Slurry suction mold and paper-plastic buffer injection molding device

Abstract

The utility model provides a pulp suction mold and a paper-plastic buffer part injection molding device. A slurry suction mold comprises a mold main body, and a forming groove is formed in the surface of the mold main body; the first slurry suction hole is formed in the top surface of the forming groove; the second slurry suction hole is formed in the side wall of the forming groove, and the second slurry suction hole is communicated with the first slurry suction hole. The second slurry suction holes are additionally formed in the side wall of the forming groove of the slurry suction mold, so that the side wall of the forming groove can share more pressure when the slurry suction mold sucks slurry in a slurry pool and the bottom of the slurry pool exhausts air, and more slurry can be gathered on the side wall of the forming groove to form a local reinforcing area; therefore, the subsequent finished paper-plastic buffer piece is ensured to meet the drop test.

Description

Technical Field

[0001] This disclosure relates to the field of paper-plastic injection molding technology, and more particularly to a suction mold and a paper-plastic buffer injection device. Background Technology

[0002] Currently, the production of paper-plastic cushioning components generally includes pulping, slurry suction forming, transfer, drying, rehydration, hot pressing, trimming, and packaging. Among these, slurry suction forming and hot pressing are crucial in determining the compliance of the paper-plastic cushioning component products. The key to slurry suction forming lies in the slurry suction mold, and the key to hot pressing is the hot pressing forming mold. Conventional slurry suction molds have suction holes on their front side, and two layers of steel mesh are laid on the surface of the mold. We have found that semi-finished products (i.e., wet blanks) made using this type of mold have insufficient sidewall strength in certain areas. Furthermore, when using conventional hot pressing forming molds for subsequent hot pressing, the mold pushes the slurry from the sidewalls of the semi-finished product onto the front structure, resulting in poor molding of the finished paper-plastic cushioning component and insufficient sidewall strength in certain areas. This leads to problems during actual drop tests and non-compliance. Utility Model Content

[0003] This disclosure provides a suction mold and a paper-plastic buffer injection device to at least solve one of the technical problems existing in the prior art.

[0004] In a first aspect, this disclosure provides a suction mold, comprising:

[0005] A mold body, the surface of which has forming grooves;

[0006] The first suction hole is opened on the top surface of the forming groove;

[0007] The second suction hole is formed on the side wall of the forming groove, and the second suction hole is connected to the first suction hole.

[0008] In one embodiment, the sidewall of the molding tank is provided with multiple rows of vertically arranged second suction holes spaced apart circumferentially, with each row of vertically arranged second suction holes spaced apart from each other.

[0009] Grooves are formed on the side wall surface of the forming groove, and at the positions of the second suction holes arranged vertically in each row.

[0010] In one embodiment, the second suction hole is an oblique hole, with the axis of the oblique hole inclined toward the side closer to the central axis, taking the central axis of the first suction hole connected thereto as a reference.

[0011] In one embodiment, the included angle between the second suction hole and the first suction hole is 30° to 60°.

[0012] In one possible embodiment, the diameter of the second suction hole is 3.0 ± 0.1 mm;

[0013] The spacing between adjacent first suction holes is 8~10mm, and the spacing between adjacent second suction holes is 8~10mm.

[0014] In one embodiment, the width of the groove is greater than the diameter of the second suction hole, and the difference between the two is between 0.5 and 1 mm.

[0015] Secondly, this disclosure also provides a paper-plastic cushioning injection molding apparatus, including a hot-pressing forming mold and a suction mold in any of the above-described embodiments.

[0016] In one embodiment, the hot pressing forming mold includes a male mold and a female mold. In the mold-closed state, the gap T1 at the bottom position of the hot pressing forming mold is T0 + 1mm, where T0 is the thickness of the finished paper-plastic buffer part, and the gap T2 at the top position of the hot pressing forming mold is (1.5~2) × T0.

[0017] In one embodiment, the draft angle α of the female mold is 87°~90°.

[0018] In one embodiment, the draft angle b of the male mold is equal to the draft angle of the female mold minus 3°~5°.

[0019] Compared with the prior art, the advantages of this application are: 1) This application adds a second suction hole to the side wall of the forming groove of the suction mold, so that the suction mold can suck up the slurry in the slurry pool. When the bottom of the slurry pool is evacuated, the side wall of the forming groove can bear more pressure, so that the slurry can gather more on the side wall of the forming groove to form a local reinforcement area, thereby ensuring that the finished paper-plastic buffer parts meet the drop test requirements.

