Pla container and process for manufacturing thereof

Abstract

The application belongs to the technical field of container processing, and particularly relates to a PLA container and a manufacturing process thereof. The PLA container manufacturing process comprises the following steps: S1, setting a viscous wear-resistant material in a forming cavity; S2, pre-molding; S3, low-pressure and low-speed injection; S4, high-pressure and low-speed molding; and S5, post-processing. The PLA container has the following advantages: the wear-resistant material on the surface of the PLA container is at least partially embedded in the surface of the PLA container, so that the phenomenon of wear-resistant material falling off is eliminated, and the service life of the PLA container can be greatly prolonged.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of container processing, and particularly relates to a PLA container and a manufacturing process thereof. BACKGROUND

[0002] The PLA container made of PLA material has the advantages of being degradable and environmentally friendly. However, the PLA material has a poor strength performance compared with plastic, and the surface of the PLA container is prone to cracking, and the service life is short.

[0003] In order to prolong the service life, a layer of wear-resistant material is sprayed on the inner wall and the outer wall of the PLA container after the PLA container is formed. The wear-resistant material layer is generally ceramic material. This method obviously prolongs the service life of the PLA container. However, the spraying is performed after the PLA container is completely formed, and the wear-resistant material is only attached to the inner wall and the outer wall of the PLA container. Due to the low adhesion, the sprayed layer is prone to falling off after repeated use of the PLA container. SUMMARY

[0004] The application aims to solve the above technical problems, and provides a PLA container manufacturing process and a combination.

[0005] To achieve the above purpose, the application adopts the following technical scheme:

[0006] The PLA container manufacturing process comprises the following steps:

[0007] S1, a viscous wear-resistant material is arranged in a forming cavity, and the wear-resistant material is added to the forming surface of the female die and / or the male die by coating or spraying when the female die and the male die of the PLA container forming die are not closed;

[0008] S2, pre-molding is performed, so that the female die and the male die are pre-molded and a gap is reserved between the first matching end face of the female die and the second matching end face of the male die. At this time, an unclosed forming cavity is formed between the female die and the male die, and the unclosed forming cavity comprises a container bottom forming area and a container wall forming area which are in communication with each other;

[0009] S3, low-pressure and low-speed injection, along the closing direction of the female die and the male die, the PLA material is in a soft mud state and is injected into the unclosed forming cavity in a low-pressure and low-speed state, and the PLA material is accumulated in the center area of the container bottom forming area;

[0010] S4, high pressure and low speed mold closing, so that the female mold and the male mold in the S3 step are closed at a high pressure and low speed, in the process of mold closing, the accumulated PLA material extends radially outward from the center area of the container bottom molding area and enters the container wall molding area, and after the female mold and the male mold are closed in place, a closed molding cavity is formed between the female mold and the male mold, and a PLA container is molded in the closed molding cavity;

[0011] S5, post-processing, after the S4 step, pressure holding crystallization, and finally cooling and opening the mold to obtain a PLA container finished product.

[0012] In the above PLA container manufacturing process, in the above S1 step, the composition of the wear-resistant material includes ceramic powder and water-based transparent paint.

[0013] In the above PLA container manufacturing process, in the above S1 step, the mold temperature of the female mold and the male mold is 85-95°C respectively.

[0014] In the above PLA container manufacturing process, in the above S2 step, the pre-mold closing pressure of the female mold and the male mold is 15MPa-25MPa.

[0015] In the above PLA container manufacturing process, in the above S2 step, the gap is 1.5mm-4.0mm.

[0016] In the above PLA container manufacturing process, in the above S3 step, the low pressure of the low pressure and low speed injection is 15MPa-25MPa, and the low speed of the low pressure and low speed injection is 8CM 3 / s-12CM 3 / s.

[0017] In the above PLA container manufacturing process, in the above S4 step, the high pressure of the high pressure and low speed mold closing is 120MPa-140MPa, and the low speed of the high pressure and low speed mold closing is 8CM 3 / s-12CM 3 / s.

