to one embodiment of the present disclosure. [Diagram 44] 3A-3C are schematic cross-sectional views illustrating exemplary stages of the injection molding method of FIG. 2 according to one embodiment of the present disclosure. [Diagram 45] 3A-3C are schematic cross-sectional views illustrating exemplary stages of the injection molding method of FIG. 2 according to one embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The following disclosure provides many different embodiments or examples for implementing different features of the provided subject matter. To simplify the disclosure, specific examples of components and arrangements are described below. These are, of course, merely examples and are not intended to be limiting. For example, the formation of a first feature above or on a second feature in the following description may include embodiments in which the first feature and the second feature are formed in direct contact with each other, and may also include embodiments in which an additional feature may be formed between the first feature and the second feature such that the first feature and the second feature do not have to be in direct contact with each other. Furthermore, the disclosure may repeat reference numbers and / or letters in various examples. This repetition is for the purposes of brevity and clarity, and does not in itself dictate a relationship between the various embodiments and / or configurations discussed.

[0012] Additionally, spatially relative terms such as "lower," "below," "bottom," "upper," "top," and the like may be used herein for ease of description to describe the relationship of one element or feature to another element or feature as depicted in the figures. The spatially relative terms are intended to encompass different orientations of the device during use or operation in addition to the orientation depicted in the figures. The apparatus may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein may likewise be interpreted accordingly.

[0013] Although the numerical ranges and parameters setting forth the broad scope of the present disclosure are approximations, the numerical values ​​set forth in the specific examples are reported as precisely as possible. However, any numerical value inherently contains certain errors necessarily resulting from the standard deviation found in the respective testing measurements. Also, as used herein, the term "about" generally means within 10%, 5%, 1%, or 0.5% of a given value or range. Alternatively, the term "about" means within an acceptable standard error of the mean as considered by one of ordinary skill in the art. Other than in the procedures / examples, or unless otherwise expressly stated, all numerical ranges, amounts, values, and percentages disclosed herein, such as amounts of materials, durations of time, temperatures, operating conditions, ratios of amounts, and the like, should be understood in all instances to be modified by the term "about". Thus, unless indicated to the contrary, the numerical parameters set forth in the present disclosure and the appended claims are approximations that may vary as desired. At the very least, each numerical parameter should be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Ranges can be expressed herein as from one endpoint to another endpoint, or between two endpoints. All ranges disclosed herein include the endpoints unless otherwise specified.

[0014] 1 is a schematic diagram of an injection molding system 10 according to some embodiments of the present disclosure. The injection molding system 10 includes a mixing unit 120, an injection unit 110, and a molding apparatus 100.

[0015] The mixing unit 120 is configured to generate a mixture of the polymeric material and the physical foaming agent. The mixture is then delivered to the injection unit 110 through at least one delivery channel 122. The injection unit 110 is configured to discharge the mixture. The mixture is then discharged through one or more discharge channels 111 of the injection unit engaged with the molding apparatus 100. The mixture can flow from the injection unit 110 into the molding apparatus 100. The molding apparatus 100 is configured to form an article including the polymeric material. In some embodiments, the article is formed inside the molding apparatus 100 by physical foaming. The mixture undergoes physical foaming and then forms a foamed article. In some embodiments, the article is a part of footwear (outsole, insole, midsole, etc.) or any other product.

[0016] 2 is a flow chart illustrating an injection molding method 20 according to some embodiments of the present disclosure. The injection molding method 20 includes operations S210-S270, and the description and illustration should not be construed as limiting the order of operations S210-S270. FIGS. 3-45 are schematic cross-sectional views of various stages of the injection molding method 20. In some embodiments, the operations of the injection molding method 20 can be repeated and performed automatically.

[0017] In some embodiments, the injection molding method 20 is performed by the injection molding system 10 of FIG. 1. In operation S210, a molding apparatus 100 is provided that includes a mold cavity defined by a first mold and a second mold engaged with each other. In operation S220, the injection unit 110 is configured to inject a first mixture from the mixing unit 120 into the mold cavity of the molding apparatus 100 through a first supply port and a corresponding discharge channel 111 of the molding apparatus 100, and form a first component from the first mixture in operation S230. In operation S240, the injection unit 110 is configured to inject a second mixture from the mixing unit 120 into the mold cavity of the molding apparatus 100 through a second supply port and a corresponding discharge channel 111 of the molding apparatus 100, and form a second component from the second mixture in operation S250. In operation S260, the injection unit 110 is configured to inject the third mixture from the mixing unit 120 into a mold cavity of the molding apparatus 100 through a third supply port and corresponding discharge channel 111 of the molding apparatus 100, and in operation S270, form a third component from the third mixture.

[0018] In some embodiments, operations S220 and S230 are replaced by an additional operation of preforming the first component into a mold cavity of molding apparatus 100. Depending on the additional operation, the third mixture and the second mixture are the same. In some embodiments, the mold cavity is defined by the second mold and the fourth component held by the first mold.

[0019] In some embodiments, the flow rates / volumes of the first, second and third mixtures are the same or different. In some embodiments, the first, second and third mixtures are different, such that the first, second and third components have different physical properties. The first, second and third components are formed in different regions or portions of the article. In some embodiments, the second component is at least partially in contact with the first and third components, i.e., the second component is sandwiched between the first and third components. In some embodiments, the second component is separated from the first component by the third component.

[0020] In some embodiments, the second mixture is softer than the first mixture and the third mixture is softer than the second mixture, hi some embodiments, the harder mixture is injected first and the softer mixture is injected later.

[0021] Various embodiments are provided below to illustrate the concepts and injection molding method 20 of the present disclosure. However, the present disclosure is not intended to be limited to the specific embodiments. Furthermore, the elements, conditions, or parameters illustrated in different embodiments can be combined or modified to form different combinations of embodiments, as long as the elements, parameters, or conditions used are not contradictory. For ease of description, reference numbers having similar or similar functions and characteristics are repeated in different embodiments and figures.

[0022] 3 is a schematic diagram of the molding apparatus 100 of FIG. 1 according to some embodiments of the present disclosure. The molding apparatus 100 includes a first mold 101 and a second mold 102. The first mold 101 is engageable with the second mold 102. The molding apparatus 100 is in a closed state when the first mold 101 is engaged with the second mold 102. In some embodiments, the first mold 101 is a lower mold and the second mold 102 is an upper mold, with the first mold 101 below the second mold 102. In some embodiments, the molding apparatus 100 includes a mold cavity 103 defined by the first mold 101 and the second mold 102 when the first mold 101 is engaged with the second mold 102. The mold cavity 103 is configured to hold a mixture or an article formed from the mixture.

