Method for adding additive in mold and mold

Abstract

The invention belongs to the field of fiber molding processing, and particularly relates to a method for adding an additive in a mold and the mold, and the method comprises the following steps: S1, putting a wet paper pulp blank into a cavity of a lower mold; s2, the hydraulic forming machine drives the upper mold and the lower mold to be closed; s3, coating a layer of wear-resistant oil on the surface of the paper pulp wet blank during mold closing; s4, the mold is heated, the wet paper pulp blank is dried, a fiber molded product is prepared, meanwhile, the wear-resistant oil is subjected to a cross-linking effect under the pressure effect, and a protective layer is formed on the surface of the fiber molded product; s5, the mold is opened after cooling, and a fiber molded product is taken out; when the method is used, a protective layer is formed on the dried fiber molded product, and the wear resistance of the product is effectively improved by virtue of the compact protective layer structure, so that the problems of fiber falling and dust falling of the product caused by the damage of friction to the fiber layer during transportation are avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of fiber molding processing, and particularly relates to a method for adding additives in a mold and a mold. BACKGROUND

[0002] At present, fiber molded products (paper trays) are mainly made of mixed materials such as sugarcane pulp board (short fibers), bamboo pulp board (medium-length fibers), and wood pulp (long fibers) using molding technology, but the interlayer bonding force between fibers and surface roughness determine the poor wear resistance of fiber molding.

[0003] As a green packaging product, paper pulp molding has the advantage of recycling and is widely used in the packaging of electronic products, food, and baby products. However, the paper pulp molding without sizing in the pulp and without PE film covering on the product in the prior art generally has the problem of fiber shedding. During packaging and transportation, the falling fibers may cause dust or particles, which may be harmful to electronic products and food. Therefore, technical means are needed to solve this problem.

[0004] Defects in the prior art: The traditional method for solving the problem of fiber shedding in paper pulp molding is to add additives in the pulp or to spray additives on the surface. However, for paper pulp molding that directly contacts food or baby products, the amount and type of additives in and outside the pulp need to be controlled to ensure environmental protection and safety. However, the current technology cannot achieve the ideal anti-shedding effect with less or no additives in and outside the pulp. In addition, factors such as unbalanced fiber morphology, excessive proportion of short fibers, insufficient long fiber flossing, and excessive fillers may also cause weak bonding between fibers, fillers, and sizing, which may exacerbate the problem of fiber shedding.

[0005] Effect of grinding process: The grinding process plays a key role in fiber bonding. If the fiber is excessively cut during the grinding process and the fine fiberization is insufficient, the hydrogen bonding area between fibers will be reduced, resulting in loose fiber network structure and making the paper pulp molding prone to shedding. Therefore, optimizing the grinding process, such as using shallow tooth wide slot type grinding plate to strengthen fiber flossing, controlling the grinding concentration and beating degree, etc., is an important way to improve fiber bonding and solve the problem of fiber shedding.

[0006] Effect of forming process: Precise control of the forming process is also important for reducing fiber shedding. For example, the hanging type suction filtration forming method and device can make the pulp more uniformly distributed on the surface of the suction filtration forming mold, and make the suction filtration forming mold enter or move out of the pulp stably and accurately, reducing the damage of the paper pulp wet blank during the transfer process, thereby reducing the possibility of fiber shedding

[0007] However, the existing technology cannot solve the problem of fiber shedding and dust during transportation of fiber molding. Therefore, a method for adding additives in a mold and a mold are proposed to solve the above problems. SUMMARY

[0008] In order to make up for the deficiencies of the prior art, solve the technical problems of fiber drop and dust in the transportation process of fiber molding in the background art, the application provides an additive adding method in a mold and a mold.

