CN215800681U - Wet pressing mould for paper-plastic products - Google Patents

Abstract

The utility model relates to a wet pressing mould for paper-plastic products, which is characterized by comprising the following components: a lower die having a lower die cavity, the lower die cavity including a lower die face corresponding to a first surface of the paper-plastic article; an upper die having an upper die cavity, the upper die cavity including an upper die face corresponding to a second surface opposite the first surface of the paper-plastic article; wherein the lower die face is provided with an exhaust groove and an exhaust hole, and wherein the exhaust hole comprises a plurality of exhaust hole units, the exhaust hole units are discretely distributed and each exhaust hole unit comprises one or more exhaust holes, and the diameter of the exhaust hole is 0.3-0.8 mm.

Description

Wet pressing mould for paper-plastic products

Technical Field

The utility model relates to a wet pressing mold for paper-plastic products.

Background

In modern society, with the enhancement of environmental awareness of people, the demand for paper-plastic products is increasing. One common type of paper-plastic product is paper-plastic tableware, such as paper-plastic lunch boxes. Another common situation is paper-plastic packaging, such as trays used to hold products within electronic product packaging. These paper-plastic articles are made by shaping pulp in a wet-pressing mold. In this process, the pulp needs to be molded and dried.

In order to dewater the wet blank evenly and quickly, one method commonly used in the prior art is to densely distribute the whole mold core with air holes with the diameter of 2 mm, and to avoid the air holes sucking the salient points out of the surface of the product, a layer of stainless steel net is welded on the surface of the mold core. But the smoothness of the back of the product obtained with this method is not high. To address this problem, another method has been proposed in the prior art in which a stainless steel mesh is left only in the planar portion of the core. However, the stainless steel net is generally obtained by hand cutting, which brings about disadvantages of low dimensional accuracy and smoothness of the net edge. If machine cutting is used, considerable costs are incurred.

In addition, the stainless steel mesh is exposed to high-temperature and high-pressure working environment for a long time, and the defects of warping, desoldering, local cracking and the like are generated. The maintenance costs associated therewith are also high. For example, maintenance time for a one-core four-cavity mold is typically on the order of ten hours, and with more mold cavities, the maintenance time and manpower required would multiply, perhaps reaching 1/3 times the operating time of the molding machine, thereby resulting in reduced throughput. And the stainless steel net-covered portion generally has a large amount of scale and impurities left thereon, which oxidize and corrode the mold, so that a rough tool (e.g., a wire brush, a sanding head, rough sandpaper) is used for maintenance of the mold, and thus, the dimensional accuracy of the mold is completely lost after a plurality of maintenance, and additional costs are incurred for re-machining the mold.

SUMMERY OF THE UTILITY MODEL

The utility model provides a wet pressing mold for paper-plastic products, which can ensure the quality of products while realizing the rapid and uniform dehydration of wet blanks without using a stainless steel net, and particularly remarkably improve the quality of the back of the products.

The wet-pressing mold for paper-plastic products according to the present invention comprises: a lower die having a lower die cavity, the lower die cavity including a lower die face corresponding to a first surface of the paper-plastic product; the upper die is provided with an upper die cavity, and the upper die cavity comprises an upper die surface corresponding to a second surface opposite to the first surface of the paper-plastic product; wherein, the lower die surface is provided with an exhaust groove and an exhaust hole; and wherein the vent comprises a plurality of vent units, the vent units being discretely distributed and each vent unit comprising one or more vents; and the diameter of the vent hole is 0.5 to 1 mm.

Preferably, the diameter of the vent hole is 0.7 to 1 mm.

Preferably, the diameter of the vent hole is 0.8 to 1 mm.

