Molded pulp packaging product as well as inward convex forming process and production process thereof

Abstract

The invention relates to a molded pulp packaging product, and an inward convex forming process and a production process of the molded pulp packaging product. The defects of unreasonable design and the like in the prior art are overcome. The inward convex forming process of the molded pulp packaging product comprises the following steps: at least forcing the outer diameter of the original side wing wall thickness of a molded pulp wet blank product to be kept unchanged; the paper pulp molding wet blank product is sleeved with a shaping internal expansion mold, the shaping internal expansion mold applies radial internal expansion force from inside to outside to the original side wing wall thickness, and the radial internal expansion force enables the original side wing wall thickness to be compressed and thinned to the set side wing wall thickness; and when the original side wing wall thickness is forced to be compressed and thinned by the radial internal expansive force, an internal protrusion arranged in the direction opposite to the radial internal expansive force is shaped between at least part of the inner wall of the original side wing wall thickness and the shaping internal expanding die. The method has the advantages that the inner convex structure is shaped in the hot-pressing shaping stage, the risk that the inner diameter of the inner convex structure is further enlarged during post-treatment processing demolding can be prevented, and a molded pulp packaging product has better fastening tightness.

Description

Technical Field

[0001] The invention belongs to the technical field of pulp molded products, and in particular relates to a pulp molded packaging product, and an inner convex molding process and a production process thereof. Background Art

[0002] Pulp molded packaging products include pulp molded cup lids. The inner wall of the side wing of the existing pulp molded cup lids is provided with an inner convex buckle during wet blank molding, and the inner convex buckle is buckled on the open mouth of the cup body to prevent the pulp molded cup lid from falling off. However, this method is not conducive to subsequent demoulding during hot pressing shaping. During demoulding, the inner diameter of the inner convex buckle increases, which greatly reduces the buckling tightness with the cup body and reduces production efficiency.

[0003] Of course, some inventors have designed a molding method in which the outer wall of the side wing is rolled or spun inward or mechanically pressed inward after the pulp molded cup lid is hot-pressed and fixed, such as CN200910041616.2, a manufacturing process for a disposable cup lid and a cup lid made by the process, the specific steps of which are raw material beating - batching - molding - hot-pressing shaping - trimming and punching - pressing the inverted hook groove. Although the product terminal has a structure with an inner convex buckle on the inner wall of the side wing, the above scheme will destroy the structural strength of the side wing, affect the final buckle tightness with the cup body, and the added step of pressing the inverted hook groove will delay the production cycle and affect production efficiency. Summary of the invention

[0004] The object of the present invention is to provide a pulp molded packaging product, and an inner convex molding process and a production process thereof, which can solve the above technical problems.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] The molded pulp packaging article has a set side wing wall thickness.

[0007] The inner convex forming process of the pulp molded packaging product comprises the following steps:

[0008] At least the outer diameter of the original side wing wall thickness of the pulp molded green embryo product is forced to remain unchanged;

[0009] The pulp molded wet embryo product is sleeved in a shaping inner expansion mold, and the shaping inner expansion mold applies a radial inner expansion force from inside to outside to the original side wing wall thickness, and the radial inner expansion force compresses and thins the original side wing wall thickness to the set side wing wall thickness; and

[0010] When the radial internal expansion force forces the original flank wall thickness to be compressed and thinned, an inner bulge arranged in the opposite direction to the radial internal expansion force is formed between at least a portion of the inner wall of the original flank wall thickness and the shaping internal expansion mold.

[0011] In the above-mentioned inner convex forming process of pulp molded packaging products, the shaping inner bulging mold has an inner convex forming groove, and the inner convex is formed in the inner convex forming groove.

[0012] In the above-mentioned inner convex forming process of the pulp molded packaging product, when the shaping inner expansion mold contracts radially, the inner convex forming groove is forced to separate from the inner convex.

[0013] In the above-mentioned inner bulging forming process of pulp molded packaging products, the shaping inner bulging mold is a hot pressing shaping inner bulging convex mold.

