Foaming and injection method for plates for container and refrigerated container

Abstract

The invention provides a foaming and injecting method for a plate for a container and the refrigerated container. The foaming injection method for the plate for the container comprises the injection steps that first area injection is conducted, specifically, an injection gun extends into a to-be-filled cavity of the plate from an injection opening, foaming raw materials are injected at a first angle alpha 1 according to a first flow q1, and the injection time is t1; the material injection gun is rotated around the material injection opening to a second angle alpha 2, material injection is conducted according to a second flow q2 in the rotating process of the material injection gun, and the material injection time is t2; the material injection gun injects materials at a second angle alpha 2 according to a third flow q3, and the material injection time is t3; wherein q1 = q2 = q3, t1 = t3, and the material injection gun at the first angle alpha 1 and the material injection gun at the second angle alpha 2 are symmetrical with the axis where the material injection port is located as the symmetry axis. The injection gun injects materials at different angles, so that the problems of nonuniform foaming, insufficient foam body strength and the like caused by long flowing distance and poor foaming material flowability in a traditional injection method can be effectively solved.

Description

Technical Field

[0001] The present application relates to the technical field of containers, and more particularly to a method for foaming and injecting materials for container plates and a refrigerated container. Background Art

[0002] As an important multi-modal transportation tool, refrigerated containers play an important role in the cold chain logistics industry. A refrigerated container consists of a refrigeration unit and a refrigerated insulation box. The refrigeration unit provides continuous cold energy input to the container body, while the refrigerated insulation box plays a role in heat preservation and insulation.

[0003] Commonly, polyurethane rigid foam is often used for heat preservation in refrigerated containers. In the industry, a multi-stage foaming process is mostly adopted. After the "sandwich" closed-mold foaming is formed on each side of the refrigerated container, it is then assembled into a refrigerated container.

[0004] The panel materials of refrigerated containers are conventionally processed by a closed-mold foaming process. Specifically, two guns are used to inject materials in a closed mold in the width direction of the plate. Since the length of the plate reaches 12m, the foaming material often needs to have very good fluidity, a long flow distance, and a slow reaction time. And due to the too long flow distance, at the end of the foaming material filling, the foam bubbles and the foam body strength will be weak. During subsequent painting and stacking in the yard, quality problems such as delamination between the surface material and the foam often occur due to temperature stimulation. In addition, due to the too long flow distance, in order to achieve filling at the end of the flow, too much injection volume often needs to be injected, resulting in an increase in cost.

[0005] Therefore, a method for foaming and injecting materials for container plates and a refrigerated container are needed to at least partially solve the above problems. Summary of the Invention

[0006] A series of simplified concepts are introduced in the Summary of the Invention section, which will be further described in detail in the Detailed Description section. The Summary of the Invention section of the present application does not mean to attempt to define the key features and essential technical features of the claimed technical solution, nor does it mean to attempt to determine the protection scope of the claimed technical solution.

[0007] To at least partially solve the above problems, a first aspect of the present application provides a method for foaming and injecting materials for container plates.

[0008] The method for foaming and injecting materials for container plates, the injection steps include the following steps:

[0009] Injection in the first area: Insert the injection gun into the cavity to be filled of the plate from the injection port, and inject the foaming raw material at the first angle α1 at the first flow rate q1 for the injection time t1;

[0010] Injecting material into the middle area: Rotate the material injection gun around the injection port to the second angle α2. During the rotation of the material injection gun, inject material at the second flow rate q2 for an injection time of t2;

[0011] Injecting material into the second area, the material injection gun injects material at the third flow rate q3 at the second angle α2 for an injection time of t3;

[0012] Among them, q1 = q2 = q3, t1 = t3, and the material injection gun at the first angle α1 and the material injection gun at the second angle α2 are symmetric with respect to the axis where the injection port is located.

[0013] According to the foaming material injection method for the container board in the first aspect of the present application, the material injection gun injects material at different angles, which can effectively solve problems such as uneven foaming and insufficient foam strength caused by long flow distance and poor fluidity of the foaming material in the traditional material injection method, and finally can fill different areas of the board more evenly.