Compared with the technical scheme of the prior art that the vent holes are densely distributed on the whole mold core and have the diameter of about 2 millimeters, in the scheme of the utility model, the number of the vent holes is greatly reduced due to the discrete distribution of the vent hole units, and the diameter of the vent holes is also obviously reduced. In the utility model discloses in, the size that distributes and reduce the exhaust hole through the discrete form of exhaust hole unit makes, under the condition that does not use stainless steel net, the appearance quality of the second surface (front) of paper plastic products has reached the same level with the quality when using stainless steel net, and the quality of the first surface (the back) of paper plastic products is obviously superior to the quality when using stainless steel net, has better smoothness. Moreover, the wet pressing die does not use a stainless steel net, so that the defects caused by the stainless steel net are eliminated under the condition of improving the quality of the paper-plastic product, the maintenance and production cost is obviously reduced, the labor is saved, the productivity is improved, and the damage to the die is reduced.

Preferably, the width of the vent slot is less than or equal to 0.3 mm.

Preferably, the vent unit includes 3 to 6 vents.

Preferably, the vent unit has a first diameter and extends from the lower die face to an opening having a second diameter, the opening being disposed in the lower die material interior and communicating with the external environment, the second diameter being greater than the first diameter. The process of forming a plurality of small-diameter holes such as the vent holes of the present invention in a mold is a time-consuming and difficult operation, and therefore, the plurality of vent holes are collected and extended from the lower mold surface to the inside of the material for a distance to communicate with the opening having a larger size communicating with the external environment, which can not only improve the processing efficiency of the mold but also increase the dehydration efficiency.

Preferably, the exhaust hole unit is integrally formed on the lower mold.

Preferably, the vent hole unit is provided on an air plug inlaid in the lower mold. In this case, a through hole having a larger size, for example, a through hole having a second diameter may be previously bored in the lower mold surface in the lower mold, and then an air plug having a vent hole unit previously machined may be inserted into the through hole from the lower mold surface.

Preferably, the gas plug is a stainless steel gas plug. A stainless steel air plug is arranged in the stainless steel mold core, and the position of the air plug is not easy to collapse.

Preferably, the exhaust groove communicates with the exhaust hole. The air discharge duct is formed by wire-electrode cutting, and the air discharge duct and the setting of exhaust hole intercommunication make can increase wire-electrode cutting speed, and simultaneously, in process of production, the air discharge duct is more difficult for blockking up. It will be appreciated that this arrangement of the vent grooves in communication with the vent holes may also be applied to vent grooves and vent holes in other locations.

Drawings

FIG. 1 is a schematic perspective view of one embodiment of a wet-pressing mold according to the present invention, the wet-pressing mold being in an open state;

FIG. 2 is a schematic exploded perspective view of the wet-pressing mold of FIG. 1, wherein the paper-plastic article 9 is shown with the upper mold of the wet-pressing mold turned over to show the upper mold cavity;

FIG. 3 is an enlarged schematic perspective view of the lower die shown in FIG. 2;

FIG. 4 is a schematic top view of the lower die shown in FIG. 3;

FIG. 5 is a partial schematic perspective view of the lower die shown in FIG. 3;

FIG. 6 is a schematic perspective view of a lower die of a wet-pressing mold according to another embodiment of the present invention;

fig. 7 is a schematic perspective cross-sectional view of the lower die shown in fig. 6, taken in a section through two vent holes in one vent hole unit.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the drawings of the embodiments of the present invention.

Unless defined otherwise, technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention belongs. The word "comprising" or "comprises", and the like, means that the element or item preceding the word covers the element or item listed after the word and its equivalents, but does not exclude other elements or items. The plane in which the wet pressing die is placed when the wet pressing die works normally is called a working plane, and the direction which is perpendicular to the working plane and points to the upper die is the height direction. The terms "upper" or "lower" are defined according to the height direction of the mold during normal operation.

The wet-pressing mold 1 according to the present invention will be described with reference to fig. 1 and 2. The wet-pressing mold 1 is particularly used for press forming of paper-plastic articles. In normal operation, the lower mold of the wet-pressing mold 1 is fixed in a work plane, which is usually the work top of the molding machine.