[0020] 2) In order to increase the amount of slurry absorbed by the sidewall, this application provides grooves on the sidewall of the molding tank and on the second slurry suction holes in each row along the vertical direction. The grooves extend from the top surface of the molding tank downward to the bottom surface, connecting the second slurry suction holes in each vertical row of the sidewall, further increasing the slurry suction pressure of the sidewall, and ensuring that when the slurry suction mold is suctioning slurry, more slurry can be gathered on the sidewall of the molding tank, so as to increase the strength of the sidewall and form a local reinforced area.

[0021] 3) When the gap at the bottom of the hot pressing forming mold of this application is T1 and the gap at the top is T2, it can effectively reduce the side wall slurry from being squeezed to the front area during the hot pressing process, and the resulting paper-plastic buffer product can meet the drop test requirements.

[0022] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this disclosure, nor is it intended to limit the scope of this disclosure. Other features of this disclosure will become readily apparent from the following description. Attached Figure Description

[0023] The above and other objects, features, and advantages of this disclosure will become readily apparent from the following detailed description of exemplary embodiments, taken in conjunction with the accompanying drawings. Several embodiments of this disclosure are illustrated in the drawings by way of example and not limitation, in which:

[0024] In the accompanying drawings, the same or corresponding reference numerals indicate the same or corresponding parts.

[0025] Figure 1 A schematic diagram of a suction mold according to an embodiment of the present disclosure is shown;

[0026] Figure 2 A schematic diagram of another structure of the suction mold according to an embodiment of the present disclosure is shown;

[0027] Figure 3 A schematic diagram of the structure of one of the forming grooves of the suction mold according to an embodiment of the present disclosure is shown;

[0028] Figure 4 It shows Figure 3 A partial sectional view along direction AA in the middle;

[0029] Figure 5 The following diagram illustrates the relationship between paper-plastic strength and density, and moisture content during hot pressing, according to an embodiment of this disclosure (wherein, Figure 5 (a) shows the relationship between paper-plastic strength and density. Figure 5 (b) shows the relationship between paper-plastic strength and moisture content during hot pressing.

[0030] Figure 6 A schematic diagram of the hot pressing forming mold structure of an embodiment of this disclosure is shown. Figure 6 (A) is a schematic diagram of the male and female molds of a hot pressing forming mold in related technologies when they are closed. Figure 6 (B) is a schematic diagram of the male and female molds of the hot pressing forming mold of this application when they are closed.

[0031] The numbers in the diagram are explained as follows: 1-Suction mold, 11-Mold body, 12-First suction hole, 13-Second suction hole, 14-Groove, 111-Forming groove, 2-Hot pressing forming mold, 21-Male mold, 22-Female mold. Detailed Implementation

[0032] To make the objectives, features, and advantages of this disclosure more apparent and understandable, the technical solutions in the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this disclosure, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0033] The current production process of paper-plastic cushioning components generally includes pulping, slurry suction molding, transfer, drying, rehydration, hot pressing and shaping, edge trimming, and packaging. The semi-finished product after slurry suction molding is called wet blank. The wet blank is a loose and high-moisture state with a moisture content of about 70% and a thickness of 2 to 2.5 times that of the final product. The wet blank is dried (moisture content less than 5%), rehydrated, and then hot-pressed and shaped.

[0034] Among them, the suction molding process uses a suction mold, and the hot pressing shaping process uses a hot pressing shaping mold. Currently, in related technologies, the suction mold for paper-plastic cushioning components is located on the front of the forming groove (i.e., as shown in the image). Figure 3 The top surface of the forming tank (as shown) has suction holes, typically 2.5mm in diameter. Two layers of steel mesh, with mesh sizes of 40 and 80, are then laid on the surface of the suction mold. However, we have found that in the suction process, where the mold is submerged in the slurry tank and air is drawn from the bottom, the pressure on the front of the forming tank is high, resulting in more slurry being absorbed from the front and less from the sides. This leads to insufficient sidewall strength in the resulting wet preform. Consequently, the paper-plastic cushioning parts obtained through subsequent hot-pressing and shaping processes often fail drop tests due to insufficient sidewall strength. Therefore, based on the above problems, this application provides a suction mold.

[0035] According to one embodiment of this disclosure, such as Figure 1-3 As shown, this utility model provides a suction mold 1, comprising:

[0036] Mold body 11, the surface of which has forming groove 111;

[0037] The first suction hole 12 is opened on the top surface of the forming groove 111;

[0038] The second suction hole 13 is opened on the side wall of the forming groove 111, and the second suction hole 13 is connected to the first suction hole 11.

