Preparation method of recycled polyester porous fiber-based sound-absorbing tapestry

Abstract

The invention discloses a method for preparing a regenerated polyester porous fiber-based sound-absorbing tapestry. The sound-absorbing tapestry is woven on a double-needle-bar Raschel warp knitting machine using regenerated polyester sound-absorbing fibers as pile yarns and ordinary polyester yarns as pile yarns. The tapestry has good sound-absorbing effect, is environmentally friendly, has a simple production process, and is low in cost. The tapestry can be applied on a large scale to the industrialized production of Raschel blankets.

Description

Technical Field

[0001] The invention relates to the technical field of tapestry production, in particular to a method for preparing a recycled polyester porous fiber-based sound-absorbing tapestry. Background Art

[0002] As living standards continue to improve, people have higher expectations for a better living environment. Meanwhile, with the continuous development of modern society, various noises permeate urban life, and noise pollution has become a major component of environmental pollution, second only to air pollution. Therefore, the research and development of new porous ultra-fine denier velvet recycled polyester fiber-based sound-absorbing tapestries plays a vital role in reducing the impact of noise on people.

[0003] In recent years, common methods for combating noise pollution include soundproof walls, soundproof enclosures, soundproof floors, doors, and windows. For example, insulating glass can block ordinary human voices, but it has trouble blocking even slightly louder noises. Due to the high cost and heaviness of laminated glass, a combination of insulating and laminated glass is used, but this is not very effective against sounds of 70 decibels or above. Vacuumed glass, however, is not completely vacuum-proof, has a short lifespan, and offers poor soundproofing. Commonly used sound-absorbing materials include glass, slag wool, felt, foam plastic, and cotton wool, but these materials have low sound absorption coefficients and are ineffective. Other soundproofing materials are either bulky or expensive.

[0004] Currently, commercially available sound-absorbing materials often use inorganic materials (glass fiber, rock wool, sponge, etc.) or metal materials as their base materials. Inorganic materials have the potential to be difficult to manufacture, have high density, and are prone to problems such as reduced sound absorption efficiency due to powder loss and cracking. Metal materials, on the other hand, have the disadvantages of high specific gravity, high thermal conductivity, poor insulation, and complex construction. Therefore, developing sound-absorbing materials that are effective, lightweight, economical, simple to manufacture, and environmentally friendly has become a hot topic of research.

[0005] The emergence of hollow polyester fibers has broadened the application of polyester fibers. However, research on these fibers has largely been limited to thermal insulation and heat transfer. Few reports have examined the preparation of sound-absorbing materials using recycled polyester hollow fibers and the relationship between hollow fiber specifications and sound absorption coefficient. Polyester fibers offer advantages such as high strength, light weight, controllable fiber diameter, and large surface area. The interstices formed by aggregation effectively block sound transmission, making them a promising sound-absorbing material. Based on the Huygens absorption principle, this study used polyester hollow fibers of varying specifications and sheath-core thermally bonded fibers as raw materials. These materials were prepared through a "hot air consolidation" process. The goal was to create a porous structure at the macro, micro, and micro levels, thereby increasing resistance to sound wave transmission, increasing dissipated energy, and improving sound absorption. A "multidimensional" sound absorption and noise reduction mechanism based on hollow fibers was proposed, and the influence of material thickness on sound absorption was investigated. The results are of great significance for expanding the application of recycled polyester fibers and advancing the research and development of sound-absorbing materials. Summary of the Invention

[0006] The present invention aims to provide a method for preparing a regenerated polyester porous fiber-based sound-absorbing tapestry, wherein the sound-absorbing tapestry is woven on a double-needle-bar Raschel warp knitting machine using regenerated polyester sound-absorbing fibers as pile yarns and ordinary polyester yarns as pile yarns. The tapestry has good sound absorption effect, is environmentally friendly, has a simple production process, and is low in cost, and can be applied on a large scale to the industrial production of Raschel blankets.

[0007] A method for preparing a recycled polyester porous fiber-based sound-absorbing tapestry comprises the following steps:

[0008] (1) Preparation of recycled polyester materials

[0009] Waste polyester materials are sorted, crushed, cleaned, and dehydrated to obtain clean bottle flakes. The clean flakes are then pre-crystallized, dried at high temperature, and extruded into granules to obtain recycled polyester granules. The purpose of the pre-crystallization treatment is to reach the glass transition temperature to obtain an initial melt while separating some elemental impurities.

