Auxiliary exhaust method for box foaming

Abstract

The present invention relates to an auxiliary exhaust method for box foaming, belonging to the technical field of box foaming, and the auxiliary exhaust method comprises the following steps: when assembling the box, a cut-off block is installed between the injection hole and the exhaust hole opened on the bottom surface of the box shell; when installing the box liner, the cut-off block is pressed by the box liner, and the length of the cut-off block is greater than the diameter of the exhaust hole, so that the cut-off block blocks the straight path from the injection hole to the exhaust hole; during the inverted foaming process of the box, the foaming material injected from the injection hole is blocked by the cut-off block when flowing in the foaming cavity of the box after it is foamed, so that the local area of ​​the cut-off block including the exhaust hole on the side opposite to the injection hole becomes a foaming intersection area, and during the flow of the foaming material, the gas in the foaming cavity is squeezed by the foaming material and gathered to the foaming intersection area and discharged from the exhaust hole. The auxiliary exhaust method can control the flow direction of the foaming material, thereby ensuring complete exhaust.

Description

Technical Field

[0001] The invention belongs to the technical field of box foaming, and in particular relates to an auxiliary exhaust method for box foaming. Background Art

[0002] Cabinet foaming generally refers to rigid polyurethane foaming. The foaming process is usually to mix white material (combined polyether) containing a foaming agent and black material (isocyanate) through a foaming machine mixing head at high pressure, and then inject it into the cavity between the cabinet shell and the inner liner from the cabinet injection hole to react, quickly fill the cavity and squeeze out excess air to form a polyurethane foam layer. The foaming layer plays a role in heat preservation and support in the refrigerator / freezer cabinet. Therefore, the production process of cabinet foaming determines the performance of the refrigerator / freezer.

[0003] In the existing box foaming production, due to the product structure and the limitations of the existing production line equipment, the original gas in the foaming cavity is difficult to discharge during the foaming process of the box (especially for boxes with deeper depth and larger volume), resulting in cavitation and box liner separation defects after foaming, affecting product performance and even causing the box to be scrapped, causing economic losses to the company.

[0004] The conventional solution in the industry to solve the problems of cavitation and bulging caused by foaming of the cabinet is to add exhaust holes in the gas collection area of ​​the cabinet to enhance exhaust. However, for the cabinet of refrigerator / freezer, due to its complex structure and the obstructions of internal pipes, wiring harnesses, etc., the gas usually gathers on the side wall of the cabinet. But the side wall is the appearance surface, and drilling holes on the side wall will affect the display effect. Therefore, exhaust holes are usually added to the bottom of the cabinet. Although this solution alleviates the cavitation and bulging phenomenon to a certain extent, it still cannot completely solve the exhaust problem because the exhaust holes are not in the gas collection area. Summary of the invention

[0005] In view of the above-mentioned problems existing in the foaming process of the refrigerator / freezer body, the present invention provides an auxiliary exhaust method for body foaming, which can control the flow direction of the foaming material to ensure complete exhaust, and is particularly suitable for the foaming process of the refrigerator / freezer body where it is impossible to open exhaust holes in the gas gathering area.

[0006] The present invention provides an auxiliary exhaust method for box foaming, comprising the following steps:

[0007] When assembling the box, install a cut-off block between the injection hole and the exhaust hole opened on the bottom surface of the box shell. When installing the box liner, use the box liner to press the cut-off block. The length of the cut-off block is greater than the diameter of the exhaust hole, so that the cut-off block blocks the straight path from the injection hole to the exhaust hole.

[0008] During the inverted foaming process of the box, the foaming material injected from the injection hole is blocked by the interception block when flowing in the foaming cavity of the box after it starts to foam, so that the local area including the exhaust hole on the side of the interception block facing away from the injection hole becomes the foaming intersection area. During the flow of the foaming material, the gas in the foaming cavity is squeezed by the foaming material and gathered in the foaming intersection area and discharged from the exhaust hole.

[0009] In some of the embodiments, when the injection hole and the exhaust hole are respectively opened at the lateral ends of the bottom surface of the box shell, the cut-off block is arranged close to the exhaust hole, the cut-off block is perpendicular to the line connecting the exhaust hole and the injection hole, and the cut-off block is symmetrical relative to the line connecting the exhaust hole and the injection hole.

[0010] In some embodiments, the distance between the intercepting block and the exhaust hole is 150-200 mm.