[0023] In some embodiments, the mold cavity 103 can be divided into multiple sub-cavities 103a, 103b, and 103c by at least one partition 104. Two of the adjacent sub-cavities 103a, 103b, and 103c are separated by a partition 104. For example, the partition 104a separates the sub-cavity 103a from the sub-cavity 103b, and the partition 104b separates the sub-cavity 103b from the sub-cavity 103c. In some embodiments, the partition 104 is movable relative to the first mold 101 or the second mold 102. In some embodiments, the partition 104 is extendable or retractable within the mold cavity 103, either manually or automatically.

[0024] In some embodiments, the partition 104 protrudes from the first mold 101 or the second mold 102. In some embodiments, the partition 104 can be extendable into or retractable from the mold cavity 103. For example, the partition 104 can extend from the first mold 101 into the mold cavity 103 or can be retracted from the mold cavity 103 into the first mold 101.

[0025] In some embodiments, the sub-cavity 103a is defined by the first mold 101, the second mold 102, and the partition 104a. The sub-cavity 103b is defined by the first mold 101, the second mold 102, and the partitions 104a and 104b, and the sub-cavity 103c is defined by the first mold 101, the second mold 102, and the partitions 104a and 104b. In some embodiments, the sub-cavities 103a, 103b, and 103c are not communicable with each other when the partitions 104a and 104b are inside the mold cavity 103, as shown in FIG. 3. In some embodiments, the partitions 104a and 104b have the same or different thicknesses in the X direction and the same height in the Z direction. The sub-cavities 103a, 103b, and 103c have the same or different widths in the X direction and the same height in the Z direction. In some embodiments, the sub-cavities 103a, 103b and 103c have the same length in the Y direction.

[0026] In some embodiments, the supply port 105 is disposed in the first mold 101 or the second mold 102. The supply port 105 is configured to receive the mixture from the discharge channel 111 of the injection unit 110 of FIG. 1 when the discharge channel 111 engages with the molding apparatus 100. The mixture can flow into the mold cavity 103 through the supply port 105. In the embodiment of FIG. 1, there are three supply ports 105a, 105b, and 105c that can communicate with the sub-cavities 103a, 103b, and 103c, respectively, when the partitions 104a, 104b, and 104c are disposed in the mold cavity 103. In some embodiments, each of the sub-cavities 103a and 103b corresponds to one or more supply ports 105. In some embodiments, the supply ports 105a, 105b, and 105c have the same or different widths in the X-direction. In some embodiments, the supply ports 105a, 105b, and 105c allow fluid to flow at the same flow rate or at different flow rates.

[0027] 4-10 are schematic cross-sectional views illustrating exemplary stages of the injection molding method 20 of FIG. 2 according to a first embodiment of the present disclosure.

[0028] In FIG. 4, the first mold 101 is engaged with the second mold 102 and the first partition 104a is disposed within the mold cavity 103. In some embodiments, the first partition 104a is disposed by extending the first partition 104a from the first mold 101 to the second mold 102. In some embodiments, the engagement of the first mold 101 and the second mold 102 occurs before or after disposing the first partition 104a. In some embodiments, after engaging the first mold 101 with the second mold 102 and disposing the first partition 104a, a first gas is injected into the sub-cavity 103a to increase the pressure within the first sub-cavity 103a. In some embodiments, the first gas is air or the like. In some embodiments, the first sub-cavity 103a is defined by the first mold 101, the second mold 102, and the first partition 104a.

[0029] As described in operation S220 of FIG. 2, the first mixture M1' is injected into the first sub-cavity 103a through the first supply port 105a. In some embodiments, the first mixture M1' is injected into the first sub-cavity 103a filled with a first gas. In some embodiments, the exhaust channel 111 of FIG. 1 is engaged with the first supply port 105a, and then the first mixture M1' is injected from the exhaust channel 111 through the first supply port 105a into the first sub-cavity 103a. In some embodiments, the first mixture M1' includes a polymeric material (such as thermoplastic polyurethane (TPU), polyurethane (PU), plastic, etc.) and a physical blowing agent (such as gaseous nitrogen, carbon dioxide, supercritical fluid, etc.). In some embodiments, the first mixture M1' is foamable or slightly foamable.

[0030] In some embodiments, after injection of the first mixture M1', the first mixture M1' undergoes physical foaming in the first sub-cavity 103a to become the first component M1, as described in operation S230. In some embodiments, during the physical foaming of the first mixture M1' and / or after the formation of the first component M1, the pressure in the first sub-cavity 103a is reduced by venting at least a portion of the first gas from the first sub-cavity 103a and / or venting a portion of the physical foaming agent released from the first mixture M1' from the first sub-cavity 103a. In some embodiments, after the physical foaming of the first mixture M1', the first component M1 is formed having a first skin layer 106a. The first skin layer 106a is adjacent to or in contact with the first partition 104a. The first skin layer 106a has a higher density than a central portion of the first component M1 away from the first partition 104a. The first skin layer 106a has a lower degree of physical foaming than the center of the first component M1. In other words, the center of the first component M1 has a higher degree of physical molding than the periphery of the first component M1. In some embodiments, the first skin layer 106a has a thickness of less than 0.5 mm.

[0031] In some embodiments, after the formation of the first component M1, the first partition 104a is removed from the mold cavity 103, as shown in FIG. 5. In some embodiments, the first partition 104a is extracted from the mold cavity 103 by pulling the first partition 104a away from the second mold 102 and back to the first mold 101. In some embodiments, after the removal of the first partition 104a, a second sub-cavity 103b is formed, defined by the first component M1, the second partition 104b, and the second mold 102, as shown in FIG. 5. Furthermore, the second sub-cavity 103b in FIG. 5 is wider in the X-direction than the sub-cavity 103b in FIG. 3. In some embodiments, the second partition 104b is disposed in the mold cavity 103 after the removal of the first partition 104a. In some embodiments, the second partition 104b is disposed in the mold cavity 103 before the injection of the first mixture M1′. In some embodiments, the second partition 104b is positioned by extending the second partition 104b from the first mold 101 to the second mold 102. In some embodiments, engagement of the first mold 101 and the second mold 102 occurs before or after positioning the second partition 104b.

[0032] In some embodiments, a second gas is injected into the second sub-cavity 103b to increase the pressure in the second sub-cavity 103b after placement of the second partition 104b. In some embodiments, the second gas is air, or the like.