[0014] The present application also provides a production process of pulp molded packaging products, comprising the following steps:

[0015] S1, wet embryo molding, obtaining a pulp molded wet embryo product with original flank wall thickness by pulp molding;

[0016] S2, hot pressing and shaping, at least forcing the outer diameter of the original flank wall thickness in S1 to remain unchanged; and

[0017] The pulp molded wet embryo product is sleeved in a shaping inner expansion mold, and the shaping inner expansion mold applies a radial inner expansion force from inside to outside to the original side wing wall thickness, and the radial inner expansion force compresses and thins the original side wing wall thickness to a set side wing wall thickness; and

[0018] When the radial inner expansion force forces the original flank wall thickness to be compressed and thinned, an inner bulge is formed between at least a portion of the inner wall of the original flank wall thickness and the shaping inner expansion die in a direction opposite to the radial inner expansion force;

[0019] S3, demoulding, the shaping inner expansion mold in S2 is radially contracted so that the shaping inner expansion mold is separated from the inner convexity.

[0020] In the production process of the above-mentioned pulp molded packaging products, in the above-mentioned S2, a hot pressing shaping die similar to the outer contour of the pulp molded wet embryo product is provided, and the shaping inner expansion mold is a hot pressing shaping inner expansion convex mold similar to the inner contour of the pulp molded wet embryo product, and either the hot pressing shaping die or the shaping inner expansion mold moves relative to the other and forces the shaping inner expansion mold to apply a radial inner expansion force from the inside to the outside to the original flank wall thickness.

[0021] In the production process of the pulp molded packaging product, during the process of forming the inner bulge, the shaping inner bulge mold and the hot pressing shaping concave mold heat and dry the pulp molded wet embryo product respectively.

[0022] In the production process of the pulp molded packaging product, the shaping inner expansion mold has an inner convex molding groove, and the inner convex is molded in the inner convex molding groove.

[0023] In the production process of the pulp molded packaging product, in the above S1, the pulp molded wet embryo product is a pulp molded wet embryo cup lid with uniform wall thickness.

[0024] The present application also provides a pulp molded packaging product, and the pulp molded packaging product is produced by the production process of the pulp molded packaging product.

[0025] Compared with the existing technology, the advantages of this application are:

[0026] Shaping the inner convex structure in the hot pressing shaping stage can prevent the risk of further enlargement of the inner diameter of the inner convex during post-processing and demoulding, so that the pulp molded packaging product has better fastening tightness.

[0027] Shaping the convex structure during the hot pressing shaping stage can simplify the production process. For example, the step of separately pressing the inverted hook after hot pressing molding is omitted. It can also avoid the risk of the inner diameter of the convex being further enlarged during demolding due to the hot pressing shaping steps caused by directly forming the convex in the wet embryo. This can improve production efficiency and ensure stable product quality.

[0028] The inner convex structure is formed in the hot pressing forming stage to prevent the phenomenon that the thickness of the side wing wall and its strength become worse due to spinning, rolling or pressing of the undercut hook. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the changes of the pulp molded packaging product obtained after the pulp molded wet embryo product provided by the present invention is subjected to hot pressing and shaping;

[0030] Figure 2 It is a process flow chart of the inner convex molding provided by the present invention;

[0031] Figure 3 It is a schematic diagram of the structure of the hot pressing shaping mold provided by the present invention;

[0032] Figure 4 yes Figure 3 A is an enlarged structural diagram;

[0033] Figure 5 This is a production process flow chart of the pulp molded packaging product provided by the present invention;

[0034] Figure 6 It is a schematic diagram of the mold opening state of the hot pressing shaping mold provided by the present invention;

[0035] Figure 7 It is a schematic diagram of a pulp molded wet embryo product provided by the present invention being sleeved on a shaping inner expansion mold;

[0036] Figure 8It is a schematic diagram of the mold closing state of the hot pressing shaping mold provided by the present invention;

[0037] Fig. 9 It is a schematic diagram of the hot pressing shaping mold provided by the present invention in the state of reopening the mold;

[0038] Fig.10 It is a schematic diagram of the hot pressing shaping mold provided by the present invention in a fully opened mold state.

