Regenerated polyester fiber and application thereof in wall cloth, curtain and window screen

Abstract

The invention relates to the technical field of synthetic polymer artificial filament manufacturing, and particularly discloses a regenerated polyester fiber and application thereof in wall cloth, curtains and window screens. The fiber is prepared from 100% post-consumer polyester bottle chips as a raw material through the steps of automatic sorting and cleaning, deep purification, boiling crystallization and drying, micro-alcohol demodulation, melting and granulation, precise blending and drying with functional master batches, spinning, cooling, drafting, sizing, network and high-precision winding, the linear density of the fiber is 55-666 dtex, and the fiber has specific mechanical and shrinkage performance. The preparation method integrates a waste heat recovery system, a water circulation system and a solar energy utilization system. Wall cloth, curtain or window screen fabric prepared from the fiber not only has excellent dimensional stability and dyeing uniformity, but also has multiple functional characteristics. According to the invention, complete, green and high-value cyclic utilization from the waste bottles to the high-quality decorative fabrics is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of synthetic polymer artificial filament manufacturing, and more particularly, to a regenerated polyester fiber and its application in wall cloth, curtain and screen. BACKGROUND

[0002] With the global emphasis on sustainable development and circular economy concept, the textile industry is facing the urgent need to reduce dependence on petroleum-based virgin polyester and reduce environmental footprint. Using post-consumer polyester bottles and other waste resources to produce regenerated polyester fiber has become an important way to alleviate resource pressure and realize green transformation of textile materials. Such fibers have shown significant application potential and market prospects, especially in the field of decorative fabrics such as wall cloth, curtain and screen, which have high requirements for environmental properties and durability.

[0003] Currently, the existing technology for producing regenerated polyester fiber from post-consumer polyester bottles has several urgent aspects to be improved. In terms of raw material pretreatment, the automation and refinement of bottle piece cleaning and sorting are insufficient, which may affect the purity and uniformity of the subsequent spinning grade raw material. In terms of key production processes, the traditional melt regeneration process often fails to effectively integrate processes such as "micro-alkali solution conditioning" aimed at improving the spinnability and stability of the melt, resulting in fluctuations in the quality of regenerated chips, which in turn affects the consistency of key indicators such as strength, elongation and boiling water shrinkage of the final fiber. In addition, the existing production system has limited functional expansion, making it difficult to flexibly and accurately add multiple functional master batches on the same production line to achieve product differentiation. Meanwhile, there are also deficiencies in systematic design in terms of energy and resource recycling, such as granulation waste heat recovery, efficient reuse of production wastewater, and integration of clean energy, etc. These deficiencies collectively restrict the further improvement of regenerated polyester fiber, especially in terms of performance stability, functional diversity and overall environmental friendliness, when applied to high-end decorative fabrics.

[0004] Therefore, in view of the above problems, a regenerated polyester fiber and its application in wall cloth, curtain and screen are proposed to overcome the deficiencies in the prior art, provide a regenerated polyester fiber with more excellent performance, a more integrated and green production process, and a preparation method thereof, and expand its application in high-quality decorative fabrics such as wall cloth, curtain and screen, in order to meet the market demand for high-performance, multi-functional and truly sustainable textile materials. SUMMARY

[0005] In order to overcome the above-mentioned defects of the prior art, the embodiments of the present application provide a regenerated polyester fiber and its application in wall cloth, curtain and screen to solve the problems raised in the background art.

[0006] To achieve the above object, the present application provides the following technical scheme: a regenerated polyester fiber is prepared from 100% post-consumer polyester bottle flakes through a cyclic regeneration process; the linear density of the fiber ranges from 55 dtex to 666 dtex, the breaking strength is greater than or equal to 3.5 cN / dtex, the elongation at break is between 20% and 30%, and the boiling water shrinkage is between 6.5% and 8.5%.

