A tape casting device and method for degradable breathable film

Abstract

The present invention provides a tape-casting device and method for producing a degradable breathable film in the field of film production technology, comprising a film processing assembly and an extrusion assembly. The extrusion assembly comprises a die head assembly for continuously conveying and discharging material, and a die lip assembly, the die lip assembly being located at the bottom side of the die head assembly for switching and cleaning the extrusion position. The film processing assembly comprises a casting roller located below the die lip assembly, and a homogenizing assembly for scraping and recovering the extrudate in a liquid state. The homogenizing assembly is located on the side of the die lip assembly discharging material from the casting roller. The present invention has the advantages of ensuring uniformity of material when extruded through the die lip and uniform thickness of the film when continuously cast on the casting roller.

Description

Technical Field

[0001] The present invention relates to the technical field of film production, and in particular to a tape-casting molding device and method for a degradable breathable film. Background Art

[0002] Cast film is a plastic film production process. The raw materials are first plasticized and melted through an extruder, extruded through a T-shaped forming die, and cast in sheet form onto the roller surface of a steadily rotating cooling roller. The film is cooled and shaped on the cooling roller, and then the product is wound after being pulled and trimmed. However, when the material is extruded, it is easy to accumulate at the extrusion position. The common method is to shut down the equipment, disassemble the mold, clean it thoroughly, and then put it into use again.

[0003] With the increasing awareness of environmental protection, more and more consumers choose to use packaging made of degradable materials to reduce the harm of plastic products to the environment. Among them, degradable breathable films made with calcium carbonate as the main raw material are very popular among consumers. For example, the degradable film component CN106220961B previously applied for by the applicant is also suitable for making degradable breathable films.

[0004] For example, Chinese patent CN217258247U discloses a high-efficiency cast extrusion molding device, which includes a mold body, a bracket, a die head, a tooth column, and a fixing rod. The two ends of the mold body are slidably connected to the bracket, and the bottom of the mold body is equipped with a mold head. The utility model is provided with a mold body, a bracket, a die head, a tooth column, and a fixing rod.

[0005] However, in this technical solution, although it is possible to separate the mold body and clean the condensed particles located at the die lip during mold extrusion to ensure uniformity during casting, this method requires the mold to be disassembled, which makes it easy to stop the machine and disassemble the mold during film production, thereby reducing the production efficiency of film products. Summary of the Invention

[0006] The purpose of the present invention is to address the shortcomings of the prior art and provide a cast molding device for a degradable breathable membrane, wherein the masterbatch is melted by a die head assembly and sent to a die lip assembly through an extrusion channel, and the extrusion is controlled by the mutual approach of the upper die lip assembly, so that the lower die lip assembly first leaves the extrusion channel in the thickness direction and then leaves to one side in the width direction before reaching the extrusion channel again, and then the upper die lip assembly leaves the extrusion channel, and the extrusion control is continued by the lower die lip assembly, and the solidified material is cleaned at the extrusion position of the lower die lip by the cleaning assembly, and the extrusion material cast on the casting roller is blown by the blowing assembly, so that the extrusion material remains in a molten state and close to the casting roller, and the excess part is scraped off by a scraper, and recovered by a receiving assembly, so as to solve the technical problems described in the background technology.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A tape-casting device for a degradable breathable film is characterized in that it includes a film processing component and an extrusion component; the extrusion component includes: a die head component that continuously conveys the blanking material; and a die lip component, wherein the die lip component is arranged on the bottom side of the die head component for switching the extrusion position back and forth and cleaning; the film processing component includes: a casting roller, wherein the casting roller is arranged below the die lip component; and a homogenizing component, wherein the homogenizing component is arranged on the side of the die lip component that discharges the material from the casting roller and is arranged to scrape and recover the extrudate in a liquid state.

