Dual-density foam tray forming method

Abstract

The invention provides a dual-density foam tray forming method, and belongs to the technical field of mold forming. The problems that an existing dual-density foam tray needs two sets of molds, the cost is high, and the forming efficiency is low are solved. According to the dual-density foam tray forming method, the finished dual-density foam tray is obtained by preheating a mold forming cavity, closing the mold, feeding, heating, secondarily feeding, secondarily heating, cooling and opening the mold. The tray bodies and the buffer plates with different densities are molded together in the same mold, and the molding efficiency is high.

Description

Technical Field

[0001] The invention belongs to the technical field of mold forming and relates to a double-density foam tray forming method. Background Art

[0002] With the rapid development of the logistics industry and the improvement of intelligent automation technology, the demand for transit pallets has gradually increased, especially for the transportation of electronic products such as computers. To this end, the applicant has invented a double-density foam pallet structure [authorization announcement number is CN217023301U], including a pallet body, the upper end surface of the pallet body is provided with an inwardly recessed cavity, a buffer plate is provided in the cavity, and the upper end surface of the buffer plate is flush with the upper end surface of the pallet body, and the material density of the buffer plate is less than the material density of the pallet body. The buffer plate is made of low-density foam material, which can play a role in shock absorption and buffering of the goods on the pallet, and minimize the vibration impact of the items during transportation; the pallet body is made of high-density foam material, which is dense and hard, and has a strong anti-collision function.

[0003] The existing method for processing the above-mentioned pallet is to first form the pallet body in a first set of molds, then move the pallet body to a second set of molds, and form the buffer plate onto the pallet body in the second set of molds, which has low forming efficiency and low precision. Summary of the invention

[0004] In order to overcome the defects existing in the above-mentioned prior art, the object of the present invention is to provide a double-density foam pallet forming method with high forming efficiency.

[0005] In order to achieve the above-mentioned object of the present invention, the present invention provides a dual-density foam tray forming method, which comprises the following steps:

[0006] S1, take a mold of a double-density foam pallet molding cavity formed by a movable mold and a fixed mold for standby use, the double-density foam pallet molding cavity comprises a first molding cavity for filling a first-density filler and a second molding cavity for filling a second-density filler, a core-pulling body is slidably provided on the movable mold, and the core-pulling body has two positioning positions on the movable mold, wherein when the core-pulling body is at the first positioning position on the movable mold, the double-density foam pallet molding cavity only has the first molding cavity, and when the core-pulling body is at the second positioning position on the movable mold, the double-density foam pallet molding cavity has the first molding cavity and the second molding cavity;

[0007] S2, adjusting the core-pulling body to a first positioning position on the movable mold, preheating the first molding cavity at a high temperature by steam blowing, and then closing the mold;

[0008] S3, filling the first molding cavity with a filler of a first density by vacuum feeding;

[0009] S4, introducing high-temperature steam into the first-density filler in the first molding cavity until the first-density filler is completely melted to form the tray body, and then exhausting the steam;

[0010] S5, quickly adjusting the core-pulling body to the second positioning position on the movable mold;

[0011] S6, filling the second molding cavity with a filler of a second density by vacuum feeding;

[0012] S7, introducing high-temperature steam into the second density filler in the second molding cavity until the second density filler is completely melted to form a buffer plate, and then exhausting the steam;

[0013] S8, water-cooling the mold and the integral double-density foam tray therein, and after the water-cooling setting time, vacuum cooling the double-density foam tray molding cavity;

[0014] S9. Open the mold to obtain the finished double-density foam pallet.

[0015] In the above dual-density foam pallet forming method, the preheating temperature in step S2 is 95° C. to 108° C., and the preheating time is 20s to 60s.

[0016] In the above dual-density foam pallet forming method, in step S4 and step S7, the pressure of high-temperature steam in the dual-density foam pallet forming cavity is 0.03 MPa to 0.15 MPa.

[0017] In the above dual-density foam pallet forming method, the first density filler and the second density filler are both EPS beads, and the first density filler is a high-density filler, and the second density filler is a low-density filler.

[0018] In the above dual-density foam pallet forming method, the step S9 comprises:

[0019] S9-1, the core-pulling body slides, and vacuum is drawn toward the fixed mold side of the double-density foam pallet forming mold cavity, and compressed air is blown toward the movable mold side, so that the movable mold is separated from the fixed mold and the double-density foam pallet is finished;

[0020] S9-2, blowing compressed air toward the fixed mold side of the double-density foam pallet forming cavity, and ejecting the finished double-density foam pallet through a mechanical ejector.

[0021] In the above-mentioned dual-density foam pallet molding method, the movable mold has a first injection hole, and the first density filler is injected into the first molding cavity through the first injection hole; the core pulling body has a second injection hole, and the second density filler is injected into the second molding cavity through the second injection hole.

