Cold chain package

Abstract

A first phase-change material and a second phase-change material are arranged on a base material for preparing the cold chain package, the first phase-change material has a first phase-change temperature, the difference value between the first phase-change temperature and the cold chain upper limit temperature is T, the second phase-change material is arranged outside the first phase-change material, the second phase-change material has a second phase-change temperature, the difference value between the first phase-change temperature and the cold chain upper limit temperature is T, and the difference value between the second phase-change temperature and the cold chain upper limit temperature is T; the second phase change temperature is higher than the first phase change temperature. According to the cold chain package, when the cold chain temperature is lower than the first phase change temperature, the first phase change material and the second phase change material are in a solid state; when the cold chain temperature is higher than the first phase change temperature but lower than the second phase change temperature, the first phase change material is gradually molten into a liquid state, and in the phase change process of the first phase change material, phase change heat absorption of the first phase change material is beneficial to maintaining the temperature in the cold chain package; the second phase change material which is arranged on the outer side and is in a solid state has good heat insulation performance, external heat can be prevented from entering the cold chain package, and therefore a thermosensitive product is protected.

Description

Technical Field

[0001] The present invention relates to the technical field of packaging, and in particular to a cold chain packaging. Background Art

[0002] The existing corrugated boxes have the following problem when used for cold chain transportation: due to the poor thermal insulation ability of the corrugated boxes, in some weak links of cold chain management, as the external temperature rises, the heat-sensitive products built into the corrugated boxes are prone to absorb heat and deteriorate. Summary of the invention

[0003] Based on this, it is necessary to provide a cold chain packaging to solve the above problems.

[0004] A cold chain package, wherein a first phase change material and a second phase change material are arranged on a substrate for preparing the cold chain package, the first phase change material has a first phase change temperature, the difference between the first phase change temperature and the upper limit temperature of the cold chain is T, the second phase change material is arranged outside the first phase change material, the second phase change material has a second phase change temperature, and the second phase change temperature is higher than the first phase change temperature.

[0005] In one embodiment, the packaging substrate is corrugated paper, and the corrugated paper includes face paper, corrugated core paper and lining paper.

[0006] In one embodiment, the first phase change material is disposed on the inner paper, and the second phase change material is disposed on the surface paper and / or the corrugated core paper.

[0007] In one embodiment, the amount of the first phase change material is 5 g to 30 g per square meter.

[0008] In one embodiment, the first phase change material is selected from at least one of n-tetradecane, n-decanol, oleyl alcohol, isopropyl myristate, pentadecane or ethyl myristate.

[0009] In one embodiment, the second phase transition temperature is ≥ 40°C.

[0010] In one embodiment, the second phase change material is selected from at least one of heneicosane, methyl stearate, elaidic acid, lauric acid, myristic acid, octacosane, palmitic acid, stearic acid, arachidic acid, stearyl glyceride, hexadecanoic acid, behenic acid, tetradecanoic acid, paraffin, triacontanoic acid and dotriacontanoic acid.

[0011] In one embodiment, the amount of the second phase change material is 5 g to 100 g per square meter.

[0012] In one embodiment, the second phase change material is mixed with heat-expandable microspheres.

[0013] In one embodiment, the mass ratio of the second phase change material to the heat-expandable microspheres is 100:1 to 100:10.

[0014] In the above-mentioned cold chain packaging, a first phase change material and a second phase change material are arranged on the substrate. Since the difference between the first phase change temperature and the upper limit temperature of the cold chain is T, the second phase change material is arranged outside the first phase change material, and the second phase change temperature is higher than the first phase change temperature. Therefore, when the cold chain temperature is lower than the first phase change temperature, the first phase change material and the second phase change material are in a solid state at the same time; when the cold chain temperature is higher than the first phase change temperature but lower than the second phase change temperature, the first phase change material gradually melts into a liquid state after absorbing heat, while the second phase change material is always in a solid state. During the phase change of the first phase change material, on the one hand, the phase change heat absorption of the first phase change material helps to maintain the temperature inside the cold chain packaging; on the other hand, the second phase change material in a solid state arranged on the outside has good thermal insulation properties, which can prevent external heat from entering the cold chain packaging, thereby protecting heat-sensitive products. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic structural diagram of a corrugated paperboard according to an embodiment;

[0016] Figure 2 The present invention is a conventional structure of cold chain packaging according to one embodiment. DETAILED DESCRIPTION

[0017] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

[0018] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected" or "communicated" with another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "upper", "lower", "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.