[0039] For example, such as Figure 2 As shown, the mold body 11 of the suction mold 1 of this application has a plurality of forming grooves 111 along its length direction, which are adapted to the structural shape of the paper-plastic buffer. Figure 3As shown, the top surface 1111 of the molding tank 111 is provided with a plurality of first suction holes 12, and the side wall of the molding tank is also provided with second suction holes 13 (for ease of display, the second suction holes 13 are shown on the side wall of the molding tank). Figure 2 (Not shown in the image).

[0040] The suction mold 1 of this application adds a side wall suction hole (i.e., a second suction hole 13) to the side wall of the forming groove 111 of the suction mold in the current related technology, so that the suction mold 1 can suck up the slurry in the slurry pool. When the bottom of the slurry pool is evacuated, the side wall of the forming groove 111 can bear more pressure, thereby allowing more slurry to accumulate on the side wall of the forming groove, forming a local reinforced area, and thus ensuring that the subsequent paper-plastic cushioning parts meet the drop test requirements.

[0041] In some embodiments, such as Figure 3 As shown, the sidewall of the molding tank 111 is provided with multiple rows of vertically arranged second suction holes 13 at intervals along its circumference, and each row of vertically arranged second suction holes 13 is provided at intervals; an independent groove 14 is provided on the sidewall surface of the molding tank 111, along each row of vertically arranged second suction holes.

[0042] For example, the term "independent trench" refers to each trench being associated with only the second suction hole in a single vertical row.

[0043] like Figure 3 As shown, in order to increase the amount of slurry absorbed by the sidewall of the molding tank 111, this application provides grooves 14 on the sidewall of the molding tank 111, on the second slurry absorption holes in each row along the vertical direction. The grooves 14 extend from the front of the molding tank (i.e., Figure 3 The top surface of the forming groove (shown) extends downward to the bottom surface, connecting the second suction holes 13 in each vertical row of the side wall, further increasing the suction pressure of the side wall of the forming groove, ensuring that when the suction mold 1 suctions the slurry, the slurry can accumulate more on the side wall of the forming groove, thereby increasing the strength of the side wall and forming a local reinforced area.

[0044] For example, the width of the groove 14 is greater than the diameter of the second suction hole 13, and the difference between the two is between 0.5 and 1 mm. For example, the second suction hole 13 is generally 3.0 ± 0.1 mm, and the width of the groove 14 is about 4 mm. The width of the groove 14 is greater than the diameter of the second suction hole 13, which increases the suction pressure on the side wall and ensures that the slurry can accumulate more on the side wall of the molding tank during suction.

[0045] In some embodiments, such as Figure 4 As shown, the second suction hole 13 is an inclined hole. With the central axis of the first suction hole 12 connected to it as a reference, the axis of the inclined hole is inclined to the side closer to the central axis of the first suction hole.

[0046] For example, the angle between the second suction hole 13 and the first suction hole 12 is 30° to 60°. Preferably, the angle between the second suction hole 13 and the first suction hole 12 is about 45°. Setting the second suction hole 13 as an angled hole facilitates processing and manufacturing on the suction mold.

[0047] For example, the diameter of the first suction hole 12 is 2.5 mm. For example, the spacing between adjacent first suction holes 12 is 8-10 mm, and the spacing between adjacent second suction holes 13 is 8-10 mm. Further, the spacing between both the first and second suction holes is 8 mm. By densely distributing the first and second suction holes, the adsorption capacity of the slurry can be further increased.

[0048] For dry-pressed paper-plastic products, the mechanical properties of the paper-plastic are determined by the density of the material after hot pressing and the moisture content during hot pressing. Figure 5 As shown, Figure 5 (a) shows the relationship between paper-plastic strength and density. Figure 5 (b) shows the relationship between paper-plastic strength and moisture content during hot pressing. Therefore, the wet preform made by the slurry suction mold needs to be hot-pressed and shaped by the hot pressing and shaping mold to obtain the final product. We found that using the original hot pressing and shaping mold to hot-press the wet preform causes the slurry on the side wall of the wet preform to be pushed onto the front structure again, ultimately resulting in insufficient side wall strength in some areas of the finished paper-plastic cushioning part, while the front area has particularly high strength, leading to problems in actual drop tests.