[0022] In the above-mentioned dual-density foam pallet molding method, a steam chamber is arranged on the side of the mold, and the steam chamber is connected with the dual-density foam pallet molding cavity through the air plug air channel on the movable mold and the core-pulling body.

[0023] In the above-mentioned double-density foam pallet forming method, a cold water tank is arranged on the side of the mold, and the cold water tank is connected to the double-density foam pallet forming cavity through a water pipe and an air plug air channel on the movable mold and the core-pulling body.

[0024] In the above dual-density foam pallet forming method, the lower end of the mold is provided with a drainage valve.

[0025] Compared with the prior art, this double-density foam tray forming mold has the following advantages:

[0026] The pallet body and the buffer plate of different densities are molded together in the same mold, with high molding efficiency, simple molding process and low cost.

[0027] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0029] Figure 1 It is a cross-sectional view of a mold formed by a movable mold and a fixed mold in the present invention.

[0030] In the figure, 1 is a fixed mold; 2 is a movable mold; 3 is a core-pulling body; 31 is a second injection hole. DETAILED DESCRIPTION

[0031] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0032] In the description of the present invention, unless otherwise specified and limited, it should be noted that the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a mechanical connection or an electrical connection, or it can be the internal connection between two components. It can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to the specific circumstances.

[0033] The present invention provides an embodiment of a dual-density foam tray forming method, which specifically comprises the following steps:

[0034] S1, take a mold of a double-density foam pallet molding cavity formed by a movable mold 2 and a fixed mold 1 for standby use, the double-density foam pallet molding cavity includes a first molding cavity for filling a first density filler and a second molding cavity for filling a second density filler, a core-pulling body 3 is slidably arranged on the movable mold 2, and the core-pulling body 3 has two positioning positions on the movable mold 2, wherein when the core-pulling body 3 is in the first positioning position on the movable mold 2, the double-density foam pallet molding cavity only has the first molding cavity, and when the core-pulling body 3 is in the second positioning position on the movable mold 2, the double-density foam pallet molding cavity has the first molding cavity and the second molding cavity, such as Figure 1 shown.

[0035] S2, adjusting the core-pulling body 3 to the first positioning position on the movable mold 2, preheating the first molding cavity at high temperature by steam blowing, and then closing the mold.

[0036] S3, filling the first molding cavity with a filler of the first density by vacuum feeding.

[0037] S4, introducing high-temperature steam into the first density filler in the first molding cavity until the first density filler is completely melted to form the tray body, and then exhausting the steam.

[0038] S5, quickly adjust the core-pulling body 3 to the second positioning position on the movable mold 2.

[0039] S6. Filling the second molding cavity with a filler of the second density by vacuum feeding.

[0040] S7, introducing high-temperature steam into the second density filler in the second molding cavity until the second density filler is completely melted to form a buffer plate, and then exhausting the steam.

[0041] S8. The mold and the integral double-density foam tray therein are water-cooled. After the water-cooling setting time, the double-density foam tray molding cavity is vacuum-cooled.

[0042] S9. Open the mold to obtain the finished double-density foam pallet.

[0043] The mold in this embodiment has the basic functions of a conventional mold, such as the matching relationship between the movable mold and the fixed mold, the finished product ejection function of the mechanical ejector, etc. This is a conventional technical means in this technical field and will not be illustrated or described in detail here.

[0044] Here, the movable mold 2 and the fixed mold 1 in the mold are combined to form a double-density foam tray molding cavity. Due to the use requirements of the double-density foam tray, the pallet body and the buffer plate have different use strength requirements. Therefore, the use density between the two components is also different, and then the molding is also different. This embodiment uses the same mold to complete the compression molding of the double-density material. In addition to being applicable to the compression molding of the double-density foam tray in this embodiment, it can also be extended to the compression molding of multi-density materials.

[0045] This embodiment utilizes the core-pulling body 3 structure on the movable mold 2 in the mold and its positioning relationship to form multiple molding cavities of the foam tray with multiple gradients, so as to perform multi-stage feeding, heating and melting molding, thereby achieving a press molding process for parts with different densities on the same mold.

[0046] Specifically, the movable mold 2 has a first injection hole (not shown), and the first density filler is injected into the first molding cavity through the first injection hole; the core-pulling body 3 has a second injection hole 31, and the second density filler is injected into the second molding cavity through the second injection hole 31. The first density filler and the second density filler of the double-density foam tray formed in this embodiment are both EPS beads, and the first density filler is a high-density filler, and the second density filler is a low-density filler. In actual applications, the material and density requirements can be changed according to specific material requirements.

[0047] A steam chamber is provided on the side of the mold, and the steam chamber is connected to the double-density foam tray molding cavity through the air plug air channel on the movable mold 2 and the core-pulling body 3. At the same time, a cold water tank is provided on the side of the mold, and the cold water tank is connected to the double-density foam tray molding cavity through a water pipe and the air plug air channel on the movable mold 2 and the core-pulling body 3. A drain valve is provided at the lower end of the mold. Through a series of functional settings on the mold, the functions of heating, cooling, vacuuming, blowing, etc. in the molding method are realized, and each connecting air channel is individually controlled by a valve.