[0019] The cold chain packaging will be further described in detail below mainly in conjunction with the accompanying drawings and specific embodiments.

[0020] In one embodiment of the cold chain packaging, a first phase change material and a second phase change material are disposed on a substrate for preparing the cold chain packaging, and the second phase change material is disposed outside the first phase change material to protect the first phase change material.

[0021] Optional substrates include, but are not limited to: corrugated paper, hollow board, plastic or other packaging materials.

[0022] In this embodiment, the substrate is corrugated cardboard. As a common raw material for paper boxes, corrugated cardboard has good adsorption properties and low cost, especially the adsorption of the first phase change material and the second phase change material.

[0023] Specifically, see Figure 1 The corrugated board includes three hierarchical structures of stacked face paper 10, corrugated core paper 20 and lining paper 30. The face paper 10 is located at the outermost layer of the corrugated board, and is usually made of high-strength kraft paper or cardboard. The corrugated core paper 20 is the core part of the corrugated board, located between the face paper 10 and the lining paper 30, and is composed of corrugated paper, which provides the necessary strength and cushioning performance for the corrugated board. The corrugated core paper 20 can usually be divided into different corrugated forms such as A, B, C, E, F, G, N, etc. according to the shape and size of the corrugation, and different corrugated forms can be suitable for different packaging needs. The lining paper 30 is located at the innermost layer of the corrugated board, and is usually made of low-strength kraft paper or cardboard. Since the face paper 10, the corrugated core paper 20 and the lining paper 30 of the corrugated board all have good adsorption properties, they are particularly suitable as the substrate of the present invention.

[0024] In this embodiment, the first phase change material and the second phase change material are disposed on the substrate by adsorption.

[0025] Optionally, the first phase change material is disposed on the inner paper 30 by adsorption, and the second phase change material is disposed on the surface paper 10 or the corrugated core paper 20 by adsorption.

[0026] Optionally, the first phase change material is disposed on the inner paper 30 and the corrugated core paper 20 by adsorption, and the second phase change material is disposed on the outer paper 10 by adsorption.

[0027] The first phase change material has a specific first phase change temperature, and the difference between the first phase change temperature and the upper limit temperature of the cold chain is T. When the ambient temperature is lower than the first phase change temperature, the first phase change material is in a solid state. When the ambient temperature is higher than the first phase change temperature, the first phase change material gradually melts and eventually becomes liquid. During the phase change process, the temperature of the first phase change material remains unchanged, but it needs to absorb a large amount of heat from the environment. Therefore, it is often used as an energy storage material.

[0028] Optionally, on each hierarchical structure of the corrugated board, the amount of the first phase change material is set at 5g to 30g per square meter, and the amount can be controlled by controlling the mesh number of the anilox roller and the number of coatings. By limiting the amount of the first phase change material, on the one hand, it can be ensured that the cold chain packaging has a strong thermal insulation performance, and on the other hand, it can be ensured that the substrate will not be oversaturated with adsorption, so that when the first phase change material is in a liquid state, it will not penetrate and contaminate the heat-sensitive products in the cold chain packaging.

[0029] Optionally, T≤±2℃. Under normal circumstances, the normal temperature of the cold chain is 3℃-8℃, and its upper limit temperature is 8℃. At this time, optionally, the first phase change temperature is 6℃-10℃, and a first phase change material with a first phase change temperature in this range is used. When the cold chain temperature is near the upper limit temperature of the cold chain, the first phase change material undergoes phase change and absorbs heat, thereby ensuring that the temperature inside the cold chain package is maintained within the range of 6℃-10℃, thereby protecting heat-sensitive products.

[0030] Preferably, 0℃≤T≤2℃. At this time, the first phase change temperature is optionally 8℃-10℃. The first phase change material will not undergo a phase change at normal cold chain temperature. Only when the cold chain temperature is higher than the upper limit temperature of the cold chain, the first phase change material will absorb heat and undergo a phase change, thereby avoiding the first phase change material from undergoing a phase change when the cold chain temperature is higher than the upper limit temperature, thereby achieving precise temperature protection.

[0031] Table 1 provides some first phase change materials with optional phase change temperatures of 5°C-11°C. It should be understood that other phase change materials with first phase change temperatures near the upper limit temperature of the cold chain can also be used as the first phase change material of the present invention.

