Online composite processing system and method for modified PBT (polybutylene terephthalate) film

Abstract

The invention belongs to the technical field of high polymer material processing, particularly relates to an online composite processing system and method of a modified PBT (polybutylene terephthalate) film, and is particularly suitable for the fields of electronic insulating materials, capacitor media, packaging materials and the like. The invention provides an online composite processing system and method for a modified PBT (polybutylene terephthalate) film. The system integrates an automatic feeding module, a double-screw modification treatment module, a multi-layer co-extrusion module, an online detection module, a hot-pressing composite module and an intelligent control module. The core of the system is that integrated continuous production from raw material modification to composite film forming is realized through a central control system, feed-forward compensation and closed-loop regulation and control are carried out by utilizing online detection data, and the system is equipped with automatic roll changing and quality tracing functions. According to the method, the granulation link of a traditional off-line process is omitted, the problems of tedious procedures, high energy consumption and unstable composite quality are effectively solved, the film thickness uniformity, interlayer binding force and production efficiency are remarkably improved, and the method is suitable for flexible manufacturing of high-performance films such as electronic insulation films and capacitor media.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of polymer material processing, and particularly relates to an online composite processing system and method for modified PBT film, which is especially suitable for continuous and intelligent composite production of high-performance modified PBT film in the fields of electronic insulating materials, capacitor dielectric, packaging materials and the like. BACKGROUND

[0002] PBT film is widely used in the electronic, automotive, packaging and other industries due to its excellent mechanical properties, heat resistance, electrical insulation and dimensional stability. In order to meet the demand for higher performance, PBT is often modified by adding nano fillers, flame retardants, antistatic agents and other functional additives to form modified PBT film. However, the traditional modified PBT film adopts an offline process of "first modification and granulation, then film blowing or casting, and finally compounding", which has problems such as complicated process, high energy consumption, poor interfacial bonding, low production efficiency and the like.

[0003] The existing composite processing equipment is mostly of a segmented structure, lacks integrated modification, compounding and quality control, and is difficult to realize continuous online production. In addition, the control precision of key parameters such as temperature, pressure and tension in the compounding process is insufficient, resulting in uneven product thickness, low interlayer peeling strength and low yield. Moreover, there is a lack of real-time quality feedback adjustment mechanism, making it difficult to adapt to rapid switching of different formulations and thicknesses.

[0004] Therefore, it is urgent to develop an online composite processing system and method for modified PBT film, which integrates modification, online compounding, intelligent detection and closed-loop regulation, so as to improve product quality, production efficiency and flexible manufacturing capability. SUMMARY

[0005] The present application aims to overcome the shortcomings of the prior art and provide an online composite processing system and method for modified PBT film, which realizes integrated, continuous and intelligent production from raw material modification to film compounding, and solves the problems of dispersed process, unstable compounding quality and low automation degree in the prior art.

[0006] The technical solution of the present application is as follows: an online composite processing system for modified PBT film, comprising an automatic feeding device, a modification processing module, a filtration and metering system, a multi-layer co-extrusion die, a casting cooling device, an online detection device, a compounding processing unit and a winding device connected in sequence, and a central control system connected with signals of each unit for realizing whole-process parameter acquisition and closed-loop regulation.

[0007] As a preferred embodiment, the modification processing module is a twin-screw melt blending extruder, which is provided with at least five independent temperature control zones and a vacuum exhaust device, and is equipped with an online rheological monitoring sensor.

[0008] As a preferred embodiment, the composite processing unit comprises a pair of adjustable gap hot pressing composite rollers, the roller surface is super-precision ground and chrome plated, the gap adjustment range is 0.01-0.1 mm, and the heating mode is electromagnetic induction heating with a temperature control accuracy of ±1℃.

[0009] As a preferred embodiment, the online detection device comprises an infrared thickness gauge, a surface defect visual recognition camera and a corona treatment detector, and the detection data is uploaded to the central control system in real time.

[0010] As a preferred embodiment, the winding device is equipped with a servo motor drive and an automatic roll changing mechanism, and a tension sensor is used to realize constant tension control with a tension fluctuation range of ≤±5%.