As shown in fig. 1 and 2, the wet-pressing mold 1 includes a lower mold 10 and an upper mold 20. The upper die 20 is movable relative to the lower die 10 to open and close the wet-pressing die 1. Also shown in fig. 2 is a paper plastic article 9, the paper plastic article 9 being press-formed when the wet-pressing mold 1 is closed. As shown, the lower mold 1 has a lower mold cavity 11, and the lower mold cavity 11 includes a lower mold surface 110 corresponding to a first surface (not shown) of the paper-plastic article 9. Correspondingly, the upper mold 20 has an upper cavity 21 comprising an upper mold surface 210 corresponding to the second surface 92 of the paper-plastic product 9, which is opposite to the first surface. In general, the first surface (not shown) of the paper-plastic article 9 is also referred to as the back surface, and the second surface 92 is referred to as the front surface. Taking the package of the electronic thermometer as an example, a paper-plastic container for accommodating electronic products is usually placed in the outer packaging box, the side of the paper-plastic container for accommodating the electronic thermometer which can be observed in a normal placement state is referred to as a front side, and the side opposite to the front side is referred to as a back side.

The lower mold 10 of the wet-pressing mold 1 according to the present invention is described in detail below with reference to fig. 3 to 5. In the example shown in fig. 3 and 4, the lower die 10 forms a product having two containing units 15 and 16 which are die-cut after forming to form individual containing units. As shown in fig. 3 and 4, the lower die surface 110 of the lower die 10 may include a top surface 120, a bottom surface 130, an outer side surface 140, and an inner side surface 141. Both top surface 120 and bottom surface 130 face upper die 20 as shown. The outer side 140 extends downward from the top surface 120 to the bottom surface 130 and connects the top surface 120 and the bottom surface 130. In a single housing unit, the outer side 140 may extend in the entire circumferential direction to form a surface closed in the circumferential direction. The outer side 140 may be generally perpendicular to the work surface or may be inclined relative to the work surface. The outer side 140 may also be a curved surface. The lower mold surface 110 is provided with vent grooves 131. as shown in fig. 3, the vent grooves 131 may be provided on the top surface 120, the bottom surface 130, the outer side surface 140, and the inner side surface 141 for dehydrating the wet mat. The vent grooves are slots, as shown in fig. 3, which may be formed in the lower die surface by wire cutting. The plurality of exhaust grooves are distributed in a spaced manner with a certain distance between adjacent exhaust grooves. Thereby, moisture can be uniformly discharged. Preferably, the width of the air discharge groove 131 is less than or equal to 0.3 mm. In this preferable range, the air discharge grooves are set as wide as possible to ensure the dewatering efficiency while the first surface of the paper-plastic article 9 is as flat as possible.

With continued reference to fig. 3, the lower die surface 110 may be provided with vent holes 126. In the example shown in fig. 3, the exhaust holes 126 are provided in the top surface 120 and the bottom surface 130, but the exhaust holes 126 may be provided in the outer side surface 140 and the inner side surface 141. In the wet-pressing mold according to the present invention, the vent holes are formed in the form of discrete units occupying only a small portion of the top and bottom surfaces 120 and 130, rather than densely packing the entire surface or planar portions of the core as in the prior art. Specifically, the vent may include a plurality of vent units 125. Each vent unit 125 may include one or more vents 126. In the embodiment shown in fig. 1-5, the vent unit 125 includes one vent 126. In the embodiment shown in fig. 6 and 7, the vent unit 125 includes four vents 126. It is understood that some vent units 125 may include one vent 126, and other vent units 125 may include a plurality of vents 126 in the same wet-pressing mold 1. It should also be understood that the number of the exhaust holes 126 included in the exhaust hole unit 125 is not limited to that shown in the drawings, for example, the exhaust hole unit 125 may include two, three, five, six, or even more number of the exhaust holes 126. The diameter of the air vent 126 is 0.5 to 1 mm, so that the first surface of the paper-plastic article obtained therefrom is as flat as possible. Preferably, the diameter of the vent 126 is 0.7 to 1 mm. More preferably, the diameter of the vent 126 is 0.8 to 1 millimeter. In the wet-pressing mold according to the present invention, it is exemplified that the vent holes and/or the vent hole units are discretely distributed. For example, the length, width and height of the mold core are about 24 cm, 22 cm and 80 cm, respectively, and the distance between the vent holes with the diameter of 0.6 to 0.8 mm and/or the vent hole unit comprising a plurality of vent holes with such diameter is about 1.3 cm, rather than the vent holes with the diameter of about 2 mm densely distributed on the surface of the mold core as in the prior art. In the present invention, the distribution of the vent holes/vent units is sparse.