[0032] Table 1: Some first phase change materials with phase change temperatures of 5°C-11°C

[0033]

[0034]

[0035] It is worth noting that the first phase change material is mostly an oily material with high chemical stability. After the substrate adsorbs the first phase change material, its hydrophobicity will be greatly enhanced.

[0036] The second phase change material is arranged outside the first phase change material, and the second phase change material has a second phase change temperature, and the second phase change temperature is higher than the first phase change temperature. When the ambient temperature is lower than the first phase change temperature, both the first phase change material and the second phase change material are in a solid state. When the ambient temperature is higher than the first phase change temperature but lower than the second phase change temperature, the first phase change material gradually melts and eventually becomes liquid, but the second phase change material remains solid. At this time, the provision of the second phase change material has the following beneficial effects: (1) The strength of the corrugated cardboard hierarchical structure adsorbed with the liquid first phase change material will be greatly reduced under the action of liquid tension. However, the strength of the corrugated cardboard hierarchical structure adsorbed with the second phase change material is greatly enhanced under the action of the solid second phase change material, thereby offsetting the negative effects of the first phase change material. (2) According to the law of molecular motion, the higher the temperature, the greater the molecular motion speed, and the heat transfer capacity of the material is also enhanced. Therefore, the thermal conductivity of the second phase change material in solid state is much lower than that in liquid state. Therefore, the solid second phase change material can play a good heat insulation effect, thereby preventing external heat from entering the cold chain package, thereby protecting the heat-sensitive products in the cold chain package.

[0037] Optionally, the amount of the second phase change material on any hierarchical structure of the corrugated cardboard is 5g to 100g per square meter. Since the second phase change material is solid at room temperature, there is no need to consider whether the substrate is oversaturated with the second phase change material. After saturated adsorption, excess second phase change material will accumulate in solid form on the surface of the substrate, or even in the middle of the corrugation. Supersaturated adsorption helps to improve the thermal insulation effect of the substrate while increasing the strength of the substrate.

[0038] Preferably, the second phase change temperature is ≥40°C, which is higher than the room temperature in most cases. Therefore, even if the cold chain is out of control, under this temperature condition, the second phase change material remains in a solid state, thereby preventing external heat from entering the cold chain packaging at room temperature, thereby protecting heat-sensitive products.

[0039] Table 2 provides some optional second phase change materials with phase change temperatures above 40°C.

[0040] Table 2 Some second phase change materials with phase change temperatures above 40°C

[0041] Serial number Material Name Second phase transition temperature(℃) 1 Heneicosane 40 2 Methyl stearate 41 3 Elaidic Acid 44 4 Lauric acid 44 5 Myristic acid 54 6 Octacosane 62 7 Palmitic acid 63 8 Stearic acid 70 9 Arachidic acid 77 10 Glyceryl Stearate 78 11 Hexadecanoic acid 88 12 Behenic acid 80 13 Tetracosanoic acid 80 14 paraffin 50-80 15 Triacontanic acid 94 16 Dotriacontanoic acid 95

[0042] It is worth noting that the second phase change material is mostly oily material with high chemical stability. After the substrate adsorbs the second phase change material, its hydrophobicity will be greatly enhanced.

[0043] Furthermore, the second phase change material is paraffin, which has a phase change temperature between 50°C and 80°C, and has the characteristics of strong heat insulation and low cost. Experimental data show that the thermal conductivity of solid paraffin is only 0.15W / (mK), while the thermal conductivity of liquid paraffin is 0.2W / (mK).