[0009] The application solves the technical problems by adopting the technical scheme of the additive adding method in the mold, which comprises the following steps:

[0010] S1: placing the paper pulp wet blank inside the cavity of the lower mold;

[0011] S2: driving the upper mold and the lower mold to close by the hydraulic forming machine;

[0012] S3: coating a layer of wear-resistant oil on the surface of the paper pulp wet blank when the molds are closed;

[0013] S4: heating the mold, drying the paper pulp wet blank, and obtaining the fiber molded product, and the wear-resistant oil is cross-linked under the action of pressure to form a protective layer on the surface of the fiber molded product;

[0014] S5: opening the mold after cooling and taking out the fiber molded product, and adopting the above method, a protective layer is formed on the fiber molded product after drying, the wear resistance of the product is effectively improved by relying on the dense protective layer structure, thereby avoiding the damage of friction to the fiber layer during transportation, and the problems of fiber drop and dust are solved.

[0015] Preferably, in S3, the mold core of the upper mold is provided with uniformly distributed oil holes, and the upper mold is provided with an oil cavity in communication with the oil holes, wear-resistant oil is injected into the oil cavity, the wear-resistant oil flows out along the oil holes and is distributed on the surface of the paper pulp wet blank, and the wear-resistant oil is coated on the surface of the paper pulp wet blank by the above method, and the wear-resistant oil is uniformly and quickly distributed on the surface of the product by relying on the oil holes of the upper mold and the pressure, the uniformity of the thickness of the protective layer is improved, the problem of missing protective layer caused by missing wear-resistant oil in some areas is reduced, the stability of the overall wear resistance is ensured, and the distribution density of the oil holes matches the surface curvature of the mold core.

[0016] Preferably, the inside of the oil cavity is provided with an oil-absorbing material, the wear-resistant oil is injected into the oil cavity before the molds are closed, the oil-absorbing material can absorb the wear-resistant oil in the oil cavity, the oil-absorbing material is attached to the end of the oil hole, the wear-resistant oil is squeezed out by extruding the oil-absorbing material, and then the wear-resistant oil flows into the oil hole, in production, the sponge layer effectively absorbs the wear-resistant oil and can uniformly attach the wear-resistant oil to the surface of the paper pulp wet blank under the action of pressure, the coating uniformity is further improved, the local oil accumulation phenomenon caused by excessive oil is avoided, the protective layer is dense and has consistent thickness, and the surface quality stability of the fiber molded product is improved.

[0017] Preferably, the thickness of the protective layer formed after drying in S4 is 10-45 microns.

[0018] Preferably, the mold is provided with a movable pressing block, and the pressing block is pressed to extrude the oil-absorbing material.

[0019] Preferably, the oil-absorbing material is any one of porous sponge, absorbent cotton and polyester oil-absorbing fiber.

[0020] A mold suitable for the additive adding method described above, the mold comprises an upper mold and a lower mold, and the upper mold is provided with a wear-resistant oil delivery channel capable of applying wear-resistant oil on the surface of the pulp wet blank.

[0021] The present application has the advantages of:

[0022] 1. The present application forms a protective layer on the fiber molded product after drying by applying wear-resistant oil on the surface of the product, effectively improves the wear resistance of the product by the dense protective layer structure, thereby avoiding the damage of friction to the fiber layer during transportation, and the problem of fiber and dust falling from the product;

[0023] 2. The present application improves the uniformity of wear-resistant oil distribution by providing an oil-absorbing material, and improves the uniformity of wear-resistant oil distribution by extruding the oil-absorbing material to uniformly adhere wear-resistant oil on the surface of the pulp wet blank, further improves the uniformity of coating, and avoids the local oil accumulation phenomenon caused by excessive oil, ensures the density and uniform thickness of the protective layer, and improves the surface quality stability of the fiber molded product. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiment or prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and those skilled in the art can obtain other drawings according to these drawings without creative labor.

[0025] Figure 1 The flowchart of the additive adding method of the present application;

[0026] Figure 2 The schematic diagram of the mold structure of the present application.

[0027] In the figure: 1, upper mold; 2, lower mold. DETAILED DESCRIPTION

[0028] With reference to the drawings of the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of the present application.

