Mold for injection molded part and injection molding method for injection molded part

Abstract

The invention relates to the technical field of injection molds, and discloses a mold for injection molding of a part and an injection molding method for injection molding of the part, the mold for injection molding of the part comprises: a mold main body, which comprises a cavity and an injection molding feed port, and the cavity communicates with the injection molding feed port; and the feeding part is arranged at the injection molding feeding port, the feeding part is used for injecting an injection molding material into the cavity, the feeding part is provided with a buffer runner, the inlet width of the buffer runner is smaller than the outlet width of the buffer runner, and the buffer runner communicates with the injection molding feeding port. By arranging the mold main body comprising the cavity and the injection molding feed port, the injection molding part is obtained. The feeding part provided with the buffer runner is arranged, and the inlet width of the buffer runner is smaller than the outlet width of the buffer runner, so that the speed of an injection molding material in the buffer runner is reduced through the buffer runner. Further, the shearing rate of the injection molding material is reduced, gas generated by decomposition of the injection molding material is reduced, and the problem of sprue marks is solved.

Description

Technical Field

[0001] This application relates to the technical field of injection molds, for example, to a mold for injection molded parts and an injection molding method for injection molded parts. Background Art

[0002] Currently, in household appliances such as air conditioners, there are more and more applications of parts such as decorative strips of thick-walled injection molded parts.

[0003] In the related art, an injection molding material is injected into a mold provided with a cavity to obtain an injection molded part.

[0004] In the process of implementing the embodiments of the present disclosure, it is found that at least the following problems exist in the related art:

[0005] When using the mold in the related art, obvious gate marks often appear at the position corresponding to the gate of the mold in the produced injection molded part, affecting the aesthetics of the injection molded part.

[0006] It should be noted that the information disclosed in the above background art section is only used to enhance the understanding of the background of this application, and thus may include information that does not constitute the prior art known to those of ordinary skill in the art. Summary of the Invention

[0007] To have a basic understanding of some aspects of the disclosed embodiments, a simple summary is given below. This summary is not a general review, nor is it intended to identify key / important constituent elements or delineate the protection scope of these embodiments, but rather serves as a preface to the subsequent detailed description.

[0008] The embodiments of the present disclosure provide a mold for injection molded parts and an injection molding method for injection molded parts to reduce the problem of gate marks appearing at the position corresponding to the gate of the mold in the produced injection molded parts and improve the aesthetics of the produced injection molded parts.

[0009] In some embodiments, a mold for injection molded parts is provided, including: a mold body including a cavity and an injection feed port, the cavity being in communication with the injection feed port; a feed portion provided at the injection feed port, the feed portion being configured to inject an injection molding material into the cavity, the feed portion having a buffer flow channel, an inlet width of the buffer flow channel being smaller than an outlet width of the buffer flow channel, the buffer flow channel being in communication with the injection feed port.

[0010] Optionally, the feed portion includes: a gate plate provided at the injection feed port, the gate plate including a first flow channel, the buffer flow channel including the first flow channel, the first flow channel being in communication with the injection feed port; one end of the first flow channel being a first feed port and the other end of the first flow channel being a first discharge port.

[0011] Optionally, the width of the first feed port is greater than or equal to 6 mm; the width of the first discharge port is greater than or equal to 12 mm.

[0012] Optionally, the maximum wall thickness of the injection molded part is h; the first runner is sectioned in a direction perpendicular to the feed, obtaining the cross-section of the first runner, and the length of the cross-section of the first runner is H; the relationship between H and h satisfies: H≥1 / 3×h.

[0013] Optionally, the extending direction of the gate piece is the same as the demolding direction of the injection molded part.

[0014] Optionally, the width of the first feed port is greater than the width of the first discharge port, and between the first feed port and the first discharge port, the side wall of the first runner is a curved side wall.

[0015] Optionally, the feed part further includes: a cold runner piece, including a second runner, one end of the second runner is a second feed port, the other end of the second runner is a second discharge port, the second discharge port is connected to the first feed port, and the width of the second feed port is less than the width of the second discharge port; between the second feed port and the second discharge port, the side wall of the second runner is a curved side wall; wherein, the buffer runner includes the first runner and the second runner.