[0033] In FIG. 6, the second mixture M2' is injected into the second sub-cavity 103b through the second supply port 105b, as described in operation S240 in FIG. 2. Note that the first partition 104a is removed from the mold cavity 103 before the injection of the second mixture M2'. In some embodiments, the second mixture M2' is injected into the second sub-cavity 103b filled with the second gas. In some embodiments, the discharge channel 111 of FIG. 1 is engaged with the second supply port 105b, and then the second mixture M2' is injected from the discharge channel 111 through the second supply port 105b into the second sub-cavity 103b. In some embodiments, the second mixture M2' comprises a polymeric material (such as thermoplastic polyurethane (TPU), polyurethane (PU), plastic, etc.) and a physical blowing agent (such as gaseous nitrogen, carbon dioxide, supercritical fluid, etc.). In some embodiments, the second mixture M2' is foamable or slightly foamable. In some embodiments, the first mixture M1' and the second mixture M2' comprise the same or different materials. In some embodiments, the first mixture M1' and the second mixture M2' have different physical properties, such as density, hardness, Young's modulus, etc. In some embodiments, the second mixture M2' is softer than the first mixture M1'. In some embodiments, the first mixture M1' is denser than the second mixture M2'. In some embodiments, the first skin layer 106a of the first component M1 is in contact with the second mixture M2'.

[0034] In some embodiments, after injection of the second mixture M2, the second mixture M2' undergoes physical foaming in the second sub-cavity 103b to become the second component M2, as described in operation S250 of FIG. 2. In some embodiments, during physical foaming of the second mixture M2' and / or after formation of the second component M2, the pressure in the second sub-cavity 103b is reduced by venting at least a portion of the second gas from the second sub-cavity 103b and / or venting a portion of the physical foaming agent released from the second mixture M2' from the second sub-cavity 103b. In some embodiments, after physical foaming of the second mixture M2', a second component M2 having a second skin layer 106b is formed. In some embodiments, the second skin layer 106b is adjacent to or in contact with the second partition 104b. In some embodiments, the second skin layer 106b is in contact with the first skin layer 106a of the first component M1. The second skin layer 106b has a higher density than the central portion of the second component M2 away from the second partition 104b. The second skin layer 106b has a lower degree of physical foaming than the central portion. In other words, the central portion of the second component M2 has a higher degree of physical molding than the peripheral portion of the second component M2. In some embodiments, the second skin layer 106b has a thickness of less than 0.5 mm.

[0035] In some embodiments, after formation of the second component M2, the second partition 104b is removed from the mold cavity 103, as shown in Figure 7. In some embodiments, the second partition 104b is extracted from the mold cavity 103 by pulling the second partition 104b away from the second mold 102 and back into the first mold 101. In some embodiments, after removal of the second partition 104b, a third sub-cavity 103c defined by the second component M2, the first mold 101, and the second mold 102 is formed, as shown in Figure 7. Additionally, the third sub-cavity 103c in Figure 7 is wider in the X-direction than the sub-cavity 103c in Figure 3.

[0036] In some embodiments, after removing the second partition 104b, a third gas is injected into the third sub-cavity 103c to increase the pressure in the third sub-cavity 103c. In some embodiments, the third gas is air, or the like.

[0037] In FIG. 8, the third mixture M3' is injected into the third sub-cavity 103c through the third supply port 105c as described in operation S260 of FIG. 2. In some embodiments, the third mixture M3' is injected into the third sub-cavity 103c filled with the third gas. In some embodiments, the exhaust channel 111 of FIG. 1 is engaged with the third supply port 105c, and then the third mixture M3' is injected from the exhaust channel 111 through the third supply port 105c into the third sub-cavity 103c. In some embodiments, the third mixture M3' comprises a polymeric material (such as thermoplastic polyurethane (TPU), polyurethane (PU), plastic, etc.) and a physical blowing agent (such as gaseous nitrogen, carbon dioxide, supercritical fluid, etc.). In some embodiments, the third mixture M3' is foamable or slightly foamable. In some embodiments, the first mixture M1', the second mixture M2', and the third mixture M3' comprise the same or different materials. In some embodiments, the first mixture M1', the second mixture M2', and the third mixture M3' have different physical properties, such as density, hardness, etc. In some embodiments, the third mixture M3' is softer than the second mixture M2' and the first mixture M1'. In some embodiments, the second mixture M2' and the first mixture M1' are denser than the third mixture M3'. In some embodiments, the second skin layer 106b of the second component M2 is in contact with the third mixture M3'.

[0038] In some embodiments, after injection of the third mixture M3', the third mixture M3' undergoes physical foaming in the third sub-cavity 103c to become the third component M3, as described in operation S270 of FIG. 2. In some embodiments, during the physical foaming of the third mixture M3' and / or after the formation of the third component M3, the pressure in the third sub-cavity 103c is reduced by venting at least a portion of the third gas from the third sub-cavity 103c and / or venting a portion of the physical foaming agent released from the third mixture M3' from the third sub-cavity 103c. In some embodiments, after the physical foaming of the third mixture M3', a third component M3 having a third skin layer 106c is formed. In some embodiments, the third skin layer 106c is adjacent to or in contact with the second component M2. In some embodiments, the second skin layer 106b of the second component M2 is in contact with the third skin layer 106c of the third component M3. The third skin layer 106c has a higher density than the central portion of the third component M3. The third skin layer 106c has a lower degree of physical foaming than the central portion. In other words, the central portion of the third component M3 has a higher degree of physical molding than the peripheral portion of the third component M3. In some embodiments, the third skin layer 106c has a thickness of less than 0.5 mm.

[0039] In FIG. 9, after the formation of the third component M3, the first mold 101 is released from the second mold 102. After the formation of the third component M3, an article 107 is formed having the first component M1, the second component M2, and the third component M3, where the second component M2 is sandwiched between the first component M1 and the third component M3. The article 107 is formed in the mold cavity 103. In some embodiments, after the first mold 101 and the second mold 102 are released, the article 107 is removed from the mold cavity 103, as shown in FIG. 10. In some embodiments, the above operations can be repeated and performed automatically.

[0040] In some embodiments, the first component M1 is directly attached to the second component M2, and the second component M2 is directly attached to the third component M3. In other words, no additional components or materials (such as adhesives) are disposed between the first component M1 and the second component M2, and between the second component M2 and the third component M3. In some embodiments, the article 107 has a range of densities or hardnesses.

[0041] In the embodiment of FIG. 10, the top surfaces of components M1, M2, and M3 are formed at the same level defined by the second mold 102, and the bottom surfaces of components M1, M2, and M3 are formed at the same level defined by the first mold 101. In some embodiments, the top surfaces of components M1, M2, and M3 are formed at different levels. In some embodiments, the bottom surfaces of components M1, M2, and M3 are formed at different levels. In some embodiments, components M1, M2, and M3 have the same or different thicknesses. Furthermore, the first component M1 is separated from the third component M3 by the second component M2.

