Pulp molding negative angle container and its processing method

Abstract

The present invention discloses a pulp molding negative angle container comprising a conical pulp container which is open on the upper end, wherein: the inner wall of the open end of the pulp container has a separation space which is inclined downwards and set outwards; a protruding shoulder is provided on the outer wall of the open end of the pulp container, wherein the outer diameter of the protruding shoulder is larger than the inner diameter of the hole on the open end; wherein when two pulp containers are nested over each other, the protruding shoulder is placed on the upper hole of the open end and a separation gap is formed between the separation space on one pulp container and the outer wall on the other pulp container. The process comprises: A. injection; B. demolding. The present invention can greatly reduce the difficulty of separation.

Claims

1. A processing method for manufacturing a pulp molding negative angle container, the processing method comprising: injecting pulp material into a forming mold with a mold cavity, the forming mold having a base with the mold cavity and a cover plate disposable on the base, and having an annular inner mold inside the forming mold and mold cavity, wherein the forming mold has a step on an inner wall in the mold cavity, an outer wall of the annular inner mold has an outer inclined surface which is inclined outwards from a top of the outer wall to a bottom of the outer inclined surface, and the forming mold has an annular groove body arranged within the cover plate in the top of the mold cavity, and wherein the pulp material flows within the mold cavity between the forming mold and the annular inner mold; heating the pulp material to obtain at least one pulp container attached to a pulp panel extending through the forming mold and the annular inner mold, wherein an outer edge of the pulp panel projects upwards within the annular groove body to form an annular skirt; and an inner wall of an open end of the pulp container has a separation space which matches with the outer inclined surface and is inclined downwards and disposed outwards; demolding the pulp container by heating the forming mold, cooling the annular inner mold, and when the temperature of the forming mold is higher than the temperature of the annular inner mold separating the base from the cover plate and annular inner mold of the forming mold; and separating the pulp container by jetting air though the annular inner mold into the pulp container, wherein the annular skirt forces the airflow to expand the pulp container to achieve demolding from the annular inner mold.

2. The processing method according to claim 1, wherein: the separation space is a conical separation countersink and an inner diameter of the conical separation countersink is larger at the bottom than at the top, an outer diameter of a protruding shoulder of the inner wall of the pulp container is larger than the inner diameter of an upper hole of the conical separation countersink.

3. The processing method according to claim 1, wherein: the inner wall of the open end of the pulp container has at least two separation spaces, symmetrically arranged about a central axis line of the pulp container, and the distance between the protruding shoulders is larger than the distance between the upper ends of the separation steps.

4. A processing method for manufacturing a pulp molding negative angle container, the processing method comprising: injecting pulp material into a forming mold with a mold cavity, the forming mold having a base with the mold cavity and a cover plate disposable on the base, and having an annular inner mold inside the forming mold, wherein an outer wall of the annular inner mold has an outer inclined surface which is inclined outwards from a top of the outer wall to a bottom of the outer inclined surface and the forming mold has an annular groove body arranged within the cover plate in communication with and surrounding the mold cavity, and wherein the pulp material flows within the mold cavity between the forming mold and the annular inner mold; heating the pulp material to obtain a molded pulp panel extending through the forming mold and the annular inner mold, wherein an outer edge of the pulp panel projects upwards within the annular groove body to form an annular skirt; and an inner wall of a pulp container molded within the pulp panel adjoins the outer inclined surface and is inclined downwards and disposed outwards; demolding the pulp panel by heating the forming mold, cooling the annular inner mold, and when the temperature of the forming mold is higher than the temperature of the annular inner mold separating the base from the cover plate and annular inner mold of the forming mold; and separating the pulp panel by jetting air between the annular inner mold and the pulp panel, wherein the annular skirt forces the airflow to expand the pulp container to achieve demolding from the annular inner mold.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a schematic structural diagram of a single pulp container provided by the present invention.

(2) FIG. 2 is a schematic structural diagram of a plurality of pulp containers provided by the present invention.

(3) FIG. 3 is a schematic structural diagram of a nesting structure provided by the present invention.

(4) FIG. 4 is a schematic structural diagram of a mold provided by the present invention.

(5) FIG. 5 is a schematic structural diagram provided by a second embodiment of the present invention.

(6) FIG. 6 is a schematic structural diagram provided by a third embodiment of the present invention.

(7) In the Figures: pulp panel 1, annular skirt 11, pulp container 2, open end 21, separation space 22, protruding shoulder 23, annular conical surface 24, straight surface 25, forming mold 3, step 31, annular groove body 32, annular inner mold 4, outer inclined surface 41, first angle a, second angle b.

DETAILED DESCRIPTION

(8) Next, a detailed explanation will be given for exemplary embodiments with reference to the drawings. In the following description of the drawings, a same or like reference sign is given to a same or like part. The drawings schematically represent configurations according to the exemplary embodiments of the present invention. Furthermore, the exemplary embodiments of the present invention described below are examples and may be modified as appropriate as long as the nature of the present invention is not altered.

First Embodiment

(9) As shown in FIGS. 1-2, a pulp molding negative angle container according to present invention comprises a pulp panel 1 having an upwardly folded annular skirt 11 at its outer edge.

(10) The annular skirt 11 enables the air flow to converge and seal at the time of demolding, preventing the air flow from running off.

(11) At least one conical pulp container 2 which is open on the upper end is attached to the pulp panel 1. Alternatively, several pulp containers 2 arranged in an array could be connected to the pulp panel 1.

(12) A single or multiple structures could be produced according to the actual requirements of the production.