[0016] Optionally, the width of the first feed port is equal to the width of the first discharge port, and the width value is A, and the value range of A is: 15 mm≥A≥12 mm; the length of the first runner is B, and the value range of B is: 10 mm≥B≥8 mm.

[0017] Optionally, the feed part further includes: a third runner, the discharge port of the third runner is connected to the injection feed port; a fourth runner, the feed port of the third runner is connected to the discharge port of the fourth runner; wherein, the buffer runner includes the third runner and the fourth runner, the width of the third discharge port is C, the width of the fourth feed port is D, and C = 1.8D.

[0018] In some embodiments, an injection molding method for an injection molded part is provided, including: injecting an injection molding material into the mold for an injection molded part according to any one of the above embodiments; after the injection molding material is cooled, demolding the cooled injection molding material; trimming the sprue on the cooled injection molding material to obtain the injection molded part.

[0019] The mold for an injection molded part and the injection molding method for an injection molded part provided by the embodiments of the present disclosure can achieve the following technical effects:

[0020] The mold for injection molded parts provided by the embodiments of the present disclosure includes: a mold body and a feeding part. The mold body includes a cavity and an injection feeding port, and the cavity is in communication with the injection feeding port. The feeding part is arranged at the injection feeding port and is used for injecting injection molding material into the cavity. The feeding part is provided with a buffer flow channel, the inlet width of the buffer flow channel is smaller than the outlet width of the buffer flow channel, and the buffer flow channel is in communication with the injection feeding port. By providing the mold body including the cavity and the injection feeding port, it is possible to inject the injection molding material into the cavity through the injection feeding port to obtain an injection molded part. By providing the feeding part with a buffer flow channel and the inlet width of the buffer flow channel being smaller than the outlet width of the buffer flow channel, it is possible to reduce the speed of the injection molding material in the buffer flow channel through the buffer flow channel. Furthermore, the shear rate of the injection molding material is reduced, and the gas generated by the decomposition of the injection molding material is reduced, thereby reducing the problem of gate marks.

[0021] The injection molding method for injection molded parts provided by the embodiments of the present disclosure realizes the production of injection molded parts by injecting injection molding material into the mold for injection molded parts described in any one of the above embodiments and trimming the sprue on the cooled injection molding material after the injection molding material is cooled. Moreover, the speed of the injection molding material is reduced and the gas generated by the decomposition of the injection molding material is reduced, thereby reducing the shear rate of the injection molding material while the injection molding material is in the buffer channel from the inlet of the buffer channel to the outlet of the buffer flow channel. Furthermore, the problem of gate marks at the position corresponding to the gate of the mold in the produced injection molded parts can be reduced, and the aesthetics of the produced injection molded parts can be improved.

[0022] The above general description and the following description are only exemplary and explanatory and are not used to limit the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] One or more embodiments are exemplarily illustrated by corresponding drawings. These exemplary illustrations and the drawings do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings are shown as similar elements. The drawings do not constitute a scale limitation, and among them:

[0024] Figure 1 is a schematic diagram of the mold for injection molded parts provided by the embodiments of the present disclosure;

[0025] Figure 2 is a schematic diagram of a mold for injection molded parts provided by the embodiments of the present disclosure;

[0026] Figure 3 is a schematic diagram of another mold for injection molded parts provided by the embodiments of the present disclosure;

[0027] Figure 4 is Figure 3 a front view of the gate piece in the illustrated embodiment;

[0028] Figure 5 is Figure 4 The side view of the gate piece in the illustrated embodiment;

[0029] Figure 6 is a schematic diagram of another mold for injection molded parts provided by an embodiment of the present disclosure;

[0030] Figure 7 is a schematic diagram of another mold for injection molded parts provided by an embodiment of the present disclosure;

[0031] Figure 8 is Figure 6 The front view of the cold gate piece in the illustrated embodiment;

[0032] Figure 9 is Figure 6 The front view of the gate piece in the illustrated embodiment;

[0033] Figure 10 is a schematic diagram of the simulation of the shear rate of the injection molding material in the cavity provided by an embodiment of the present disclosure;

[0034] Figure 11 is a schematic flow diagram of an injection molding method for injection molded parts provided by an embodiment of the present disclosure.