[0018] In the above PLA container manufacturing process, in the above S5 step, the pressure holding pressure is 75MPa-85MPa.

[0019] In the above PLA container manufacturing process, the ratio of the ceramic powder and the water-based transparent paint is 1:1.

[0020] The application also provides a PLA container, which is processed by the PLA container manufacturing process.

[0021] Compared with the prior art, the application has the advantages that:

[0022] The application is beneficial to directly setting the wear-resistant material on the forming surface of the female die and / or the male die, and then beneficial to the synchronous step method of pre-die, low-pressure and low-speed injection and high-pressure and low-speed die, so that the PLA material can be stretched, and the wear-resistant material set on the forming surface of the female die and / or the male die is uniformly and heat-fused on the surface of the PLA material during the stretching, and finally the PLA container is formed, and the wear-resistant material on the surface of the PLA container is at least partially embedded in the surface of the PLA container, the phenomenon of the wear-resistant material falling off is eliminated, and the service life of the PLA container can be greatly prolonged. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 is a PLA container manufacturing process flowchart provided by the application.

[0024] Figure 2 is a PLA container manufacturing process mold change state diagram provided by the application.

[0025] In the figure, PLA container forming die 1, female die 10, first matching end face 100, male die 11, second matching end face 110, and gap L. DETAILED DESCRIPTION

[0026] The following is a specific embodiment of the application and further describes the technical solutions of the application in combination with the drawings, but the application is not limited to these embodiments. Example 1

[0027] As shown in Figure 1 and Figure 2 , the PLA container manufacturing process includes the following steps: S1, setting a viscous wear-resistant material in a forming cavity-S2, pre-die-S3, low-pressure and low-speed injection-S4, high-pressure and low-speed die-S5, post-processing.

[0028] Specifically, the components of the wear-resistant material include ceramic powder and water-based transparent paint. The ceramic powder is 8000-mesh ceramic powder.

[0029] The specific processing process of the wear-resistant material is as follows:

[0030] The ceramic powder and the water-based transparent paint are added to the stirrer in a ratio of 1:1, the stirring speed of the stirrer is 5000 revolutions / minute, and the continuous operation lasts at least 4 minutes, for example, 5 minutes, so that the two materials are fully mixed, that is, the wear-resistant material is obtained. Since the wear-resistant material is viscous, it will not flow randomly after being set on the forming surface of the female die 10 and the male die 11, ensuring that the wear-resistant material covers the PLA container.

[0031] Specifically, the wear-resistant material is added to the molding surface of the cavity die 10 and the punch die 11 by coating or spraying when the cavity die 10 and the punch die 11 are not closed. Before the wear-resistant material is added, the mold temperature of the cavity die 10 and the punch die 11 is 85-95°C, that is, the cavity die 10 and the punch die 11 have a certain temperature.

[0032] The mold temperature of the cavity die 10 and the punch die 11 can be equal or unequal. For example, the mold temperature of the cavity die 10 and the punch die 11 is 90°C respectively. The temperature of the cavity die 10 and the punch die 11 can shorten the subsequent molding time, and the temperature of the cavity die 10 and the punch die 11 can heat the wear-resistant material to better fuse with the PLA material.

[0033] Of course, the temperature of the cavity die 10 can also be 85°C or 95°C, or any temperature between 85-95°C. The temperature of the punch die 11 can also be 85°C or 95°C, or any temperature between 85-95°C.

[0034] Specifically, the cavity die 10 and the punch die 11 are pre-assembled and a gap L is reserved between the first matching end surface 100 of the cavity die 10 and the second matching end surface 110 of the punch die 11, that is, the cavity die 10 and the punch die 11 are not completely closed.

[0035] At this time, an unclosed molding cavity is formed between the cavity die 10 and the punch die 11, and the unclosed molding cavity includes a container bottom molding area and a container wall molding area that are in communication with each other.