[0011] An online composite processing method of modified PBT film based on a processing system, comprising the following steps: raw material proportioning and feeding, melt blending modification, filtration and metering, multi-layer co-extrusion casting, cooling and shaping, online quality detection, parameter dynamic adjustment, hot pressing composite, cooling and winding, and quality traceability and archiving.

[0012] As a preferred embodiment, the melt blending temperature is 230-260℃, the screw rotation speed is 200-600 rpm, and the devolatilization treatment is carried out under vacuum conditions.

[0013] As a preferred embodiment, the hot pressing composite temperature is 100-180℃, the linear pressure is 5-20 kN / m, and the extrusion speed and tension are fed forwardly compensated and adjusted according to the online detection results before composite.

[0014] As a preferred embodiment, when the product specification is changed, the central control system calls a preset process template, and the reconstruction of preset temperature, pressure, speed and tension parameters and equipment calibration are completed.

[0015] As a preferred embodiment, the whole process parameters are recorded by the central control system and a unique quality traceability code is generated, which is associated with the serial number of each roll of product and supports the whole process quality traceability.

[0016] After the above technical scheme is adopted, the beneficial effects of the present application are: The system integrates automatic feeding, modification, multi-layer co-extrusion, online detection and intelligent control modules, realizes integrated continuous production from raw material modification to composite film production, and aims to solve the problems of complicated traditional offline process, high energy consumption and unstable composite quality.

[0017] Through integrated design, the traditional granulation and reprocessing links are omitted, energy consumption is significantly reduced, and production efficiency is improved; closed-loop regulation and control are realized by using online detection and central control system, film thickness uniformity and interlayer adhesion are greatly improved; constant tension control is effectively ensured by feedforward compensation adjustment and automatic roll changing technology, and the waste rate is reduced; the traceability of products is enhanced by whole-process parameter recording and quality traceability function, and the flexible manufacturing demand of high-performance film in high-end field is met. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0019] Figure 1 It is a schematic diagram of the overall structure of the system of the present application. Figure 2 It is a connection structure diagram of the modification treatment module and the composite processing unit. Figure 3 It is an information interaction flowchart of the online detection and central control system. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application. EMBODIMENT

[0021] An online composite processing system of modified PBT film includes: an automatic feeding device, a modification treatment module, a filtration and metering system, a multi-layer co-extrusion die, a casting cooling device, an online detection device, a composite processing unit and a winding device arranged in sequence along the production line direction; each unit works collaboratively through networking by a central control system. The automatic feeding device is used for quantitative conveying of PBT base material and modification additives according to the proportion, to ensure accurate raw material proportioning and improve product quality. The modification treatment module includes a twin-screw melt blending extruder, which is configured with multiple temperature control sections and vacuum exhaust ports to realize uniform plasticization of raw materials and efficient dispersion of modification additives, thereby improving the performance stability of the materials. The length-diameter ratio (L / D) of the twin-screw melt blending extruder is preferably 40:1 to 56:1. The screw combination is enhanced by setting reverse thread elements in the shear block dispersion section to enhance the shear dispersion force of the nanofiller or flame retardant, ensuring that the modification additives are uniformly dispersed at the nanoscale in the PBT matrix, avoiding agglomeration. The filtration and metering system is provided with a precision filter and a melt gear pump to remove impurities and stabilize the melt flow, ensuring material uniformity. The multi-layer co-extrusion die combines the modified PBT melt with other functional layers (such as adhesive layers, protective layers) to form a multi-layer structure melt film, enhancing the functionality of the film. The casting cooling device uses mirror stainless steel cooling rollers and air knife attachment technology to achieve rapid and uniform cooling and shaping, improving production efficiency and product consistency. The internal multi-loop closed-loop temperature control system of the mirror stainless steel cooling roller controls the roller surface temperature fluctuation within ±1℃. By precisely controlling the cooling rate, premature crystallization of the PBT melt is suppressed, ensuring that the base film has high transparency and low haze, while also providing good longitudinal orientation to the film, providing a stable mechanical foundation for subsequent compounding processes. The online detection device integrates an infrared thickness gauge, a corona treatment detector, and a surface defect visual recognition system to monitor product thickness, surface energy, and defects in real time, ensuring that product quality meets standards. The compounding unit includes a hot press compounding roller set and a multi-section tension control mechanism to complete multi-layer film compounding under precise temperature and pressure, improving compounding strength and precision. In the hot press compounding roller set, at least one roller surface is coated with a polyamide elastic rubber layer with a Shore A hardness of 80-90 to accommodate different thicknesses of film and eliminate surface micro-defects. Under the action of a temperature of 100-180℃ and a linear pressure of 5-20kN / m, the modified PBT melt layer undergoes micro-flow, forming mechanical anchoring and physical adsorption with the PET functional film surface, significantly improving interlayer peel strength. The winding device is equipped with a servo drive and an automatic roll changing mechanism to achieve constant tension winding, ensuring the stability of the winding process. The central control system is based on PLC and industrial Internet of Things platform, receiving detection data and dynamically adjusting extrusion speed, temperature, pressure, and tension parameters to realize closed-loop control, improving production automation and efficiency.