[0035] Reference numerals:

[0036] 100, mold for injection molded parts; 200, injection molded parts;

[0037] 10, mold body;

[0038] 20, feeding part; 201, gate piece; 2011, first feeding port; 2012, first discharging port; 2013, first runner; 2014, injection section; 2015, buffer section; 202, cold gate piece; 2021, second feeding port; 2022, second discharging port. Detailed implementation manners

[0039] In order to be able to understand the features and technical content of the embodiments of the present disclosure in more detail, the implementation of the embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. The accompanying drawings are for reference and illustration purposes only and are not used to limit the embodiments of the present disclosure. In the following technical description, for the sake of explanation, a sufficient understanding of the disclosed embodiments is provided through multiple details. However, one or more embodiments can still be implemented without these details. In other cases, well-known structures and devices may be shown in a simplified manner to simplify the drawings.

[0040] In the description, claims and drawings of the embodiments of the present disclosure, terms such as "first", "second", etc. are used to distinguish similar objects, and do not necessarily describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so as to implement the embodiments of the present disclosure described herein. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion.

[0041] Unless otherwise specified, the term "plurality" means two or more.

[0042] In the embodiments of the present disclosure, the character " / " indicates that the front and rear objects are in an "or" relationship. For example, A / B means: A or B.

[0043] The term "and / or" is an associative relationship describing an object, indicating that there can be three relationships. For example, A and / or B means: A or B, or, the three relationships of A and B.

[0044] The term "corresponding" can refer to an associative relationship or a binding relationship. A corresponding to B means that there is an associative relationship or a binding relationship between A and B.

[0045] Gate marks are a type of defect that often appears in injection-molded parts, and there are many forms of manifestation. Some are manifested as color differences, some as line traces, and some as halo spots, and so on.

[0046] By observing the injection-molded parts produced by the molds in the related art, it is found that the main form of the gate mark defect of the injection-molded part is one or more fingerprint-like lines similar to unfolded and elongated ones, and the phenotype type belongs to line traces. In addition, compared with other positions, there is a very serious fogging phenomenon. By touching the abnormal trace area of the gate area of the injection-molded part, it is found that the touch feeling is different from the smooth feeling of other positions. This position is not smooth and has a concave-convex feeling along the line.

[0047] Due to the particularity of the appearance of such defects near the gate. Analyze the phenomena and characteristics when the injection material flows through the gate position during the filling process, mainly focusing on two aspects: the gate structure and the properties of the injection material.

[0048] Specifically, the injection material includes polymer materials. After the polymer materials are heated to become polymer melts, injection molding is carried out.

[0049] First, the gate of the injection mold of the injection-molded part is the channel through which the polymer melt enters the mold cavity via the runner. It is the channel with the smallest cross-sectional area and the shortest flow length in the runner system. If the gate structure is unreasonable, or the volume flow rate is not optimized and adjusted at this position, then the flow line velocity of the polymer melt at the gate position will be very fast. As a result, the streamline of the polymer melt in this area will be disordered, and the trend of flow instability will be enhanced.

[0050] Second, the injection molding material is generally a polymer material, and the polymer melt has a significant die swell effect. During the injection molding process, the polymer melt undergoes tensile and shear deformations in areas such as the runner and gate. During the flow process, only a part of the polymer melt is relaxed, and the remaining part of the polymer melt undergoes elastic recovery after entering the cavity, resulting in the phenomenon of polymer melt extrusion swelling. Regarding the die swell effect, scientific experiments have relevant conclusions. Measures such as increasing the temperature, reducing the velocity at the die, and adding fillers to the material to reduce the elastic deformation of the polymer melt can significantly reduce the extrusion swelling phenomenon.

[0051] In addition, scientific experiments show that when the polymer melt enters the cavity from the gate, when the rate or the stress it receives is too high, that is, when it exceeds a certain critical shear rate γ or critical shear stress τ, elastic turbulence is likely to occur, resulting in unstable flow and distortion of the extrudate. The distortion can be divided into surface distortion and overall distortion. When the injection rate is higher, surface distortion and overall distortion will occur simultaneously, and even fragmentation of the extrudate will occur. This phenomenon is called the melt fracture phenomenon. And the experimental conclusions show that optimizing the die material, optimizing the gate shape, reconfiguring the injection molding material, and adjusting the process conditions can all optimize this phenomenon.