[0039] In the figure, pulp molded wet embryo product Z0, original flank wall thickness Z01, top Z02, transverse part Z03, pulp molded packaging product Z1, flank wall thickness Z10, inner convex Z11, shaping inner bulging mold 1, inner convex molding groove 1a, guide displacement outer mold 10, first blind hole 100, accommodating groove 101, third blind hole 102, inner bulging mold 11, transverse spring 12, fourth blind hole 120, top mold 13, demolding air channel 130, extension part 131, through hole 2 132, transverse air path 133, hot pressing shaping die 2, mold base 3, guide groove 30, second blind hole 300, elastic component 31, frustum 32, through hole 320, through hole 1 33, cylindrical part 330. DETAILED DESCRIPTION

[0040] The following are specific embodiments of the invention and combined with the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0041] like Figure 1 As shown, the pulp molded packaging product Z1 has a set side wing wall thickness Z10, and an inner convexity Z11 is provided on the inner wall of the set side wing wall thickness Z10. The inner convexity Z11 can be a full ring structure or a plurality of arc structures distributed in a circle.

[0042] Pulp molded packaging product Z1 is further introduced as follows, taking pulp molded cup lid as an example:

[0043] Embodiment 1

[0044] like Figure 1 As shown, the inner convex forming process of the pulp molded packaging product is mainly used to manufacture the inner convex Z11 and is in the hot pressing shaping stage.

[0045] Different from the prior art, the inner convex Z11 of this embodiment is obtained by hot pressing and shaping, and the finished product is directly obtained after hot pressing and shaping, which can completely solve the above-mentioned many prior art problems of the prior art.

[0046] Specifically, Figure 1-Figure 3 As shown, the inner convex forming process of this embodiment includes the following steps:

[0047] At least the outer diameter of the original flank wall thickness Z01 of the pulp molded wet embryo product Z0 is forced to remain unchanged; in the wet embryo state, the thickness of the original flank wall thickness Z01 is greater than the set flank wall thickness Z10.

[0048] The above outer diameter restriction remains unchanged and a hot pressing shaping die 2 is used. The hot pressing shaping die 2 can limit the outer contour surface of the pulp molded wet embryo product Z0, so that the original flank wall thickness Z01 can be subjected to the following shaping, compression and thinning processing.

[0049] Secondly, the pulp molded wet embryo product Z0 is sleeved on the shaping inner expansion mold 1, which is a hot-pressing shaping inner expansion convex mold. At this time, the shaping inner expansion mold 1 is in a radially contracted state, so that the pulp molded wet embryo product Z0 can be inserted. The outer wall of the shaping inner expansion mold 1 at least has a matching contact surface that matches the original flank wall thickness Z01, and the shaping inner expansion mold 1 applies a radial inner expansion force from the inside to the outside to the original flank wall thickness Z01. The application of the radial inner expansion force can make the original flank wall thickness Z01 thinner. At the same time, the axis of the pulp molded wet embryo product Z0 can be passively coincided with the axis of the shaping inner expansion mold 1, and finally the original flank wall thickness Z01 has a uniform thickness. The radial inner expansion force compresses and thins the original flank wall thickness Z01 to a set flank wall thickness Z10;

[0050] The radial internal expansion force is applied in a plane perpendicular to the axis of the pulp molded wet embryo product Z0. When the radial internal expansion force compresses the original flank wall thickness Z01 to become thinner, an inner convex Z11 arranged in the opposite direction to the radial internal expansion force is formed between at least part of the inner wall of the original flank wall thickness Z01 and the shaping inner expansion mold 1. Here, it is explained that an inner convex forming chamber is reserved between the inner wall of the original flank wall thickness Z01 and the shaping inner expansion mold 1. Because the wall thickness becomes thinner during shaping, part of the material of the original flank wall thickness Z01 is squeezed into the inner convex forming chamber, and the inner convex Z11 is formed.