[0014] Optionally, the ranges of the first angle α1 and the second angle α2 are: 30° ≤ α1 = α2 ≤ 45°.

[0015] Optionally, in the step of injecting material into the middle area, the material injection gun rotates at a constant speed, and the angular velocity ω of the rotation of the material injection gun is (180° - α1 - α2) / t2.

[0016] Optionally, the injection volume in the step of injecting material into the first area is V1, and the injection volume in the step of injecting material into the second area is V3, V1 = V3;

[0017] The total amount of the foaming raw material injected in the step of injecting material into the first area is m1, and the total amount of the foaming raw material injected in the step of injecting material into the second area is m3, m1 = m3 = V1 * ρ, where ρ is the feeding density of the foaming raw material before foaming.

[0018] Optionally, the injection times in the step of injecting material into the first area and the step of injecting material into the second area: t1 = t2 = m1 / q1.

[0019] Optionally, in the step of injecting material into the middle area, the injection volume is V2 = V - V1 - V3, where V is the volume of the cavity to be filled;

[0020] V1 = (L / 2 - L3 * cosα1) * w * h, where L is the length of the cavity to be filled, L3 is the length of the material injection gun extending into the cavity to be filled, w is the width of the cavity to be filled, and h is the thickness of the cavity to be filled.

[0021] Optionally, the board is provided with n such injection ports, and the injection volume V of each injection port is V0 / n, where V0 is the total volume of the board.

[0022] Optionally, each of the injection ports is located at the midline of the corresponding injection area.

[0023] Optionally, before the injection step, the following steps are further included:

[0024] Formwork erection step: Place the lower plate on the pallet, and install formwork at the edge of the lower plate;

[0025] Mold closing step: Cover the upper plate onto the formwork so that the upper plate, the lower plate and the formwork enclose a cavity to be filled, transport the pallet into the fixture, and perform mold closing under the clamping of the upper plate fixture and the lower plate fixture;

[0026] After the injection step, the following steps are further included:

[0027] Curing step: The foaming raw material in the cavity to be filled expands and cures to complete curing;

[0028] Formwork removal step: Transport the pallet out of the fixture, remove the formwork, and obtain a foamed board.

[0029] The second aspect of the present application provides a refrigerated container, including the board prepared by the above-mentioned foaming injection method.

[0030] For the refrigerated container according to the second aspect of the present application, by using the above-mentioned foamed board, the temperature inside the container can be kept stable. Description of the Drawings

[0031] The following drawings of the embodiments of the present application are hereby taken as a part of the present application for understanding the present application. The embodiments and descriptions thereof shown in the drawings are used to explain the principles of the present application. In the drawings,

[0032] Figure 1 is a schematic flow chart of the injection step of the foaming injection method for the container board in a preferred embodiment of the present application;

[0033] Figure 2 is a schematic flow chart of the foaming injection method for the container board in a preferred embodiment of the present application;

[0034] Figure 3 is a schematic diagram of the injection process of the foaming injection method for the container board in a preferred embodiment of the present application;

[0035] Figure 4 is a schematic diagram of the foaming injection area of the container board in a preferred embodiment of the present application, with two injection guns arranged in the figure;

[0036] Figure 5 is a schematic diagram of the foaming injection area of the container board in a preferred embodiment of the present application;

[0037] Figure 6 Schematic three-dimensional view of a container according to a preferred embodiment of the present application;

[0038] Figure 7 Foam quality diagram of the foam end formed by two foam injection methods. In the figure, (a) is a foam board using the traditional injection method, and (b) is a foam board using the injection method of the present application.

[0039] Explanation of reference numerals

[0040] 10: Container

[0041] 20: Injection gun

[0042] 30: Injection port

[0043] 100: Cavity to be filled

[0044] 110: First region

[0045] 120: Second region

[0046] 130: Intermediate region Detailed implementation manners

[0047] In the following description, numerous specific details are given to provide a more thorough understanding of the present application. However, it is obvious to those skilled in the art that the embodiments of the present application can be implemented without one or more of these details. In other instances, in order to avoid confusion with the embodiments of the present application, some well-known technical features are not described.