[0044] Furthermore, the second phase change material is paraffin, and a large number of heat-expandable microspheres are mixed in the second phase change material, and the heat-expandable microspheres have a core-shell structure, the shell is a polymer, and the core is a gas. The mixture of the second phase change material in a liquid state and the heat-expandable microspheres can be arranged on the substrate by spraying. In this process, the following beneficial effects will be produced: before spraying, the temperature of the liquid second phase change material is higher than the second phase change temperature. At this time, the polymer shell of the heat-expandable microspheres is in a softened state, and the gas in the core increases in pressure when heated, and the heat-expandable microspheres will undergo secondary expansion. After spraying, the temperature of the second phase change material gradually decreases. As the temperature decreases, the shell of the heat-expandable microsphere will be fixed on the outer surface of the face paper 10 or the corrugated core paper 20 as the second phase change material solidifies, forming a heat-expandable microsphere layer. At the same time, the shell of the heat-expandable microsphere hardens again as the temperature decreases. Since paraffin has good air tightness, under the protection of paraffin, the atmospheric pressure will not be able to directly act on the shell of the heat-expandable microsphere. Therefore, the volume of the heat-expandable microsphere will no longer change. Due to the drop in ambient temperature, the inner core air pressure of the heat-expandable microsphere will gradually decrease, and the molecular collision frequency will also decrease accordingly. After entering the cold chain, its thermal conductivity can even be one order of magnitude lower than that of paraffin. Therefore, by setting a heat-expandable microsphere layer, the cold chain packaging will have an excellent thermal insulation effect, thereby preventing external heat from entering the cold chain packaging.

[0045] Preferably, the mass ratio of the second phase change material to the heat-expandable microspheres is 100:1 to 100:10.

[0046] Alternatively, any commercially available expanded heat-expandable microspheres can be used as the heat-expandable microspheres of the present invention.

[0047] It should be understood that when the substrate is a hollow plate, the first phase change material and the second phase change material can be disposed in the cavity of the hollow plate. When the substrate is plastic or other packaging materials, the first phase change material and the second phase change material can be disposed on both sides of the substrate.

[0048] It should be understood that the present invention does not limit the structure of the cold chain packaging, and conventional structures or unconventional structures can be used as the cold chain packaging structure of the present invention, which will not be described in detail here. Figure 2 Shown is a conventional cold chain packaging

[0049] In the above-mentioned cold chain packaging, a first phase change material and a second phase change material are arranged on the substrate. Since the difference between the first phase change temperature and the upper limit temperature of the cold chain is T, the second phase change material is arranged outside the first phase change material, and the second phase change temperature is higher than the first phase change temperature. Therefore, when the cold chain temperature is lower than the first phase change temperature, the first phase change material and the second phase change material are in a solid state at the same time; when the cold chain temperature is higher than the first phase change temperature but lower than the second phase change temperature, the first phase change material gradually melts into a liquid state after absorbing heat, while the second phase change material is always in a solid state. During the phase change of the first phase change material, on the one hand, the phase change heat absorption of the first phase change material helps to maintain the temperature inside the cold chain packaging; on the other hand, the second phase change material in a solid state arranged on the outside has good thermal insulation properties, which can prevent external heat from entering the cold chain packaging, thereby protecting heat-sensitive products.

[0050] The following are specific embodiments.

[0051] Example 1

[0052] See also Figure 1 The present embodiment provides a cold chain package. The substrate for preparing the cold chain package is a corrugated cardboard. A first phase change material is arranged on the inner paper 30 of the corrugated cardboard. A second phase change material is arranged on the face paper 10 and the corrugated core paper 20 of the corrugated cardboard. The first phase change material has a first phase change temperature. The difference between the first phase change temperature and the upper limit temperature of the cold chain is T. The second phase change material is arranged outside the first phase change material. The second phase change material has a second phase change temperature, and the second phase change temperature is higher than the first phase change temperature.

[0053] In this embodiment, the first phase change material is oleyl alcohol, having a first phase change temperature of 6°C, and the second phase change material is myristic acid, having a second phase change temperature of 54°C.

[0054] For the above-mentioned cold chain packaging, since the difference between the first phase change temperature and the upper limit temperature of the cold chain is 2°C, when the cold chain temperature is 6°C lower than the first phase change temperature, the first phase change material and the second phase change material are both in a solid state; when the cold chain temperature is 6°C higher than the first phase change temperature but lower than the second phase change temperature of 65°C, the first phase change material gradually melts into a liquid state after absorbing heat, while the second phase change material remains in a solid state. During the phase change of the first phase change material, on the one hand, the phase change heat absorption of the first phase change material helps maintain the temperature inside the cold chain packaging; on the other hand, the second phase change material in a solid state on the outside has good thermal insulation properties, which can prevent external heat from entering the cold chain packaging, thereby protecting heat-sensitive products.

[0055] Example 2

[0056] This embodiment provides a cold chain package, which is similar to the cold chain package provided in Example 1, except that: (1) the first phase change material is pentadecane, which has a first phase change temperature of 9°C; (2) the second phase change material is lauric acid, which has a second phase change temperature of 44°C.