[0051] Specifically: Figure 4 As shown, the shaping inner expansion mold 1 has an inner convex molding groove 1a, and the inner convex Z11 is formed in the inner convex molding groove 1a. The single-side cross-section of the inner convex molding groove 1a is C-shaped, U-shaped, or V-shaped, and of course it can also be semicircular. The inner convex molding groove 1a is at least two arc grooves centered on the axis of the shaping inner expansion mold 1 and distributed in a circumference.

[0052] Secondly, when the shaping inner expansion mold 1 contracts radially, the inner convex molding groove 1a is forced to separate from the inner convex Z11. This structure can facilitate demoulding to prevent the inner diameter of the inner convex Z11 from expanding during demoulding.

[0053] like Figure 3As shown, the shaping inner expansion mold 1 and the hot pressing shaping concave mold 2 cooperate with each other to form a hot pressing shaping profiling chamber for accommodating the pulp molded wet embryo product Z0. In this compression and thinning process, the shaping inner expansion mold 1 expands radially and makes the shaping inner expansion mold 1 have a radial inner expansion force, and the outward expansion of the radial inner expansion force compresses and thins the original flank wall thickness Z01.

[0054] An inclined internal expansion guide mechanism is arranged between the shaping internal expansion mold 1 and the hot pressing shaping concave mold 2, and the inclined internal expansion guide mechanism enables the shaping internal expansion mold 1 to expand radially outward. The shaping internal expansion mold 1 moves up and down relative to the mold base 3 in the vertical direction, and the side of the shaping internal expansion mold 1 away from the hot pressing shaping concave mold 2 is connected to the hot pressing shaping concave mold 2 through an elastic component 31.

[0055] The shaping inner bulge mold 1 moves up and down relative to the mold base 3 in the vertical direction, and the side of the shaping inner bulge mold 1 away from the hot pressing shaping concave mold 2 is connected to the hot pressing shaping concave mold 2 through an elastic component 31. Specifically, at least part of the shaping inner bulge mold 1 is accommodated in the guide groove 30 of the mold base 3, that is, the shaping inner bulge mold 1 and the guide groove 30 are linearly slidably matched to achieve the displacement of the shaping inner bulge mold 1, and the side of the shaping inner bulge mold 1 away from the hot pressing shaping concave mold 2 is connected to the bottom of the guide groove 30 through the elastic component 31. The elastic expansion direction of the elastic component 31 is the displacement direction of the shaping inner bulge mold 1.

[0056] The functions of the hot pressing shaping die 2 are as follows:

[0057] The elastic component 31 forces the shaping inner expansion mold 1 to stay away from the bottom of the guide groove 30, that is, at this time, there is a gap between the bottom surface of the shaping inner expansion mold 1 and the bottom of the guide groove 30, and the hot pressing shaping die 2 is driven by power to make the hot pressing shaping die 2 and the shaping inner expansion mold 1 close together. At this time, the pulp molded wet embryo product Z0 is received in the hot pressing shaping profiling chamber. As the hot pressing shaping die 2 continues to descend, the elastic component 31 is continuously elastically compressed. In this process, the shaping inner expansion mold 1 and the hot pressing shaping die 2 can heat and dry the pulp molded wet embryo product Z0, and compress and thin the wall thickness of the pulp molded wet embryo product Z0, that is, hot pressing shaping.

[0058] like Figure 1 and Figure 3As shown, the pulp molded wet embryo product Z0 includes a top Z02 and an original side wing wall thickness Z01 connected to the top Z02. Of course, the original side wing wall thickness Z01 has a transverse portion Z03 that is parallel or approximately parallel to the top Z02. When the hot pressing shaping die 2 is molded with the shaping inner bulge die 1 and the elastic component 31 is continuously compressed, the inclined inner bulge guide mechanism set between the shaping inner bulge die 1 and the mold base 3 at this time allows the shaping inner bulge die 1 to expand radially outward. That is, the mold closing movement of the hot pressing shaping die 2 can drive the shaping inner bulge die 1 to compress and thin the original side wing wall thickness Z01 in the radial direction, and compress and thin the top Z02 and the transverse portion Z03. The wall thickness of the pulp molded packaging product Z1 after compression and thinning is uniform, except for the local thickness of the inner bulge Z11.