[0048] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular forms are also intended to include the plural forms. In addition, it should also be understood that when the terms "comprises" and / or "includes" are used in this specification, they specify the presence of the described 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 their combinations.

[0049] In this document, the ordinal numbers such as "first" and "second" cited in the present application are only identifiers and do not have any other meanings, such as a specific order, etc. Moreover, for example, the term "first component" does not imply the existence of a "second component" by itself, and the term "second component" does not imply the existence of a "first component" by itself.

[0050] In this text, terms such as "upper", "lower", "front", "rear", "left", and "right" are only used to represent the relative positional relationships between relevant parts, rather than defining the absolute positions of these relevant parts.

[0051] In this text, terms such as "equal" and "same" are not strict mathematical and / or geometric limitations, and also include allowable errors that can be understood by those skilled in the art and are permitted in manufacturing or use, etc.

[0052] Unless otherwise specified, the numerical ranges in this text include not only the entire range within its two endpoints, but also several sub-ranges contained therein.

[0053] Now, exemplary embodiments according to the present application will be described in more detail with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many different forms and should not be construed as being limited only to the embodiments set forth herein. It should be understood that these embodiments are provided so that the disclosure of the present application is thorough and complete, and the concepts of these exemplary embodiments are fully conveyed to those of ordinary skill in the art.

[0054] Referring to Figures 2 to 5 , the present application provides a method for foaming and injecting materials into a plate for a container 10. The injection step S2 includes the following steps:

[0055] S21. Injection into the first region 110: Insert the injection gun 20 into the cavity 100 to be filled of the plate from the injection port 30, and inject the foaming raw material at the first flow rate q1 at the first angle α1 for an injection time of t1.

[0056] S22. Injection into the middle region 130: Rotate the injection gun 20 around the injection port 30 to the second angle α2, and during the rotation of the injection gun 20, inject the material at the second flow rate q2 for an injection time of t2.

[0057] S23. Injection into the second region 120. The injection gun 20 injects the material at the third flow rate q3 at the second angle α2 for an injection time of t3.

[0058] Wherein, q1 = q2 = q3, t1 = t3, and the injection gun 20 at the first angle α1 and the injection gun 20 at the second angle α2 are symmetric with respect to the axis where the injection port 30 is located. In this solution, the first angle α1 is the angle between the injection gun 20 and one side of the cavity wall where the injection port 30 is located, and the second angle α2 is the angle between the injection gun 20 and the other side of the cavity wall where the injection port 30 is located.

[0059] In this solution, the foaming raw material is a foaming liquid such as polyurethane or polystyrene. The injection gun 20 rotates around the injection port 30 to different angles. This setting enables the foaming liquid to be injected more uniformly inside the board, avoiding the phenomena of "injection accumulation" or "poor flow" that may be caused by traditional single-direction injection. By this method, the foaming liquid can cover the entire injection area, thereby improving the uniformity of the foaming effect.

[0060] The injection gun 20 injects materials at different angles, which can effectively solve the problems of uneven foaming and insufficient foam strength caused by long flow distance and poor fluidity of the foaming material in the traditional injection method, and ultimately can fill different areas of the board more uniformly.

[0061] Among them, during the injection process of the injection gun 20 in the middle area 130, the head of the gun moves in an arc, so that the injection gun 20 moves in a fan shape within the cavity 100 to be filled. By this moving method, it is ensured that the foaming material can cover a larger area during the injection process, avoiding the situation in the traditional injection method where the foaming material is mainly concentrated in the straight-line trajectory direction of the injection gun 20, resulting in excessive injection in some areas and insufficient injection in other areas.

[0062] The injection gun 20 uses symmetric injection in the first area 110 and the second area 120, and the injection flow rate and injection time are the same in these two areas, so that the fluidity of the foaming material in the two end areas within the cavity 100 to be filled is similar, avoiding uneven foaming effect caused by the difference in flow distance, and ensuring the stability and mechanical properties of the foam.