[0052] According to the morphology of the gate mark at the gate of this injection molded part, linear distribution, concave-convex touch, and fogging, combined with the filling animation in the previous simulation analysis stage, it is determined that there is no melt convergence phenomenon at this position. It can be preliminarily inferred that the gate mark is mainly caused by the shear action of the polymer melt flowing at high speed.

[0053] Specifically, the polymer material includes PC (Polycarbonate).

[0054] Taking the injection molding material of this injection molded part as PC as an example, PC is a linear polymer containing carbonate groups in its molecular chain. According to the comparative observation of the changes in the appearance of the extruded distortion of the molecular chain melt with different topological structures obtained from scientific experiments, as the shear rate increases, surface regular distortion will occur first, and the overall extrudate is straight. When the shear rate continues to increase, the overall will also be distorted. Based on the observation of the current state of the injection molded part, it is inferred that only surface distortion has occurred.

[0055] Specifically, excessive shear rate will cause surface distortion of the injection molded part, and, combined with Figure 10 as shown, the position where the gate is connected to the injection molded part is usually the position with the largest shear rate. Therefore, by optimizing the design of the gate structure to reduce the shear rate, and thus reducing the problem of surface distortion at the gate of the injection molded part.

[0056] Specifically, the shear stress of the melt is equal to the product of the viscosity of the melt and the shear rate of the melt, and the shear rate of the melt is equal to the ratio of the velocity of the melt to the thickness of the melt. Thus, the shear rate of the melt can be reduced by reducing the velocity of the melt, thereby reducing the shear stress of the melt.

[0057] In some embodiments, in combination with Figures 1 to 8 As shown, a mold 100 for an injection molded part is provided, including: a mold body 10 and a feeding part 20. The mold body 10 includes a cavity and an injection feeding port, and the cavity is in communication with the injection feeding port. The feeding part 20 is disposed at the injection feeding port, and the feeding part 20 is used to inject injection material into the cavity. The feeding part 20 is provided with a buffer flow channel, the inlet width of the buffer flow channel is smaller than the outlet width of the buffer flow channel, and the buffer flow channel is in communication with the injection feeding port.

[0058] For the mold 100 for an injection molded part provided by the embodiments of the present disclosure, by providing the mold body 10 including a cavity and an injection feeding port, it is possible to inject injection material into the cavity through the injection feeding port to obtain an injection molded part 200. By providing the feeding part 20 provided with a buffer flow channel, and the inlet width of the buffer flow channel is smaller than the outlet width of the buffer flow channel, it is possible to reduce the velocity of the injection material in the buffer flow channel through the buffer flow channel. Furthermore, the shear rate of the injection material is reduced, and the gas generated by the decomposition of the injection material is reduced, thereby reducing the problem of gate marks.

[0059] Specifically, when the injection material is under a high shear rate, it will decompose to generate gas, causing bubbles to exist in the injection molded part 200.

[0060] Specifically, the outlet of the buffer flow channel is in communication with the injection feeding port. Since the inlet width of the buffer channel is smaller than the outlet width of the buffer flow channel, and the buffer flow channel has a space that gradually increases from the inlet of the buffer flow channel to the outlet of the buffer flow channel, the volumetric flow rate of the injection material is optimized. So that in the buffer channel, from the inlet of the buffer channel to the outlet of the buffer flow channel, the velocity of the injection material is reduced, and the gas generated by the decomposition of the injection material is reduced, thereby reducing the shear rate of the injection material.

[0061] Optionally, in combination with Figures 2 to 5 As shown, the feeding part 20 includes: a gate piece 201. The gate piece 201 is disposed at the injection feeding port. The gate piece 201 includes a first flow channel, and the buffer flow channel includes a first flow channel. The first flow channel is in communication with the injection feeding port. One end of the first flow channel is a first feeding port 2011, and the other end of the first flow channel is a first discharge port 2012.

[0062] In this embodiment, by providing the gate piece 201 including a first flow channel, and the first flow channel is in communication with the injection feeding port, it is convenient to inject injection material into the cavity through the first flow channel.