[0059] After the hot pressing shaping is completed, post-processing such as trimming can be carried out. The post-processing does not require the pulp molded packaging product Z1 to be put into the corresponding profiling fixture again, thus eliminating the risk of the inner diameter of the inner convex Z11 being enlarged twice or multiple times.

[0060] Specifically, Figure 1 and Figure 3 As shown, the structure of the shaping inner expansion mold 1 includes a guide displacement outer mold 10 that is at least partially slidably matched with the mold base 3, and a plurality of circumferentially uniformly distributed inner expansion molds 11 that are at least partially received in the guide displacement outer mold 10.

[0061] Specifically, at least a portion of the guide displacement outer mold 10 is slidably matched with the guide groove 30 , and the elastic component 31 includes a plurality of springs, one end of the spring acts on the guide displacement outer mold 10 , and the other end of the spring acts on the guide groove 30 . In order to enable the spring to stably exert elastic force, a first blind hole 100 is provided at the bottom of the guide displacement outer mold 10, and a second blind hole 300 is provided at the bottom of the guide groove 30. One end of the spring extends into the first blind hole 100 and the end of the spring acts on the bottom of the first blind hole 100, and the other end of the spring extends into the second blind hole 300 and the end of the spring acts on the bottom of the second blind hole 300. At this time, the guide displacement outer mold 10 can move relative to the guide groove 30. When the spring is not compressed, the shaping inner expansion mold 1 is in an unexpanded state. When the spring is compressed to a set length (when the bottom surface of the guide displacement outer mold 10 contacts the bottom of the guide groove 30), the shaping inner expansion mold 1 expands into place, completing the wall thickness compression and thinning processing of the pulp molded wet embryo product Z0.

[0062] At least part of the inner expansion molds 11 are evenly distributed in the circumference and are at least partially received in the guide displacement outer mold 10. Further, a receiving groove 101 is provided on the upper part of the guide displacement outer mold 10, and at least part of the inner expansion mold 11 is in the receiving groove 101. In a preferred embodiment, the bottom of the receiving groove 101 and the bottom surface of the inner expansion mold 11 are in sliding contact to achieve radial displacement stability of the inner expansion mold 11. Secondly, a transverse spring 12 is provided between the outer side of the inner expansion mold 11 and the guide displacement outer mold 10. For example, the outer end of the transverse spring 12 extends into the third blind hole 102 of the vertical groove wall of the receiving groove 101, and the inner end of the transverse spring 12 extends into the fourth blind hole 120 on the outer side of the inner expansion mold 11. The corresponding ends of the transverse spring 12 abut against the bottom of the third blind hole 102 and the bottom of the fourth blind hole 120.

[0063] That is, each inner expansion mold 11 is matched with at least one transverse spring 12, and the transverse spring 12 and the elastic component 31 are vertically distributed, that is, the transverse spring 12 provides transverse elastic force, and the elastic component 31 provides vertical elastic force. The elastic force of the transverse spring 12 can make the inner expansion mold 11 return radially inward after radially expanding outward, and at the same time, the transverse spring 12 can also play a buffering role when the inner expansion mold 11 expands radially outward, so that the inner expansion mold 11 expands smoothly.

[0064] In addition, the receiving groove 101 is a stepped groove, the bottom groove wall of the receiving groove 101 parallel to the transverse spring 12 is in sliding contact with the inner expansion mold 11, and the lateral groove wall of the receiving groove 101 and the transverse spring 12 are perpendicular to each other and play a role in limiting the inner expansion mold 11 from moving outward to the limit.

