Uniform-cooling forming mold for EPS (Expandable Polystyrene) packaging foam production

Abstract

The utility model discloses a uniform-cooling forming mold for EPS packaging foam production, and belongs to the field of EPS packaging foam production.The forming mold comprises an upper mold body and a lower mold body, the upper mold body and the lower mold body are oppositely arranged, and a cavity is formed between the upper mold body and the lower mold body; cooling channels are arranged in the upper mold and the lower mold, the cooling channels are spirally distributed around the mold cavity, a liquid inlet is formed in one end of each cooling channel, and a liquid outlet is formed in the other end of each cooling channel; and a plurality of heat dissipation bulges are arranged on the surfaces of the cavities of the upper mold and the lower mold. The cooling channel which is spirally distributed around the cavity is formed in the mold, so that the cooling medium can uniformly flow through the periphery of the cavity, and uniform cooling of the cavity is realized; meanwhile, the heat dissipation protrusions are arranged on the surface of the cavity, the heat dissipation area is increased, the heat dissipation efficiency is improved, and the cooling uniformity is further guaranteed, so that the forming quality of the EPS packaging foam is improved, the defects such as deformation and cracking are reduced, and the production efficiency is improved.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of EPS packaging foam production, and particularly relates to a forming mold for uniformly cooling EPS packaging foam production. BACKGROUND

[0002] In the modern packaging industry, EPS packaging foam (polystyrene foam) is widely used in the fields of electronic products, household appliances, food, etc. as a kind of high polymer material with light weight, heat insulation and excellent shock resistance. The preparation principle is to mix polystyrene resin with a foaming agent, release gas after softening by heating, and form foam plastic with a hard closed-cell structure. In the production process, the forming mold is the core component that determines the quality of the foam product, and directly affects the uniformity of foaming, cooling efficiency and demolding effect. The traditional production process is usually as follows: the EPS raw material particles are put into the mold cavity, and after foaming by steam heating, cooling water is introduced to solidify the foam and separate it from the metal mold, and finally the mold is opened and demolded.

[0003] A Chinese utility model patent with the authorization announcement number CN219634338U discloses a forming mold for uniformly cooling EPS packaging foam production. The mold is connected with an external cooling system through a circulating discharge pipe and a circulating access pipe, and three groups of disc-type pipe circulation cooling structures are constructed to realize uniform cooling through the layout of the disc pipe in the top wall region. The scheme stabilizes the mold through the sleeve pipe guide pile structure, and accelerates cooling through the sliding groove buckling of the forming cavity plate and the auxiliary pipe, thereby improving the heat dissipation efficiency of the top wall region to a certain extent.

[0004] The disc-type pipe of the prior art is only distributed in the inside of the mold cavity top shell, and the cooling range is limited to the top wall region, so the mold cavity side wall, bottom surface and corner cannot be effectively cooled. Since the thermal conductivity coefficient of EPS foam is low, the heat in the non-top wall region of the mold cavity is difficult to be quickly conducted out through the single top wall cooling structure, so that the temperature difference between different regions is significant. Such uneven cooling can cause inconsistent shrinkage of the foam during solidification, resulting in defects such as deformation, cracking and surface shrinkage of the product, and seriously affecting the structural strength and appearance quality of the packaging foam.

[0005] Therefore, the application provides a forming mold for uniformly cooling EPS packaging foam production to solve the above problems. CONTENT OF THE UTILITY MODEL

[0006] The application provides a forming mold for uniformly cooling EPS packaging foam production, which aims to solve the problems of the prior art that the cooling channel layout of the existing forming mold can only cool the top wall of the mold cavity, the cooling uniformity is poor, and the EPS foam is deformed, cracked and has surface shrinkage defects due to a large temperature difference between different parts during forming.

[0007] To achieve the above object, the present application provides the following technical scheme: a forming mold for EPS packaging foam production with uniform cooling, comprising an upper mold and a lower mold, the upper mold and the lower mold are oppositely arranged, and a forming cavity is formed between the upper mold and the lower mold; a cooling channel is arranged in the upper mold and the lower mold, the cooling channel is distributed in a spiral shape around the forming cavity, one end of the cooling channel is provided with a liquid inlet, and the other end is provided with a liquid outlet; the surface of the forming cavity of the upper mold and the lower mold is provided with a plurality of heat dissipation protrusions. By arranging the cooling channel which is distributed in a spiral shape around the forming cavity in the mold, the cooling medium can uniformly flow around the forming cavity, and the uniform cooling of the forming cavity is realized; at the same time, the heat dissipation protrusions are arranged on the surface of the forming cavity, the heat dissipation area is increased, the heat dissipation efficiency is improved, and the uniformity of cooling is further ensured, so that the forming quality of the EPS packaging foam is improved, the defects such as deformation and cracking are reduced, and the production efficiency is improved.

