Production system of PVDC coating film

Abstract

The utility model belongs to the technical field of coating films, and particularly relates to a production system of a PVDC (Polyvinyl Dichloride) coating film. Comprising an unwinding machine, a corona device, a primer unit, a primer dryer, a PVDC latex coating unit, an infrared heater, a latex dryer, a cooling roller and a winding machine which are sequentially arranged, the PVDC latex coating unit comprises a latex tank, a coating roller is arranged in the latex tank, a PVDC latex preparation kettle is connected with the bottom of one side of the latex tank through a latex feeding tank and a diaphragm pump, and the coating roller is connected with the bottom of the other side of the latex tank. The top of the other side of the latex tank is connected with a defoaming mechanism through a pipeline, the defoaming mechanism is connected with a latex feeding tank, and a bubble isolating and removing device is arranged on the side, connected with the latex tank, of the diaphragm pump. The PVDC latex is baffled by the first baffle plate, foam is left at one end of the baffle plate, the latex without the foam is in contact with the coating roller, the foam on one side of the first baffle plate is regularly pumped to the standing tank by the transmission pump for standing and defoaming, and the foam is transported back to the latex tank for use by the diaphragm pump through the recycling pipeline after defoaming is finished.

Description

Technical Field

[0001] This utility model belongs to the field of coating film technology, specifically relating to a production system for PVDC coated films. Background Technology

[0002] In the process of coating PVDC (polyvinylidene chloride) latex onto a membrane, the latex in the latex tank is one of the key raw materials for the coating process, and its state directly affects the quality and performance of the final membrane product. However, in actual operation, air bubbles often form in the latex tank due to factors such as feeding. If these air bubbles are not properly handled, they will have many adverse effects on the membrane product, thereby affecting the product's market competitiveness and application prospects.

[0003] PVDC latex is a polymer material with excellent barrier properties, chemical resistance, and thermal stability, and is widely used in food packaging, pharmaceutical packaging, and other fields. During the coating process, air bubbles in the latex tank mainly originate from friction between the pump and the tank walls and bottom during feeding. These bubbles exist in a heterogeneous system within the latex, increasing the surface area and energy of the latex system, thus placing the latex in a thermodynamically unstable state.

[0004] The presence of air bubbles disrupts the uniformity and continuity of the coating layer, leading to imperfections and defects on the film surface. These imperfections not only affect the appearance quality of the film product but may also cause defects such as pinholes and craters, reducing the barrier properties and mechanical strength of the film. In the food packaging industry, these defects may lead to leakage or contamination of the packaged goods, seriously affecting the product's shelf life and safety. Air bubbles can also affect the adhesion and weather resistance of the coating layer. The presence of air bubbles weakens the bond between the coating layer and the substrate, making the coating prone to peeling or cracking. At the same time, air bubbles can also become channels for the penetration of external media such as moisture and oxygen, accelerating the aging and degradation of the film. In outdoor applications, this effect is particularly significant, severely shortening the service life of the film product. Air bubbles can also adversely affect the stability and production efficiency of the coating process. The formation and aggregation of air bubbles can interfere with the normal operation of the coating process, leading to problems such as reduced coating speed and uneven coating thickness. This not only increases production costs and energy consumption but may also affect product delivery time and market competitiveness.

[0005] Therefore, it is necessary to take effective measures to prevent and control the problem of air bubbles in the latex tank during the PVDC latex coating process. Utility Model Content

[0006] This invention provides a PVDC coating film production system to solve the problem of air bubbles in the latex tank during the PVDC latex coating process.

[0007] To solve the above problems, the technical solution of this utility model is:

[0008] The PVDC coating film production system of this utility model includes an unwinding machine, a corona device, a base adhesive unit, a base adhesive dryer, a PVDC latex coating unit, an infrared heater, a latex dryer, a cooling roller, and a winding machine arranged in sequence. The PVDC latex coating unit includes a latex tank with a coating roller inside. The PVDC latex preparation kettle is connected to the bottom of one side of the latex tank through a latex feed trough and a diaphragm pump. The top of the other side of the latex tank is connected to a defoaming mechanism through a pipeline. The defoaming mechanism is connected to the latex feed trough. A bubble isolation and removal device is provided on the side where the diaphragm pump is connected to the latex tank.

[0009] Furthermore, the PVDC latex preparation vessel is connected to the latex feed tank via a first filter.

[0010] Furthermore, the diaphragm pump is connected to the latex tank via a second filter.

[0011] Furthermore, the defoaming mechanism includes a defoaming tank, and a second baffle is provided inside the defoaming tank.

[0012] PVDC latex flowing directly from the latex tank back to the latex feed tank is prone to foaming. After passing through the second baffle plate in the defoaming tank, the PVDC latex flowing back to the latex feed tank is foam-free.