[0009] Furthermore, the die lip assembly includes: a machine base, an extrusion channel is provided in the middle of the machine base installed below the die head assembly; an upper die lip assembly, the upper die lip assembly that moves back and forth along the extrusion thickness direction to adjust the extrusion thickness is provided on the bottom side of the die head assembly; a lower die lip assembly, the lower die lip assembly that leaves the extrusion channel along the extrusion thickness direction and evacuates along the extrusion width direction and then reaches the extrusion channel again is provided on the bottom side of the upper die lip assembly; and a cleaning assembly, the cleaning assembly being used to clean the inflection point of the die mouth of the evacuated lower die lip assembly, the cleaning assembly being arranged on both sides of the lower die lip assembly.

[0010] Furthermore, the upper die lip assembly includes: upper die lips arranged on both sides of the extrusion channel and with end surfaces obliquely arranged; and an upper die drive assembly, and the upper die drive assembly installed on the machine base is installed on the machine base.

[0011] Furthermore, the lower die lip assembly includes: a guide rail opened on the machine base; a lower die lip, which is arranged on both sides of the extrusion channel, with the end surface arranged obliquely, the top of the lower die lip slidingly arranged with the upper die lip and the bottom side slidingly arranged in the guide rail; and a lower die drive assembly, which is used to drive the lower die lip to move back and forth along the guide rail and is installed on the machine base.

[0012] Furthermore, the cleaning component includes: an insulation chamber, the insulation chamber corresponding to the lower mold lip is opened on both sides of the machine base; a scraper mold assembly, the scraper mold assembly for cleaning along the length direction of the lower mold lip is installed on the machine base; and a material cleaning component, the material cleaning component for removing material from the scraper mold assembly is arranged at the end of the stroke of the scraper mold assembly.

[0013] Furthermore, the scraper mold assembly includes: scraper mold parts on both sides corresponding to the oblique side ends of the lower mold lip; and a scraper mold power part, which drives the scraper mold parts to adjust the scraper mold height and move the scraper mold toward the length direction of the lower mold lip, and is installed on the machine base.

[0014] Furthermore, the material cleaning component includes: a driving seat; a side cleaning component, which drives the side cleaning components that clamp the front and rear sides of the scraper mold and is installed on the driving seat; an end cleaning component, which drives the end cleaning components that elastically clamp the left and right ends of the scraper mold and is installed on the driving seat; and a lifting driving component, which drives the lifting driving component that drives the driving seat to reciprocate up and down and is installed on the machine base.

[0015] Furthermore, the homogenizing component includes: a blowing component that blows hot air to treat the extrudate and makes the extrudate close to the surface of the casting roller; a scraper, which is tangentially arranged on the blowing side and located above the extrudate and is installed below the blowing component; and a collecting component, which is provided on the scraper for collecting the material scraped off by the scraper.

[0016] Furthermore, the material receiving assembly includes: a material receiving chamber provided on the scraper; and a material receiving roller, the material receiving roller rotatably provided above the scraper is located at an opening on one side of the material receiving chamber; a material carrying space is provided circumferentially on the material receiving roller.

[0017] In order to achieve the above object, the present invention provides a method for producing a degradable breathable film using a tape casting device, which is characterized by comprising the following steps:

[0018] Step 1: feeding, melting and extruding the masterbatch through the die head assembly to the die lip assembly and unloading;

[0019] Step 2: The die lips alternate. The lower die lip assembly extrude the blank. Then, the upper die lip assembly first reaches both sides of the extrusion channel, then leaves both sides in the thickness direction, and evacuates to one side in the width direction. Then, the lower die lip reaches both sides of the extrusion channel again. Then, the upper die lip leaves both sides in the width direction of the extrusion channel, and the lower die lip is used to control extrusion again, and this cycle repeats.

[0020] Step 3: Cleaning the die lip: While the heat preservation chamber is keeping the lower die lip warm, the die scraper assembly cleans along the length of the lower die lip. After the cleaning is completed, the cleaning assembly cleans the die scraper assembly and then reuses it.