[0063] Specifically, in combination with Figure 2 and Figure 3 as shown, the first side wall and the third side wall of the gate piece 201 are opposite side walls, and the second side wall and the fourth side wall of the gate piece 201 are opposite side walls. The first side wall and the third side wall are trapezoidal. The second side wall and the fourth side wall are rectangular or trapezoidal. In this way, the width of the first runner can be gradually increased from the first feed port 2011 to the first discharge port 2012, so as to reduce the speed of the injection molding material, and further reduce the shear rate of the injection molding material.

[0064] Specifically, in this embodiment, the first feed port 2011 is the inlet of the buffer runner, and the first discharge port 2012 is the outlet of the buffer runner.

[0065] Optionally, the width of the first feed port 2011 is greater than or equal to 6 mm. The width of the first discharge port 2012 is greater than or equal to 12 mm.

[0066] In this embodiment, by setting the width of the first feed port 2011, it is convenient to inject the injection molding material into the mold, and reduce the problem that the injection speed of the injection molding material is too slow due to the too small width of the first feed port 2011, resulting in too fast cooling of the injection molding material in the cavity and the injection molding material cannot be completely injected. At the same time, by limiting the width of the first discharge port 2012, and the width of the first discharge port 2012 is greater than the width of the first feed port 2011, it is realized that the width of the inlet of the buffer runner is less than the width of the outlet of the buffer runner, and the speed of the injection molding material is reduced. In order to realize reducing the shear rate of the injection molding material through the buffer runner, and reducing the gas generated by the decomposition of the injection molding material, and further realizing reducing the problem of gate marks.

[0067] Specifically, in combination with Figure 4 as shown, along the direction perpendicular to the extension direction of the first runner, cross-sections are respectively made on the first feed port 2011 and the first discharge port 2012 of the first runner, and the width M of the first feed port 2011 and the width N of the first discharge port 2012 are obtained.

[0068] Optionally, in combination with Figure 5 as shown, the maximum wall thickness of the injection molded part 200 is h. A cross-section of the first runner is made along the direction perpendicular to the feeding direction, and the cross-section of the first runner is obtained, and the length of the cross-section of the first runner is H. The relationship between H and h satisfies: H≥1 / 3×h.

[0069] In this embodiment, by setting the relationship between the maximum wall thickness of the injection molded part 200 and the length of the cross-section of the first runner, while reducing the shear rate of the injection molding material during the process of entering the cavity from the first runner, the injection speed of the injection molding material is ensured, and the problem that the injection speed of the injection molding material is too slow due to the too small width of the first feed port 2011, resulting in too fast cooling of the injection molding material in the cavity and the injection molding material not being completely injected is reduced. Moreover, the gas hidden in the gate piece 201 can be reduced, so as to reduce the gas brought into the cavity by the injection molding material, and further reduce the air bubbles in the injection molded part 200.

[0070] Optionally, the extending direction of the gate piece 201 is the same as the demolding direction of the injection molded part 200. In this way, during the demolding process of the injection molded part 200, the gate piece 201 can be smoothly demolded at the same time, reducing the demolding difficulty of the injection molded part 200 and improving the practicability of the gate piece 201.

[0071] Optionally, as shown in Figures 2 to 5 the width of the first feed port 2011 is greater than the width of the first discharge port 2012, and between the first feed port 2011 and the first discharge port 2012, the side wall of the first runner is a curved side wall.

[0072] In this embodiment, by setting the side wall of the first runner as a curved side wall, the distance between the side walls in the first runner is gradually increased, reducing the influence of the die swell effect on the injection molding material. So that after the injection molding material enters the first feed port 2011, in the gradually increasing space in the first runner, the speed of the injection molding material gradually decreases, and then the shear rate of the injection molding material is gradually reduced, and the gas generated by the decomposition of the injection molding material is reduced. The degree of reduction of the shear rate of the injection molding material is more stable, reducing the problem that the speed of the injection molding material suddenly slows down when entering the cavity due to the dead angle between the side wall of the first runner and the cavity, resulting in the cooled injection molding material accumulating in the cavity near the injection feed port and the appearance of gate marks.

[0073] Optionally, as shown in Figure 6 , Figure 7 and Figure 8 the feeding part 20 further includes: a cold runner piece 202. The cold runner piece 202 includes a second runner. One end of the second runner is a second feed port 2021, and the other end of the second runner is a second discharge port 2022. The second discharge port 2022 is communicated with the first feed port 2011. The width of the second feed port 2021 is smaller than the width of the second discharge port 2022. Between the second feed port 2021 and the second discharge port 2022, the side wall of the second runner is a curved side wall. Among them, the buffer runner includes the first runner and the second runner.