[0013] Furthermore, the bubble isolation and removal device includes a removal pipeline located on the upper side of one side of the latex tank, a transfer pump is provided on the removal pipeline, the other end of the removal pipeline is connected to a settling tank, and the bottom of the settling tank is connected to the feed end of the diaphragm pump through a reuse pipeline.

[0014] Furthermore, the bubble isolation and removal device also includes a first baffle plate, which is disposed inside the latex tank, near the diaphragm pump connected to the latex tank near the coating roller.

[0015] PVDC latex passes through the first baffle plate, where foam remains at one end of the baffle plate, while the foam-free latex comes into contact with the coating roller. The foam that accumulates on one side of the first baffle plate is periodically pumped by the transfer pump to the settling tank for settling and defoaming. After defoaming, the latex is transported back to the latex tank for use through the reuse pipeline via the diaphragm pump and the second filter.

[0016] Working principle:

[0017] The base film is unwound by an unwinding machine, undergoes corona treatment by a corona device, then passes through a base coater for base coating, and is dried in a base coater. After drying, it passes through a PVDC latex coating unit for coating. The prepared PVDC latex, filtered through a first filter, is fed into the latex feed tank from a diaphragm pump. The PVDC latex is then filtered through a second filter and enters from one side of the latex tank. The latex passes through a first baffle plate, where foam remains on one side, while the foam-free latex contacts the coating rollers and is evenly coated onto the base film. To maintain the PVDC latex in the latex tank... The liquid level inside is fixed, and an outlet hole is opened. The defoaming tank is connected through a pipeline. PVDC latex flowing directly from the latex tank back to the latex feed tank is prone to generating foam. After being deflected by the second baffle plate in the defoaming tank, the PVDC latex flowing back to the latex feed tank is foam-free. The foam accumulated on one side of the first baffle plate is periodically pumped to the settling tank by the transfer pump for settling and defoaming. After defoaming, it is transported back to the latex tank for use through the reuse pipeline via the diaphragm pump and the second filter. The base film coated with PVDC latex is heated by an infrared heater, dried by a latex dryer, cooled by a cooling roller, and then wound up by a winding machine.

[0018] The beneficial effects of this utility model are as follows:

[0019] (1) The PVDC latex described in this utility model is deflected by the first baffle plate and the foam remains on one side of the baffle plate. The latex without foam comes into contact with the coating roller. The foam accumulated on one side of the first baffle plate is periodically pumped to the settling tank by the transfer pump for settling and defoaming. After defoaming, it is transported back to the latex tank for use through the reuse pipeline via the diaphragm pump and the second filter.

[0020] (2) The present invention is equipped with a defoaming tank. PVDC latex is prone to foaming when it flows directly back from the latex tank to the latex feed tank. After being deflected by the second baffle plate of the defoaming tank, the PVDC latex that flows back to the latex feed tank is foam-free. Attached Figure Description

[0021] The accompanying drawings, which are included to provide a further understanding of the present invention, form part of this invention. In the drawings:

[0022] Figure 1 This is a schematic diagram of the production system for the PVDC coated film of this utility model;

[0023] In the diagram: 1. Unwinder; 2. Corona discharge device; 3. Primer unit; 4. Primer dryer; 5. PVDC latex coating unit; 501. Coating roller; 502. First baffle plate; 503. Latex tank; 504. Transfer pump; 505. Settling tank; 506. Recycled pipeline; 6. PVDC latex preparation vessel; 7. First filter; 8. Latex feed trough; 9. Diaphragm pump; 10. Second filter; 11. Defoaming tank; 1101. Second baffle plate; 12. Infrared heater; 13. Latex dryer; 14. Cooling roller; 15. Rewinder. Detailed Implementation

[0024] The present invention will be explained in detail below with reference to the embodiments.

[0025] Example 1

[0026] like Figure 1 As shown, the PVDC coated film production system includes, in sequence, an unwinding machine 1, a corona device 2, a base adhesive unit 3, a base adhesive dryer 4, a PVDC latex coating unit 5, an infrared heater 12, a latex dryer 13, a cooling roller 14, and a winding machine 15. The PVDC latex coating unit 5 includes a latex tank 503, in which a coating roller 501 is installed. A PVDC latex preparation kettle 6 is connected to the bottom of one side of the latex tank 503 through a latex feed trough 8 and a diaphragm pump 9. The top of the other side of the latex tank 503 is connected to a defoaming mechanism through a pipeline. The defoaming mechanism is connected to the latex feed trough 8. A bubble isolation and removal device is provided on the side of the diaphragm pump 9 connected to the latex tank 503.

[0027] Understandably, the PVDC latex preparation vessel 6 is connected to the latex feed tank 8 via the first filter 7.

[0028] Understandably, the diaphragm pump 9 is connected to the latex tank 503 via the second filter 10.

[0029] Understandably, the defoaming mechanism includes a defoaming tank 11, and a second baffle plate 1101 is provided inside the defoaming tank 11.

