Continuous drying method and drying system for foam products

Abstract

The invention relates to the field of foam drying, solves the problem of high production cost caused by the fact that an existing drying mode cannot be adaptively adjusted according to the shape of a foam packaging material, and provides a continuous drying method for a foam product, which comprises the following steps: acquiring first shape data of the foam product; the first shape data comprises height, average thickness and groove depth; obtaining the available maximum drying temperature of the foam product; obtaining the water content of the foam product; and obtaining the transportation speed of the foam product according to the first shape data, the highest drying temperature and the water content of the foam product. The highest drying temperature suitable for the foam products is adopted as the drying temperature, the drying efficiency can be improved, the conveying speed of the foam products is adjusted and controlled according to the shapes of the different foam products, the drying time of the foam products is shortened on the premise that drying of the foam products is guaranteed, the utilization rate of drying heat can be further increased, and the production efficiency is improved. The production cost is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of foam drying, in particular to a continuous drying method and drying system for foam products. BACKGROUND

[0002] Foam packaging material is a light and effective protective packaging material, which is widely used in various fields. For example, due to the fragile nature of glass bottles, foam packaging material is used to protect the bottle body during packaging, which can greatly reduce the possibility of glass bottle breakage under external force. However, the foam packaging material used for the bottle body generally has a groove matched with the outer shape of the bottle body, and the presence of the groove causes the residual water to collect in the groove to different degrees after cleaning, thereby requiring different drying processes for subsequent drying. When a uniform drying method is used for foam packaging materials of different shapes, there is inevitably a surplus of heat, increasing the economic cost. SUMMARY

[0003] The purpose of the present application is to provide a continuous drying method and drying system for foam products, which solves the problem that the existing drying method cannot be adaptively adjusted according to the shape of the foam packaging material, resulting in high production cost.

[0004] The embodiments of the present application are implemented by the following technical solutions:

[0005] A continuous drying method for foam products, comprising:

[0006] Obtaining first shape data of the foam product; the first shape data includes height, average thickness and groove depth;

[0007] Obtaining the maximum drying temperature available for the foam product;

[0008] Obtaining the moisture content of the foam product;

[0009] According to the first shape data, the maximum drying temperature and the moisture content of the foam product, the transportation speed of the foam product is obtained.

[0010] Preferably, when the foam product uses the maximum drying temperature, the relationship curve of the first shape data, the moisture content and the minimum drying time is obtained through historical data;

[0011] According to the first shape data and the moisture content of the current foam product, the actual drying time of the foam product is obtained, and the transportation speed of the foam product is obtained according to the actual drying time.

[0012] Preferably, the first shape data M=a1H+a2D+a3Z; wherein H is the height of the foam product, D is the average thickness of the foam product, Z is the groove depth of the foam product; a1, a2 and a3 are constants; a1+a2+a3=1.

[0013] Preferably, the method for obtaining the water content of the foam product after cleaning comprises:

[0014] According to the historical data, the relationship between the cleaning parameters, the second shape data and the water content is obtained; the cleaning parameters include: the spray flow and the spray time; the second shape data includes: the convex surface area and the concave surface area;

[0015] According to the actual cleaning parameters and the second shape data, the water content of the foam product after cleaning is obtained.

[0016] Preferably, the concave surface area includes: the upper concave surface area and the side concave surface area.

[0017] Preferably, the second shape data X=b1S1+b2 S2+b3 S3; wherein S1 is the convex surface area of the foam product, S2 is the upper concave surface area of the foam product, S3 is the side concave surface area of the foam product; b1, b2 and b3 are constants; b2>b3.

[0018] Preferably, the transportation path of the foam product during drying includes: a preheating section and a drying section; the temperature of the drying section is the highest drying temperature available to the foam product; the temperature of the preheating section is less than the highest drying temperature available to the foam product.

[0019] The method for obtaining the water content of the foam product after preheating comprises:

[0020] According to the water content of the foam product after cleaning, the temperature of the preheating section and the preheating time, the water content of the foam product after preheating is obtained.

[0021] According to the first shape data of the foam product, the highest drying temperature and the water content after preheating, the transportation speed of the foam product in the drying section is obtained.

[0022] A continuous drying system, which adopts the continuous drying method.

[0023] The system comprises: a transportation device, an image acquisition device, a drying device and a water content detection device; the transportation device is used for transporting the foam product; the image acquisition device is arranged above the transportation device; the image acquisition device is used for acquiring the first shape data and the second shape data; at least a part of the transportation device is arranged in the preheating section and the drying section of the drying device; the starting point and the ending point of the preheating section are both provided with the water content detection device.