[0029] The specific embodiments are given below.

[0030] Please refer to Figure 1 The method for adding additives in a mold comprises the following steps:

[0031] S1: placing the paper pulp wet blank inside the cavity of the lower mold;

[0032] S2: driving the upper mold and the lower mold to close by the hydraulic forming machine;

[0033] S3: coating a layer of wear-resistant oil on the surface of the paper pulp wet blank when the molds are closed;

[0034] S4: heating the mold, drying the paper pulp wet blank, and obtaining the fiber molded product, and the wear-resistant oil is cross-linked under the action of pressure to form a protective layer on the surface of the fiber molded product;

[0035] S5: opening the mold after cooling and taking out the fiber molded product;

[0036] In use, a protective layer is formed on the fiber molded product after drying by the above method, and the wear resistance of the product is effectively improved by relying on the dense protective layer structure, thereby avoiding the damage of friction to the fiber layer during transportation, and the problem of fiber and dust falling from the product.

[0037] Further, in S3, the mold core of the upper mold is provided with uniformly distributed oil holes, and the upper mold is provided with an oil cavity in communication with the oil holes. The wear-resistant oil is injected into the oil cavity, flows out along the oil holes, and is distributed on the surface of the paper pulp wet blank, so as to coat the wear-resistant oil on the surface of the paper pulp wet blank;

[0038] In production, the wear-resistant oil is coated on the surface of the paper pulp wet blank by the above method, and the wear-resistant oil is uniformly and quickly distributed on the surface of the product by relying on the oil holes of the upper mold and the pressure, so as to improve the uniformity of the thickness of the protective layer, reduce the problem of missing protective layer caused by missing wear-resistant oil in some areas, and ensure the stability of the overall wear resistance. At the same time, the distribution density of the oil holes matches the surface curvature of the mold core.

[0039] Further, the oil cavity is internally provided with oil-absorbing material, and the wear-resistant oil is injected into the oil cavity before the mold is closed, the oil-absorbing material can absorb the wear-resistant oil in the oil cavity, the oil-absorbing material is attached to the end of the oil passage, and the wear-resistant oil is squeezed out by extruding the oil-absorbing material, and then the wear-resistant oil flows into the oil passage;

[0040] In production, the wear-resistant oil in the oil cavity is effectively adsorbed by the oil-absorbing material shell, and the wear-resistant oil is uniformly attached to the surface of the pulp wet blank by extruding the oil-absorbing material, thereby improving the uniformity of the wear-resistant oil distribution, further improving the coating uniformity, avoiding the local oil accumulation phenomenon caused by excessive oil, ensuring the density and uniform thickness of the protective layer, and improving the surface quality stability of the fiber molded product.

[0041] Further, in S4, the thickness of the protective layer formed after drying is 10-45 μm; in production, the thickness of the protective layer formed after drying is between 10-45 μm, which can ensure that the protective layer has sufficient wear resistance and will not crack or peel due to excessive thickness, and reduce the amount of wear-resistant oil.

[0042] Further, the mold is provided with a press block that can slide, and the press block is pressed to extrude the oil-absorbing material.

[0043] Further, the oil-absorbing material is any one of porous sponge, absorbent cotton and polyester oil-absorbing fiber; in production, the oil-absorbing material is preferably porous sponge, which has high porosity and good resilience and can uniformly release wear-resistant oil under pressure, and the oil-absorbing material can also be absorbent cotton and polyester oil-absorbing fiber.

[0044] Please refer to Figure 2 As shown in FIG. 1, a mold is suitable for the additive adding method of the mold, and the mold includes an upper mold 1 and a lower mold 2, and the upper mold is provided with a wear-resistant oil conveying passage capable of coating wear-resistant oil on the surface of the pulp wet blank.