[0065] The top mold 13 is placed on the top of the inner expansion mold 11. The top mold 13 is shaped like the top Z02. The inner expansion mold 11 slides to support the bottom surface of the top mold 13. That is to say, the top mold 13 will not move radially, etc. The top mold 13 will only move up and down to compress and thin the wall thickness of the top Z02.

[0066] like Figure 1 and Figure 3 As shown, the inclined internal expansion guiding mechanism includes the following structure:

[0067] The truncated cone 32 is fixed to the guide groove 30. The truncated cone 32 is fixed to the central area of ​​the guide groove 30. The outer wall of the truncated cone 32 has a conical surface. The inner wall of the inner expansion mold 11 has an inclined matching surface that matches the outer wall of the truncated cone 32. When the pulp molded wet embryo product Z0 is in an uncompressed and thinned state, the upper side of the inclined matching surface exceeds the top of the truncated cone 32 (because of the elastic force of the elastic component 31). When the hot pressing shaping die 2 moves downward, the inner expansion mold 11 at this time moves downward relative to the truncated cone 32. During this displacement process, the wall thickness of the pulp molded wet embryo product Z0 is continuously compressed and thinned. At the same time, When the bottom of the guided displacement outer mold 10 contacts the bottom of the guide groove 30, and the outer wall of the inner expansion mold 11 abuts against the lateral groove wall of the accommodating groove 101, the inner expansion mold 11 is now in the position of internal expansion and cannot continue to move radially outward. After the inner expansion mold 11 stays for at least a certain time, the hot pressing shaping die 2 is reset upward, and the inner expansion mold 11 is also reset upward at this time. Due to the radial inward contraction of the inner expansion mold 11, it can be avoided that the inner expansion mold 11 expands the inner diameter of the inner convex Z11 during demolding. In addition, because the inner convex Z11 is shaped during hot pressing shaping, the risk of expanding the inner diameter of the inner convex Z11 again during post-processing can be eliminated.

[0068] In order to facilitate the demoulding of the top Z02 from the top mold 13, a plurality of demoulding air channels 130 with open upper ends are opened inside the top mold 13 and / or the inner expansion mold 11. The demoulding air channels 130 are connected to the air source. When the inner expansion mold 11 is separated from the inner convex Z11, the demoulding air channels 130 at this time perform the action of introducing air pressure to enable the top Z02 to be demoulded from the top mold 13.

[0069] In addition, an extension portion 131 extending downward is provided at the center of the lower surface of the top mold 13, a through hole 320 is provided in the axial direction of the truncated cone 32, the extension portion 131 is columnar and inserted into the through hole 320, the extension portion 131 and the through hole 320 are clearance-matched, a through hole 1 33 is provided on the mold base 3, a through hole 2 132 penetrating the through hole 1 33 is provided in the axial direction of the extension portion 131, the lower end of the demoulding airway 130 is respectively connected with the transverse airway 133, and the transverse airway 133 is connected through the air supply pipeline penetrating through the through hole 1 33 and the through hole 2 132. And the transverse airway 133 is at least one and both ends of the transverse airway 133 are also connected with the outside world, and the transverse airway 133 and the demoulding airway 130 can form different orientations for demoulding operations.

[0070] As another form of air supply pipeline, a cylindrical portion 330 is provided at the upper opening of the through hole 33, and the extension portion 131 and the cylindrical portion 330 are mutually sleeved and movably sealed. For example, the extension portion 131 is inserted into the cylindrical portion 330, and the two are dynamically sealed and slidably matched, such as by providing a sealing ring. In this case, blowing and demoulding can be achieved by providing an air source at the lower opening of the through hole 33.

[0071] Embodiment 2

[0072] Based on the first embodiment, this embodiment further discloses the following contents:

[0073] like Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, the production process of pulp molded packaging products includes the following steps:

[0074] S1, wet embryo molding, obtaining a pulp molded wet embryo product Z0 with an original side wing wall thickness Z01 by pulp molding; the pulp molded wet embryo product Z0 is a pulp molded wet embryo cup cover with the same wall thickness.