[0021] Step 4: The material is homogenized and continues to fall onto the casting roller through the die lip assembly. The extrudate is treated with hot air from the blowing assembly and adheres to the casting roller. The scraper scrapes off the excess material according to the predetermined thickness. As the excess material accumulates, the receiving roller rotates to bring the excess material into the receiving chamber through the carrying space. Subsequently, the extrudate is cooled, thickness measured, pulled, trimmed, and corona treated before being wound up.

[0022] The beneficial effects of the present invention are:

[0023] (1) The present invention can ensure uniformity in film extrusion through the cooperation between the die lip assembly and the homogenizing assembly, thereby ensuring uniform thickness of the cast film;

[0024] (2) The present invention can realize mutual switching between the lower die lip assembly and the upper die lip assembly through the mutual cooperation between the upper die lip assembly and the lower die lip assembly, so as to realize that the lower die lip assembly is temporarily separated and the upper die lip assembly is used to continue to ensure the extrusion control of the material, thereby realizing the continuity of the material extrusion. At the same time, the cleaning switch of the lower die lip assembly during continuous extrusion is realized to ensure that the extrusion control of the material is completed in a relatively clean state after the surface treatment of the lower die lip assembly;

[0025] (3) The present invention can realize the mutual cooperation between the lower die lip and the guide rail, so that the lower die lip can be moved away from the sides along the thickness direction of the extrusion channel before being withdrawn, thereby solving the problem of the extruded film surface being damaged when the lower die lip is directly withdrawn along the width direction of the extrusion channel;

[0026] (4) The present invention can realize the use of the scraper assembly to clean the lower die lip while the cleaning assembly is used to ensure the cleanliness of the scraper assembly surface through the mutual cooperation between the scraper assembly and the cleaning assembly, so as to facilitate the next cleaning work;

[0027] (5) The present invention can further ensure the uniformity of film thickness during casting through the mutual cooperation between the blowing component and the scraping component, and can facilitate the collection of excess scraped material through the structural design of the receiving component;

[0028] In summary, the present invention has the advantages of being able to ensure uniformity of the material when it is extruded through the die lip and being able to ensure uniformity of the film thickness when it is continuously cast on the casting roller. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0030] Figure 2 For the present invention Figure 1 A magnified view of the structure;

[0031] Figure 3 It is a structural schematic diagram of the membrane treatment component of the present invention;

[0032] Figure 4 For the present invention Figure 3 Enlarged view of point A in the middle;

[0033] Figure 5 Schematic diagram of the structure of the die assembly of the present invention;

[0034] Figure 6 It is a structural schematic diagram of the cleaning component of the present invention;

[0035] Figure 7 It is a structural schematic diagram of the scraper mold assembly of the present invention;

[0036] Figure 8 It is a structural schematic diagram of the material cleaning component of the present invention;

[0037] Figure 9 For the present invention Figure 6 Cross-sectional view of the FF;

[0038] Figure 10 For the present invention Figure 6 Cross-sectional view of NN;

[0039] Figure 11 For the present invention Figure 6 Cross-sectional view of the middle MM;

[0040] Figure 12 Flowchart of the molding method of the present invention. DETAILED DESCRIPTION

[0041] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0042] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like to indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0043] Example 1

[0044] like Figure 1 、 2As shown in Figure 5, a cast molding device for a degradable breathable membrane comprises a membrane processing component 1 and an extrusion component 2; the extrusion component 2 comprises: a die head component 21 for continuously conveying the blanking material; and a die lip component 22, the die lip component 22 for switching and cleaning the extrusion position is arranged on the bottom side of the die head component 21; the membrane processing component 1 comprises: a casting roller 11, the casting roller 11 is arranged below the die lip component 22; and a homogenizing component 12, the homogenizing component 12 for cleaning and recovering the extrudate in a liquid state is arranged on the side of the die lip component 22 that discharges the material from the casting roller 11.