[0024] The present application has at least the following beneficial effects:

[0025] The drying temperature of the present application adopts the highest drying temperature applicable to the foam product, which can improve the drying efficiency, and according to the shape of different foam products, the transportation speed of the foam product is regulated, the drying time of the foam product is reduced under the premise of ensuring the drying of the foam product, the utilization rate of drying heat can be further improved, the production efficiency is improved, and the production cost is reduced. DETAILED DESCRIPTION

[0026] In order to make the purpose, method scheme and advantages of the embodiments of the present application more clear, the method scheme in the embodiments of the present application is described clearly and completely, obviously, the described embodiments are part of the embodiments of the present application, not all the embodiments.

[0027] Embodiment 1: A continuous drying method for foam products, comprising:

[0028] Obtaining first shape data of the foam product; the first shape data includes height, average thickness and groove depth;

[0029] Obtaining the highest drying temperature applicable to the foam product;

[0030] Obtaining the moisture content of the foam product;

[0031] According to the first shape data of the foam product, the highest drying temperature and the moisture content, the transportation speed of the foam product is obtained.

[0032] In the specific implementation process, the foam packaging material is generally in the form of a column, such as a cylindrical column and a rectangular column, and then a recess for accommodating a bottle body is arranged on the top wall of the column structure. After the foam packaging material is cleaned by the spraying device, it needs to be sent to the drying device for drying. During the spraying cleaning process, the foam product is placed vertically, and the recess is located at the upper part, which facilitates the contact between the recess and the water body, and thus the cleaning is clean, and when drying, the foam product can be placed vertically or upside down. When the foam product is placed upside down, a turnover mechanism needs to be arranged on the production line, such as a turnover mechanical hand. The upside-down has the advantage that the recess will not become a water collection point, but the turnover process and the arrangement of the turnover mechanism will also reduce the production efficiency and increase the production cost. The inverted foam product also does not utilize the hot air to directly contact the inner wall of the recess. When the foam product is placed vertically, the water remaining on the side wall of the recess will flow to the bottom wall of the recess to some extent, so that the remaining water on the bottom wall of the recess is more than other parts of the foam product, and thus when other parts of the foam product have been dried, there may be some residual water in the recess bottom. As can be seen from the foregoing, when the foam packaging product with different shapes and recesses adopts uniform drying parameters, there will inevitably be a situation of excess heat energy or incomplete drying. The applicant hopes that different drying parameters can be selected according to different shapes of the foam product, so as to ensure the drying effect while reducing energy consumption and improving production efficiency.

[0033] Since the foam packaging product is mainly square and the groove is mainly cylindrical, the wall thickness of the side wall of the foam packaging product is variable, so the average thickness is obtained in this embodiment. The shape data of the foam product can be directly obtained from the size data designed during production of the product, or can be detected by an image detection device. The groove depth affects the drying efficiency of the residual water in the groove; the average thickness affects the heat transfer in the side wall of the product; and the height affects the temperature distribution around the product. Generally, the closer to the heat source, the higher the temperature of the drying area, such as the drying area close to the hot air outlet.

[0034] In this embodiment, the highest drying temperature available for the material of the foam product is selected as the drying temperature, which improves the drying efficiency while ensuring that the temperature does not cause deformation or performance changes of the product.

[0035] The water content of the foam product can be detected by near-infrared spectroscopy, resistance / capacitance method, and weight method. The near-infrared moisture detector can realize rapid measurement of moisture, and can be applied to foam products in continuous transportation.

[0036] In this embodiment, when the foam product uses the highest drying temperature, the relationship curve of the first shape data, water content, and minimum drying time is obtained through historical data.

[0037] According to the first shape data and water content of the current foam product, the actual drying time of the foam product is obtained, and the transportation speed of the foam product is obtained according to the actual drying time.

[0038] In the specific implementation process, the minimum drying time refers to the shortest time required for the foam product to be completely dried. The water content of the foam product after cleaning and the shape of the foam product both affect the time required for drying. Therefore, this embodiment constructs a relationship curve of the three through experiments, and then the minimum drying time corresponding to the shape of the foam product and the water content after cleaning on the current production line can be obtained according to the aforementioned relationship curve, and the transportation speed of the transportation device can be adjusted to control the time of the foam product passing through the drying area.

[0039] In this embodiment, the first shape data M = a1H + a2D + a3Z; wherein H is the height of the foam product, D is the average thickness of the foam product, and Z is the groove depth of the foam product; a1, a2, and a3 are constants; a1 + a2 + a3 = 1.