[0057] In the above-mentioned cold chain packaging, the first phase change material will not undergo phase change at normal cold chain temperature. Only when the cold chain temperature is higher than the first phase change temperature, the first phase change material will absorb heat and undergo phase change, thereby avoiding the situation where the first phase change material has undergone phase change when the cold chain temperature is higher than the upper limit temperature, thereby achieving precise temperature protection.

[0058] Example 3

[0059] The present embodiment provides a cold chain package, which is similar to the cold chain package provided in Example 2, except that: (1) the second phase change material is paraffin wax, and has a second phase change temperature of 70°C; (2) the second phase change material is mixed with heat-expandable microspheres in a mass ratio of 100:5. In the present embodiment, the heat-expandable microspheres are provided by Beijing Yijin Technology Co., Ltd., model 46SSW, and particle size is 20-30 μm.

[0060] In the above cold chain packaging, the heat-expandable microspheres have a core-shell structure, the shell is a polymer, and the core is a gas. The mixture of the second phase change material in a liquid state and the heat-expandable microspheres can be disposed on the substrate by spraying. In this process, the following beneficial effects will be produced: before spraying, the temperature of the liquid second phase change material is higher than the second phase change temperature. At this time, the polymer shell of the heat-expandable microspheres is in a softened state, and the gas in the core increases in pressure when heated, and the heat-expandable microspheres will undergo secondary expansion. After spraying, the temperature of the second phase change material gradually decreases. As the temperature decreases, the shell of the heat-expandable microsphere will be fixed on the outer surface of the face paper 10 or the corrugated core paper 20 as the second phase change material solidifies, forming a heat-expandable microsphere layer. At the same time, the shell of the heat-expandable microsphere hardens again as the temperature decreases. Since paraffin has good air tightness, under the protection of paraffin, the atmospheric pressure will not be able to directly act on the shell of the heat-expandable microsphere. Therefore, the volume of the heat-expandable microsphere will no longer change. Due to the drop in ambient temperature, the inner core air pressure of the heat-expandable microsphere will gradually decrease, and the molecular collision frequency will also decrease accordingly. After entering the cold chain, its thermal conductivity can even be one order of magnitude lower than that of paraffin. Therefore, by setting a heat-expandable microsphere layer, the cold chain packaging will have an excellent thermal insulation effect, thereby preventing external heat from entering the cold chain packaging.

[0061] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A cold chain packaging, characterized in that: A first phase change material and a second phase change material are arranged on a substrate for preparing the cold chain packaging, the first phase change material has a first phase change temperature, the difference between the first phase change temperature and the upper limit temperature of the cold chain is T, the second phase change material is arranged outside the first phase change material, the second phase change material has a second phase change temperature, and the second phase change temperature is higher than the first phase change temperature.

2. The cold chain packaging according to claim 1, characterized in that: The packaging substrate is corrugated paper, which includes face paper, corrugated core paper and lining paper.

3. The cold chain packaging according to claim 2, characterized in that: The first phase change material is arranged on the inner paper, and the second phase change material is arranged on the surface paper and / or the corrugated core paper.

4. The cold chain packaging according to claim 3, characterized in that: The amount of the first phase change material is 5 g to 30 g per square meter.

5. The cold chain packaging according to claim 4, characterized in that: The first phase change material is selected from at least one of n-tetradecane, n-decanol, oleyl alcohol, isopropyl myristate, pentadecane or ethyl myristate.

6. The cold chain packaging according to claim 1, characterized in that: The second phase transition temperature is ≥40°C.

7. The cold chain packaging according to claim 6, characterized in that: The second phase change material is selected from at least one of heneicosane, methyl stearate, elaidic acid, lauric acid, myristic acid, octacosane, palmitic acid, stearic acid, arachidic acid, stearyl glyceride, hexadecanoic acid, behenic acid, tetradecanoic acid, paraffin, triacontanoic acid and dotriacontanoic acid.

8. The cold chain packaging according to claim 7, characterized in that: The amount of the second phase change material is 5 g to 100 g per square meter.

9. The cold chain packaging according to claim 8, characterized in that: The second phase change material is mixed with heat-expandable microspheres.

10. The cold chain packaging according to claim 9, characterized in that: The mass ratio of the second phase change material to the heat-expandable microspheres is 100:1 to 100:10.

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