[0042] In some embodiments, the article 107 includes a visible boundary between two adjacent components. For example, a first visible boundary 108a exists between the first component M1 and the second component M2, and a second visible boundary 108b exists between the second component M2 and the third component M3. In some embodiments, the first visible boundary 108a and the second visible boundary 108b are each straight lines, curves, splines, polylines, etc. from a top view of the article 107. In some embodiments, the first visible boundary 108a extends across the top surfaces of the first component M1 and the second component M2, and the second visible boundary 108b extends across the top surfaces of the second component M2 and the third component M3. In some embodiments, the first visible boundary 108a extends from the top surface to the bottom surface of the first component M1 and the second component M2, and the second visible boundary 108b extends from the top surface to the bottom surface of the second component M2 and the third component M3.

[0043] 11-16 are schematic cross-sectional views illustrating exemplary stages of the injection molding method 20 of FIG. 2 according to a second embodiment of the present disclosure. In the second embodiment, the third component M3 is formed prior to the formation of the second component M2.

[0044] 11, the first mold 101 is engaged with the second mold 102, and the first partition 104a and the second partition 104b are disposed in the mold cavity 103. The mold cavity 103 is divided into sub-cavities 103a, 103b, and 103c by the first partition 104a and the second partition 104b. The sub-cavity 103b is defined by the first mold 101, the second mold 102, and the partitions 104a and 104b, and the sub-cavity 103c is defined by the first mold 101, the second mold 102, and the partition 104b.

[0045] The first mixture M1' is injected into the first sub-cavity 103a through the first supply port 105a, as described in operation S220 of Figure 2. After injection of the first mixture M1', the first mixture M1' undergoes physical foaming in the first sub-cavity 103a to become the first component M1, as described in operation S230. In some embodiments, the first component M1 includes a first skin layer 106a adjacent to or in contact with the first partition 104a.

[0046] In Figure 12, after the formation of the first component M1, as described in operation S240 of Figure 2, the third mixture M3' is injected into the third sub-cavity 103c through the third supply port 105c. After the injection of the third mixture M3', the third mixture M3' undergoes physical foaming to become the third component M3, as described in operation S250. In some embodiments, the third component M3 includes a third skin layer 106c adjacent to or in contact with the second partition 104b.

[0047] In some embodiments, compared with the third component M3 formed in the third sub-cavity 103c in Fig. 8, the third component M3 is formed before the formation of the second component M2 in Fig. 12. Also, the third component M3 in Fig. 12 has a wider width in the X direction than the third component M3 in Fig. 8. In other words, by adjusting the formation order of the third component M3, the third component M3 can have different sizes.

[0048] In Fig. 13, after the formation of the third component M3, the first partition 104a and the second partition 104b are simultaneously or sequentially removed from the mould cavity 103. After removing the first partition 104a and the second partition 104b, the second sub-cavity 103b is defined by the first mould 101, the second mould 102, the first component M1 and the second component M2. Thus, the second sub-cavity 103b in Fig. 12 is wider in the X-direction than the sub-cavity 103b in Fig. 13.

[0049] In Figure 14, a second mixture M2' is injected into the second sub-cavity 103b as described in operation S260 of Figure 2. In some embodiments, the second mixture M2' is in contact with the first component M1 and the third component M3. In some embodiments, the second mixture M2' undergoes physical foaming to become the second component M2 as described in operation S270 of Figure 2. In some embodiments, the second component M2 includes a second skin layer 106b adjacent to or in contact with the first component M1 and the third component M3.

[0050] In some embodiments, compared with the second component M2 formed in the second sub-cavity 103b in Fig. 6, the second component M2 is formed after the formation of the third component M3 in Fig. 14. Also, the second component M2 in Fig. 14 has a wider width in the X direction than the second component M2 in Fig. 6. In other words, by adjusting the formation order of the second component M2, the second component M2 can have different sizes.

[0051] After the formation of the second component M2, the article 107 is formed, as shown in FIG. 15. The article 107 is removed from the mold cavity 103 after the first mold 101 and the second mold 102 are separated, as shown in FIG. 16. In some embodiments, the second component M2 is softer than the first component M1 and the third component M3. In some embodiments, the first component M1 and the third component M3 are denser than the second component M2. In some embodiments, the above steps can be repeated and performed automatically.

[0052] 17-21 are schematic cross-sectional views illustrating exemplary stages of the injection molding method 20 of FIG. 2 according to a third embodiment of the present disclosure. In the third embodiment, the second partition 104b and the third component M3 are removed. Thus, the third sub-cavity 103c is not present in the mold cavity 103, and the third component M3 is not present in the article 107. In some embodiments, the first partition 104a and one of the first component M1 and the second component M2 are removed.

[0053] In Figure 17, the first mixture M1' is injected into the first sub-cavity 103a from the first supply port 105a as described in operation S220 of Figure 2. In some embodiments, the first sub-cavity 103a is defined by the first mold 101, the second mold 102, and the partition 104a. After formation of the first component M1 as described in operation S230, the first partition 104a is removed as shown in Figure 18.

[0054] In FIG. 19, after removing the first partition 104a, the second mixture M2′ is injected into the second sub-cavity 103b through one or more feed ports 105b, 105c, as described in operation S240 of FIG. 2. In some embodiments, the second sub-cavity 103b is defined by the first component M1, the first mold 101, and the second mold 102. In some embodiments, the second mixture M2′ flows through the second feed port 105b and the third feed port 105c at the same or different flow rates. In some embodiments, the second mixture M2′ undergoes physical foaming to become the second component M2, as described in operation S250 of FIG. 2. In some embodiments, the second component M2 includes a second skin layer 106b adjacent to or in contact with the first component M1. In the embodiment of FIG. 19, the second component M2 has a width in the X direction that is greater than the first component M1.

[0055] In Figure 20, article 107 is formed after formation of second component M2. Article 107 is removed from mold cavity 103 after demolding of first mold 101 and second mold 102, as shown in Figure 21. In some embodiments, second component M2 is softer than first component M1. In some embodiments, first component M1 is denser than second component M2.

[0056] 22-26 are schematic cross-sectional views illustrating exemplary stages of the injection molding method 20 of FIG. 2 according to a fourth embodiment of the present disclosure. In the fourth embodiment, the partition 104 is skipped, i.e., the first partition 104a and the second partition 104b are not disposed in the mold cavity 103.

[0057] In FIG. 22, the first mixture M1′ is injected into the mold cavity 103 through the first feed port 105a (S220 in FIG. 2), and the first mixture M1′ undergoes physical foaming to become the first component M1 (S230 in FIG. 2). In some embodiments, a gas is injected into the mold cavity 103 prior to the injection of the first mixture M1′ to increase the pressure in the mold cavity 103. After the formation of the first component M1, the first skin layer 106a is formed. In some embodiments, the first skin layer 106a is configured to prevent a mixture subsequently injected into the mold cavity 103 from mixing with the first mixture M1′ or the first component M1. In some embodiments, during or after the physical foaming of the first mixture M1′, a portion of the gas and / or a portion of the physical foaming agent released from the first mixture M1′ is vented from the mold cavity 103.