[0022] Further, the modification treatment module is provided with an online rheological monitoring sensor to real-time feedback melt viscosity changes, which is used to accurately judge dispersion uniformity and ensure material performance stability.

[0023] Further, the hot-pressing roller surface in the composite processing unit is subjected to super-precision grinding and chrome plating treatment, the roller gap is adjustable in the range of 0.01-0.1 mm, the heating mode is high-efficiency electromagnetic induction heating, and the temperature control precision is as high as ±1℃, thereby ensuring the uniformity and high quality of the composite product.

[0024] Further, the system further comprises an edge trimming and edge material recycling device, realizes automatic cutting and recycling of the edge material, improves the utilization rate of the material and reduces waste.

[0025] In an embodiment, a flame-retardant antistatic modified PBT composite film is produced, and the formula is: PBT resin 94wt%, decabromodiphenyl ethane 4wt%, antimony trioxide 2wt%. The extrusion temperature gradient is set to 230℃→250℃→260℃→255℃, the screw rotation speed is 450 rpm, and the vacuum degree is -0.08 MPa. The melt is delivered to the die by the gear pump at a constant flow rate after passing through the 5 μm filter. After casting and cooling, the film thickness is 50±3 μm, and after passing the detection, it enters the composite unit, and is compounded with a layer of PET functional film at 160℃ and a pressure of 15 kN / m. The final product has a peel strength of >1.2 N / mm, a surface resistivity of <1×10 9 Ω / sq, meeting the standard of electronic insulating materials.

[0026] Comparative experiment: the same formula PBT composite film is produced by the traditional "pelletizing-blowing film-composite" offline process. The results show that the peel strength of the product of the offline process is only 0.8 N / mm, and the thickness fluctuation standard deviation reaches ±5 μm, while the thickness fluctuation standard deviation of the product of the online composite process of the present application is controlled within ±2 μm. This proves that by omitting the granulation and melting link, the thermal degradation of PBT molecular chain is reduced, and the thickness uniformity is significantly improved by online closed-loop control.

[0027] An online composite processing method of a modified PBT film, comprising the following steps: S1 raw material proportioning and melting modification: PBT resin particles and modification aids are put into an automatic feeding device according to the set proportion; melting and blending are carried out in a double-screw melting and blending extruder, the temperature gradient is controlled to be 230-260℃, the screw rotation speed is 200-600 rpm, and devolatilization treatment is carried out under vacuum condition; S2 melt filtration metering and co-extrusion casting: the melt is filtered through a precision filter to remove impurities, and is metered by a melt gear pump at a constant flow rate; then it is delivered to a multi-layer co-extrusion die to be combined with the melt of an auxiliary functional layer; the melt film is rapidly cooled and shaped at 20-50℃ by a casting and cooling device to form a base film; S3 online quality detection and dynamic compensation: the thickness and surface quality data of the base film are obtained in real time by using an infrared thickness gauge and a visual recognition camera; the central control system adjusts and compensates the extrusion speed and the traction tension according to the detection results to ensure the consistency of the film material; S4 hot pressing and cooling: the modified PBT-based film and another functional film are sent into a composite processing unit; hot pressing is performed under the conditions of a temperature of 100-180 DEG C and a linear pressure of 5-20 kN / m; after the composite, the film is cooled and flattened by a cooling roller; S5 constant tension winding: the composite film is wound by a winding device, and constant tension control is realized by combining a tension sensor with a servo motor, so that the tension fluctuation range is controlled within ≤±5%.