[0075] S2, hot pressing and shaping, at least forcing the outer diameter of the original flank wall thickness Z01 in S1 to remain unchanged; and

[0076] The pulp molded wet embryo product Z0 is sleeved on the shaping inner expansion mold 1, and the shaping inner expansion mold 1 applies a radial inner expansion force from inside to outside to the original flank wall thickness Z01, and the radial inner expansion force compresses and thins the original flank wall thickness Z01 to a set flank wall thickness Z10; and

[0077] When the radial inner expansion force forces the original flank wall thickness Z01 to be compressed and thinned, an inner bulge Z11 set in the opposite direction to the radial inner expansion force is formed between at least part of the inner wall of the original flank wall thickness Z01 and the shaping inner expansion mold 1;

[0078] like Figure 3 and Figure 6-Figure 10 As shown, the specific steps of S2 are as follows:

[0079] S21, placing the pulp molded wet embryo product Z0 between the shaping inner expansion mold 1 and the hot pressing shaping concave mold 2 in the mold opening state;

[0080] S22, putting the pulp molded wet embryo product Z0 into the shaping inner expansion mold 1;

[0081] S23, the shaping inner bulge mold 1 and the hot pressing shaping concave mold 2 are closed and the pulp molded wet embryo product Z0 is subjected to hot pressing shaping. At this time, a dry pulp molded packaging product Z1 having at least a set side wing wall thickness Z10 is obtained, and an inner convex Z11 is obtained by shaping the inner wall of the set side wing wall thickness Z10; and the top Z02 and the lateral part Z03 are compressed and thinned to a state where the thickness is equal to the set side wing wall thickness Z10.

[0082] S24, the hot pressing shaping die 2 opens relative to the shaping inner expansion die 1, and the shaping inner expansion die 1 radially contracts under the elastic force of the transverse spring 12, so that the inner convex forming groove 1a of the shaping inner expansion die 1 is separated from the inner convex Z11, and at the same time the elastic component 31 forces the shaping inner expansion die 1 to reset upward.

[0083] Of course, the elastic component 31 can drive the plastic inner expansion mold 1 and the hot pressing plastic mold 2 that is clamped on the plastic inner expansion mold 1 to reset upward together. When the hot pressing plastic mold 2 is reset into place, external force is used to open the hot pressing plastic mold 2 relative to the plastic inner expansion mold 1.

[0084] S25. After the shaping inner expansion mold 1 is separated from the pulp molded packaging product Z1, the pulp molded packaging product Z1 is taken out.

[0085] like Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown:

[0086] S3, demoulding, the shaping inner expansion mold 1 in S2 is radially contracted so that the shaping inner expansion mold 1 is separated from the inner convex Z11.

[0087] In the above-mentioned S2, a hot pressing shaping die 2 is provided which is similar to the outer contour of the pulp molded wet embryo product Z0, and a shaping inner expansion mold 1 is a hot pressing shaping inner expansion convex mold which is similar to the inner contour of the pulp molded wet embryo product Z0. Either the hot pressing shaping die 2 or the shaping inner expansion mold 1 moves relative to the other and forces the shaping inner expansion mold 1 to apply a radial inner expansion force from the inside to the outside to the original flank wall thickness Z01.

[0088] In this embodiment, the hot pressing shaping die 2 moves relative to the shaping inner expansion die 1 .

[0089] During the process of forming the inner convex Z11, the shaping inner expansion mold 1 and the hot pressing shaping concave mold 2 heat and dry the pulp molded wet embryo product Z0 respectively. The heating and drying adopts electric heating or steam heating and the like.

[0090] Embodiment 3

[0091] like Figure 1 As shown, this embodiment provides a pulp molded packaging product, which is produced by the production process of the pulp molded packaging product of Example 2.