[0011] In some of the embodiments, when the injection hole is opened at the center of the bottom surface of the box shell and the exhaust hole is opened at a lateral end of the bottom surface of the box shell, the cut-off block includes a first cut-off block and a second cut-off block, the first cut-off block is arranged close to the exhaust hole, and the second cut-off block is arranged close to the injection hole, the first cut-off block and the second cut-off block are both perpendicular to the line connecting the exhaust hole and the injection hole, and the first cut-off block and the second cut-off block are both symmetrical relative to the line connecting the exhaust hole and the injection hole.

[0012] In some embodiments, the distance between the first intercepting block and the exhaust hole is 150-200 mm, and the distance between the second intercepting block and the injection hole is 100-120 mm.

[0013] In some embodiments, the material of the interception block is the same as that of the foaming material.

[0014] In some embodiments, the cut-off block has a length of 90-110 mm and a width of 45-55 mm.

[0015] Compared with the prior art, the advantages and positive effects of the present invention are:

[0016] 1. The auxiliary exhaust method for box foaming provided by the present invention blocks the straight path from the injection hole to the exhaust hole by setting a cut-off block, so that the local area including the exhaust hole on the side of the cut-off block facing away from the injection hole becomes a foaming intersection area. During the foaming process, the flow direction of the foaming material is controlled by the cut-off block, so that the gas in the foaming cavity is gathered to the foaming intersection area and discharged from the exhaust hole, ensuring complete exhaust, solving the exhaust problem in the box foaming process, greatly reducing the product scrap rate, and is particularly suitable for the box foaming process of refrigerators / freezers where exhaust holes cannot be opened in the gas gathering area.

[0017] 2. The auxiliary exhaust method for box foaming provided by the present invention only requires adding a cutoff block to the existing box foaming process, which is easy to implement and will not increase production costs too much, thus having significant economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0019] Figure 1 It is a schematic diagram of the flow of the foaming material in the bottom surface of the box body when the box body is foaming in one embodiment of the auxiliary exhaust method for box body foaming of the present invention;

[0020] Figure 2 It is a schematic diagram of the vertical flow of the foaming material when the box body is foamed in one embodiment of the auxiliary exhaust method for box body foaming of the present invention;

[0021] Figure 3 It is a schematic diagram of the flow of the foaming material in the bottom surface of the box body when the box body is foaming in another embodiment of the auxiliary exhaust method for box body foaming of the present invention;

[0022] Figure 4 It is a schematic diagram of the vertical flow of the foaming material when the box body is foamed in another embodiment of the auxiliary exhaust method for box body foaming of the present invention;

[0023] Figure 5 This is a distribution diagram of the sampling points of the box body in the first embodiment of the auxiliary exhaust method for box body foaming of the present invention.

[0024] In the figure:

[0025] 1. Box body; 11. Outer shell; 12. Inner liner; 13. Foaming chamber; 2. Injection hole; 3. Exhaust hole; 4. Cut-off block; 41. First cut-off block; 42. Second cut-off block; 5. Foaming intersection area. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0027] In the description of the present invention, it is necessary to understand that the orientations or positional relationships indicated by terms such as "center", "lateral", "longitudinal", "top", "bottom", "inside" and "outside" are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0028] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features.

[0029] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0030] The present invention provides an auxiliary exhaust method for box foaming, comprising the following steps:

[0031] S1: When assembling the box body 1, the interception block 4 is installed between the injection hole 2 and the exhaust hole 3 opened on the bottom surface of the box shell 11. When installing the box liner 12, the interception block 4 is pressed by the box liner 12. The length of the interception block 4 is greater than the diameter of the exhaust hole 3, so that the interception block 4 blocks the straight path from the injection hole 2 to the exhaust hole 3;

[0032] S2: During the inverted foaming process of the box body 1, the foaming material injected from the injection hole 2 is blocked by the intercepting block 4 when flowing in the foaming cavity 13 of the box body 1 after it is foamed, so that the local area including the exhaust hole 3 on the side of the intercepting block 4 facing away from the injection hole 2 becomes the foaming intersection area 5. During the flow of the foaming material, the gas in the foaming cavity 13 is squeezed by the foaming material and gathered in the foaming intersection area 5 and discharged from the exhaust hole 3.