[0063] By combining the above two injection methods, the flow path of the foaming material is optimized, enabling the foaming material to flow smoothly and fill every corner within the cavity 100 to be filled, making the distribution of the foaming material in the entire board cavity more uniform, and reducing the structural non-uniformity and instability of the foam bubbles.

[0064] According to this solution, the precise control of the injection angle, injection time, and flow rate makes the foaming process more efficient, improves the controllability and consistency of the production process, and at the same time reduces the proportion of unqualified products, further improving the production efficiency and the yield rate.

[0065] In this solution, the injection gun 20 is installed at the injection port 30 and can rotate around the injection port 30. The rotation driving method of the injection gun 20 includes but is not limited to manual, motor, and mechanical transmission.

[0066] In some embodiments of this application, the ranges of the first angle α1 and the second angle α2 are: 30° ≤ α1 = α2 ≤ 45°.

[0067] When the angle between the injection gun 20 and the cavity boundary is less than 30°, the distance between the injection gun 20 and the boundary of the cavity 100 to be filled becomes too narrow, which will affect the flow distribution of the foaming liquid at the edge. After the foaming liquid is ejected from the injection gun 20, it will spread within a small angle range. Especially in the edge area of the plate, the distribution of the foaming liquid may become uneven, resulting in the foaming liquid not being able to fully cover the edge area of the cavity. When the angle between the injection gun 20 and the cavity boundary is greater than 45°, the movement range of the injection gun 20 will become concentrated, and the spraying range of the injection gun 20 will become relatively narrow. Too concentrated injection will result in a longer flow path of the foaming liquid, poor fluidity of the foaming liquid in the edge area of the plate, and even the phenomenon that there is not enough foaming material to fill the edge area.

[0068] In some embodiments of the present application, during the injection step in the middle region 130, the injection gun 20 rotates at a constant speed. By rotating at a constant speed, the injection gun 20 can distribute the foaming liquid regularly within the middle region 130, so as to achieve a uniform injection distribution, avoid too much or too little foaming liquid in certain areas, and avoid generating an uneven foaming layer. The angular velocity ω of the injection gun 20 rotating is (180° - α1 - α2) / t2.

[0069] In some embodiments of the present application, the injection volume in the injection step in the first region 110 is V1, and the injection volume in the injection step in the second region 120 is V3, and V1 = V3, that is, the volume of the foaming liquid injected into the first region 110 and the volume of the foaming liquid injected into the second region 120 are equal.

[0070] As can be seen from the foregoing, the same flow rate is used in the first region 110 and the second region 120, and the injection time for each region is also the same. In this case, the volume of the injected foaming liquid is equal. Therefore, the total mass of the used foaming liquid will also be equal. Specifically, the total amount of the foaming liquid injected in the injection step in the first region 110 is m1, and the total amount of the foaming liquid injected in the injection step in the second region 120 is m3, and m1 = m3 = V1 * ρ, where ρ is the feeding density of the foaming raw material before foaming.

[0071] During the injection process, the foaming liquid is injected into the cavity at a certain flow rate. Therefore, the injection time is directly affected by the injection flow rate and the volume of the foaming liquid to be injected. The injection time in the injection step in the first region 110 and the injection step in the second region 120: t1 = t2 = m1 / q1. The masses of the foaming liquid injected into the first region 110 and the second region 120 are equal. Therefore, the volumes of the foaming liquid they inject are also equal. In order to inject the same volume of the foaming liquid, at the same flow rate, the injection time is equal. Keeping the same injection time and flow rate in the two regions can ensure the uniform distribution of the foaming liquid in each region, thereby ensuring the heat insulation performance and strength of the plate.