[0048] In order to meet the requirements of the molding process, the preheating temperature in step S2 is 95°C to 108°C, and the preheating time is 20s to 60s. Taking the filler of this embodiment as EPS beads as an example, in steps S4 and S7, the pressure of high-temperature steam in the double-density foam tray molding cavity is 0.03MPa to 0.15Mpa, so that the EPS beads are fully melted and molded in each molding cavity.

[0049] Finally, in step S9, the mold opening process may include the steps of:

[0050] S9-1, the core-pulling body 3 slides, and vacuum is drawn toward the fixed mold side of the double-density foam tray forming mold cavity, and compressed air is blown toward the movable mold side, so that the movable mold 2 is separated from the fixed mold 1 and the double-density foam tray finished product;

[0051] S9-2, blowing compressed air to the fixed mold side of the double-density foam pallet forming mold cavity, and ejecting the finished double-density foam pallet through a mechanical ejector.

[0052] By combining multiple actions in step 9, the stability and reliability of demoulding of the finished product are improved.

[0053] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" 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 invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0054] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A dual-density foam tray forming method, characterized in that: The following steps are included: S1. Take a mold for use, which is formed by a movable mold (2) and a fixed mold (1) to form a double-density foam pallet molding cavity. The double-density foam pallet molding cavity comprises a first molding cavity for filling a first-density filler and a second molding cavity for filling a second-density filler. A core-pulling body (3) is slidably arranged on the movable mold (2). The core-pulling body (3) has two positioning positions on the movable mold (2). When the core-pulling body (3) is at the first positioning position on the movable mold (2), the double-density foam pallet molding cavity only has the first molding cavity. When the core-pulling body (3) is at the second positioning position on the movable mold (2), the double-density foam pallet molding cavity has the first molding cavity and the second molding cavity. S2, adjusting the core-pulling body (3) to a first positioning position on the movable mold (2), preheating the first molding cavity at a high temperature by steam blowing, and then closing the mold; S3, filling the first molding cavity with a filler of a first density by vacuum feeding; S4, introducing high-temperature steam into the first-density filler in the first molding cavity until the first-density filler is completely melted to form the tray body, and then exhausting the steam; S5, quickly adjusting the core-pulling body (3) to be at a second positioning position on the movable mold (2); S6, filling the second molding cavity with a filler of a second density by vacuum feeding; S7, introducing high-temperature steam into the second density filler in the second molding cavity until the second density filler is completely melted to form a buffer plate, and then exhausting the steam; S8, water-cooling the mold and the integral double-density foam tray therein, and after the water-cooling setting time, vacuum cooling the double-density foam tray molding cavity; S9. Open the mold to obtain the finished double-density foam pallet.

2. A dual-density foam pallet forming method according to claim 1, characterized in that: In step S2, the preheating temperature is 95° C. to 108° C., and the preheating time is 20 s to 60 s.

3. A dual-density foam pallet forming method according to claim 1, characterized in that: In step S4 and step S7, the pressure of high temperature steam in the dual-density foam tray forming cavity is 0.03 MPa to 0.15 MPa.

4. A dual-density foam pallet forming method according to claim 1, characterized in that: The first density filler and the second density filler are both EPS beads, and the first density filler is a high-density filler, and the second density filler is a low-density filler.

5. A dual-density foam pallet forming method according to claim 1, characterized in that: The step S9 comprises: S9-1, the core-pulling body (3) slides, and vacuum is drawn toward the fixed mold side of the double-density foam tray forming mold cavity, and compressed air is blown toward the movable mold side, so that the movable mold (2) is separated from the fixed mold (1) and the double-density foam tray finished product; S9-2, blowing compressed air toward the fixed mold side of the double-density foam pallet forming cavity, and ejecting the finished double-density foam pallet through a mechanical ejector.

6. A dual-density foam pallet forming method according to claim 1, characterized in that: The movable mold (2) has a first injection hole, through which the first density filler is injected into the first molding cavity; the core-pulling body (3) has a second injection hole (31), through which the second density filler is injected into the second molding cavity.

7. A dual-density foam pallet forming method according to claim 1, characterized in that: A steam chamber is arranged on the side of the mould, and the steam chamber is connected with the double-density foam tray forming mould cavity through the air plug air passage on the movable mould (2) and the core-pulling body (3).

8. A dual-density foam pallet forming method according to claim 7, characterized in that: A cold water tank is arranged on the side of the mold, and the cold water tank is connected to the double-density foam tray forming mold cavity through a water pipe and an air plug air channel on the movable mold (2) and the core-pulling body (3).

9. A dual-density foam pallet forming method according to claim 1, characterized in that: The lower end of the mold is provided with a drain valve.

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