[0010] (2) Preparation of recycled polyester hollow fibers

[0011] Recycled polyester particles and water-soluble polyester are used as the raw materials for the sheath layer, and water-soluble polyester is used as the raw material for the core layer. Composite melt spinning is carried out, and after being extruded through a composite spinning circular spinneret, side-blown air cooling is carried out, and the fibers are bundled and oiled. Then, two-stage drafting, relaxation and heat setting treatment are carried out, and then winding is carried out. Finally, alkaline solution treatment is carried out to completely decompose the water-soluble polyester in the sheath layer and the core layer to form recycled polyester hollow fibers.

[0012] (3) Preparation of recycled polyester sound-absorbing fiber

[0013] Recycled polyester hollow fibers of different specifications are blended with core-sheath thermal bonding fibers in a certain mass ratio to form composite yarns, which are then hot-air consolidated under constant pressure and stretched to obtain recycled polyester sound-absorbing fibers.

[0014] (4) Preparation of recycled polyester fiber-based sound-absorbing tapestry

[0015] The sound-absorbing tapestry is woven on a double-needle-bar Raschel warp knitting machine using ordinary polyester yarn as the plush yarn and recycled polyester sound-absorbing fiber as the base yarn.

[0016] Preferably, the amount of waste polyester material added during the pulverization in step (1) does not exceed 2 / 3 to 4 / 5 of the pulverizer. The temperature of the inner wall of the pulverizer during the pulverization in step (1) is ≤ 60°C.

[0017] Preferably, in step (1), detergent is first added to the ultrasonic cleaner for cleaning. If the detergent formula is an anionic surfactant, soap solution is selected, the washing time is 20 minutes to 30 minutes, and the water washing temperature is between 30°C and 40°C.

[0018] Preferably, in step (1), detergent is first added to the ultrasonic cleaner for cleaning. If the detergent formula is a non-ionic surfactant, an APG detergent is selected, the washing time is 15 minutes to 20 minutes, and the water washing temperature is between 20°C and 30°C.

[0019] Preferably, the secondary cleaning in step (1) is performed by rinsing once with deionized water, the water washing temperature is 30°C to 50°C, and the water washing time is 20 minutes.

[0020] Preferably, the dehydration in step (1) is carried out in a common oven at a temperature of 60° C. for a time of 25 min to 40 min.

[0021] Preferably, step (1) is carried out in a pre-crystallization oven at a temperature of 120° C. to 140° C. until the fragments become transparent.

[0022] Preferably, the extrusion granulation in step (1) adopts a single-screw extruder, the aspect ratio of the machine is between 25:1 and 30:1, and the temperature of the die is controlled between 240°C and 265°C.

[0023] In step (1), the high temperature drying temperature is 90-100°C and the time is 6-8 hours.

[0024] In step (2), the mass percentage composition of the components of the cortex raw material is: 75-90% recycled polyester particles, 10-25% water-soluble polyester.

[0025] In step (2), the cortex of the recycled polyester hollow fiber accounts for 60-90wt%, and the core layer accounts for 10-40wt%.

[0026] In step (2), in the two-stage drawing, the drawing temperature of the first-stage drawing is 75-90°C, and the drawing ratio is 2-4 times; the drawing temperature of the second-stage drawing is 95-100°C, and the drawing ratio is 1-2 times.

[0027] In step (2), the temperature of the relaxation heat setting is 100-140°C and the time is 40-100 minutes.

[0028] In step (2), the alkaline solution treatment conditions are: sodium hydroxide alkaline solution concentration is 1-5 g / L, temperature is 95-100° C., and treatment time is 5-40 min.

[0029] In step (3), the constant pressure is 0.8 MPa-1.2 MPa.

[0030] In step (3), the temperature of hot air consolidation is set to 120°C-135°C, and the consolidation time is 70-90 minutes.

[0031] In step (3), the mass percentages of the recycled polyester hollow fiber and the sheath-core thermal bonding fiber are: 55% to 65% of the recycled polyester hollow fiber and 35% to 45% of the sheath-core thermal bonding fiber.

[0032] The beneficial effects of the present invention are:

[0033] (1) The present invention uses sheath-core thermal bonding fiber and recycled polyester hollow fiber to form recycled polyester sound-absorbing fiber, and then uses ordinary polyester yarn as plush yarn to weave a sound-absorbing tapestry on a double-needle bed Raschel warp knitting machine. The sound-absorbing tapestry has good sound absorption effect, can utilize waste polyester materials, is environmentally friendly, has a simple production process, and is low in cost.