[0072] In some embodiments of the present application, in the filling step of the middle region 130, the filling volume is V2 = V - V1 - V3, where V is the volume of the cavity 100 to be filled. V1 = (L / 2 - L3 * cosα1) * w * h, where L is the length of the cavity 100 to be filled, L3 is the length of the filling gun 20 extending into the cavity 100 to be filled, w is the width of the cavity to be filled, and h is the thickness of the cavity to be filled. V can be calculated by the volume of the plate. As shown in the figure, L is the length of the cavity 100 corresponding to one filling gun 20, w is the width of the cavity 100 corresponding to one filling gun 20, h is the thickness of the cavity 100 corresponding to one filling gun 20, V = L * w * h. Similarly, V1 = L1 * w * h. L1 = L / 2 - L3 * cosα1.

[0073] It can be understood that the foaming liquid is flowing during the injection into the panel of the refrigerated container 10. The filling volume described in this solution is not simply distributed according to a fixed volume, but according to the volume occupied by the foaming liquid. The foaming liquid is flowing during the injection process, and its flow path, expansion process, and transition between regions will cause the distribution shape of the foaming liquid in different regions to be inconsistent. At the same time, the filling of the first region 110, the middle region 130, and the second region 120 is continuous, that is, there is no obvious dividing line. Therefore, the size of the filling volume corresponding to each region is determined, and the shape is indefinite.

[0074] In some embodiments of the present application, the plate is provided with n filling ports 30, and the filling volume V of each filling port 30 is V = V0 / n, where V0 is the total volume of the plate. When there are multiple filling ports 30 on the plate, a more uniform filling distribution can be achieved when the length of the plate is relatively large.

[0075] Exemplarily, the plate is provided with 2 filling ports 30. The filling volume of each filling port 30 is 1 / 2 of the total volume of the plate.

[0076] Each filling port 30 is located at the midline of the filling region it corresponds to. The filling port 30 being located at the midline position can enable the foaming liquid to fill the entire filling region more evenly after injection, reducing the situation of insufficient filling or accumulation in the edge region.

[0077] Refer to Figure 1 , in some embodiments of the present application, before the filling step S2, it further includes:

[0078] S1. Formwork support step: Place the lower plate on the pallet and install formwork supports at the edges of the lower plate;

[0079] S2. Mold closing step: Cover the upper plate onto the supporting mold so that the upper plate, the lower plate and the supporting mold enclose the cavity 100 to be filled. Transport the pallet into the fixture and perform mold closing under the clamping of the upper plate fixture and the lower plate fixture. The purpose of mold closing is to ensure good sealing between the upper plate, the lower plate and the supporting mold so that the subsequent foaming liquid can be injected and expand in the filling cavity to form the required foam structure.

[0080] In some embodiments of the present application, after the filling step S2, it further includes:

[0081] S4. Curing step: The foaming liquid in the cavity 100 to be filled expands and cures to complete curing;

[0082] S5. Demolding step: Transport the pallet out of the fixture, remove the supporting mold to obtain the foamed board.

[0083] The board for the container 10 prepared by the above foaming and filling method has a uniform foam structure throughout the board. This uniform foam structure can effectively improve the thermal insulation performance of the panel of the refrigerated container 10, reduce the heat transfer, achieve a better heat preservation effect, and can be used for the refrigerated container 10. According to this solution, through the optimization of the filling process, the filling distribution of each batch of the panel of the refrigerated container 10 is more stable and uniform. In long-term and large-scale production, the quality of the board will be more consistent, reducing the fluctuations and quality fluctuations in the production process.

[0084] Refer to Figure 7 , the foam quality diagrams of the foaming ends formed by two foaming and filling methods. It can be seen from the figure that due to the long flow distance at the end, the traditional filling method has more bubbles and drawn foam, and the foam quality is poor. When using the method provided by the present application for filling, due to the large falling area and the short distance between the falling point position and the flow end, the foam quality is better.

[0085] Refer to Figure 6 , the present invention also provides a refrigerated container 10 prepared from the refrigerated board produced by this foaming process. The board is further processed through assembly, welding, coating, and corner foaming, etc. The walls, top and bottom of the refrigerated container 10 are usually formed by splicing multiple foamed boards. Each panel is fixed in shape through special connection methods, such as card slots, slots, screws or welding, etc. By using the above foamed board, the temperature inside the container 10 can be kept stable.