[0045] It is not difficult to find out from the above content that in the process of tape casting of the breathable mold, the film-making masterbatch is loaded by using the die head assembly 21, the pellets are melted at high temperature, and enter the die lip assembly 22 for extrusion of the material. At the same time, the extrudate will reach the casting roller 11 for tape casting, and during tape casting, in order to ensure the uniformity of the film thickness, the homogenizing assembly 12 will heat the film that has just flowed onto the casting roller 11 to ensure the fluid state, and scrape off the excess thickness for recycling. Among them, when the die lip assembly 22 is extruding, the extrusion position will be automatically cleaned to ensure that the technical problem of uneven extrusion caused by the solidification of the extrudate at the extrusion position of the mold during extrusion is solved.

[0046] It should also be added that the film treatment assembly 1 further includes a cooling roller 13 , a guide roller 14 , a thickness gauge 15 , a traction roller 16 , a corona treatment device 17 and a winding roller 18 .

[0047] like Figure 9 As shown, the die lip assembly 22 includes: a machine base 221, an extrusion channel 2211 is provided in the middle of the machine base 221 installed below the die head assembly 21; an upper die lip assembly 222, the upper die lip assembly 222 moves back and forth along the extrusion thickness direction to adjust the extrusion thickness and is arranged on the bottom side of the die head assembly 21; a lower die lip assembly 223, the lower die lip assembly 223 leaves the extrusion channel 2211 along the extrusion thickness direction and reaches the extrusion channel 2211 again after evacuating along the extrusion width direction, is arranged on the bottom side of the upper die lip assembly 222; and a cleaning assembly 224, the cleaning assembly 224 for cleaning the die inflection point of the evacuated lower die lip assembly 223 is arranged on both sides of the lower die lip assembly 223.

[0048] In this embodiment, during the switching process of the die lip assembly 22, when the lower die lip assembly 223 continues to control extrusion, the upper die lip assembly 222 reaches both sides of the extrusion channel 2211 to control extrusion, and then the lower die lip assembly 223 withdraws, so that the original position for extrusion control reaches the cleaning assembly 224 for cleaning the die lip surface to ensure that the extrudate forms particles and condenses on the die lip to affect the uniformity of extrusion. During the processing of the cleaning assembly 224, the other side of the lower die lip assembly 222 reaches both sides of the extrusion channel 2211, and the upper die lip assembly 222 leaves, and the lower die lip assembly 222 on both sides of the extrusion channel 2211 is used to control extrusion, and this process is repeated to realize the back and forth switching of the lower die lip assembly 222.

[0049] It should be supplemented that the die assembly 21 includes a hopper 211 and a die 212 for melting the masterbatch and outputting it downward.

[0050] like Figure 9 As shown, the upper die lip assembly 222 includes: an upper die lip 2221 arranged on both sides of the extrusion channel 2211 and arranged obliquely on the end surface; and an upper die driving assembly 2222, and the upper die driving assembly 2222 installed on the machine base 221 is installed on the machine base 221.

[0051] The upper mold driving assembly 2222 is preferably a cylinder.

[0052] like Figure 9-11 As shown, the lower die lip assembly 223 includes: a guide rail 2231 opened on the machine base 221; a lower die lip 2232, which is arranged on both sides of the extrusion channel 2211, and the top of the lower die lip 2232 with the end surface obliquely arranged is slidably arranged with the upper die lip 2221 and the bottom side is slidably arranged in the guide rail 2231; and a lower die driving assembly 2233, which is used to drive the lower die lip 2232 to move back and forth along the guide rail 2231. The lower die driving assembly 2233 is installed on the machine base 221.

[0053] In this embodiment, when the lower die driving assembly 2233, which is preferably a cylinder, drives the lower die lip 2232 to move back and forth, the lower end of the lower die lip 2232 will move back and forth through the guide rail 2231, which is preferably a guide member, so as to realize the departure of the lower die lip 2232 toward both sides of the thickness of the extrusion channel 2211. Through this departure method, the extrudate can be left in the fastest way while solving the technical problem of unevenness of the film surface caused by the lower die lip 2232 leaving directly along both sides of the width direction of the extrusion channel 2211. It should also be added that the power end of the lower die driving assembly 2233 is slidably connected to the lower die lip 2232.