[0034] (2) Different sound-absorbing materials are prepared by using recycled polyester hollow fibers and core-shell thermal bonding fibers of different specifications as raw materials and adopting "hot air consolidation" molding to increase the resistance of the sound wave transmission process, improve the dissipated energy, and improve the sound absorption effect. The porous structure also has good warmth retention, breathability, moisture resistance and lightness.

[0035] (3) The recycled polyester porous fiber-based sound-absorbing tapestry obtained by the present invention meets the development requirements of functional textiles. It not only meets the needs of interior decoration, but also can reduce outdoor noise. It is in line with the concept of healthy living of modern people, will bring new social and economic benefits, and has huge development potential and broad market prospects.

[0036] (4) There are a large number of pores between the fibers of recycled polyester hollow fibers, which block the transmission of sound and increase the loss of sound energy. The difficulty is that it is easy to deform due to its various cross-sectional shapes. Experiments have found that the circular cross-sectional shape has a higher sound absorption efficiency; the concentration of the alkaline solution is controlled to obtain excellent hollow fibers; the circular cross-sectional shape is formed by spinning through a circular spinneret; the skin-core thermal bonding fiber can maintain the stable morphological structure of the recycled polyester hollow fiber under the hot air consolidation process, thereby enhancing the strength of the composite fiber. DETAILED DESCRIPTION

[0037] The technical solution of the present invention is further described in detail below through specific embodiments.

[0038] In the present invention, unless otherwise specified, the raw materials and equipment used can be purchased from the market or are commonly used in the art. The methods in the following examples, unless otherwise specified, are all conventional methods in the art.

[0039] Example 1: Preparation of recycled polyester hollow fibers

[0040] The steps include:

[0041] Step 1: Preparation of recycled polyester fiber:

[0042] Sorting out waste polyester materials; the volume is 2 / 3 of the pulverizer, and water is added during pulverization to ensure that the inner wall temperature does not exceed 60°C; first, adding 10% owf APG detergent (model APG-1214) in an ultrasonic washer for cleaning, washing time for 20 minutes at a temperature of 20°C; then rinsing with deionized water at a temperature of 30°C for 20 minutes; dehydrating in a conventional oven at a temperature of 60°C for 25 minutes to obtain clean bottle flakes; placing the clean bottle flakes in an oven at a temperature of 120°C until the fragments are transparent; then placing them in a drying oven at 90°C for high-temperature drying for 8 hours; placing the clean fragments in a single-screw extruder with a machine aspect ratio of 25:1 and a head temperature controlled at 240°C, and extruding and granulating to obtain recycled polyester particles.

[0043] Step 2: Preparation of recycled polyester hollow fiber

[0044] 60% of the sheath polyester (composed of 75% of recycled polyester and 25% of commercially available water-soluble polyester) is fed into a sheath screw extruder, and 40% of the water-soluble polyester is fed into a core screw extruder for composite melt spinning. After being extruded through a composite spinning circular spinneret, the fibers are cooled by side blowing, oiled, and assembled into bundles, which are then wound and bundled before undergoing two-stage drawing: a first-stage drawing temperature of 75°C and a drawing ratio of 2 times; a second-stage drawing temperature of 95°C and a drawing ratio of 2 times; a relaxation heat setting treatment at a temperature of 100°C for 100 minutes; and finally a sodium hydroxide alkaline solution treatment at a concentration of 1 g / L and a temperature of 100°C for 40 minutes to completely decompose the water-soluble polyester in the sheath and core layers, thereby forming recycled polyester hollow fibers.

[0045] Example 2: Preparation of recycled polyester hollow fibers

[0046] The steps include:

[0047] Step 1: Preparation of recycled polyester fiber:

[0048] Sorting out waste polyester materials; the volume is 4 / 5 of the pulverizer, and water is added during pulverization to ensure that the inner wall temperature does not exceed 60°C; first, adding 20% ​​owf APG detergent (model APG-1214) in an ultrasonic washer for cleaning, the washing time is 15 minutes, and the temperature is 30°C; then rinsing with deionized water at a temperature of 50°C for 20 minutes; in an ordinary oven, the temperature is 60°C and the time is 40 minutes to obtain clean bottle flakes; the clean bottle flakes are placed in an oven at a temperature of 140°C until the fragments are transparent; then placed in a drying oven at 100°C and high-temperature dried for 6 hours; the clean fragments are placed in a single-screw extruder with a machine aspect ratio of 30:1 and a head temperature controlled at 265°C, and extruded into granules to obtain recycled polyester particles.