[0086] Unless otherwise defined, the technical and scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art to which this application belongs. The terms used herein are for the purpose of describing particular embodiments only and are not intended to limit this application. Terms such as "arranged" as used herein can mean that one component is directly attached to another component or that one component is attached to another component through an intermediate component. Features described in one embodiment herein can be applied to another embodiment alone or in combination with other features, unless the feature is not applicable or otherwise stated in that other embodiment.

[0087] This application has been described by the above embodiments, but it should be understood that the above embodiments are for illustrative and explanatory purposes only and are not intended to limit this application to the scope of the described embodiments. Those skilled in the art can understand that more variations and modifications can be made according to the teachings of this application, and these variations and modifications all fall within the scope claimed by this application.

Claims

1. A method for foaming and injecting material into a container plate, characterized in that: The injection step includes the following steps: Injection into the first area: insert the injection gun from the injection port into the cavity to be filled of the plate, inject the foaming raw material at the first angle α1 according to the first flow rate q1, and the injection time is t1; Injection in the middle area: the injection gun is rotated around the injection port to a second angle α2. During the rotation of the injection gun, injection is performed according to the second flow rate q2. The injection time is t2. Injection in the second area: the injection gun injects at a third flow rate q3 at a second angle α2, and the injection time is t3; Among them, q1=q2=q3, t1=t3, the injection gun at the first angle α1 and the injection gun at the second angle α2 are symmetrical with the axis where the injection port is located as the axis of symmetry.

2. The method for foaming and injecting material into a container sheet material according to claim 1, characterized in that: The range of the first angle α1 and the second angle α2 is: 30°≤α1=α2≤45°.

3. The method for foaming and injecting material into a plate material for a container according to claim 1, characterized in that: In the middle area injection step, the injection gun rotates at a constant speed, and the angular velocity ω of the injection gun is (180°-α1-α2) / t2.

4. The method for foaming and injecting material into a plate material for a container according to claim 1, characterized in that: The injection volume in the first region injection step is V1, and the injection volume in the second region injection step is V3, V1=V3; The total amount of foaming raw material injected in the first zone injection step is m1, and the total amount of foaming raw material injected in the second zone injection step is m3, m1=m3=V1*ρ, where ρ is the feed density of the foaming raw material before foaming.

5. The method for foaming and injecting material into a plate material for a container according to claim 4, characterized in that: The filling time in the first region filling step and the second region filling step is: t1 = t2 = m1 / q1.

6. The method for foaming and injecting material into a plate material for a container according to claim 4, characterized in that: In the middle area filling step, the filling volume is V2=V-V1-V3, where V is the volume of the cavity to be filled; V1=(L / 2-L3*cosα1)*w*h, where L is the length of the cavity to be filled, L3 is the length of the injection gun extending into the cavity to be filled, w is the width of the cavity to be filled, and h is the thickness of the cavity to be filled.

7. The method for foaming and injecting material into a plate material for a container according to any one of claims 1 to 6, characterized in that: The plate is provided with n injection ports, and the injection volume of each injection port is V=V0 / n, where V0 is the total volume of the plate.

8. The method for foaming and injecting material into a container plate material according to claim 7, characterized in that: Each of the injection ports is located at the center line of the corresponding injection area.

9. The method for foaming and injecting material into a container plate material according to claim 1, characterized in that: Before the injection step, the method further comprises: Formwork step: placing the lower plate on the support plate, and installing the formwork at the edge of the lower plate; Mold closing step: covering the upper plate onto the supporting mold so that the upper plate, the lower plate and the supporting mold form a cavity to be filled, transporting the support plate into the fixture, and performing mold closing under the clamping of the upper plate fixture and the lower plate fixture; After the injection step, the method further comprises: Curing step: the foaming material in the cavity to be filled expands and solidifies to complete the curing; Demolding step: transport the support plate out of the fixture, remove the supporting mold, and obtain the foamed board.

10. A refrigerated container, comprising a plate material prepared by the foaming injection method according to any one of claims 1 to 9.

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