[0058] In FIG. 23, after the formation of the first component M1, the second mixture M2′ is injected into the mold cavity 103 through the second supply port 105b, as described in operation S240 of FIG. 2. In some embodiments, gas is injected into the mold cavity 103 prior to the injection of the second mixture M2′ to increase the pressure in the mold cavity 103. The second mixture M2′ is in contact with the first component M1. The second mixture M2′ then undergoes physical foaming to become the second component M2, as described in operation S250 of FIG. 2. After the formation of the second component M2, the second skin layer 106b is formed. In some embodiments, the second skin layer 106b is configured to prevent the mixture subsequently injected into the mold cavity 103 from mixing with the second mixture M2′ or the second component M2. In some embodiments, during or after the physical foaming of the second mixture M2′, a portion of the gas and / or a portion of the physical foaming agent released from the second mixture M2′ is expelled from the mold cavity 103.

[0059] In FIG. 24, after the formation of the second component M2, the third mixture M3′ is injected into the mold cavity through the third supply port 105c, as described in operation S260 of FIG. 2. In some embodiments, gas is injected into the mold cavity 103 before the injection of the third mixture M3′ to increase the pressure in the mold cavity 103. The third mixture M3′ is in contact with the second component M2. The third mixture M3′ then undergoes physical foaming to become the third component M3, as described in operation S270 of FIG. 2. After the formation of the third component M3, a third skin layer 106c is formed. In some embodiments, the third skin layer 106c is configured to prevent mixing with the second mixture M2′ or the second component M2. In some embodiments, during or after the physical foaming of the third mixture M3′, a portion of the gas and / or a portion of the physical foaming agent released from the third mixture M3′ is vented from the mold cavity 103.

[0060] In Figure 25, article 107 is formed and article 107 can be removed from mold cavity 103 after demolding of first mold 101 and second mold 102, as shown in Figure 26. As described above, article 107 includes a first visible boundary line 108a between first component M1 and second component M2, and a second visible boundary line 108b between second component M2 and third component M3.

[0061] 27-31 are schematic cross-sectional views illustrating exemplary stages of the injection molding method 20 of FIG. 2 according to a fifth embodiment of the present disclosure. In the fifth embodiment, the first component M1 is surrounded by the second component M2 within the article 107. In some embodiments, the second supply port 105b is removed from the second mold 102.

[0062] 27, the first component M1 is disposed in a second sub-cavity 103b defined by the first partition 104a, the second partition 104b, the first mold 101, and the second mold 102. In some embodiments, the first component M1 is temporarily fixed in the second sub-cavity 103b by the first partition 104a and the second partition 104b. Furthermore, a portion of the second sub-cavity 103b is not filled with the first component M1.

[0063] In some embodiments, after placement of the first component M1, the second mixture M2' is injected into the first sub-cavity 103a and the third sub-cavity 103c, as shown in FIG. 28. In some embodiments, gas is injected into the first sub-cavity 103a and / or the third sub-cavity 103c before injection of the second mixture M2' to increase the pressure in the first sub-cavity 103a and / or the third sub-cavity 103c. In some embodiments, the mixture M2' is injected into the first sub-cavity 103a and the third sub-cavity 103c through the first supply port 105a and the third supply port 105c, respectively. In some embodiments, the mixture M2' is injected into the first sub-cavity 103a and the third sub-cavity 103c simultaneously. In some embodiments, the mixture M2' is injected into the first sub-cavity 103a and the third sub-cavity 103c sequentially.

[0064] In some embodiments, the first partition 104a and the second partition 104b are withdrawn from the mold cavity 103 when the second mixture M2' nearly or completely fills the first sub-cavity 103a and the third sub-cavity 103c. In some embodiments, after withdrawing the first partition 104a and the second partition 104b, the second mixture M2' flows into the second sub-cavity 103b and contacts the first component M1, as shown in FIG. 29. The second mixture M2' then undergoes physical foaming to become the second component M2. After the formation of the second component M2, the second skin layer 106b is formed. In some embodiments, during or after the physical foaming of the second mixture M2', a portion of the gas and / or a portion of the physical foaming agent released from the second mixture M2' is exhausted from the mold cavity 103. In a fifth embodiment, the second component M2 and the first component M1 have different heights in the Z direction. The top surface of the first component M1 is lower than the top surface of the second component M2. Furthermore, the second component M2 overlaps the top surface of the first component M1 in the Z direction (e.g., from a top view of the article 107), and the top surface of the first component M1 is surrounded by the second component M2.

[0065] In some embodiments, the article 107 is formed as shown in Figure 30, and the article 107 can be removed from the mold cavity 103 after the first mold 101 and the second mold 102 are demolded as shown in Figure 31. In some embodiments, the second component M2 is softer than the first component M1. In some embodiments, the first component M1 is denser than the second component M2.

[0066] 32-39 are schematic cross-sectional views illustrating exemplary stages of the injection molding method 20 of FIG. 2 according to a sixth embodiment of the present disclosure. In the sixth embodiment, the first component M1 is surrounded by the second component M2 within the article 107. In some embodiments, the second supply port 105b is removed from the second mold 102.

[0067] In FIG. 32, the molding apparatus 100 includes a first mold 101 and a second mold 102a engageable with the first mold 101. A fourth mold cavity 103d is formed when the first mold 101 engages with the second mold 102a. The fourth mold cavity 103d is defined by the first mold 101 and the second mold 102a. In some embodiments, a fourth mixture M4' is injected into the fourth mold cavity 103d through a fourth supply port 105d. In some embodiments, a fourth gas is injected into the fourth mold cavity 103d before the injection of the fourth mixture M4' to increase the pressure in the fourth mold cavity 103d. In some embodiments, the fourth mixture M4' includes a polymeric material (such as thermoplastic polyurethane (TPU), polyurethane (PU), plastic, etc.) and a physical blowing agent (such as gaseous nitrogen, carbon dioxide, supercritical fluid, etc.). In some embodiments, the fourth mixture M4' is foaming or slightly foaming.