[0074] In this embodiment, by providing a cold runner sheet 202 including a second runner, the width of the second inlet 2021 of the second runner is smaller than the width of the second outlet 2022 of the second runner, and the buffer runner includes a first runner and a second runner, so that the width of the inlet of the buffer runner is smaller than the width of the outlet of the buffer runner. This enables the injection molding material in the buffer channel to reduce its speed from the inlet of the buffer channel to the outlet of the buffer runner, thereby reducing the shear rate of the injection molding material and further reducing the gas generated by the decomposition of the injection molding material.

[0075] Specifically, when the buffer runner includes a first runner and a second runner, the first outlet 2012 is the outlet of the buffer runner, and the second inlet 2021 is the inlet of the buffer runner.

[0076] Optionally, as shown in combination with Figure 6 , Figure 7 and Figure 9 , the width of the first inlet 2011 is equal to the width of the first outlet 2012, and the width value is A for both, where the value range of A is: 15 mm ≥ A ≥ 12 mm. The length of the first runner is B, and the value range of B is: 10 mm ≥ B ≥ 8 mm.

[0077] In this embodiment, by setting the widths of the first inlet 2011 and the first outlet 2012, as well as the length of the first runner, the length and width of the gate sheet 201 are defined. By keeping the width of the gate sheet 201 unchanged, the length of the runner between the second outlet 2022 and the injection inlet is extended, so that after the injection molding material decelerates in the second runner, its speed becomes stable through the first runner.

[0078] Specifically, when the injection molding material is a polymer material, the speeds of the molecules within the injection molding material are made the same within the first runner, so as to reduce the problem of gate marks appearing on the injection molded part 200 due to different speeds of the molecules within the injection molding material.

[0079] Optionally, as shown in combination with Figure 8 , the width of the second inlet 2021 is M, and the width of the second outlet 2022 is N. And the width of the first inlet 2011 is equal to the width of the second outlet 2022.

[0080] Optionally, the first runner includes an injection section 2014 and a buffer section 2015. The distance between the second sidewall and the fourth sidewall remains unchanged from the inlet to the outlet of the injection section 2014. The distance between the second sidewall and the fourth sidewall gradually increases from the inlet to the outlet of the buffer section 2015, and both the second sidewall and the fourth sidewall are curved sidewalls.

[0081] In this embodiment, by providing a curved sidewall structure at the connection between the first runner and the injection feed port, there is no transitional dead angle at the connection between the gate piece 201 and the cavity, so as to further reduce the speed of the injection material in the gradually increasing space in the first runner, and then gradually reduce the shear rate of the injection material. The degree of reduction of the shear rate of the injection material is made more stable, reducing the problem that the speed of the injection material suddenly slows down when the injection material enters the cavity due to the dead angle between the sidewall of the first runner and the cavity, resulting in the accumulation of the injection material in the cavity near the injection feed port and the appearance of gate marks. Moreover, it can reduce the gas entrapment problem existing in the transitional dead angle.

[0082] Optionally, the feeding part 20 further includes: a third runner and a fourth runner. The discharge port of the third runner is communicated with the injection feed port. The feed port of the third runner is communicated with the discharge port of the fourth runner. Among them, the buffer runner includes the third runner and the fourth runner, the width of the third discharge port is C, the width of the fourth feed port is D, and C = 1.8D.

[0083] In this embodiment, by setting the ratio between the width of the third discharge port and the width of the fourth feed port, the inlet width of the buffer runner is made smaller than the outlet width of the buffer runner, so as to reduce the speed of the injection material through the buffer runner, thereby reducing the shear rate of the injection material, and reducing the gas generated by the decomposition of the injection material, and then reducing the problem of the appearance of gate marks. Moreover, this can reduce the gas entrapment in the third runner. Further, by providing the third runner and the fourth runner, the transfer efficiency of the injection material pressure is increased, the pressure holding effect of the thick-walled product is ensured, and its volume shrinkage rate is optimized.

[0084] Specifically, the third runner can also be communicated with the second feed port 2021.