[0045] Working principle, in use, a protective layer is formed on the fiber molded product after drying by the above method, and the dense protective layer structure effectively improves the wear resistance of the product, thereby avoiding damage to the fiber layer caused by friction during transportation, and the problem of product fiber loss and dust;

[0046] In production, the wear-resistant oil is coated on the surface of the pulp wet blank by the above method, and the wear-resistant oil is uniformly and quickly distributed on the surface of the product by the oil passage of the upper mold and the pressure, thereby improving the uniformity of the thickness of the protective layer, reducing the problem of missing protective layer caused by the lack of wear-resistant oil in some areas, thereby ensuring the stability of the overall wear-resistant performance, and the distribution density of the oil passage matches the surface curvature of the mold core;

[0047] In production, the sponge layer effectively adsorbs the wear-resistant oil and can uniformly attach the wear-resistant oil on the surface of the pulp wet blank under pressure, further improves the coating uniformity, avoids the local oil accumulation phenomenon caused by excessive oil, ensures the density and uniform thickness of the protective layer, and improves the surface quality stability of the fiber molded product;

[0048] In the production process, the thickness of the protective layer formed after drying is between 10 and 45 microns, which can ensure that the protective layer has sufficient wear resistance and will not crack or peel due to excessive thickness, and reduce the amount of wear-resistant oil; the oil absorption material is preferably a porous sponge, which has high porosity and good resilience, and can uniformly release wear-resistant oil under pressure; the oil absorption material can also be absorbent cotton and polyester oil absorption fiber.

[0049] In the description of the present specification, the description of the terms "one embodiment", "example", "specific example" and the like means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0050] The above shows and describes the basic principles, main features and advantages of the present application. Those skilled in the art should understand that the present application is not limited to the above embodiments, and the above embodiments and descriptions in the specification are only to illustrate the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the claimed present application.

Claims

1. A method of adding an in-mold additive characterized by: The method comprises the following steps: S1: placing a paper pulp wet blank inside a cavity of a lower mold; S2: driving the upper mold and the lower mold to close by a hydraulic molding machine; S3: applying a layer of wear-resistant oil on the surface of the paper pulp wet blank when the molds are closed; S4: heating the molds to dry the paper pulp wet blank, and obtaining a fiber molded product, while the wear-resistant oil is cross-linked under pressure to form a protective layer on the surface of the fiber molded product; S5: opening the molds after cooling and taking out the fiber molded product.

2. A method of adding an additive in a mold according to claim 1, characterized by: In the step S3, the mold core of the upper mold is provided with uniformly distributed oil holes, and the upper mold is provided with an oil cavity connected with the oil holes, so that the wear-resistant oil is injected into the oil cavity, flows out of the oil holes and is distributed on the surface of the paper pulp wet blank, so as to coat the wear-resistant oil on the surface of the paper pulp wet blank.

3. A method of adding an additive in a mold according to claim 2, characterized by: The inside of the oil cavity is provided with an oil-absorbing material, the wear-resistant oil is injected into the oil cavity before the molds are closed, the oil-absorbing material can absorb the wear-resistant oil in the oil cavity, the oil-absorbing material is attached to the end of the oil hole, and the wear-resistant oil is squeezed out by squeezing the oil-absorbing material, and then the wear-resistant oil flows into the oil hole.

4. A method of adding an additive in a mold according to claim 1, characterized by: In the step S4, the thickness of the protective layer formed after drying is 10-45 μm.

5. The method of adding an additive in a mold and the mold according to claim 3, characterized by: The mold is provided with a slideable pressing block, and the wear-resistant oil is squeezed out by pressing the pressing block.

6. A method of adding an additive in a mold according to claim 3, characterized by: The oil-absorbing material is any one of porous sponge, degreasing cotton and polyester oil-absorbing fiber.

7. A mold characterized by: The mold is suitable for the additive adding method of any one of claims 1-6, and the mold comprises an upper mold (1) and a lower mold (2), and the upper mold is provided with a wear-resistant oil delivery channel capable of coating wear-resistant oil on the surface of the paper pulp wet blank.

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