Compared with the technical scheme of the prior art that the vent holes are densely distributed on the whole mold core and have the diameter of about 2 millimeters, in the scheme of the utility model, the number of the vent holes is greatly reduced due to the discrete distribution of the vent hole units, and the diameter of the vent holes is also obviously reduced. In the utility model, through the discrete distribution of the exhaust hole units and the reduction of the size of the exhaust holes, the appearance quality of the second surface (front surface) of the paper-plastic product reaches the same high level as that when the stainless steel net is used under the condition of not using the stainless steel net, and the quality of the first surface (back surface) of the paper-plastic product is obviously superior to that when the stainless steel net is used, so that the paper-plastic product has better smoothness. Moreover, the wet pressing die does not use a stainless steel net, so that the quality of the paper-plastic product is improved, the defects caused by the stainless steel net are eliminated, the maintenance and production cost is obviously reduced, the labor is saved, the productivity is improved, and the damage to the die is reduced.

Reference is now made to fig. 5, which is a partially schematic perspective view of the lower die shown in fig. 3. As shown in fig. 5, in the wet-pressing mold 1 according to the present invention, the vent groove 131 may communicate with the vent hole 126. Specifically, in the example shown in fig. 5, the outer side surface 140 may enclose a substantially rectangular frame, and an exhaust groove 131 may be disposed at a boundary between two adjacent surfaces of the rectangular frame, and one end of the exhaust groove 131 is disposed in an exhaust hole 126. As described above, the vent grooves are formed by wire cutting, and the vent grooves 131 are provided to communicate with the vent holes 126 so that the wire cutting can be performed from the vent holes 126, thereby increasing the wire cutting speed, and at the same time, the vent grooves are less likely to be clogged during the production process. It will be appreciated that this arrangement of the vent grooves in communication with the vent holes may also be applied to vent grooves and vent holes in other locations.

Fig. 6 to 7 show a wet-pressing mold 1 according to another embodiment of the present invention. The same reference numerals in fig. 6 and 7 as in the previous figures indicate the same components, the function and participation of which are also similar to those in the previous embodiment and will not be described again.

In the embodiment shown in fig. 6 and 7, a plurality of vent units 125 are discretely distributed on the lower die surface 110. The exhaust hole unit 125 may include four exhaust holes 126. The vent hole unit 125 has a first diameter D1. The first diameter D1 is defined as the diameter of the smallest circle C that encloses all of the vent holes 126 of the vent hole unit 125, as schematically shown in fig. 7. In the case where the vent hole unit 125 includes only one vent hole 126, the first diameter D1 is the diameter of the vent hole.