[0049] Therefore, based on the requirements of mass production dry-pressed paper-plastic composites, we made multiple adjustments to achieve enhanced local strength. After multiple adjustments and tests, we determined the gap size of the hot-press forming mold. Simultaneously, the wall thickness of the hot-press mold also affects the appearance quality. Hot-press forming involves drying the paper-plastic composite while simultaneously shaping its surface. When the fibers lose water, due to the surface tension of water, numerous wrinkles appear on the paper-plastic composite surface. Eliminating these wrinkles is also crucial due to the gap size of the hot-press forming mold. Therefore, this application balances the performance and surface smoothness of the finished paper-plastic cushioning component by adjusting the gap of the hot-press forming mold.

[0050] Based on this, the present invention also provides a paper-plastic buffer injection molding device, including a hot pressing forming mold 2 and a suction mold 1 as described in any of the above embodiments.

[0051] For example, such as Figure 6 As shown, where Figure 6 (A) is a schematic diagram of the structure of a hot-press forming mold during mold closing in the related technology. Figure 6 (B) is a schematic diagram of the hot-pressing forming mold of this application during mold closing. Wherein... Figure 6As shown in (B), the hot pressing forming mold 2 includes a male mold 21 and a female mold 22. In the mold-closed state, the gap T1 at the bottom position of the hot pressing forming mold 2 is T0 + 1mm, where T0 is the design thickness of the finished paper-plastic buffer part. The gap T2 at the top position of the hot pressing forming mold 2 is (1.5~2) × T0.

[0052] For example, the so-called "gap at the bottom position of the hot pressing forming mold 2" refers to the gap between the male mold 21 and the female mold 22 when the mold is closed. The gap between the male mold 21 and the female mold 22 at the bottom position is T1, and the gap between the male mold 21 and the female mold 22 at the top position is T2.

[0053] For example, such as Figure 6 As shown in (B), the outer surface of the male mold 21 at the top position is a convex arc surface, and the gap between the highest point of the outer surface of the male mold 21 at the top position and the female mold 22 is T2.

[0054] Furthermore, the draft angle 'a' of the female mold 22 is 87°~90°. The draft angle 'b' of the male mold 21 is equal to the draft angle of the female mold 22 minus 3°~5°. The draft angle of the female mold 22 of the hot pressing forming mold 2 remains unchanged from its original design angle. Generally, the draft angle 'a' of the female mold 22 is 87°~90°, and the draft angle 'b' of the male mold 21 is a - (3°~5°). When the hot pressing forming mold satisfies T1=T0+1mm, T2=(1.5~2)×T0, the draft angle 'a' of the female mold 22 is 87°~90°, and the draft angle 'b' of the male mold 21 is equal to the draft angle of the female mold 22 minus 3°~5°, the side wall slurry can be effectively reduced from being squeezed to the front area during the hot pressing process, so that the resulting paper-plastic buffer part can balance strength and flatness.

[0055] For example, assuming the design thickness of the paper-plastic cushioning component is 1mm, its final thickness is determined by the hot-press forming mold. Currently, the gap between the male and female molds in related technologies is 1mm. However, since the thickness of the semi-finished product (wet blank) before hot pressing is 2~2.5mm, during the mold closing process, the mold will push part of the slurry from the side wall of the product onto the front structure. This results in insufficient strength on the side wall of the paper-plastic cushioning component in some areas, while the strength in the front area is particularly high. In actual drop tests, the side wall will be directly impacted and cannot meet the usage requirements. Therefore, it is necessary to ensure the molding effect and strength in this area. Therefore, this application improves the gap of the hot-press forming mold 2. The gap at the bottom of the hot-press forming mold is T1, and the gap at the top is T2. This can effectively reduce the slurry from the side wall being squeezed onto the front area during hot pressing. In order to balance the strength and flatness of the paper-plastic cushioning component, we have conducted multiple rounds of verification. The results show that when T1 and T2 meet the above requirements, the effect is the best, and the finished paper-plastic cushioning component can meet the drop test requirements.

[0056] Below, we made a series of adjustments to the gaps T1 and T2 of the hot pressing forming mold, the draft angle of the female mold, and the draft angle of the male mold. We then conducted drop tests on the paper-plastic buffer parts obtained by hot pressing forming. The test results are shown in Table 1 below.

[0057] Table 1. Drop test results of paper-plastic cushioning components made with different hot-pressing molding dies.

[0058]

[0059] In Table 1, the designed thickness T0 of the finished paper-plastic cushioning component is 1.2 mm. Items 1-6 are conventional paper-plastic cushioning components obtained using current related technologies' hot-press forming molds. The draft angle of both the female and male molds in these hot-press forming molds is 87°. The drop test results for items 1-6 show that none of these conventional paper-plastic cushioning components passed the drop test. The short-side breakage was between 20 and 23 mm.