[0068] In some embodiments, after injection of the fourth mixture M4', the fourth mixture M4' undergoes physical foaming in the fourth mold cavity 103d to become the fourth component M4. In some embodiments, during the physical foaming of the fourth mixture M4' and / or after the formation of the fourth component M4, the pressure in the fourth mold cavity 103d is reduced by venting at least a portion of the fourth gas from the fourth mold cavity 103d and / or venting a portion of the physical foaming agent released from the fourth mixture M4' from the fourth mold cavity 103d. In some embodiments, after the physical foaming of the fourth mixture M4', a fourth component M4 having a fourth skin layer 106d is formed. The fourth skin layer 106d has a higher density than the center of the fourth component M4. The fourth skin layer 106d has a lower degree of physical foaming than the center. In some embodiments, the fourth skin layer 106d has a thickness of less than 0.5 mm.

[0069] In FIG. 33, after the formation of the fourth component M4, the second mold 102a is removed and replaced with the third mold 102b. In some embodiments, the first partition 104a and the second partition 104b extend between the fourth component M4 and the third mold 102b. In some embodiments, the first partition 104a and the second partition 104b can extend from and be retracted from the third mold 102b. In some embodiments, the mold cavity 103 is further defined by the fourth component M4 disposed within the first mold 101 and the third mold 102b.

[0070] In Figure 33, after the first partition 104a is positioned, the first mixture M1' is injected into the first sub-cavity 103a through the first feed port 105a, as described in operation S220 of Figure 2. In some embodiments, the first sub-cavity 103a is defined by the third mold 102b, the fourth component M4, and the first partition 104a.

[0071] In some embodiments, prior to injection of the first mixture M1', a first gas is injected into the first sub-cavity 103a to increase the pressure in the first sub-cavity 103a. In some embodiments, after injection of the first mixture M1', the first mixture M1' undergoes physical foaming in the first sub-cavity 103a to become the first component M1, as described in operation S230 of FIG. 2. In some embodiments, after formation of the first component M1, the first partition 104a is removed, as shown in FIG.

[0072] In FIG. 35, the second mixture M2′ is injected into the second sub-cavity 103b through the second supply port 105b, as described in operation S240 of FIG. 2. In some embodiments, prior to the injection of the second mixture M2′, a second gas is injected into the second sub-cavity 103b to increase the pressure in the second sub-cavity 103b. In some embodiments, the second sub-cavity 103b is defined by the first component M1, the fourth component M4, the second partition 104b, and the third mold 102b. In some embodiments, after the injection of the second mixture M2′, the second mixture M2′ undergoes physical foaming in the second sub-cavity 103b to become the second component M2, as described in operation S250 of FIG. 2. In some embodiments, after the formation of the second component M2, the second partition 104b is removed, as shown in FIG. 36.

[0073] In FIG. 37, after the formation of the second component M2, the third mixture M3′ is injected into the third sub-cavity 103c through the third supply port 105c, as described in operation S260 of FIG. 2. In some embodiments, the third sub-cavity 103c is defined by the second component M2, the fourth component M4, and the third mold 102b. In some embodiments, prior to the injection of the third mixture M3′, a third gas is injected into the third sub-cavity 103c to increase the pressure in the third sub-cavity 103c. In some embodiments, after the injection of the third mixture M3′, the third mixture M3′ undergoes physical foaming in the third sub-cavity 103c to become the third component M3, as described in operation S270 of FIG. 2.

[0074] In some embodiments, after the formation of the third component M3, the first mold 101 is released from the third mold 102b, as shown in FIG. 38. After the formation of the third component M3, an article 107 having a first component M1, a second component M2, a third component M3, and a fourth component M4 is formed, as shown in FIG. 39. The article 107 is formed in a mold cavity defined by the first mold 101 and the third mold 102b. In some embodiments, after the first mold 101 and the third mold 102b are released, the article 107 is removed from the mold cavity, as shown in FIG. 39.

[0075] In some embodiments, the first component M1 is directly attached to the second component M2, and the second component M2 is directly attached to the third component M3. In other words, no additional components or materials (such as adhesives) are disposed between the first component M1 and the second component M2, and between the second component M2 and the third component M3. In some embodiments, the fourth component M4 is separable / detachable from the first component M1, the second component M2, and the third component M3. In some embodiments, the fourth component M4 has protrusions / recesses that can engage with the recesses / protrusions of the first component M1, the recesses / protrusions of the second component M2, and / or the recesses / protrusions of the third component M3, such that the fourth component M4 is attachable to the first component M1, the second component M2, and / or the third component M3.

[0076] In some embodiments, the fourth skin layer 106d contacts the bottom surfaces of components M1, M2, and M3. The second component M2 is surrounded by the first component M1, the fourth component M4, and the third component M3. The first component M1 is surrounded by the fourth component M4 and the second component M2. The side of the first component M1 (e.g., the left first skin layer 106a) contacts the fourth skin layer 106d of the fourth component M4. And the third component M3 is surrounded by the fourth component M4 and the second component M2. The side of the third polymer component (e.g., the right third skin layer 106c) contacts the fourth skin layer 106d of the fourth component M4.

[0077] In some embodiments, the article 107 includes a visible boundary between two adjacent components. For example, a first visible boundary 108a exists between a first component M1 and a second component M2, and a second visible boundary 108b exists between the second component M2 and a third component M3. In some embodiments, the first visible boundary 108a and the second visible boundary 108b are each a straight line, a curve, a spline, a polyline, etc. from a top view of the article 107.

[0078] In some embodiments, the article 107 has a variety of densities or hardnesses. In some embodiments, the fourth component M4 is harder and denser than the first component M1, the second component M2, and the third component M3. In some embodiments, the third component M3 is softer than the second component M2 and the first component M1. In some embodiments, the first component M1 is denser than the second component M2 and the third component M3.

[0079] 40-43 are schematic cross-sectional views illustrating exemplary stages of the injection molding method 20 of FIG. 2 according to a seventh embodiment of the present disclosure. In the seventh embodiment, the operation of the injection unit 110 is illustrated.

[0080] As described above, the injection molding system 10 includes the mixing unit 120, the injection unit 110, and the molding apparatus 100. The mixing unit 120 is configured to generate a mixture of a polymeric material and a physical blowing agent. The mixture is then delivered to the injection unit 110.

[0081] In FIG. 40, the injection unit 110 is configured to discharge the mixture. The mixture is then discharged through one or more discharge channels 111a, 111b, and 111c of the injection unit 110 engaged with the molding apparatus 100. The mixture can flow from the injection unit 110 into the molding apparatus 100. In some embodiments, the mixture can flow from the injection unit 110 into the mold cavity 103 through the discharge channels 111a, 111b, and 111c and the supply ports 105a, 105b, and 105c. In some embodiments, each discharge channel corresponds to a respective supply port. For example, the discharge channels 111a, 111b, and 111c correspond to the supply ports 105a, 105b, and 105c, respectively. In some embodiments, the partition 104 is not disposed in the mold cavity 103.