[0007] Preferably, the preparation method comprises the following steps: S1, raw material pretreatment: recycling post-consumer polyester bottles are subjected to automatic material color selection, cleaning and deep purification to obtain spinning grade polyester bottle flakes; S2, bottle flake crystallization and drying: the spinning grade polyester bottle flakes are sequentially subjected to boiling crystallization and continuous drying; S3, melting and granulation: the dried bottle flakes are melted by a screw, and after micro-alkali solution conditioning, they are granulated to obtain regenerated polyester chips; the cooling water in the granulation process uses a recycling system, and the waste heat generated by melting is recycled and utilized; S4, chip blending and drying: the regenerated polyester chips are pre-crystallized and blended and dried with at least one master batch selected from functional master batch, color master batch or matting master batch through a continuous loss-on-ignition metering system, so that the moisture content of the mixture is not higher than 30 ppm; S5, spinning and winding: the dried mixture is melted by a screw, filtered, and statically mixed, and then delivered to a spinning assembly by a metering pump to form a nascent fiber, which is cooled by side blowing, bundled and oiled, drawn, shaped and networked, and then wound into a regenerated polyester drawn yarn by a high-precision fully automatic winding equipment; S6, inspection and post-processing: the wound yarn cake is subjected to grading inspection, and the qualified products are automatically packaged and stored in a digital management three-dimensional warehouse.

[0008] Preferably, in step S3, the recovered waste heat is used for the drying process of the master batch in step S4.

[0009] Preferably, in step S5, the high-precision fully automatic winding equipment is a winding forming machine with full-automatic switching function.

[0010] Preferably, in step S6, the grading inspection includes 100% full inspection of appearance quality and intrinsic quality; the identification of automatic packaging includes product grade, quantity, net weight, production batch number and execution standard information; the three-dimensional warehouse realizes partition of storage location and automatic warehouse entry and exit through a warehouse management system.

[0011] Preferably, the preparation method integrates an environmental protection and energy recycling unit in the whole production system, including: a sewage treatment center for treating and recycling bottle flake cleaning wastewater, and a solar photovoltaic power generation system arranged on the roof of a factory building.

[0012] A wall cloth, curtain or window screen comprising a fabric woven or knitted from the regenerated polyester fiber described above.

[0013] Preferably, the regenerated polyester fiber is a functionalized fiber with functional master batches added during preparation, so that the fabric has at least one functional property selected from flame retardant, antibacterial, cool feeling, dope coloring, graphene modification or cationic dyeability.

[0014] Preferably, the regenerated polyester fiber constituting the fabric is sourced from a complete waste polyester bottle recycling and production chain, and is produced through the whole process from bottle flake cleaning processing, purification and granulation to chip spinning.

[0015] Preferably, the regenerated polyester fiber used in the fabric has product factory inspection conforming to the following internal control indicators: linear density deviation rate is within ± 2%, linear density coefficient of variation is not greater than 1.5%, breaking strength coefficient of variation is not greater than 6.0%, breaking elongation coefficient of variation is not greater than 12.0%, and dyeing uniformity color judgment level reaches gray scale card 4 or 5.

[0016] Technical effects and advantages of the present application: Compared with the prior art, the present application constructs a complete closed-loop industry chain from waste polyester bottle recycling to spinning forming, and integrates automatic material color selection, deep purification and subsequent spinning level processing technology, which ensures that the raw material is 100% post-consumer source and the purity meets the high standard spinning requirements. The system workflow is coherent, which guarantees the single nature and environmental traceability of the fiber composition from the source, effectively avoids the quality fluctuation problem caused by the complex source of traditional recycled materials, so that the regenerated polyester fiber finally prepared can achieve and maintain stable excellent performance in breaking strength, elongation and other core mechanical properties, providing a reliable raw material basis for subsequent weaving of high-quality decorative fabrics.