[0085] Optionally, the third runner is a cylinder. A cross-section of the third runner is taken along the direction perpendicular to the extension direction of the third runner, and the diameter of the cross-section of the third runner is E. A cross-section of the cavity side is taken along the direction perpendicular to the extension direction of one side of the cavity where the injection feed port is located, and the maximum thickness of the cavity side is F. Among them, the ratio of E to F is greater than or equal to a preset value G.

[0086] Specifically, the injection material includes acrylonitrile-butadiene-styrene (ABS), polypropylene (PP), polystyrene (PS), PS with glass fiber material added, and polycarbonate (PC).

[0087] Exemplarily, when the injection material is ABS, the value of G is 0.75. When the injection material is PP, the value of G is 0.7. When the injection material is PS, the value of G is 0.75. When the injection material is PS with glass fiber material added or PC, the value range of G is: G ≥ 0.9.

[0088] Combined Figure 11 As shown, an injection molding method for injection molded parts provided by an embodiment of the present disclosure includes:

[0089] S1101, injecting injection molding material into the mold for injection molded parts described in any one of the above embodiments.

[0090] S1102, after the injection molding material is cooled, taking out the cooled injection molding material from the mold.

[0091] S1103, trimming the sprue on the cooled injection molding material to obtain an injection molded part.

[0092] The injection molding method for injection molded parts provided by the embodiment of the present disclosure realizes the production of injection molded parts by injecting injection molding material into the mold for injection molded parts described in any one of the above embodiments and trimming the sprue on the cooled injection molding material after the injection molding material is cooled. Moreover, by enabling the injection molding material to be in the buffer channel, from the inlet of the buffer channel to the outlet of the buffer flow channel, the speed of the injection molding material is reduced, and the gas generated by the decomposition of the injection molding material is reduced, thereby reducing the shear rate of the injection molding material. Furthermore, it is possible to reduce the problem of gate marks appearing at the position corresponding to the gate of the mold in the produced injection molded parts, and improve the aesthetics of the produced injection molded parts.

[0093] The above description and the accompanying drawings fully illustrate the embodiments of the present disclosure, enabling those skilled in the art to practice them. Other embodiments may include structural, logical, electrical, process, and other changes. Embodiments merely represent possible variations. Unless explicitly required, individual components and functions are optional, and the order of operations may vary. Parts and features of some embodiments may be included in or replace parts and features of other embodiments. Moreover, the terms used in this application are only for describing embodiments and do not limit the claims. As used in the description of embodiments and claims, unless the context clearly indicates otherwise, the singular forms "a", "an", and "the" are intended to also include the plural forms. Similarly, as used in this application, the term "and / or" refers to any and all possible combinations including one or more of the associated listed items. Additionally, when used in this application, the term "comprise" and its variants "comprises" and / or "comprising" etc. mean the presence of the stated features, wholes, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components, and / or groups of these. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, or device comprising the element. Herein, what each embodiment focuses on can be the differences from other embodiments, and the same or similar parts among the embodiments can be referred to each other. For the methods, products, etc. disclosed in the embodiments, if they correspond to the method parts disclosed in the embodiments, the relevant parts can refer to the description of the method parts.

[0094] Those skilled in the art will realize that the units and algorithm steps of each example described in connection with the embodiments disclosed herein can be implemented in electronic hardware, or in a combination of computer software and electronic hardware. Whether these functions are executed in hardware or software can depend on the specific application and design constraints of the technical solution. The skilled person can use different methods for each specific application to implement the described functions, but such implementation should not be considered to exceed the scope of the embodiments of the present disclosure. The skilled person can clearly understand that for the sake of convenience and brevity of description, the specific working processes of the systems, devices, and units described above can refer to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0095] In the embodiments disclosed herein, the disclosed methods, products (including but not limited to devices, equipment, etc.) can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units can be merely a logical function division. In actual implementation, there can be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Additionally, the displayed or discussed couplings or direct couplings or communication connections to each other can be through some interfaces. The indirect coupling or communication connection of devices or units can be in electrical, mechanical, or other forms. The units described as separate components may or may not be physically separated. The components shown as units may or may not be physical units, that is, they can be located in one place or distributed to multiple network units. Some or all of the units can be selected according to actual needs to implement this embodiment. Additionally, in the embodiments of the present disclosure, the various functional units can be integrated in one processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit.