[0082] In some embodiments, the flow rate of the mixture exiting each of the outlet channels 111a, 111b, and 111c is individually adjustable. In some embodiments, the amount of the mixture exiting each of the outlet channels 111a, 111b, and 111c is individually adjustable. In some embodiments, the flow rate or amount of the mixture exiting each of the outlet channels 111a, 111b, and 111c is controlled by a central processor (not shown).

[0083] In some embodiments, the flow rate / amount of the mixture flowing out of each of the outlet channels 111a, 111b, 111c can be synchronized with each other. For example, the flow rate / amount of the mixture flowing out of the outlet channel 111a is set or determined (manually or automatically), and the flow rate / amount of the mixture flowing out of the remaining outlet channels 111b, 111c is automatically set to be the same as the flow rate / amount of the mixture flowing out of the outlet channel 111a. In this way, the flow rate / amount of the mixture flowing out of each of the outlet channels 111a, 111b, and 111c is synchronized. In some embodiments, such synchronization is performed automatically by a central processor.

[0084] In some embodiments, the flow rate of the mixture flowing out of one of the outlet channels 111a is set (manually or automatically) to a predetermined flow rate / amount, and then the flow rate / amount of the mixture flowing out of the remaining outlet channels 111b, 111c is adjusted (to be the same or different) based on the predetermined flow rate / amount. This allows the flow rates / amounts of the mixture flowing out of each of the outlet channels 111a, 111b, and 111c to be correlated with each other. In some embodiments, such adjustments are performed automatically and quickly by a central processor. For example, when the flow rate / amount of the mixture flowing out of one of the outlet channels 111a is changed (manually or automatically), the flow rate / amount of the mixture flowing out of the remaining outlet channels 111b, 111c also changes quickly.

[0085] In some embodiments, the mixtures exiting each of the discharge channels 111a, 111b, and 111c are the same or different materials. In some embodiments, the mixtures exiting each of the discharge channels 111a, 111b, and 111c are of the same or different physical properties (density, hardness, etc.). In some embodiments, the discharge channels 111a, 111b, and 111c exit the same mixture M' into the mold cavity 103, as shown in FIG.

[0086] In some embodiments, the outlet channels 111a, 111b, and 111c output different mixtures M1', M2', and M3', respectively, but flow into the mold cavity 103 at the same flow rate / volume, e.g., operations S220, S240, and S260 are performed simultaneously, as shown in Figure 42. In some embodiments, the flow rate / volume of mixture M1 output from outlet channel 111a is set, and the flow rates / volumes of mixtures M2' and M3' output from outlet channels 111b and 111c are set by the central processor to be the same as the flow rate / volume of mixture M1' output from outlet channel 111a.

[0087] In some embodiments, the discharge channels 111a, 111b, and 111c discharge different amounts of mixtures M1', M2', and M3' into the mold cavity 103, as shown in FIG. 43. For example, the flow rate / amount of the mixture M1' discharged from the discharge channel 111a is set, and the flow rates / amounts of the mixtures M2', M3' discharged from the discharge channels 111b, 111c are set by the central processor based on the flow rate / amount of the mixture M1' discharged from the discharge channel 111a. Furthermore, when the flow rate / amount of the mixture M2' is greater than the flow rate / amount of the mixtures M1' and M3', the second component M2 has a wider width in the X direction than the first component M1 and the third component M3.

[0088] As with the seventh embodiment, the flow rates / volumes of mixtures M1', M2', and M3' in the first to sixth embodiments can be controlled by a central processor such that the flow rates / volumes of the first, second, and third mixtures are the same or different.

[0089] Figures 44 and 45 are schematic cross-sectional views illustrating exemplary stages of the injection molding method 20 of Figure 2 according to an eighth embodiment of the present disclosure. In the eighth embodiment, operation of the injection unit 110 is shown.

[0090] In Fig. 44, the injection unit 110 is configured to discharge the mixture. The mixture is discharged through one or more discharge channels 111a, 111b, 111c, 111d, 111e, and 111f of the injection unit 110 engaged with the molding apparatus 100. The mixture can flow from the injection unit 110 into the molding apparatus 100. In some embodiments, the mixture can flow from the injection unit 110 into the mold cavity 103 through discharge channels 111a, 111b, 111c, 111d, 111e, and 111f and supply ports 105a, 105b, 105c, 105d, 105e, and 105f, respectively.

[0091] The molding apparatus 100 includes a mold cavity 103 defined by a first mold 101 and a second mold 102. In some embodiments, the mold cavity 103 includes a first sub-cavity 103a and a second sub-cavity 103b separated from the first sub-cavity 103a. The first sub-cavity 103a is not communicable with the second sub-cavity 103b. In some embodiments, the volume of the first sub-cavity 103a is substantially the same as the volume of the second sub-cavity 103b. In some embodiments, the first sub-cavity 103a is communicable with three supply ports 105a, 105b, and 105c, and the second sub-cavity 103b is communicable with three supply ports 105d, 105e, and 105f. However, there is no intention to limit the number of supply ports corresponding to one sub-cavity.

[0092] In some embodiments, when one of the exhaust channels 111a, 111b, 111c, 111d, 111e, and 111f is set or adjusted, the remaining exhaust channels 111a, 111b, 111c, 111d, 111e, and 111f are adjusted accordingly. In some embodiments, the adjustment of the remaining exhaust channels 111a, 111b, 111c, 111d, 111e, and 111f occurs immediately after the setting / adjustment of one of the exhaust channels 111a, 111b, 111c, 111d, 111e, and 111f. In some embodiments, such subsequent adjustments are performed automatically and immediately by a central processor (not shown).

[0093] For example, a parameter associated with the discharge channel 111a (e.g., flow rate, amount of mixture, injection force provided to the mixture for discharge, etc.) is set to a first value, and then a parameter associated with another discharge channel 111d is adjusted based on the first value. In some embodiments, the parameter associated with the discharge channel 111a is correlated with the parameter associated with another discharge channel 111d by a first ratio, and thus, the parameter associated with the other discharge channel 111d can be derived based on the first ratio and thus adjusted accordingly. For example, if the first ratio is 1, the parameter associated with the discharge channel 111d is adjusted to be the same as the parameter associated with the discharge channel 111a.

[0094] In some embodiments, when adjusting the parameter associated with the discharge channel 111a, the parameters of the discharge channels 111b and 111c adjust accordingly. In some embodiments, the parameter associated with the discharge channel 111a correlates with the parameter of the discharge channel 111b at a second ratio. For example, when setting the parameter associated with the discharge channel 111a to a first value, the parameter of the discharge channel 111b adjusts according to the first value and the second ratio. In some embodiments, the parameter associated with the discharge channel 111a correlates with the parameter associated with the discharge channel 111c at a third ratio. For example, when setting the parameter associated with the discharge channel 111a to a first value, the parameter of the discharge channel 111c adjusts according to the first value and the third ratio. Alternatively, in some embodiments, the parameter associated with the discharge channel 111b correlates with the parameter associated with the discharge channel 111c at a fourth ratio. Thus, after obtaining the parameter associated with the discharge channel 111b, the parameter associated with the discharge channel 111c follows the fourth ratio.