[0017] In the core preparation link, the present application introduces a cooperative treatment process including boiling crystallization, continuous drying and micro-alkali solution conditioning melt granulation. The process first controls the water content and morphology of the bottle flake through precise crystallization and drying, and then adjusts the polyester molecular chain structure through micro-alkali solution in the melting process, which improves the rheological property and uniformity of the regenerated melt. This series of operations makes the fiber spun subsequently more regular in microstructure, and in macroscopic aspect, the boiling water shrinkage is precisely controlled, the network degree is uniform and stable, which significantly improves the dimensional stability and post-processing performance of the fiber, making it more suitable for products such as wall cloth, curtain and the like which have strict deformation requirements.

[0018] In view of the problem of single product function, the application integrates a continuous weight loss type metering blending system in the slice processing stage after drying. This system can accurately meter and flexibly add various functional additives including flame retardant, antibacterial, color master batch, etc. in real time, realizing online blending modification. This way not only ensures the uniformity of the dispersion of functional components in the fiber, but also endows the production line with the ability to quickly respond to different customized needs, so as to produce a series of regenerated fibers with differentiated functions on the same process platform, thereby widening the application range of the regenerated fibers in the field of special decorative fabrics.

[0019] From the perspective of production process sustainability, the application deeply integrates resource and energy recycling concepts into process design. Specifically, the waste heat generated in the melt granulation process is recycled for master batch drying, establishing a cross-process heat energy cascade utilization; a self-built sewage treatment center is provided to realize high proportion recycling of production wastewater; and a solar photovoltaic power generation system is integrated in the factory area. These measures work together to systematically reduce external energy consumption and water consumption in the production process, reduce environmental emissions, significantly reduce the overall production footprint of the regenerated polyester fiber, and enhance its competitiveness in the green supply chain. BRIEF DESCRIPTION OF DRAWINGS

[0020] Fig. 1 The method of the application is shown in the overall workflow diagram.

[0021] Fig. 2 The core process and energy recovery flowchart of the application is shown.

[0022] Fig. 3 The quality control and function customization decision flowchart of the application is shown. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the application will be described clearly and completely below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, not all. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the application.

[0024] Embodiment one As shown in the accompanying drawings, a regenerated polyester fiber and its application in wall cloth, curtain and window screen. The technical solution takes 100% post-consumer polyester bottle chips as the only initial raw material, through a complete and systematic process chain from raw material deep purification to fiber forming and finally to final application, to prepare high-performance regenerated polyester fiber and expand its application in the field of high-quality decorative fabrics. Figs. 1 to 3

[0025] ​The preparation of the regenerated polyester fiber follows a logically rigorous and interlocking process, mainly including six core steps (S1 to S6).

[0026] Step S1, the recycled post-consumer polyester bottles are automatically sorted and deeply purified to obtain pure spinning grade chips.

[0027] Step S2, the chips are treated by a specific crystallization and drying process to stabilize their physical form and completely remove moisture.

[0028] Step S3, the dried chips are melted, and a key micro-alkali modification reaction is introduced during the melting process, followed by granulation to obtain regenerated polyester chips with improved performance.

[0029] Step S4, the regenerated chips are blended with the required functional masterbatch through a high-precision metering system, and are again deeply dried to the extremely low moisture content required for spinning.

[0030] Step S5, the blended and dried material is melt-spun, and after key processes such as drawing, heat setting, and network formation, it is wound into a bobbin by a high-precision fully automatic equipment.

[0031] Step S6, the fiber product is subjected to comprehensive quality inspection, automatic packaging, and is included in the digital three-dimensional warehouse system management.

[0032] In addition, the entire production process integrates waste heat recovery, water recycling, solar power generation and other green production units. The fiber prepared by the above systematic process has a linear density range of 55 dtex to 666 dtex, a breaking strength ≥ 3.5 cN / dtex, and breaking elongation, boiling water shrinkage and other indicators are stable in the excellent range, which is completely suitable for wall cloth, curtains and window screen products with double requirements for performance and environmental protection.