[0008] Preferably, in order to increase the heat dissipation area: the heat dissipation protrusions are conical. The conical heat dissipation protrusions can maximize the heat dissipation area without affecting the shape of the forming cavity, thereby improving the heat dissipation efficiency.

[0009] Preferably, in order to reduce the resistance of the cooling channel to the flow of the cooling medium: the cross-sectional shape of the cooling channel is circular. The cross section of the cooling channel is designed to be circular, which utilizes the characteristic that the flow resistance of a circular cross section pipe is the smallest in fluid mechanics, so as to ensure that the cooling medium flows stably in the channel at low energy consumption and high flow rate, and avoid local flow shortage or pressure unevenness caused by excessive flow resistance.

[0010] Preferably, the liquid inlet and the liquid outlet are arranged on the outside of the upper mold and the lower mold, and the liquid inlet and the liquid outlet are respectively connected with an external cooling system. By being connected with the external cooling system, the recycling of the cooling medium can be realized, the cooling efficiency is improved, and the production cost is reduced.

[0011] Preferably, in order to ensure that the upper mold moves vertically up and down on the lower mold: guide rods are fixedly inserted into the four corners of the lower mold, shaft sleeves are slidably arranged on the guide rods, and the shaft sleeves are connected with the four corners of the upper mold. By fixing the guide rods in the four corners of the lower mold and slidably connecting the shaft sleeves with the upper mold, the vertical and accurate movement of the upper mold along the guide rods can be realized. This structure avoids the problems of cavity misalignment and poor sealing caused by horizontal deviation of the upper mold during mold opening and closing, ensures the size accuracy of the cavity when the upper and lower molds are closed, reduces defects such as foam flash and material shortage; at the same time, the sliding cooperation of the guide rods and the shaft sleeves can disperse the mechanical stress during mold opening and closing, prolong the service life of the mold, and is especially suitable for high-speed mold opening and closing operation of automatic production line.

[0012] The application sets the cooling channels spirally distributed around the cavity in the upper die and the lower die, so that the flow path of the cooling medium extends evenly along the circumference of the cavity, significantly improves the contact area and contact time of the mold and the cooling medium, avoids the cooling blind area of the traditional straight channel, and thus realizes the uniform cooling of the whole cavity. Compared with the disc-shaped pipe structure in the prior art which can only cool the top wall, the design can effectively reduce the deformation, cracking and uneven density of EPS foam caused by uneven cooling, and improve the product forming precision and the qualified rate; at the same time, the spiral path prolongs the heat exchange stroke, which can shorten the cooling time and improve the production efficiency in cooperation with the external circulation system.

[0013] The application sets the cooling channels spirally distributed around the cavity in the upper die and the lower die, so that the flow path of the cooling medium extends evenly along the circumference of the cavity, significantly improves the contact area and contact time of the mold and the cooling medium, avoids the cooling blind area of the traditional straight channel, and thus realizes the uniform cooling of the whole cavity. Compared with the disc-shaped pipe structure in the prior art which can only cool the top wall, the design can effectively reduce the deformation, cracking and uneven density of EPS foam caused by uneven cooling, and improve the product forming precision and the qualified rate; at the same time, the spiral path prolongs the heat exchange stroke, which can shorten the cooling time and improve the production efficiency in cooperation with the external circulation system. BRIEF DESCRIPTION OF DRAWINGS

[0014] Fig. 1 It is a structural schematic diagram of a cooling uniform forming die for EPS packaging foam production;

[0015] Fig. 2 It is a structural schematic diagram of the cavity inside;

[0016] Fig. 3 It is a structural side view of the inside of the upper die and the lower die.

[0017] In the figure:

[0018] 1, upper die; 2, lower die; 3, cavity; 31, heat dissipation protrusion; 4, cooling channel; 41, liquid inlet; 42, liquid outlet; 5, guide rod; 51, shaft sleeve. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, not all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the application.