[0040] In the implementation process, since the first shape data essentially includes different shape parameters, in order to simply construct the relationship curve, the different shape parameters are integrated in the embodiment. Wherein, a1, a2 and a3 can be obtained by experiment. a1, a2 and a3 can be regarded as the influence degree of different shape parameters on the drying result. In the experiment, a single shape parameter can be changed under the same drying parameter, and then the influence degree of the shape parameter on the drying effect can be obtained, and then the ratio of a1, a2 and a3 can be obtained. Since the sum of the three is 1, the specific values of a1, a2 and a3 are finally obtained. Finally, the accuracy of the data can be verified by experiment. After the applicant verifies by experiment, it is found that after selecting the three shape parameters in the embodiment, the accuracy rate of the trend of the finally obtained relationship curve is more than 99%.

[0041] Exemplarily, after the height of the foam product is increased by one unit length, the foam product is dried under the same drying parameter, and the final moisture content of the foam product is increased by 4%. After the average thickness of the foam product is increased by one unit length, the foam product is dried under the same drying parameter, and the final moisture content of the foam product is increased by 2%. After the groove depth of the foam product is increased by one unit length, the foam product is dried under the same drying parameter, and the final moisture content of the foam product is increased by 10%. Further, a1:a2:a3=4:2:10, and finally a1=1 / 16, a2=1 / 8, and a3=5 / 8.

[0042] In the embodiment, the method for obtaining the moisture content of the foam product after cleaning includes:

[0043] obtaining the relationship between the cleaning parameter, the second shape data and the moisture content according to the historical data; the cleaning parameter includes: spray flow and spray time; the second shape data includes: convex surface area and concave surface area;

[0044] obtaining the moisture content of the current foam product after cleaning according to the actual cleaning parameter and the second shape data.

[0045] In the implementation process, the cleaning parameter can be the product of the spray flow and the spray time. The spray time can have a maximum value, such as 20s, that is, when the actual cleaning time exceeds 20s, the spray time is taken as 20s. Under a certain spray flow, when the spray time exceeds a certain value, the moisture content of the foam product after cleaning is almost unchanged, and thus the threshold value of the spray time under different spray flows can be obtained by experiment, and the moisture content of the foam product after cleaning is almost unchanged after exceeding the threshold value.

[0046] The concave area refers to the total area of the groove side wall and the bottom wall. The convex area refers to the area other than the concave area.

[0047] After the relationship curve between the cleaning parameters, the second shape data and the water content is obtained through the experiment, the water content of the foam product after cleaning can be obtained according to the cleaning parameters used in the actual production process and the second shape data of the foam product.

[0048] For example, when the water content of the foam product after cleaning needs to be consistent to facilitate the subsequent control of the drying parameters, the spray flow and / or the spray time can be controlled according to the required water content. Since the control of the spray time involves the control of the transportation speed, in order to avoid affecting other processes, the spray flow can be controlled.

[0049] In this embodiment, the surface area of the recess includes: the surface area of the upper recess and the surface area of the side recess.

[0050] In the actual implementation process, some foam packaging products can be provided with notches or protrusions on the side, thereby forming additional recesses. In this embodiment, the surface area of the upper recess refers to the surface area of the groove for accommodating and limiting the bottle body. The surface area of the side recess refers to the surface area of the recess formed on the side of the product due to the provision of notches or protrusions. In this embodiment, the surface area of the recess includes the side area and the bottom area of the recess.

[0051] In this embodiment, the second shape data X = b1S1 + b2S2 + b3S3; wherein S1 is the surface area of the convex part of the foam product, S2 is the surface area of the upper recess of the foam product, and S3 is the surface area of the side recess of the foam product; b1, b2 and b3 are constants; b2 > b3.

[0052] In the actual implementation process, the specific values of b1, b2 and b3 in the second shape data can refer to the acquisition method of a1, a2 and a3 in the first shape data.

[0053] For example, when the water content of the foam product after cleaning needs to be consistent to facilitate the subsequent control of the drying parameters, the spray flow and / or the spray time can be controlled according to the required water content. Since the control of the spray time involves the control of the transportation speed, in order to avoid affecting other processes, the spray flow can be controlled. 2 After cleaning under the same cleaning parameters, the final water content of the foam product increases by 2%. After the surface area of the upper recess of the foam product is increased by 1cm 2 After cleaning under the same cleaning parameters, the final water content of the foam product increases by 5%. After the surface area of the side recess of the foam product is increased by 1cm 2 After cleaning under the same cleaning parameters, the final water content of the foam product increases by 3%. Then a1:a2:a3=2:5:3, and finally b1=0.2, b2=0.5, and b3=0.3.

[0054] In this embodiment, the transportation path of the foam product during drying includes: a preheating section and a drying section; the temperature of the drying section is the highest drying temperature available for the foam product; and the temperature of the preheating section is less than the highest drying temperature available for the foam product.