[0033] Further, the core goal of step S1 (raw material pretreatment) is to achieve "spinning grade" purification of the raw material. This process begins with the automatic sorting of waste polyester bottles. Specifically, by configuring an automatic material and color sorting machine, polyester chips and non-polyester impurities (such as bottle caps, labels, etc.) are efficiently separated, which is the first key process to ensure the stability of the subsequent process and the purity of the final fiber. The sorted chips enter a multi-stage cleaning system, which is sequentially cleaned by hot alkali and mechanical friction, effectively removing oil, adhesives and attachments. Finally, using flotation separation technology, further remove the remaining light impurities by taking advantage of the density difference. This series of purification combination of physical and chemical combination ensures the high cleanliness of the output chips, providing a high-quality raw material basis for subsequent melt spinning, avoiding the introduction of impurities leading to spinning breakage or fiber defects.

[0034] Further, step S2 (bottle flake crystallization and drying) is a special process designed for the characteristics of polyester bottle flakes. If untreated wet bottle flakes are directly subjected to high-temperature drying or melting, they are extremely prone to sticking or hydrolysis. Therefore, first, a boiling crystallization process is used to make the bottle flakes rapidly crystallize on the surface in a fluidized hot air, thereby significantly increasing the softening point and preventing caking problems in subsequent processes. After the crystallization treatment, the bottle flakes are sent to a continuous drying tower for deep dehydration. The drying process uses dry hot air with a low dew point to remove the internal moisture of the bottle flakes for a long time and uniformly, and finally controls the moisture content to be ≤ 50 ppm, to meet the stringent requirements of high molecular weight polyester materials for moisture content during melt processing, and to avoid the influence of water on the hydrolytic degradation of the polymer and the molecular weight and the strength of the final product.

[0035] Further, step S3 (melting and pelletizing) is one of the core links to improve the spinnability of the recycled material. The dried bottle flakes are melted in a twin-screw extruder. Unlike simple melting, the key of the present scheme is to introduce an online micro-ethanolysis modification process. Specifically, under the action of heat and possibly existing catalysts, a small amount of ethylene glycol is accurately added to the system in a molten state to perform a controllable alcoholysis reaction on the polyester molecular chain. This process can moderately adjust the molecular weight distribution of the recycled polyester, improve the rheological uniformity and thermal stability of the melt, and thus essentially improve its spinnability, providing internal protection for spinning high-quality fibers. The pure melt after modification is filtered to remove impurities such as gel, and then an underwater pelletizing system is used to produce recycled polyester chips with uniform specifications. The waste heat generated in this link is collected by a recovery system and can be used in other processes.

[0036] Further, step S4 (chip blending and drying) realizes the flexibility and customization of product functions. The recycled polyester chips are first pre-crystallized to prevent caking during subsequent drying. Subsequently, the chips and functional master batches (such as flame-retardant master batches, color master batches, antibacterial master batches, etc.) from independent hoppers are fed into a continuous loss-on-ignition metering system. This system realizes high precision and stability of the addition ratio of main and auxiliary materials through real-time monitoring and feedback control of the material weight, which is the key to ensuring the uniform distribution of functional components in the fibers. The prepared mixture is then subjected to final pre-spinning deep drying in a combined drying tower, using dry air with deep dehumidification to reduce the moisture content to not more than 30 ppm of the spinning standard, completely eliminating the risk of hydrolysis caused by moisture during high-temperature spinning.

[0037] Further, step S5 (spinning and winding) is the forming stage of converting the high-quality material into high-performance fibers. After the dry blended material is melted by the screw, the melt is metered, filtered, and mixed, and then extruded from the spinneret to form the nascent fibers. The fibers are cooled by side blowing and oiled, and then enter the drawing and heat setting zone composed of multiple pairs of hot rollers. In this zone, the fibers are gradually stretched to increase the molecular orientation and strength, and then heat set on the hot rollers at a higher temperature to stabilize the fiber structure and effectively control the boiling water shrinkage within the target range (e.g., 7.5 ± 1%). After setting, the fibers are formed into interlaced points by a networker to increase the cohesion. Finally, the fibers are wound into a bobbin by a high-precision fully automatic winding head, which has an automatic switching function to ensure the continuity of production and the consistency of the forming quality of each cheese.