[0020] The embodiment provides a cooling uniform forming die for EPS packaging foam production, which comprises an upper die and a lower die. Figs. 1-3As shown, the forming die includes an upper die 1 and a lower die 2, the upper die 1 is arranged opposite to the lower die 2, and a forming cavity 3 is formed between the upper die 1 and the lower die 2;

[0021] The upper die 1 and the lower die 2 are both provided with cooling channels 4, the cooling channels 4 are distributed in a spiral shape around the forming cavity 3, one end of the cooling channels 4 is provided with an inlet 41, and the other end is provided with an outlet 42; by arranging the cooling channels 4 which are distributed in a spiral shape around the forming cavity 3 in the upper die 1 and the lower die 2, the flow path of the cooling medium is uniformly extended along the circumference of the forming cavity 3, which significantly improves the contact area and contact time of the die and the cooling medium, avoids the cooling blind area of the traditional straight channel, and thus realizes uniform cooling of the entire forming cavity 3. Compared with the disc type pipe structure in the prior art which can only cool the top wall, this design can effectively reduce the defects such as deformation, cracking and uneven density of EPS foam caused by uneven cooling, and improve the product forming precision and qualification rate; at the same time, the spiral path prolongs the heat exchange stroke, which can shorten the cooling time and improve the production efficiency in cooperation with the external circulation system. The external cooling system (such as a water pump and a temperature control device) pumps the constant-temperature cooling medium (such as water or cooling oil) from the inlet 41 into the spiral cooling channels 4 of the upper die 1 or the lower die 2, the cooling medium flows along the spiral path around the forming cavity 3, continuously absorbs the heat of the die (heat exchange) during the flow process, and finally flows back to the external cooling system from the outlet 42 for cooling and recycling. The spiral structure makes the cooling medium flow uniformly through the top wall, side wall and bottom of the forming cavity 3, avoiding local overheating or overcooling, and realizing uniform heat dissipation around the whole forming cavity 3.

[0022] The surface of the forming cavity 3 of the upper die 1 and the lower die 2 is provided with a plurality of heat dissipation protrusions 31. The heat dissipation protrusions 31 are conical. The heat dissipation protrusions 31 arranged on the surface of the forming cavity 3 of the upper die 1 and the lower die 2 are conical, the effective heat dissipation area of the forming cavity 3 is increased by the protrusion structure, and the generatrix design of the conical shape can maximize the contact area with the EPS foam material without changing the main profile of the forming cavity 3, and accelerate the conduction of heat from the inside of the foam to the surface of the die. At the same time, the tip of the conical protrusion is directed outward from the die, which can reduce the adsorption force between the foam after solidification and the protrusion, avoid leaving marks on the surface during demolding, and ensure that the outer surface of the product is smooth and flat while improving the heat dissipation efficiency, especially suitable for packaging foam products with high appearance precision. In the process of EPS foam foaming and molding, the conical heat dissipation protrusion 31 directly contacts the high-temperature foam material, and the increased surface area significantly increases the heat conducted to the die per unit time. The conical surface of the protrusion guides the heat to diffuse uniformly to the die body along the generatrix direction, and then is taken away by the cooling channel 4; at the same time, when the foam material shrinks during solidification, the inclined surface of the conical structure reduces the contact stress with the foam, facilitating demolding and avoiding surface defects caused by the protrusion structure.

[0023] The cooling medium can flow uniformly around the cavity 3 to uniformly cool the cavity 3 by arranging the cooling channels 4 in a spiral around the cavity 3 in the mold. Meanwhile, the heat dissipation protrusions 31 are arranged on the surface of the cavity 3 to increase the heat dissipation area and improve the heat dissipation efficiency, further ensuring the uniformity of cooling, thereby improving the forming quality of the EPS packaging foam, reducing the generation of defects such as deformation and cracking, and improving the production efficiency.

[0024] In order to reduce the resistance of the cooling channel 4 to the flow of the cooling medium, the cross-sectional shape of the cooling channel 4 is circular. The cross-section of the cooling channel 4 is designed to be circular, which utilizes the characteristic of the minimum flow resistance of the circular cross-section pipe in fluid mechanics to ensure the stable flow of the cooling medium in the channel with low energy consumption and high flow rate, avoiding local flow shortage or pressure unevenness caused by excessive flow resistance. The inner wall of the circular cross-section cooling channel 4 is smooth and the stress is uniform in all directions, and when the cooling medium (such as liquid) flows along the channel under the driving of pressure, the laminar boundary layer thickness is uniform, and vortex or flow dead zone is not easy to form.