(13) As shown in FIGS. 2-3, the inner wall of the open end 21 of the pulp container 2 has a separation space 22 inclined downwards and set outwards. The separation space 22 in this embodiment is a conical separation countersink and an inner diameter of the conical separation countersink is larger at the bottom than that on the top. The axis line of the conical separation countersink coincides with the axis line of the pulp container 2. For example, the depth of conical separation countersink is 1-5 mm.

(14) A first included angle a is formed between the hole wall of the conical separation countersink and the inner wall of the pulp container 2, and the first included angle a is: 0°<the first included angle a<180°.

(15) Moreover, a protruding shoulder 23 is provided on the outer wall of the open end of the pulp container 2, and the outer diameter of the protruding shoulder 23 is larger than the inner diameter of the hole on the open end 21. When two pulp containers 2 are nested over each other, the protruding shoulder 23 is placed on the upper hole of the open end 21 and a separation gap is formed between the separation space 22 on one pulp container 2 and the outer wall on the other pulp container 2.

(16) That is, the outer diameter of the protruding shoulder 23 is larger than the inner diameter of the upper hole of the conical separation countersink.

(17) The separation space provided in combination with the protruding shoulder can play the role of supporting as well as reducing the contact area, and effectively reduce the difficulty of separation, and at the same time, the stability after nesting is also very good and meets the production requirements of the enterprise.

(18) In addition, the longitudinal section thickness of the open end of the pulp container 2 increases gradually from bottom to top.

(19) The protruding shoulder 23 of the present embodiment is an annular protruding shoulder. There is an annular conical surface 24 on the outer wall of the protruding shoulder 23, inclining inwards from top to bottom. A third included angle is formed between the hole wall of the conical separation countersink and the annular conical surface 24, and the angle of the third included angle is 0°<the third included angle <180°.

(20) As shown in FIGS. 1-4, the processing technology for the pulp molding negative angle container includes the following steps:

(21) A. Injection: evenly stirred pulp material is injected into a forming mold 3 with mold cavity and an annular inner mold 4 is provided inside the forming mold 3. The forming mold 3 is provided with a step 31 on the inner wall of the mold cavity. The outer wall of the annular inner mold 4 has an outer inclined surface 41 which is inclined outwards from top to bottom. An annular groove body 32 is arranged on the top of the mold cavity of the forming mold 3. The pulp raw material is heated and at least one pulp container is obtained finally on the pulp panel 1 through the forming mold 3 and the annular inner mold 4. There is an annular skirt 11 on the outer edge of the pulp panel 1. The annular skirt 11 is folded upwards and matches with the annular groove body 32. The inner wall of the open end of the pulp container has a separation space 22, which matches with the outer inclined surface 41 and is inclined downwards and disposed outwards. The outer wall of the open end of the pulp container 2 is provided with the protruding shoulder 23 which matches with the step 31.

(22) B. Demolding: the pulp container is cooled gradually, while the forming mold 3 is heated and the annular inner mold 4 is cooled. The temperature of the forming mold 3 is higher than that of the annular inner mold 4. Then the forming mold 3 is detached downwards. Secondly, air is jetted into the pulp container and the annular skirt 11 forces the airflow to converge into the pulp container to achieve the final demolding. That is, a pulp molding negative angle container is obtained.

(23) The forming mold 3 includes a base with a chamber and a cover plate disposed on the base. The step 31 is disposed at the open end of the chamber, and the annular groove body 32 is disposed on the lower surface of the cover plate.

Second Embodiment

(24) The present embodiment is basically as the same as the structure and principle of the first embodiment, which will not be described in detail herein for brevity. The difference lies in that:

(25) As shown in FIG. 5, at least two separation spaces 22 are provided and it shows two symmetrically arranged separation steps. The outer diameter of the protruding shoulder 23 is larger than the distance between the upper ends of two symmetrically arranged separation steps. The separation steps are of are shape. Secondly, a second included angle b is formed between the sidewall of the separation steps and the inner wall of the pulp container 2, and the second included angle b is 0°<the second included angle b<180°.

(26) In the above-described pulp molding negative angle container, the longitudinal section thickness of the open end of the pulp container increases gradually from bottom to top. The protruding shoulder is an annular protruding shoulder with an annular conical surface that slopes inwards from top to bottom at the protruding shoulder outer wall.

Third Embodiment

(27) The present embodiment is basically as the same as the structure and principle of the first embodiment, which will not be described in detail herein for brevity. The difference lies in that:

(28) As shown in FIG. 6, the outer wall of the protruding shoulder 23 has a vertically disposed straight surface 25.

(29) In the above pulp molding negative angle container, the axis line of the conical separation countersink coincides with the axis line of the pulp container. The separation steps are arranged symmetrically with respect to the axis line of the pulp container.

(30) In the above pulp molding negative angle container, the outer edge of the pulp panel has an annular skirt folded upwards.

(31) In the above pulp molding negative angle container, a third included angle is formed between the inner wall of the conical separation countersink and the straight surface, and the angle of the third included angle is 0°<the third included angle <180°.

(32) In the above pulp molding negative angle container, the bottom of the inner wall of the pulp container has several circumferentially distributed convex parts protruding inwards, and the bottom of the outer wall of the pulp container has concavity parts corresponding to the convex parts.

(33) Although certain inventive embodiments of the present disclosure have been specifically described, the present disclosure is not to be construed as being limited thereto. Various changes or modifications may be made to the present disclosure beyond departing from the scope and spirit of the present disclosure.