[0038] Further, step S6 (inspection and post-processing) constitutes a strict quality closed loop and an efficient logistics system. Each cheese needs to undergo inspection of appearance and internal quality. The internal quality inspection is performed according to strict internal control indicators, such as a linear density deviation rate within ± 2%, a breaking strength ≥ 3.5 cN / dtex, an elongation at break between 25 ± 5%, a boiling water shrinkage between 7.5 ± 1%, a network degree between 12 ± 5 / m, an oil content between 0.95 ± 0.25%, and a dyeing uniformity reaching a gray scale card 4-5 level. The products that pass the inspection are packaged according to specifications by an automatic packaging line, with complete and accurate label information. The packaged products then enter a three-dimensional warehouse, where the automatic allocation of storage locations, the automated storage and retrieval of goods, and the information management are realized with the help of a warehouse management system (WMS) and an enterprise resource planning (ERP) system, greatly improving the efficiency and accuracy of warehousing.

[0039] Further, the recovered waste heat in step S3 is used for the drying process of the master batch in step S4, embodying the concept of energy cascade utilization within the production system. Specifically, the low-temperature waste heat collected from the melt granulation link is used to preheat the fresh air entering the master batch dryer through a heat exchange device, thereby directly reducing the heating energy consumption of this drying link and improving the overall energy efficiency.

[0040] Further, the high-precision fully automatic winding equipment in step S5 is specifically a winding head with a double-winding position automatic switching function. Its working process realizes the "uninterrupted" spinning process: when the main winding position cheese is full, the control system automatically starts the standby winding position to complete the spinning, switching, and unloading of the full cheese. This process is quickly completed under precise control, with minimal tension fluctuations in the fiber path, thereby ensuring the high consistency of the winding quality from the inside to the outside of each cheese and the smoothness of subsequent unwinding processing.

[0041] Further, the entire preparation system integrates the environmental protection and resource recycling units of the system at the factory design level. Specifically, the wastewater generated by cleaning the bottle pieces is deep treated by the self-built wastewater treatment center, and after reaching the recycling standard, most of it (the recycling rate can reach more than 80%) is recycled for primary cleaning or cooling in the production process, significantly reducing fresh water consumption. At the same time, a solar photovoltaic power generation system is installed on the roof of the factory building, which converts solar energy into electricity and is directly used for production, effectively reducing external power consumption and carbon emissions in the production process.

[0042] Further, the regenerated polyester fiber prepared by the above method is specifically applied to the manufacture of wall cloth, curtains or window screens. When applied, the fiber can be directly used for weaving or knitting. For example, when producing curtain fabrics, the dope-colored fiber added with color master batches in step S4 can be used, so that the gray fabric woven does not need to be subjected to traditional dyeing, and only needs to be finished to obtain the finished product with uniform color, which not only has long-lasting color, but also completely avoids the generation of dyeing wastewater. Since the fiber is subjected to micro-alkali solution conditioning and precise heat setting in production, it has low and stable boiling water shrinkage, which endows the final fabric with excellent dimensional stability, ensures that it is not easy to deform during subsequent use and washing, and completely meets the stringent requirements of high-end decorative fabrics on quality.

[0043] Finally, it should be pointed out that: first, in the description of the present application, it should be pointed out that unless otherwise specified and limited, the terms "mounting", "connection", "connection" should be broadly understood, which can be mechanical connection or electrical connection, or the communication between two elements, or direct connection, "up", "down", "left", "right" and the like are only used to indicate the relative positional relationship, when the absolute position of the described object changes, the relative positional relationship may change; Secondly: the drawings of the disclosed embodiments of the present application only involve the structures involved in the disclosed embodiments of the present application, other structures can refer to the usual design, and in the case of no conflict, the same embodiment and different embodiments of the present application can be combined with each other; Finally: the above only describes the preferred embodiments of the present application and is not used to limit the present application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A recycled polyester fiber, characterized in that, It is made from 100% post-consumer polyester bottle flakes through a recycling process; the linear density of the fiber ranges from 55 dtex to 666 dtex, the tensile strength is greater than or equal to 3.5 cN / dtex, the elongation at break is between 20% and 30%, and the boiling water shrinkage is between 6.5% and 8.5%.