[0055] The method for obtaining the water content of the foam product after preheating comprises:

[0056] The water content of the foam product after preheating is obtained according to the water content of the foam product after cleaning, the temperature of the preheating section and the preheating time.

[0057] The conveying speed of the foam product in the drying section is obtained according to the first shape data of the foam product, the highest drying temperature and the water content after preheating.

[0058] In the implementation process, in order to reduce the influence of thermal stress on the structure of the product, the foam product is usually preheated before drying at a higher temperature. In this embodiment, the temperature of the preheating section can be 80% of the highest drying temperature.

[0059] Exemplarily, the water content of the foam product after cleaning is controlled, and then the relationship curve between the preheating section temperature, the preheating time and the water content of the foam product after preheating can be obtained through experiments. The conveying speed of the foam product in the preheating section can be consistent with that in the drying section, and then the preheating time is constant, and when the preheating temperature is also constant, the water content of the foam product after preheating can be simply obtained according to the water content of the foam product before preheating. Of course, the water content of different foam products after preheating can also be controlled to be consistent, and then the preheating temperature can be adjusted according to the water content after preheating.

[0060] Embodiment 8: The embodiment provides a continuous drying system, which adopts the continuous drying method.

[0061] The system comprises a conveying device, an image acquisition device, a drying device and a water content detection device, the conveying device is used for conveying the foam product, the image acquisition device is arranged above the conveying device, the image acquisition device is used for acquiring first shape data and second shape data, at least a part of the conveying device is arranged in the preheating section and the drying section of the drying device, and the water content detection device is arranged at the starting point and the ending point of the preheating section.

[0062] In the implementation process, the conveying device can adopt a transmission net belt. The image acquisition device can adopt a high-definition camera, and the image acquisition device can be arranged above and on the side of the conveying device. The drying device can adopt hot air drying. The water content detection device can adopt a near-infrared moisture detector.

[0063] The above is only a preferred embodiment of the present application and is not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A continuous drying method for a foamed product, characterized in that, The method comprises: obtaining first shape data of the foam product; the first shape data comprises height, average thickness and groove depth; obtaining the maximum drying temperature available for the foam product; obtaining the moisture content of the foam product; obtaining the transport speed of the foam product according to the first shape data of the foam product, the maximum drying temperature and the moisture content.

2. The continuous drying method according to claim 1, characterized in that, When the foam product adopts the maximum drying temperature, the relationship curve of the first shape data, the moisture content and the minimum drying time is obtained through historical data; obtaining the actual drying time of the foam product according to the first shape data and the moisture content of the current foam product, and obtaining the transport speed of the foam product according to the actual drying time.

3. The continuous drying method according to claim 1, wherein, The first shape data M=a1H+a2D+a3Z; wherein H is the height of the foam product, D is the average thickness of the foam product, and Z is the groove depth of the foam product; a1, a2 and a3 are constants; a1+a2+a3=1.

4. The continuous drying method according to any one of claims 1 to 3, characterized in that, The method for obtaining the moisture content of the foam product after cleaning comprises: obtaining the relationship between the cleaning parameters, the second shape data and the moisture content according to historical data; the cleaning parameters include spray flow and spray time; the second shape data includes convex surface area and concave surface area; obtaining the moisture content of the current foam product after cleaning according to the actual cleaning parameters and the second shape data.

5. The continuous drying method according to claim 4, wherein The concave surface area includes upper concave surface area and side concave surface area.

6. The continuous drying method according to claim 5, characterized in that, The second shape data X=b1S1+b2 S2+b3 S3; wherein S1 is the convex surface area of the foam product, S2 is the upper concave surface area of the foam product, and S3 is the side concave surface area of the foam product; b1, b2 and b3 are constants; b2>b3.

7. The continuous drying method according to claim 4, wherein The transport path of the foam product during drying comprises a preheating section and a drying section; the temperature of the drying section is the maximum drying temperature available for the foam product; the temperature of the preheating section is less than the maximum drying temperature available for the foam product; The method for obtaining the moisture content of the foam product after preheating comprises: obtaining the moisture content of the foam product after preheating according to the moisture content of the foam product after cleaning, the temperature of the preheating section and the preheating time; obtaining the transport speed of the foam product in the drying section according to the first shape data of the foam product, the maximum drying temperature and the moisture content after preheating.

8. A continuous drying system characterized by, The system adopts the continuous drying method of any one of claims 1-7; The system comprises: a transport device for transporting the foam product; an image acquisition device arranged above the transport device; the image acquisition device is used to acquire first shape data and second shape data; a drying device, at least a part of the transport device passes through the preheating zone and the drying zone of the drying device; moisture content detection devices are arranged at the start and end points of the preheating zone.