The vent units 125 extend from the lower die face (e.g., top face 120) into the lower die material along a portion H1 of the height H of the lower die 10 until an opening 25 is also provided in the lower die material interior, the opening 25 being in communication with the environment outside the wet-pressing mold 1 and having a second diameter D2, the second diameter D2 being greater than the first diameter D1. Fig. 7 shows a state in which the vent unit 125 extends from the top surface 120 of the lower mold surface 110 toward the inside of the lower mold in the height direction of the lower mold. It should be understood that the vent unit 125 may also extend from other portions of the lower mold surface in other directions within the lower mold. The penetration of a plurality of small-diameter holes such as the vent holes of the present invention into a mold is time-consuming and difficult to operate, and therefore, the plurality of vent holes are collected and extended a distance from the lower mold surface toward the inside of the lower mold material to communicate with the larger-sized opening 25 communicating with the external environment inside the lower mold material, which can not only improve the processing efficiency of the mold but also increase the dehydration efficiency.

The discharge hole unit 125 may be provided on the lower mold in various forms.

In one embodiment, the discharge hole unit 125 is integrally formed on the lower mold 10, as shown in fig. 7.

In another embodiment, not shown, the discharge hole unit 125 may be formed on an air plug, which is inserted into an opening of the lower mold 10. In this case, a larger-sized through-hole, for example, a through-hole having the second diameter D2, may be pierced in the lower die from the lower die face, and then an air plug pre-machined with vent elements may be inserted into the through-hole from the lower die face.

Preferably, the gas lock is a stainless steel gas lock. A stainless steel air plug is arranged in the stainless steel mold core, and the position of the air plug is not easy to collapse.

In the wet-pressing mold according to the present invention, a high-quality product can be obtained at a significantly reduced cost without using a stainless steel net. However, the stainless steel net still covers the stainless steel net under the condition of need, and at the moment, the stainless steel net can be directly welded on the surface of the stainless steel mold core, so that the stainless steel mold core is firmly welded and is not easy to fall off.

It is to be understood that the structures described above and shown in the attached drawings are merely examples of the present invention, which can be replaced by other structures exhibiting the same or similar function for obtaining the desired end result. Furthermore, it should be understood that the embodiments described above and shown in the drawings are to be regarded as constituting only non-limiting examples of the present invention and that it can be modified in many ways within the scope of protection of the utility model.

Claims (10)

1. A wet-pressing mould (1) for paper-plastic products, characterized in that said wet-pressing mould (1) comprises:

a lower mold (10) having a lower cavity (11), the lower cavity (11) including a lower mold surface (110) corresponding to a first surface of the paper-plastic article (9),

an upper die (20) having an upper die cavity (21) comprising an upper die face (210) corresponding to a second surface (92) opposite to the first surface of the paper-plastic article (9),

wherein the lower die surface (110) is provided with an exhaust groove (131) and an exhaust hole,

and wherein the vent comprises a plurality of vent units (125), the vent units (125) being discretely distributed and each vent unit comprising one or more vents (126),

and the diameter of the vent hole is 0.5 to 1 mm.

2. The wet-pressing die of claim 1, wherein the vent holes have a diameter of 0.7 to 1 mm.

3. The wet-pressing die of claim 1, wherein the vent holes have a diameter of 0.8 to 1 mm.

4. The wet-pressing die of any one of claims 1 to 3, wherein the vent slot has a width of less than or equal to 0.3 mm.

5. A wet-pressing mold according to any one of claims 1 to 3, wherein the vent unit comprises 3 to 6 vents.

6. A wet-pressing die according to any one of claims 1 to 3, wherein said vent unit has a first diameter (D1) and extends from said lower die face to the interior of the lower die material to an opening having a second diameter (D2), said opening being provided in the interior of the lower die material and communicating with the external environment, said second diameter being greater than said first diameter.

7. The wet-pressing mold according to claim 6, wherein the vent unit (125) is integrally formed on the lower mold (10).

8. The wet-pressing mold according to claim 6, wherein the vent hole unit (125) is provided on a gas plug embedded in the lower mold (10).

9. The wet-pressing mold of claim 8, wherein said air lock is a stainless steel air lock.

10. A wet-pressing die according to any one of claims 1 to 3, wherein the vent groove (131) communicates with the vent hole (126).

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