[0033] The above auxiliary exhaust method for box foaming blocks the straight path from the injection hole 2 to the exhaust hole 3 by setting the interception block 4, so that the local area including the exhaust hole 3 on the side of the interception block 4 facing away from the injection hole 2 becomes the foaming intersection area 5. During the foaming process, the interception block 4 controls the flow direction of the foaming material, so that the gas in the foaming cavity 13 is gathered to the foaming intersection area 5 and discharged from the exhaust hole 3, ensuring complete exhaust, solving the exhaust problem in the foaming process of the box 1, greatly reducing the product scrap rate, and is particularly suitable for the foaming process of boxes such as refrigerators / freezers where the exhaust hole 3 cannot be opened in the gas gathering area. Moreover, the above auxiliary exhaust method for box foaming only needs to add the interception block 4 to the existing box foaming process, which is easy to implement and will not increase the production cost too much, and has significant economic benefits.

[0034] It should be noted that, as is well known in the art: the density of the insulation layer formed by the foaming material on the side where the flow of the foaming material is obstructed is relatively high, while a blank area with relatively low density is easily formed behind the obstruction; in view of the large difference in the density of the insulation layer of the box 1, which will affect the insulation effect of the box 1, there is a common technical prejudice in the art, that is, obstacles cannot be forcibly added when the box 1 is foamed, and obstacles such as cables in the foaming cavity 13 of the box 1 should be simplified as much as possible to avoid affecting the density of the insulation layer of the box 1. The auxiliary exhaust method for box foaming provided in the embodiment of the present invention breaks the above-mentioned technical prejudice in the art, and the change in the density of the insulation layer of the box 1 made by the auxiliary exhaust method for box foaming provided in the embodiment of the present invention will be provided with data in subsequent specific embodiments.

[0035] It should also be noted that when the refrigerator box 1 is foamed, in order to maintain the beautiful appearance of the box 1, the injection hole 2 and the exhaust hole 3 are both arranged on the bottom surface of the box shell 11; wherein, the exhaust hole 3 is usually arranged at one lateral end of the bottom surface of the box shell 11; according to the different volumes of the box 1, the injection hole 2 is generally arranged at two positions: when the volume of the box 1 is relatively small (less than 400L), the injection hole 2 is usually arranged at the other lateral end of the bottom surface of the box shell 11 opposite to the exhaust hole 3; when the volume of the box 1 is relatively large (400L to 1000L), the injection hole 2 is usually arranged at the center of the bottom surface of the box shell 11. The following describes the specific arrangement of the interception block 4 through two specific embodiments for the above two different arrangements of the injection hole 2.

[0036] like Figure 1 and Figure 2As shown, in one embodiment, the injection hole 2 and the exhaust hole 3 are respectively provided at the two lateral ends of the bottom surface of the box shell 11, and the intercepting block 4 is arranged near the exhaust hole 3. The intercepting block 4 is perpendicular to the line connecting the exhaust hole 3 and the injection hole 2, and the intercepting block 4 is symmetrical with respect to the line connecting the exhaust hole 3 and the injection hole 2. In this embodiment, the intercepting block 4 is arranged near the exhaust hole 3, so that the local area where the exhaust hole 3 is located can form a foaming intersection area 5. During foaming, the foaming material is injected from the side where the injection hole 2 is provided, flows to the other side, and finally flows to the foaming intersection area 5. The specific flow direction of the foaming material is as follows: Figure 1 and Figure 2 As shown. It should be noted that, in order to ensure complete exhaust and avoid affecting the density of the insulation layer formed by the foam material due to the setting of the interception block 4, the distance L1 between the interception block 4 and the exhaust hole 3 is preferably 150-200 mm. If the interception block 4 is too far from the exhaust hole 3, the foam material is easy to cross the interception block 4, which is not conducive to ensuring complete exhaust; on the contrary, since the density of the insulation layer formed by the foam material at the exhaust hole 3 is relatively low, and when the interception block 4 is added to hinder the flow of the foam material, the density of the insulation layer on the side of the interception block 4 close to the exhaust hole 3 is relatively low compared to the side away from the exhaust hole 3. Therefore, if the interception block 4 is too close to the exhaust hole 3, the density near the exhaust hole 3 will be lower, resulting in a large difference in the density of the insulation layer on both sides of the interception block 4, affecting the insulation effect. At the same time, when the size of the interception block 4 is constant, if the interception block 4 is too close to the exhaust hole 3, the interception effect of the interception block 4 will also be correspondingly deteriorated, which may cause incomplete exhaust.