[0025] The liquid inlet 41 and the liquid outlet 42 are arranged on the outer side of the upper mold 1 and the lower mold 2, and the liquid inlet 41 and the liquid outlet 42 are respectively connected with the external cooling system. By connecting with the external cooling system, the recycling of the cooling medium can be realized, the cooling efficiency is improved, and the production cost is reduced. The external cooling system can provide cooling medium with constant temperature, such as cooling water or cooling oil, which is communicated with the liquid inlet 41 and the liquid outlet 42 through pipeline to form a closed loop circuit of "medium supply-heat exchange-cooling return", the cooling system pumps low-temperature medium into the liquid inlet 41, the medium absorbs heat of the mold when flowing through the spiral cooling channel 4, the temperature rises, the medium after temperature rise flows back to the cooling system from the liquid outlet 42, and is cooled to the initial temperature by the refrigeration device for recycling, realizing the recycling of the cooling medium.

[0026] In order to ensure the vertical up-down movement of the upper die 1 on the lower die 2: the four corners of the lower die 2 are fixedly inserted with guide rods 5, the guide rods 5 are slidingly provided with shaft sleeves 51, and the shaft sleeves 51 are in penetration connection with the four corners of the upper die 1. The four corners of the lower die 2 are fixedly inserted with the guide rods 5, and are slidingly connected with the upper die 1 through the shaft sleeves 51, so that the vertical precise movement of the upper die 1 along the guide rods 5 can be realized. The structure avoids the problems such as mispositioning of the cavity 3, insufficient sealing and the like caused by horizontal deviation of the upper die 1 during mold opening and closing, ensures the dimensional accuracy of the cavity 3 when the upper and lower dies 2 are closed, reduces defects such as foam flash and material shortage, and at the same time, the sliding cooperation of the guide rods 5 and the shaft sleeves 51 can disperse the mechanical stress during mold opening and closing, prolong the service life of the mold, and is especially suitable for high-speed mold opening and closing operation of the automatic production line. The guide rods 5 are vertically fixed to the four corners of the lower die 2, the shaft sleeves 51 are embedded in the guide holes of the upper die 1 and are slidingly connected with the guide rods 5. When the hydraulic or mechanical device drives the upper die 1 to move up and down, the shaft sleeves 51 slide along the axis direction of the guide rods 5, the rigid support of the guide rods 5 is used to limit the horizontal displacement of the upper die 1, and only the vertical movement freedom is reserved. When closed, the guide mechanism ensures the precise butt joint of the cavity 3 of the upper die 1 and the lower die 2, avoids mispositioning of the cooling channel 4 or deformation of the cavity 3 caused by deviation, and ensures the uniformity of cooling and the molding precision of the product.

[0027] It should be noted that the various standard parts used in the present application can be obtained from the market, and the non-standard parts can be specially customized, and the connection method adopted in the present application is also a very common means in the mechanical field, which will not be described here.

[0028] The above is only the preferred specific embodiment of the present application, but the protection scope of the present application is not limited thereto, and any skilled person in the art can make equivalent replacement or change according to the technical solution and concept of the present application within the technical range disclosed by the present application, which should be covered within the protection scope of the present application.

Claims

1. A cooling uniform forming mold for EPS packaging foam production, comprising an upper mold (1) and a lower mold (2), characterized in that: the upper mold (1) is arranged opposite to the lower mold (2), and a forming cavity (3) is formed between the upper mold (1) and the lower mold (2); cooling channels (4) are arranged in the upper mold (1) and the lower mold (2), the cooling channels (4) are distributed in a spiral shape around the forming cavity (3), one end of the cooling channels (4) is provided with a liquid inlet (41), and the other end is provided with a liquid outlet (42); the surface of the forming cavity (3) of the upper mold (1) and the lower mold (2) is provided with a plurality of heat dissipation protrusions (31). The heat dissipation protrusions (31) are conical. The cross-sectional shape of the cooling channel (4) is circular. The liquid inlet (41) and the liquid outlet (42) are arranged on the outside of the upper mold (1) and the lower mold (2), and the liquid inlet (41) and the liquid outlet (42) are respectively connected with an external cooling system.

2. The cooling uniform molding mold for EPS packaging foam production according to claim 1, characterized in that: The four corners of the lower mold (2) are fixedly inserted with guide rods (5), the guide rods (5) are slidably provided with shaft sleeves (51), and the shaft sleeves (51) are penetratingly connected with the four corners of the upper mold (1).

3. The cooling uniform molding mold for EPS packaging foam production according to claim 1, characterized in that: ​ 4. The cooling uniform molding mold for EPS packaging foam production according to claim 1, characterized in that: ​ 5. The cooling uniform molding mold for EPS packaging foam production according to claim 1, characterized in that: ​

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