[0036] Preferably, the pre-assembly pressure of the cavity die 10 and the punch die 11 is 15-25 MPa. Preferably, 20 MPa. The pre-assembly pressure belongs to low pressure, and the driving of low pressure can accurately control the gap L, which is 1.5-4.0 mm.

[0037] Specifically, along the closing direction of the cavity die 10 and the punch die 11, the PLA material is in a soft mud state and is injected into the unclosed molding cavity at low pressure and low speed, and the PLA material is accumulated in the central area of the container bottom molding area. The soft mud state is equivalent to the state of playdough. The PLA material is accumulated in the central area of the container bottom molding area, so that the PLA material can extend radially outward and enter the container wall molding area when the cavity die and the punch die are assembled.

[0038] The injection hole is arranged on the cavity die 10 or the punch die 11 along the axis of the PLA container, and the injection hole communicates with the container bottom molding area.

[0039] Low pressure and low speed injection can prevent the wear-resistant material on the molding surface of the cavity die 10 and / or the punch die 11 from being completely removed due to too fast injection speed and too high pressure, so that the wear-resistant material cannot cover the PLA container.

[0040] Preferably, the low-pressure pressure of the low-pressure low-speed injection is 15 MPa-25 MPa, and the low-speed speed of the low-pressure low-speed injection is 8CM 3 / s-12CM 3 / s.

[0041] As a first way: the low-pressure pressure of the low-pressure low-speed injection is 15 MPa, and the low-speed speed of the low-pressure low-speed injection is 8CM 3 / s.

[0042] As a second way: the low-pressure pressure of the low-pressure low-speed injection is 20 MPa, and the low-speed speed of the low-pressure low-speed injection is 10CM 3 / s.

[0043] As a third way: the low-pressure pressure of the low-pressure low-speed injection is 25 MPa, and the low-speed speed of the low-pressure low-speed injection is 12CM 3 / s.

[0044] Specifically, the concave die 10 and the convex die 11 in the S3 step are closed in a high-pressure low-speed state, and in the process of closing, the accumulated PLA material extends radially outward from the center area of the container bottom forming area and enters the container wall forming area, and when the concave die 10 and the convex die 11 are closed in place, the PLA container is formed in the closed forming cavity formed between the concave die 10 and the convex die 11.

[0045] Preferably, the high-pressure pressure of the high-pressure low-speed closing is 120MPa-140MPa, and the low-speed speed of the high-pressure low-speed closing is 8CM 3 / s-12CM 3 / s.

[0046] As a first way: the high-pressure pressure of the high-pressure low-speed closing is 120MPa, and the low-speed speed of the high-pressure low-speed closing is 8CM 3 / s.

[0047] As a second way: the high-pressure pressure of the high-pressure low-speed closing is 130MPa, and the low-speed speed of the high-pressure low-speed closing is 10CM 3 / s.

[0048] As a third way: the high-pressure pressure of the high-pressure low-speed closing is 140MPa, and the low-speed speed of the high-pressure low-speed closing is 12CM 3 / s.

[0049] Specifically, after the S4 step, pressure holding crystallization is performed, and after cooling, the mold is opened to obtain the PLA container finished product. The pressure holding pressure in this step is 75MPa-85MPa. For example, the pressure holding pressure is 75MPa, the pressure holding pressure is 80MPa, or the pressure holding pressure is 85MPa.

[0050] The pressure holding crystallizes the PLA container to make the structure of the PLA container more stable and reliable.