[0060] Items 7-12 represent improvements to localized areas of the hot-press forming mold based on current related technologies. Specifically, they improve the gaps T1' at the bottom and T2' at the top of the mold, where T1' = T0 + 0.5mm = 1.7mm and T2' = T0 × 1.5 = 1.8mm. The draft angle 'a' of the female mold is 87°, and the draft angle 'b' of the male mold is 84°. The drop test results for the paper-plastic cushioning parts (items 7-12) show that the failure rate decreased to 1 / 3, and the short-side breakage length slightly decreased.

[0061] Items 13-23 are paper-plastic cushioning parts obtained using the hot-pressing forming mold of this application. The draft angle 'a' of the female mold is 87°, the draft angle 'b' of the male mold is 84°, T1 = T0 + 1 = 2.2 mm, and T2 = T0 × 2 = 2.4 mm. Drop test results for items 13-23 show that all of these paper-plastic cushioning parts passed the drop test. Furthermore, the short-side breakage length was significantly reduced, even to 10 mm. The prepared paper-plastic cushioning parts also have a relatively smooth appearance. This indicates that when the gap T1 at the bottom position of the hot-press forming mold 2 is T0 + 1mm, where T0 is the design thickness of the finished paper-plastic buffer, and the gap T2 at the top position of the hot-press forming mold 2 is (1.5~2) × T0; when the draft angle a of the female mold 22 is 87°~90° and the draft angle b of the male mold 21 is equal to the draft angle of the female mold 22 minus 3°~5°, the paper-plastic buffer obtained by hot pressing can increase its strength locally on the side wall, thus meeting the drop test requirements.

[0062] It should be understood that the various forms of processes shown above can be used to rearrange, add, or delete steps. For example, the steps described in this disclosure can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this disclosure can be achieved, and this is not limited herein.

[0063] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this disclosure, "a plurality of" means two or more, unless otherwise explicitly specified.

[0064] The terms “front,” “side,” “center,” “longitudinal,” “lateral,” “length,” “width,” “thickness,” “upper,” “lower,” “front,” “rear,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” “outer,” “clockwise,” and “counterclockwise” indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0065] The use of terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples" indicates that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this disclosure. Furthermore, the described specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of those different embodiments or examples.

[0066] The above description is merely a specific embodiment of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A suction mold, characterized in that: include: A mold body, the surface of which has forming grooves; The first suction hole is opened on the top surface of the forming groove; The second suction hole is formed on the side wall of the forming groove, and the second suction hole is connected to the first suction hole.

2. The suction mold according to claim 1, characterized in that: The sidewall of the molding tank is provided with multiple rows of vertically arranged second suction holes at intervals around the periphery, with each row of vertically arranged second suction holes spaced apart from each other. Grooves are formed on the side wall surface of the forming groove, and at the positions of the second suction holes arranged vertically in each row.

3. The suction mold according to claim 1 or 2, characterized in that: The second suction hole is an oblique hole, and with the central axis of the first suction hole connected to it as a reference, the axis of the oblique hole is inclined to the side closer to the central axis.

4. The suction mold according to claim 3, characterized in that: The angle between the second suction hole and the first suction hole is 30° to 60°.

5. The suction mold according to claim 1 or 2, characterized in that: The diameter of the second suction hole is 3.0 ± 0.1 mm; The spacing between adjacent first suction holes is 8-10 mm, and the spacing between adjacent second suction holes is 8-10 mm.

6. The suction mold according to claim 2, characterized in that: The width of the groove is greater than the diameter of the second suction hole, and the difference between the two is between 0.5 and 1 mm.

7. A paper-plastic cushioning component injection molding device, characterized in that: It includes hot-pressing shaping molds and suction molds as described in any one of claims 1-6.

8. The paper-plastic cushioning injection molding device according to claim 7, characterized in that: The hot pressing forming mold includes a male mold and a female mold. In the mold-closed state, the gap T1 at the bottom position of the hot pressing forming mold is T0 + 1mm, where T0 is the thickness of the finished paper-plastic buffer part. The gap T2 at the top position of the hot pressing forming mold is (1.5~2) × T0.

9. The paper-plastic buffer injection molding device according to claim 8, characterized in that: The draft angle α of the master mold is 87° to 90°.

10. The paper-plastic cushioning injection molding device according to claim 8, characterized in that: The draft angle b of the male mold is equal to the draft angle of the female mold minus 3° to 5°.

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