[0092] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

Claims

1. A process for forming an inner convex shape of a pulp molded packaging product, wherein the pulp molded packaging product (Z1) has a set side wing wall thickness (Z10), characterized in that: The inner convex forming process comprises the following steps: At least the outer diameter of the original flank wall thickness (Z01) of the pulp molded wet embryo product (Z0) is forced to remain unchanged; The pulp molded wet embryo product (Z0) is sleeved in a shaping inner expansion mold (1), and the shaping inner expansion mold (1) applies a radial inner expansion force from inside to outside to the original side wing wall thickness (Z01), and the radial inner expansion force compresses and thins the original side wing wall thickness (Z01) to the set side wing wall thickness (Z10); and When the radial internal expansion force forces the original flank wall thickness (Z01) to be compressed and thinned, an inner bulge (Z11) arranged in the opposite direction to the radial internal expansion force is formed between at least a portion of the inner wall of the original flank wall thickness (Z01) and the shaping internal expansion mold (1).

2. The inner convex forming process of pulp molded packaging products according to claim 1, characterized in that: The shaping inner expansion mold (1) has an inner convex molding groove (1a), and the inner convexity (Z11) is formed in the inner convex molding groove (1a).

3. The inner convex forming process of pulp molded packaging products according to claim 2, characterized in that: When the shaping inner expansion mold (1) contracts radially, the inner convex molding groove (1a) is forced to separate from the inner convex (Z11).

4. The inner convex forming process of pulp molded packaging products according to claim 1, 2 or 3, characterized in that: The shaping internal expansion die (1) is a hot pressing shaping internal expansion convex die.

5. A process for producing pulp molded packaging products, characterized in that: The production process comprises the following steps: S1, wet embryo molding, obtaining a pulp molded wet embryo product (Z0) having an original flank wall thickness (Z01) by pulp molding; S2, hot pressing and shaping, at least forcing the outer diameter of the original flank wall thickness (Z01) in S1 to remain unchanged; as well as The pulp molded wet embryo product (Z0) is sleeved in a shaping inner expansion mold (1), and the shaping inner expansion mold (1) applies a radial inner expansion force from inside to outside to the original side wing wall thickness (Z01), and the radial inner expansion force compresses and thins the original side wing wall thickness (Z01) to a set side wing wall thickness (Z10); and When the radial internal expansion force forces the original flank wall thickness (Z01) to be compressed and thinned, an inner bulge (Z11) arranged in the opposite direction to the radial internal expansion force is formed between at least a portion of the inner wall of the original flank wall thickness (Z01) and the shaping internal expansion mold (1); S3, demoulding, the shaping inner expansion mold (1) in S2 is radially contracted so that the shaping inner expansion mold (1) is separated from the inner convexity (Z11).

6. The production process of pulp molded packaging products according to claim 5, characterized in that: In the above-mentioned S2, a hot pressing shaping die (2) is provided which is similar to the outer contour of the pulp molded wet embryo product (Z0), and the shaping inner expansion mold (1) is a hot pressing shaping inner expansion convex mold which is similar to the inner contour of the pulp molded wet embryo product (Z0). Either the hot pressing shaping die (2) or the shaping inner expansion mold (1) moves relative to the other and forces the shaping inner expansion mold (1) to apply a radial inner expansion force from the inside to the outside to the original flank wall thickness (Z01).

7. The production process of pulp molded packaging products according to claim 6, characterized in that: During the process of forming the inner bulge (Z11), the shaping inner expansion mold (1) and the hot pressing shaping concave mold (2) respectively heat and dry the pulp molded wet embryo product (Z0).

8. The production process of pulp molded packaging products according to claim 6, characterized in that: The shaping inner expansion mold (1) has an inner convex molding groove (1a), and the inner convexity (Z11) is formed in the inner convex molding groove (1a).

9. The production process of pulp molded packaging products according to claim 5, characterized in that: In the above S1, the pulp molded wet embryo product (Z0) is a pulp molded wet embryo cup cover with uniform wall thickness.

10. A pulp molded packaging product, characterized in that: The pulp molded packaging product is produced by the production process of pulp molded packaging products according to any one of claims 5-9.

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