[0051] In this embodiment, the wear-resistant material is directly set on the forming surface of the concave die 10 and / or the convex die 11, and then a synchronous step method of pre-molding, low-pressure and low-speed injection, and high-pressure and low-speed molding is used, so that the PLA material can be stretched, and at the same time, the wear-resistant material set on the forming surface of the concave die 10 and / or the convex die 11 is uniformly fused on the surface of the PLA material. The wear-resistant material on the surface of the finally formed PLA container is at least partially embedded in the surface of the PLA container, which prevents the wear-resistant material from falling off and greatly prolongs the service life of the PLA container. Embodiment Two

[0052] The structure and working principle of this embodiment are basically the same as those of Embodiment One, and the difference lies in that the wear-resistant material is added to the forming surface of the concave die 10 by coating or spraying. Embodiment Three

[0053] The structure and working principle of this embodiment are basically the same as those of Embodiment One, and the difference lies in that the wear-resistant material is added to the forming surface of the convex die 11 by coating or spraying. Embodiment Four

[0054] This embodiment provides a PLA container, which is processed by the PLA container manufacturing process of Embodiment One or Embodiment Two or Embodiment Three. The PLA container includes a cup, a bowl, a plate, and the like.

[0055] The specific embodiments described herein are merely illustrative of the spirit of the present application. Those skilled in the art of the present application can make various modifications or supplements to the described specific embodiments or use similar ways to replace them, without deviating from the spirit of the present application or exceeding the scope defined by the appended claims.

Claims

1. A PLA container manufacturing process, characterized in that, The process includes the following steps: S1. A viscous wear-resistant material is provided in the molding cavity. When the concave mold (10) and convex mold (11) of the PLA container molding mold (1) are not closed, the wear-resistant material is applied to the molding surface of the concave mold (10) and / or the convex mold (11) by coating or spraying. S2, pre-molding, so that the die (10) and the punch (11) are pre-molded and a gap (L) is reserved between the first matching end face (100) of the die (10) and the second matching end face (110) of the punch (11). At this time, an unclosed molding cavity is formed between the die (10) and the punch (11). The unclosed molding cavity includes a container bottom molding area and a container wall molding area that are interconnected. S3. Low-pressure and low-speed injection: PLA material is injected into the unclosed molding cavity in a soft mud-like state along the mold closing direction of the concave mold (10) and the convex mold (11), and the PLA material accumulates in the central area of ​​the bottom molding area of ​​the container. S4. High pressure and low speed mold closing, so that the concave mold (10) and the convex mold (11) in step S3 close the mold in a high pressure and low speed state. During the mold closing process, the accumulated PLA material extends radially outward from the center area of ​​the bottom forming area of ​​the container and enters the forming area of ​​the container wall. When the concave mold (10) and the convex mold (11) are in place, the PLA container is formed in the closed forming cavity formed between the concave mold (10) and the convex mold (11). S5, post-processing: After step S4, the product undergoes pressure holding and crystallization, and finally, after cooling, it is molded to obtain the finished PLA container.

2. The PLA container manufacturing process according to claim 1, characterized in that, In step S1 above, the wear-resistant material comprises ceramic powder and water-based transparent varnish.

3. The PLA container manufacturing process according to claim 1, characterized in that, In step S1 above, the mold temperatures of the die (10) and the punch (11) are 85-95℃ respectively.

4. The PLA container manufacturing process according to claim 1, characterized in that, In step S2 above, the pre-closing pressure of the die (10) and the punch (11) is 15MPa-25MPa.

5. The PLA container manufacturing process according to claim 1, characterized in that, In step S2 above, the gap (L) is 1.5mm-4.0mm.

6. The PLA container manufacturing process according to claim 1, characterized in that, In step S3 above, the low-pressure injection pressure is 15 MPa-25 MPa, and the low-speed injection velocity is 8 cm. 3 / s-12CM 3 / s.

7. The PLA container manufacturing process according to claim 1, characterized in that, In step S4 above, the high pressure of the high-pressure low-speed mold closing is 120MPa-140MPa.

8. The PLA container manufacturing process according to claim 1, characterized in that, In step S5 above, the pressure holding pressure is 75MPa-85MPa.

9. The PLA container manufacturing process according to claim 2, characterized in that, The ratio of ceramic powder to water-based transparent varnish is 1:

1.

10. A PLA container, characterized in that, The PLA container is manufactured using the PLA container manufacturing process described in any one of claims 1-9.

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