[0095] Similarly, in some embodiments, when the parameter associated with the discharge channel 111d is adjusted, the parameters of the discharge channels 111e and 111f adjust accordingly. In some embodiments, the parameter associated with the discharge channel 111d correlates with the parameter associated with the discharge channel 111e at a fifth ratio. For example, when the parameter associated with the discharge channel 111d is set to a second value, the parameter of the discharge channel 111e adjusts according to the second value and the fifth ratio. In some embodiments, the parameter associated with the discharge channel 111d correlates with the parameter of the discharge channel 111f at a sixth ratio. For example, when the parameter associated with the discharge channel 111d is set to a second value, the parameter of the discharge channel 111f adjusts according to the second value and the sixth ratio. Alternatively, in some embodiments, the parameter associated with the discharge channel 111e correlates with the parameter associated with the discharge channel 111f at a seventh ratio. Thus, after obtaining the parameter associated with the discharge channel 111e, the parameter associated with the discharge channel 111f is adjusted according to the seventh ratio.

[0096] In some embodiments, the mixture M' is then discharged from the discharge channels 111a, 111b, 111c, 111d, 111e, and 111f and enters into the corresponding sub-cavities 103a and 103b through the supply ports 105a, 105b, 105c, 105d, 105e, and 105f, respectively, as shown in FIG. 45. The mixture is discharged according to the above-mentioned adjustment result. In some embodiments, after the injection of the mixture M', the mixture M' undergoes physical foaming in the sub-cavities 103a and 103b, respectively, to become the component M. In some embodiments, the component M has substantially the same size, weight, density, etc.

[0097] According to an embodiment of the present disclosure, an injection molding method is used to form an article with multiple hardness / density. By removing the partition 104 and / or controlling the flow rate of the mixture, mixtures with different physical properties are injected into the mold cavity 103 to form the article 107, thereby reducing the manufacturing time of an article that includes multiple parts with different physical or functional properties.

[0098] The above outlines features of some embodiments so that those skilled in the art may better understand aspects of the present disclosure. Those skilled in the art will appreciate that this disclosure may be readily used as a basis for designing or modifying other processes and structures for carrying out the same purposes and / or achieving the same advantages of the embodiments presented herein. Those skilled in the art will also recognize that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and that various changes, substitutions, and alterations may be made herein without departing from the spirit and scope of the present disclosure.

[0099] Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the processes, machines, manufacture, compositions, means, methods, and steps described herein. As one skilled in the art will readily appreciate from the disclosure of the present disclosure, any currently existing or later developed processes, machines, manufacture, compositions, means, methods, or steps that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein can be utilized in accordance with the present disclosure. Accordingly, it is intended that the appended claims include within their scope such processes, machines, manufacture, compositions, means, methods, and steps.

Claims

1. 1. An injection molding method comprising the steps of: providing a molding apparatus including a first mold, a second mold above the first mold, and a mold cavity defined by the first mold and the second mold; injecting a first mixture into the mold cavity through a first feed port; forming a first component from the first mixture; injecting a second mixture into the mold cavity through a second feed port; forming a second component from the second mixture; and Including, The second component is in at least partial contact with the first component, and the first component and the second component have different physical properties.

2. Dividing the mold cavity into a first sub-cavity and a second sub-cavity by a first partition. Further comprising:

2. The injection molding method of claim 1, wherein the first partition is removable, and the first sub-cavity of the mold cavity is defined by the first mold, the second mold, and the first partition.

3. dividing the mold cavity into a first sub-cavity, a second sub-cavity and a third sub-cavity by a first partition and a second partition, the first partition and the second partition being removable, the first sub-cavity being defined by the first mold, the second mold and the first partition, and the second sub-cavity being defined by the first mold, the second mold and the second partition; removing the first partition from the mold cavity prior to injecting the second mixture into the second sub-cavity of the mold cavity, the first component being in at least partial contact with the first partition prior to removing the first partition from the mold cavity; removing the second partition from the mold cavity after injecting the second mixture into the second sub-cavity of the mold cavity; injecting a third mixture through a third supply port into the third sub-cavity defined by the first mold, the second mold, and the second component; The injection molding method of claim 1 further comprising:

4. controlling the flow of the first mixture through the first supply port and controlling the flow of the second mixture through the second supply port at the same or different flow rates. The injection molding method of claim 1 further comprising:

5. providing a molding apparatus including the first mold and a third mold above the first mold; injecting a third mixture through a third feed port disposed in the third mold into another mold cavity defined by the first mold and the third mold; forming a third component from the third mixture; and exchanging the third mold for the second mold before injecting the first mixture into the mold cavity through the first feed port; Further comprising:

2. The injection molding method of claim 1, wherein the mold cavity is further defined by the second mold and the third component disposed within the first mold.

6. providing a molding apparatus including a first mold, a second mold above the first mold, and a mold cavity defined by the first mold and the second mold; injecting a first mixture into the mold cavity through a first feed port; forming a first component from the first mixture; injecting a second mixture into the mold cavity through a second feed port; forming a second component from the second mixture; and Including, The injection molding method, wherein the second component is separated from the first component, the first component and the second component having different physical properties.

7. Dividing the mold cavity into a first sub-cavity and a second sub-cavity by a first partition and a second partition. Further comprising: the first partition and the second partition are removable; 7. The injection molding method of claim 6, wherein the first sub-cavity of the mold cavity is defined by the first mold, the second mold, and the first partition, and the second sub-cavity of the mold cavity is defined by the first mold, the second mold, and the second partition.

8. a first polymer component having a first skin layer; a second polymeric component having a second skin layer in contact with the first skin layer; Including, an assembly, wherein the density of the first skin layer is greater than a central portion of the first polymer component and the density of the second skin layer is greater than a central portion of the second polymer component, and a visible boundary line exists between the first skin layer and the second skin layer.

9. A third polymer component having a third skin layer. Further comprising: The assembly of claim 8 , wherein the third skin layer is in contact with a fourth skin layer of the second polymeric component.

10. A fourth polymer component having a fifth skin layer. Further comprising:

10. The assembly of claim 9, wherein the fifth skin layer is in contact with bottom surfaces of the first and second polymer components and a bottom surface of a third polymer component, and a first side of the first polymer component and a second side of the third polymer component are in contact with the fifth skin layer.

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