[0030] PVDC latex flowing directly from latex tank 503 back to latex feed tank 8 is prone to foaming. After being deflected by the second baffle plate 1101 of defoaming tank 11, the PVDC latex flowing back to latex feed tank 8 is foam-free.

[0031] Understandably, the bubble isolation and removal device includes a removal pipeline located on the upper side of the latex tank 503, a transfer pump 504 is provided on the removal pipeline, and the other end of the removal pipeline is connected to the settling tank 505. The bottom of the settling tank 505 is connected to the feed end of the diaphragm pump 9 through a reuse pipeline 506.

[0032] Understandably, the bubble isolation and removal device also includes a first baffle plate 502, which is disposed inside the latex tank 503, near the diaphragm pump 9 connected to the latex tank 503 near the coating roller 501.

[0033] PVDC latex is defoamed by the first baffle plate 502, leaving foam at one end of the baffle plate. The foam-free latex comes into contact with the coating roller 501. The foam that accumulates on one side of the first baffle plate 502 is periodically pumped by the transfer pump 504 to the settling tank 505 for settling and defoaming. After defoaming, it is transported back to the latex tank 503 for use through the reuse pipeline 506, diaphragm pump 9, and second filter 10.

[0034] Working principle:

[0035] The base film is unwound by unwinder 1, undergoes corona treatment by corona device 2, then passes through primer unit 3 for primer coating, and is dried in primer dryer 4. Afterwards, it passes through PVDC latex coating unit 5 for coating. The prepared PVDC latex is filtered by first filter 7 in PVDC latex preparation tank 6 and then fed into latex feed tank 8. The PVDC latex is transported by diaphragm pump 9, filtered by second filter 10, and enters from one side of latex tank 503. Foam is retained on one side of first baffle 502, while the foam-free latex contacts coating roller 501 and is evenly coated onto the base film. To maintain a stable liquid level of PVDC latex in latex tank 503... A liquid outlet is opened and connected to the defoaming tank 11 via a pipeline. PVDC latex flowing directly from the latex tank 503 back to the latex feed tank 8 is prone to foaming. After being deflected by the second baffle plate 1101 of the defoaming tank 11, the PVDC latex flowing back to the latex feed tank 8 is foam-free. The foam accumulated on one side of the first baffle plate 502 is periodically pumped by the transfer pump 504 to the settling tank 505 for settling and defoaming. After defoaming, it is transported back to the latex tank 503 for use via the reuse pipeline 506, diaphragm pump 9, and second filter 10. The base film coated with PVDC latex is heated by the infrared heater 12, dried by the latex dryer 13, cooled by the cooling roller 14, and then wound up by the winding machine 15.

[0036] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to interchangeably. Each embodiment focuses on describing the differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments.

[0037] The above description is merely an embodiment of this utility model and is not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of this utility model should be included within the scope of the claims of this utility model.

Claims

1. A production system for PVDC coated films, characterized in that, The system includes, in sequence, an unwinding machine (1), a corona device (2), a base adhesive unit (3), a base adhesive dryer (4), a PVDC latex coating unit (5), an infrared heater (12), a latex dryer (13), a cooling roller (14), and a winding machine (15). The PVDC latex coating unit (5) includes a latex tank (503), a coating roller (501) is provided inside the latex tank (503), a PVDC latex preparation kettle (6) is connected to the bottom of one side of the latex tank (503) through a latex feed trough (8) and a diaphragm pump (9), and the top of the other side of the latex tank (503) is connected to a defoaming mechanism through a pipeline. The defoaming mechanism is connected to the latex feed trough (8), and a bubble isolation and removal device is provided on the side of the diaphragm pump (9) connected to the latex tank (503).

2. The PVDC coating film production system according to claim 1, characterized in that, The PVDC latex preparation vessel (6) is connected to the latex feed tank (8) through the first filter (7).

3. The PVDC coating film production system according to claim 1, characterized in that, The diaphragm pump (9) is connected to the latex tank (503) through the second filter (10).

4. The PVDC coating film production system according to claim 1, characterized in that, The defoaming mechanism includes a defoaming tank (11), and a second baffle plate (1101) is provided inside the defoaming tank (11).

5. The PVDC coating film production system according to claim 1, characterized in that, The bubble isolation and removal device includes a removal pipeline located on the upper side of the latex tank (503), a transfer pump (504) on the removal pipeline, and the other end of the removal pipeline connected to a settling tank (505). The bottom of the settling tank (505) is connected to the feed end of the diaphragm pump (9) through a reuse pipeline (506).

6. The PVDC coating film production system according to claim 5, characterized in that, The bubble isolation and removal device also includes a first baffle plate (502), which is disposed inside the latex tank (503) near the diaphragm pump (9) connected to the latex tank (503) near the coating roller (501).

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