[0054] The guide rail 2231 is symmetrically arranged and has a "U" shape with two sides obliquely arranged.

[0055] like Figure 7 As shown, the cleaning component 224 includes: an insulation chamber 2241, the insulation chamber 2241 corresponding to the lower die lip 2232 is opened on both sides of the machine base 221; a scraper mold component 2242, the scraper mold component 2242 for cleaning along the length direction of the lower die lip 2232 is installed on the machine base 221; and a material cleaning component 2243, the material cleaning component 2243 for removing material from the scraper mold component 2242 is arranged at the end of the stroke of the scraper mold component 2242.

[0056] In this embodiment, during the process of cleaning the lower die lip 2232, the cleaning component 224 will clean the lower die lip 2232 that reaches the insulation chamber 2241 through the scraper component 2242, and after cleaning, the cleaning component 2243 will also clean the scraper component 2242 to ensure the cleanliness of the surface of the scraper component 2242, so as to facilitate the cleaning of the lower die lip 2232 again.

[0057] like Figure 7 As shown, the scraper mold assembly 2242 includes: scraper mold parts 22421 on both sides corresponding to the oblique side ends of the lower mold lip 2232; and a scraper mold power part 22422, which drives the scraper mold part 22421 to adjust the scraper mold height and move the scraper mold toward the length direction of the lower mold lip 2232. The scraper mold power part 22422 is installed on the machine base 221.

[0058] In this embodiment, the scraping mold member 22421 is driven by the scraping mold power member 22422 to move back and forth on the surface of the lower mold lip 2232 , thereby achieving surface cleaning of the lower mold lip 2232 .

[0059] Specifically, the scraper mold power member 22422 includes a lower moving force member 224221 whose power end is connected to the scraper mold member 22421 , and a power screw rod 224222 that is threaded through the lower moving force member 224221 and installed on the machine base 221 .

[0060] In this embodiment, the power screw 224222 is driven to rotate by a servo motor, so that the scraping mold 22421 moves back and forth along the length direction of the lower die lip 2232, and the scraping mold 22421 is driven up and down by the lower moving force member 224221, which is preferably a cylinder, to reach the surface of the lower die lip 2232 for cleaning.

[0061] like Figure 8As shown, the material cleaning component 2243 includes: a driving seat 22431; a side cleaning component 22432, which drives the side cleaning component 22432 that clamps the front and rear sides of the scraper mold 22421 and is installed on the driving seat 22431; an end cleaning component 22433, which drives the end cleaning component 22433 that elastically clamps the left and right ends of the scraper mold 22421 and is installed on the driving seat 22431; and a lifting driving component 22434, which drives the lifting driving component 22434 that drives the driving seat 22431 to reciprocate up and down and is installed on the machine base 221.

[0062] In this embodiment, when the cleaning component 2243 cleans the surface of the scraper module 22421, the driving seat 22431 is first raised by the lifting drive component 22434, which is preferably a cylinder, and the side cleaning components 22432 reach both sides of the scraper module 22421 and clamp them. Then, the end cleaning component 22433 is elastically clamped on both sides of the end of the scraper module 22421, and while the lifting drive component 22434 moves downward, the side cleaning components 22432 and the end cleaning components 22433 are moved downward, and the surface of the scraper module 22421 is cleaned.

[0063] It should be supplemented that the side cleaning assembly 22432 includes a side cleaning plate 224321 and a side cleaning power member 224322 that drives the side cleaning plate 224321 to move back and forth. The side cleaning power member 224322 is preferably a cylinder.

[0064] It should also be added that the end cleaning assembly 22433 is preferably an end cleaning piece 224331, a movable seat 224332, a spring 224333 that elastically connects the end cleaning piece 224331 and the movable seat 224332, and an end cleaning power piece 224334 that drives the movable seat 224332 to move back and forth. The end cleaning power piece 224334 is preferably a cylinder.