[0037] like Figure 3 and Figure 4As shown, in another embodiment, the injection hole 2 is opened at the center of the bottom surface of the box shell 11 and the exhaust hole 3 is opened at a lateral end of the bottom surface of the box shell 11, and the cut-off block 4 includes a first cut-off block 41 and a second cut-off block 42, the first cut-off block 41 is arranged close to the exhaust hole 3, and the second cut-off block 42 is arranged close to the injection hole 2, the first cut-off block 41 and the second cut-off block 42 are both perpendicular to the line connecting the exhaust hole 3 and the injection hole 2, and the first cut-off block 41 and the second cut-off block 42 are both symmetrical relative to the line connecting the exhaust hole 3 and the injection hole 2. In this embodiment, the blocking effect of the second intercepting block 42 is provided to make the foaming material flow from the center to the side away from the exhaust hole 3 first, so as to discharge the gas on the side away from the exhaust hole 3 in the foaming cavity 13 first, thereby ensuring that the side away from the exhaust hole 3 in the foaming cavity 13 can be completely filled, and then the blocking effect of the first intercepting block 41 is provided to make the gas in the foaming cavity 13 finally converge to the foaming intersection area 5 formed by the side of the first intercepting block 41 away from the injection hole 2 and discharge from the exhaust hole 3, thereby ensuring that the gas in the foaming cavity 13 is completely discharged. It should be noted that in order to ensure complete exhaust and avoid affecting the density of the insulation layer formed by the foaming material due to the setting of the intercepting block 4, the distance L2 between the first intercepting block 41 and the exhaust hole 3 is preferably 150-200 mm, and the distance L3 between the second intercepting block 42 and the injection hole 2 is preferably 100-120 mm. If the first intercepting block 41 is too far from the exhaust hole 3, the foaming material is easy to go over the first intercepting block 41, which is not conducive to ensuring complete exhaust. On the contrary, since the density of the insulation layer formed by the foaming material at the exhaust hole 3 is relatively low, when the first intercepting block 41 is added to hinder the flow of the foaming material, the density of the insulation layer on the side of the first intercepting block 41 close to the exhaust hole 3 is relatively low compared with the side away from the exhaust hole 3. Therefore, if the first intercepting block 41 is too close to the exhaust hole 3, the density near the exhaust hole 3 will be lower, resulting in the first intercepting block 4 The density of the thermal insulation layers on both sides of the first intercepting block 41 is quite different, which affects the thermal insulation effect. At the same time, when the size of the first intercepting block 41 is constant, the first intercepting block 41 is too close to the exhaust hole 3, and the intercepting effect of the first intercepting block 41 will be correspondingly poor, which may lead to incomplete exhaust. If the second intercepting block 42 is too far away from the injection hole 2, it is not conducive to ensuring that the side of the foaming cavity 13 away from the exhaust hole 3 is completely exhausted. If the second intercepting block 42 is too close to the injection hole 2, the density of the thermal insulation layers on both sides of the second intercepting block 42 may be quite different, which affects the thermal insulation effect.

[0038] It should be further explained that the length of the intercepting block 4 is preferably 90 to 110 mm, and the width is preferably 45 to 55 mm. If the intercepting block 4 is too long or too wide, the foaming material is not easy to pass over the intercepting block 4, which may cause the density of the insulation layer on both sides of the intercepting block 4 to be quite different, affecting the insulation effect; if the intercepting block 4 is too short or too narrow, the foaming material is easy to pass over the intercepting block 4, which is not conducive to ensuring complete exhaust. It should be noted that the height of the intercepting block 4 is consistent with the thickness of the foaming cavity 13 where the intercepting block 4 is installed to ensure complete isolation. The intercepting block 4 can be attached between the box shell 11 and the box inner liner 12 using double-sided tape.

[0039] In addition, the material of the interception block 4 is preferably the same as that of the foaming material. After the foaming is completed, the interception block 4 can be integrated with the foaming material to form a thermal insulation layer together.

[0040] The present invention further provides the following specific embodiments and comparative examples to illustrate the exhaust effect of the auxiliary exhaust method for box foaming and its influence on the density of the box insulation layer.

[0041] The exhaust methods and related experimental parameters of Examples 1-6 and Comparative Examples 1-10 are shown in Table 1.

[0042] Table 1 Exhaust methods and related experimental parameters of Examples 1-6 and Comparative Examples 1-10

[0043]

[0044]

[0045] The performance of the boxes made in the above embodiments and comparative examples (including the foam cavity unsatisfactory rate and the box density) was tested, and the results are shown in Table 2 and Table 3. It should be noted that when testing the box density, the sampling point position is as follows: Figure 5 shown.