2. The recycled polyester fiber according to claim 1, characterized in that, Its preparation method includes the following steps: S1. Raw material pretreatment: The recycled post-consumer polyester bottles are subjected to automated material color sorting, cleaning and deep purification to obtain spinning-grade polyester bottle flakes. S2. Crystallization and drying of bottle flakes: The spinning-grade polyester bottle flakes are subjected to boiling crystallization and continuous drying in sequence. S3. Melting and Granulation: The dried bottle flakes are melted by a screw, and then granulated after micro-alcoholization to obtain recycled polyester chips; the cooling water in the granulation process adopts a recycling system, and the waste heat generated by melting is recovered and reused; S4. Chip blending and drying: The recycled polyester chips are pre-crystallized and blended and dried with at least one masterbatch selected from functional masterbatch, color masterbatch or matte masterbatch through a continuous loss-in-weight metering system, so that the moisture content of the mixture is not higher than 30 ppm. S5. Spinning and winding: After the dried mixture is melted by a screw, filtered by melt, and statically mixed, it is transported by a metering pump to the spinneret assembly for spinning. The resulting nascent fibers are cooled by side blowing, bundled and oiled, drawn, shaped and networked, and then wound into shape by a high-precision fully automatic winding equipment to obtain recycled polyester drawn yarn. S6. Inspection and post-processing: The wound yarn cakes are graded and inspected. Qualified products are automatically packaged and then stored in a digitally managed automated warehouse.

3. The preparation method according to claim 2, characterized in that, In step S3, the recovered waste heat is used in the drying process of the masterbatch in step S4.

4. The preparation method according to claim 2, characterized in that, In step S5, the high-precision fully automatic winding equipment is a winding forming machine with fully automatic switching function.

5. The preparation method according to claim 2, characterized in that, In step S6, the graded inspection includes 100% inspection of appearance and internal quality; the automated packaging label includes product grade, quantity, net weight, production batch number and implementation standard information; the automated warehouse realizes storage location zoning and automated inbound and outbound operations through the warehouse management system.

6. The preparation method according to claim 2, characterized in that, The preparation method integrates environmental protection and energy recovery units into the overall production system, including: a wastewater treatment center for treating and recycling bottle flake washing wastewater, and a solar photovoltaic power generation system installed on the roof of the factory buildings.

7. A type of wallpaper, curtain, or window screen, characterized in that, It comprises fabrics woven or braided from recycled polyester fibers as described in claim 1.

8. The wallpaper, curtain, or window screen according to claim 7, characterized in that, The recycled polyester fiber is a functionalized fiber in which functional masterbatch has been added during the preparation process, thereby giving the fabric at least one functional property selected from flame retardancy, antibacterial properties, cooling sensation, solution dyeing, graphene modification, or cationic dyeability.

9. The wallpaper, curtain, or screen according to claim 7, characterized in that, The recycled polyester fibers that make up the fabric are derived from a complete industrial chain of waste polyester bottle recycling and are produced through the entire process from bottle flake cleaning and processing, purification and granulation to chip spinning.

10. The wallpaper, curtain, or window screen according to claim 7, characterized in that, The recycled polyester fibers used in the fabric meet the following internal control indicators during product factory inspection: linear density deviation rate within ±2%, linear density variation coefficient not greater than 1.5%, breaking strength variation coefficient not greater than 6.0%, breaking elongation variation coefficient not greater than 12.0%, and dyeing uniformity color judgment level reaches gray sample card level 4 or 5.

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