[0065] Example 2

[0066] like Figure 3 As shown, the components identical or corresponding to those in the first embodiment are designated by the corresponding reference numerals in the first embodiment. For simplicity, only the differences from the first embodiment are described below. The second embodiment differs from the first embodiment in that:

[0067] The homogenizing component 12 includes: a blowing component 121 for blowing a hot air flow to treat the extrudate and make the extrudate close to the surface of the casting roller 11; a scraper 122, which is tangentially arranged on the blowing side and located above the extrudate and is installed below the blowing component 121; and a collecting component 123, which is provided on the scraper 122 for scraping the material off the scraper 122 for collection.

[0068] In this embodiment, when the homogenizing component 12 processes the extrudate, the blowing component 121 is first used to blow hot air on the falling extrudate so that the extrudate can be fully attached to the casting roller 11, and the scraping member 122 is used to scrape the thickness of the heated and molten extrudate during the casting process, and the scraped material is gradually collected and processed by the collecting component 123 as the height increases.

[0069] like Figure 4 As shown, the material receiving assembly 123 includes: a material receiving chamber 1231 provided on the scraper 122; and a material receiving roller 1232, the material receiving roller 1232 rotatably provided above the scraper 122 is located at an opening on one side of the material receiving chamber 1231; a material carrying space 1233 is provided circumferentially on the material receiving roller 1232.

[0070] In this embodiment, when the material receiving assembly 123 collects the material after scraping, the material receiving roller 1232 is driven to rotate by the power of a servo motor, and the scraped material is carried to the material receiving chamber 1231 through the material carrying space 1233 for collection.

[0071] Example 3

[0072] like Figure 12 As shown, a method for producing a breathable film using a tape casting device for a degradable breathable film comprises the following steps:

[0073] Step 1: feeding, melting and extruding the masterbatch through the die head assembly 21 to the die lip assembly 22 and unloading;

[0074] Step 2: The die lips alternate. The lower die lip assembly 223 extrude the blank. Subsequently, the upper die lip assembly 222 first reaches both sides of the extrusion channel 2211, then leaves both sides in the thickness direction, and evacuates to one side in the width direction. Then, the lower die lip 2232 reaches both sides of the extrusion channel 2211 again. Then, the upper die lip 2221 leaves both sides in the width direction of the extrusion channel 2211, and the lower die lip 2232 is used to control extrusion again, and this cycle repeats.

[0075] Step 3: Cleaning the die lip: While the heat preservation chamber 2241 is keeping the lower die lip 2232 warm, the die scraper assembly 2242 is cleaning along the length of the lower die lip 2232. After the cleaning is completed, the cleaning assembly 2243 will clean the die scraper assembly 2242, and then the die scraper assembly 2242 will be reused.

[0076] Step 4: The discharged material is homogenized. The extrudate continues to fall onto the casting roller 11 through the die lip assembly 22 and is adhered to the casting roller 11 by the hot air treatment of the blowing assembly 121. The scraper 122 scrapes off the excess part according to the predetermined thickness. As the excess amount accumulates, the receiving roller 1232 rotates to bring the excess material into the receiving chamber 1231 through the carrying space 1233. Subsequently, the extrudate is cooled, thickness measured, pulled, trimmed, and corona treated before being wound up.