[0046] Table 2 Box foam cavity dissatisfaction rate of Examples 1-6 and Comparative Examples 1-10

[0047] Production quantity / unit Dissatisfied quantity / unit Dissatisfaction rate Example 1 300 0 0.00％ Example 2 300 0 0.00％ Example 3 300 0 0.00％ Comparative Example 1 300 3 1.00％ Comparative Example 2 300 2 0.67％ Comparative Example 3 300 3 1.00％ Comparative Example 4 300 4 1.33％ Comparative Example 5 300 6 2.00％ Example 4 300 0 0.00％ Example 5 300 0 0.00％ Example 6 300 0 0.00％ Comparative Example 6 300 4 1.33％ Comparative Example 7 300 2 0.67％ Comparative Example 8 300 3 1.00％ Comparative Example 9 300 4 1.33％ Comparative Example 10 300 7 2.33％

[0048] Table 3 Box density of Examples 1-6 and Comparative Examples 1-10

[0049]

[0050] The calculation process of the above data is described below by taking Example 2 and Comparative Example 3 as examples. The specific data are shown in Table 4.

[0051] Table 4 Box density parameters of Example 2 and Comparative Example 3

[0052]

[0053] It can be seen from Table 2 and Table 3 that the auxiliary exhaust method for box foaming provided by the present invention can ensure complete exhaust, and the set interception block has a very small density of the box insulation layer and has no effect on the box insulation effect, which greatly reduces the product scrap rate and has significant economic benefits.

[0054] Finally, it should be noted that: the various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0055] The above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or some technical features can be replaced by equivalents without departing from the spirit of the technical solution of the present invention, which should be included in the scope of the technical solution for protection of the present invention.

Claims

1. An auxiliary exhaust method for box foaming, characterized in that: The steps include: When assembling the box, a cut-off block is installed between the injection hole and the exhaust hole opened on the bottom surface of the box shell. When installing the box liner, the cut-off block is pressed by the box liner. The length of the cut-off block is greater than the diameter of the exhaust hole, so that the cut-off block blocks the straight path from the injection hole to the exhaust hole. During the inverted foaming process of the box, the foaming material injected from the injection hole is blocked by the intercepting block when flowing in the foaming cavity of the box after it is foamed, so that the local area of ​​the intercepting block on the side opposite to the injection hole and including the exhaust hole becomes the foaming intersection area. During the foaming material flow process, the gas in the foaming cavity is squeezed by the foaming material and gathered in the foaming intersection area and discharged from the exhaust hole. When the injection hole and the exhaust hole are respectively opened at the two lateral ends of the bottom surface of the box shell, the cut-off block is arranged close to the exhaust hole, the cut-off block is perpendicular to the line connecting the exhaust hole and the injection hole, and the cut-off block is symmetrical relative to the line connecting the exhaust hole and the injection hole; the distance between the cut-off block and the exhaust hole is 150-200 mm; the length of the cut-off block is 90-110 mm, and the width is 45-55 mm.

2. The auxiliary exhaust method for box foaming according to claim 1, characterized in that: The material of the intercepting block is the same as that of the foaming material.

3. An auxiliary exhaust method for box foaming, characterized in that: The steps include: When assembling the box, a cut-off block is installed between the injection hole and the exhaust hole opened on the bottom surface of the box shell. When installing the box liner, the cut-off block is pressed by the box liner. The length of the cut-off block is greater than the diameter of the exhaust hole, so that the cut-off block blocks the straight path from the injection hole to the exhaust hole. During the inverted foaming process of the box, the foaming material injected from the injection hole is blocked by the intercepting block when flowing in the foaming cavity of the box after it is foamed, so that the local area of ​​the intercepting block on the side opposite to the injection hole and including the exhaust hole becomes the foaming intersection area. During the foaming material flow process, the gas in the foaming cavity is squeezed by the foaming material and gathered in the foaming intersection area and discharged from the exhaust hole. When the injection hole is opened at the center of the bottom surface of the box shell and the exhaust hole is opened at a lateral end of the bottom surface of the box shell, the cut-off block includes a first cut-off block and a second cut-off block, the first cut-off block is arranged close to the exhaust hole, and the second cut-off block is arranged close to the injection hole, the first cut-off block and the second cut-off block are both perpendicular to the line connecting the exhaust hole and the injection hole, and the first cut-off block and the second cut-off block are both symmetrical relative to the line connecting the exhaust hole and the injection hole; the distance between the first cut-off block and the exhaust hole is 150-200 mm, and the distance between the second cut-off block and the injection hole is 100-120 mm; the length of the cut-off block is 90-110 mm, and the width is 45-55 mm.

4. The auxiliary exhaust method for box foaming according to claim 3, characterized in that: The material of the intercepting block is the same as that of the foaming material.

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