[0096] The flowcharts and block diagrams in the accompanying drawings illustrate the possible architectures, functions, and operations of systems, methods, and computer program products according to the embodiments of the present disclosure. In this regard, each block in the flowchart or block diagram can represent a module, a program segment, or a part of code that contains one or more executable instructions for implementing the specified logical function. In some alternative implementations, the functions marked in the block can occur in a different order than that marked in the accompanying drawings. For example, two consecutive blocks can actually be executed substantially in parallel, and sometimes they can also be executed in the reverse order, which can depend on the functions involved. In the descriptions corresponding to the flowcharts and block diagrams in the accompanying drawings, the operations or steps corresponding to different blocks can also occur in a different order than that disclosed in the description. Sometimes there is no specific order between different operations or steps. For example, two consecutive operations or steps can actually be executed substantially in parallel, and sometimes they can also be executed in the reverse order, which can depend on the functions involved. Each block in the block diagram and / or flowchart, and the combination of blocks in the block diagram and / or flowchart, can be implemented by a dedicated hardware-based system for performing the specified functions or actions, or can be implemented by a combination of dedicated hardware and computer instructions.

Claims

1. A mold for injection molded parts, characterized in that, Comprising: A mold body, including a cavity and an injection molding inlet, the cavity being in communication with the injection molding inlet; A feeding part, disposed at the injection molding inlet, the feeding part being used for injecting injection molding material into the cavity, the feeding part being provided with a buffer flow channel, the inlet width of the buffer flow channel being smaller than the outlet width of the buffer flow channel, the buffer flow channel being in communication with the injection molding inlet.

2. The mold for injection molded parts according to claim 1, characterized in that, The feeding part includes: A gate piece, disposed at the injection molding inlet, the gate piece including a first flow channel, the buffer flow channel including the first flow channel, the first flow channel being in communication with the injection molding inlet; one end of the first flow channel is a first inlet, and the other end of the first flow channel is a first outlet.

3. The mold for injection molded parts according to claim 2, wherein The width of the first inlet is greater than or equal to 6 mm; The width of the first outlet is greater than or equal to 12 mm.

4. The mold for injection molded parts according to claim 2, wherein The maximum wall thickness of the injection molded part is h; The first flow channel is sectioned along a direction perpendicular to the feeding direction to obtain a cross-section of the first flow channel, and the length of the cross-section of the first flow channel is H; The relationship between H and h satisfies: H ≥ 1 / 3 × h.

5. The mold for injection molded parts according to claim 2, wherein The extending direction of the gate piece is the same as the demolding direction of the injection molded part.

6. The mold for injection molded parts according to claim 2, wherein The width of the first inlet is greater than the width of the first outlet, and between the first inlet and the first outlet, the side wall of the first flow channel is a curved side wall.

7. The mold for injection molded parts according to claim 2, characterized in that, The feeding part further includes: A cold gate piece, including a second flow channel, one end of the second flow channel is a second inlet, the other end of the second flow channel is a second outlet, the second outlet is in communication with the first inlet, the width of the second inlet is smaller than the width of the second outlet; between the second inlet and the second outlet, the side wall of the second flow channel is a curved side wall; Wherein, the buffer flow channel includes the first flow channel and the second flow channel.

8. The mold for injection molded parts according to claim 7, wherein The width of the first inlet is equal to the width of the first outlet, and the width value is A, and the value range of A is: 15 mm ≥ A ≥ 12 mm; The length of the first flow channel is B, and the value range of B is: 10 mm ≥ B ≥ 8 mm.

9. The mold for injection molded parts according to any one of claims 1 to 8, characterized in that, The feeding part further includes: A third flow channel, the outlet of the third flow channel being in communication with the injection molding inlet; A fourth flow channel, the inlet of the third flow channel being in communication with the outlet of the fourth flow channel; Wherein, the buffer flow channel includes the third flow channel and the fourth flow channel, the width of the third outlet is C, the width of the fourth inlet is D, and C = 1.8D.

10. An injection molding method for injection molded parts, characterized in that, Comprising: Injecting injection molding material into the mold for injection molded parts according to any one of claims 1 to 9; After the injection molding material is cooled, demolding the cooled injection molding material; Trimming the sprue on the cooled injection molding material to obtain the injection molded part.

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