[0028] Further, the central control system records the process parameters (temperature, pressure, speed, tension) in real time, generates a unique quality traceability code, associates each product serial number, and forms a quality traceability file.

[0029] Further, when the product specification is changed, the central control system calls a preset process template to automatically complete the reconstruction and equipment calibration of the temperature, pressure, speed and tension parameters, and realizes flexible production.

[0030] The present application successfully realizes the continuous and intelligent production of modified PBT film from raw materials to finished products by constructing an integrated processing system integrating automatic feeding, melting modification, online detection and closed-loop regulation. This scheme not only eliminates the cumbersome granulation and reprocessing links in the traditional process, significantly reduces energy consumption and improves production efficiency, but also effectively solves the problems of uneven film thickness and poor interlayer adhesion by introducing feedforward compensation adjustment and constant tension control technology. The present application provides an efficient, stable and full-process quality traceability solution for flexible manufacturing of high-performance modified PBT film.

[0031] The above is only a preferred embodiment of the present application and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A modified PBT film on-line compounding processing system, characterized in that, The application relates to a full-process production line for multilayer composite film, which comprises an automatic feeding device, a modification treatment module, a filtering and metering system, a multilayer co-extrusion die head, a casting cooling device, an online detection device, a composite processing unit and a winding device which are sequentially connected, and a central control system which is signal-connected with the units and is used for realizing full-process parameter acquisition and closed-loop regulation.

2. The modified PBT film in-line lamination processing system according to claim 1, characterized in that, The modification treatment module is a double-screw melt blending extruder which is provided with at least five independent temperature control zones and a vacuum exhaust device and is equipped with an online rheological monitoring sensor.

3. The modified PBT film in-line lamination processing system according to claim 1, wherein, The composite processing unit comprises a pair of hot-pressing composite rollers with adjustable gaps, the roller surfaces are subjected to super-precision grinding and chrome plating treatment, the gap adjusting range is 0.01-0.1 mm, the heating mode is electromagnetic induction heating, and the temperature control precision is + / -1 DEG C.

4. The modified PBT film in-line lamination processing system according to claim 1, wherein, The online detection device comprises an infrared thickness gauge, a surface defect visual recognition camera and a corona treatment detector, and detection data are uploaded to the central control system in real time.

5. The modified PBT film in-line lamination processing system of claim 1, wherein, The winding device is equipped with a servo motor driving and automatic roll changing mechanism, and realizes constant tension control in combination with a tension sensor, and the tension fluctuation range is less than or equal to + / -5%.

6. A method for on-line compounding of a modified PBT film according to any one of claims 1 to 5, characterized in that, The application further discloses a production method of the multilayer composite film, which comprises the following steps: raw material proportioning and feeding, melt blending modification, filtering and metering, multilayer co-extrusion casting, cooling and shaping, online quality detection, parameter dynamic adjustment, hot-pressing composite, cooling and winding and quality traceability and archiving.

7. The method of claim 6, wherein, The melt blending temperature is 230-260 DEG C, the screw rotating speed is 200-600 rpm, and devolatilization treatment is carried out under vacuum.

8. The method of claim 6, wherein, The hot-pressing composite temperature is 100-180 DEG C, the linear pressure is 5-20 kN / m, and the extrusion speed and tension are fed forwardly compensated and adjusted according to the online detection result before the hot-pressing composite.

9. The method of claim 6, wherein, When the product specification is changed, the central control system calls a preset process template, and the reconstruction of preset temperature, pressure, speed and tension parameters and equipment calibration are completed.

10. The method of claim 6, wherein, Full-process process parameters are recorded by the central control system and a unique quality traceability code is generated, the code is associated with the product serial number of each roll, and full-process quality traceability is supported.

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