[0077] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A tape casting device for a degradable breathable film, characterized in that: Includes film processing components and extrusion components; The extrusion assembly comprises: A die assembly that continuously delivers the material; and A die lip assembly for switching and cleaning the extrusion position is provided on one side of the bottom of the die head assembly; The membrane treatment component comprises: a casting roller, the casting roller being arranged below the die lip assembly; and A homogenizing component, which makes the extrudate in liquid state, scraped and recovered, is arranged on the side of the die lip component discharging from the casting roller; The die lip assembly comprises: A machine base is installed below the die head assembly and has an extrusion channel in the middle; An upper die lip assembly, which moves back and forth along the extrusion thickness direction to adjust the extrusion thickness, is provided on one side of the bottom of the die head assembly; a lower die lip assembly, which leaves the extrusion channel in the extrusion thickness direction and evacuates in the extrusion width direction before returning to the extrusion channel, and is provided on one side of the bottom of the upper die lip assembly; and A cleaning assembly for cleaning the die inflection point of the withdrawn lower die lip assembly. The cleaning assembly is arranged on both sides of the lower die lip assembly; The upper die lip assembly comprises: Upper die lips arranged on both sides of the extrusion channel and with obliquely arranged end surfaces; and An upper die driving assembly mounted on the machine base; The lower die lip assembly comprises: A guide track provided on the machine base; A lower die lip, arranged on both sides of the extrusion channel, with the end surface of the lower die lip arranged obliquely, the top of the lower die lip being slidably arranged with the upper die lip and the bottom side being slidably arranged in the guide track; and A lower die driving assembly, for driving the lower die lip to move back and forth along the guide track, is mounted on the machine base; The cleaning component includes: A heat preservation chamber, wherein the heat preservation chamber corresponding to the lower die lip is opened on both sides of the machine base; A scraper mold assembly for cleaning along the length direction of the lower mold lip is installed on the machine base; and A material cleaning component for removing material from the scraper mold component is arranged at the end of the stroke of the scraper mold component.

2. The tape casting device for a degradable breathable film according to claim 1, characterized in that: The scraper mold assembly includes: Scraping mold parts on both sides corresponding to the oblique side ends of the lower mold lip; and The scraper mold power component drives the scraper mold to adjust the scraper mold height and move the scraper mold toward the length direction of the lower mold lip. The scraper mold power component is installed on the machine base.

3. The tape casting device for a degradable breathable film according to claim 2, characterized in that: The material cleaning component comprises: Drive seat; A side cleaning assembly is installed on the driving seat to drive and clamp the front and rear sides of the scraper module; An end cleaning assembly drives the end cleaning assembly that elastically clamps the left and right ends of the scraper module and is installed on the driving seat; and A lifting drive assembly that drives the drive seat to move up and down is installed on the machine base.

4. A tape casting device for a degradable breathable film according to any one of claims 1 to 3, characterized in that: The homogenization component comprises: A blowing component for blowing hot air to treat the extrudate and make the extrudate close to the surface of the casting roll; A scraper, tangentially arranged on the blowing side and located above the extrudate, is installed below the blowing assembly; and The material collecting component is arranged on the scraping member to collect the material scraped off by the scraping member.

5. The tape casting device for a degradable breathable film according to claim 4, characterized in that: The material receiving component includes: a material receiving chamber provided on the scraping member; and A receiving roller is rotatably arranged above the scraper and is located at an opening on one side of the receiving chamber; The receiving roller is provided with a material carrying space on its upper surface.

6. The method for producing a breathable film using the tape casting device for a degradable breathable film according to claim 5, characterized in that: The following steps are involved: Step 1: feeding, melting and extruding the masterbatch through the die head assembly to the die lip assembly and unloading; Step 2: The die lips alternate. The lower die lip assembly extrude the blank. Then, the upper die lip assembly first reaches both sides of the extrusion channel, then leaves both sides in the thickness direction, and evacuates to one side in the width direction. Then, the lower die lip reaches both sides of the extrusion channel again. Then, the upper die lip leaves both sides in the width direction of the extrusion channel, and the lower die lip is used to control extrusion again, and this cycle repeats. Step 3: Cleaning the die lip: While the heat preservation chamber is keeping the lower die lip warm, the die scraper assembly cleans along the length of the lower die lip. After the cleaning is completed, the cleaning assembly cleans the die scraper assembly and then reuses it. Step 4: The material is homogenized and continues to fall onto the casting roller through the die lip assembly. The extrudate is treated with hot air from the blowing assembly and adheres to the casting roller. The scraper scrapes off the excess material according to the predetermined thickness. As the excess material accumulates, the receiving roller rotates to bring the excess material into the receiving chamber through the carrying space. Subsequently, the extrudate is cooled, thickness measured, pulled, trimmed, and corona treated before being wound up.

Images