[0049] Step 2: Preparation of recycled polyester hollow fiber

[0050] 90% of the sheath polyester (composed of 90% recycled polyester and 10% of water-soluble polyester) is input into the sheath screw extruder, and 10% of the water-soluble polyester is input into the core screw extruder for composite melt spinning. After being extruded through a composite spinning circular spinneret, the fibers are cooled by side blowing, oiled, and wound and bundled after being integrated. The fibers are then subjected to two-stage drawing: the first-stage drawing temperature is 90°C and the drawing ratio is 4 times; the second-stage drawing temperature is 100°C and the drawing ratio is 1 times; a relaxation heat setting treatment is performed at a temperature of 140°C for 40 minutes; and finally, the fibers are treated with a sodium hydroxide alkaline solution with a concentration of 5g / L and a temperature of 95°C for 5 minutes. The water-soluble polyester in the sheath and core layers is completely decomposed to form recycled polyester hollow fibers.

[0051] Example 3: Preparation of Recycled Polyester Hollow Fibers

[0052] The steps include:

[0053] Step 1: Preparation of recycled polyester fiber:

[0054] Sorting out waste polyester materials; the volume is 70% of the pulverizer capacity, and water is added during pulverization to ensure that the inner wall temperature does not exceed 60°C; first, adding 15% owf APG detergent (model APG-1214) in an ultrasonic washer for cleaning, the washing time is 18 minutes, and the temperature is 25°C; then rinsing with deionized water at a temperature of 40°C for 20 minutes; in an ordinary oven, the temperature is 60°C and the time is 30 minutes to obtain clean bottle flakes; the clean bottle flakes are placed in an oven at a temperature of 130°C until the fragments are transparent; then placed in a drying oven at 95°C for high-temperature drying for 7 hours; the clean fragments are placed in a single-screw extruder with a machine aspect ratio of 28:1 and a head temperature controlled at 250°C, and extruded into granules to obtain recycled polyester particles.

[0055] Step 2: Preparation of recycled polyester hollow fiber

[0056] 75% of the sheath polyester (composed of 80% recycled polyester and 20% of the water-soluble polyester) is input into the sheath screw extruder, and 25% of the water-soluble polyester is input into the core screw extruder for composite melt spinning. After being extruded through a composite spinning circular spinneret, the fibers are cooled by side blowing, oiled, and wound and bundled after being integrated. After two-stage drawing: the first-stage drawing temperature is 80°C and the drawing ratio is 3 times; the second-stage drawing temperature is 98°C and the drawing ratio is 1.5 times; a relaxation heat setting treatment is performed at a temperature of 125°C for 70 minutes; and finally, the fibers are treated with a sodium hydroxide alkaline solution with a concentration of 3 g / L and a temperature of 98°C for 20 minutes. The water-soluble polyester in the sheath and core layers is completely decomposed to form recycled polyester hollow fibers.

[0057] Example 4: Preparation of recycled polyester fiber-based sound-absorbing tapestry

[0058] The regenerated polyester hollow fiber with a linear density of 4D prepared in Example 3 was selected as the core yarn. The regenerated polyester hollow fiber was blended with a sheath-core type thermal bonding fiber with a linear density of 4.1D (commercially available, sheath-core type low-melting point polyester yarn, melting point 110°C) in a mass ratio of 6:4 to form a composite yarn. The composite yarn was then hot-air consolidated at a pressure of 0.8 MPa, a temperature of 120°C, and a time of 90 minutes. After stretching, a regenerated polyester sound-absorbing fiber with a linear density of 4D was obtained. Then, ordinary polyester yarn was used as the plush yarn and the regenerated polyester sound-absorbing fiber was used as the base yarn to weave a sound-absorbing tapestry on a double-needle-bar Raschel warp knitting machine.

[0059] Example 5: Preparation of recycled polyester fiber-based sound-absorbing tapestry

[0060] The recycled polyester hollow fiber with a linear density of 8D prepared in Example 3 was selected as the core yarn. The recycled polyester hollow fiber was blended with a sheath-core type thermal bonding fiber with a linear density of 4.1D (commercially available, sheath-core type low-melting point polyester yarn, melting point 110°C) in a mass ratio of 6:4 to form a composite yarn. The composite yarn was then hot-air consolidated at a pressure of 1.2 MPa, a temperature of 135°C, and a time of 70 minutes. After stretching, a recycled polyester sound-absorbing fiber with a linear density of 8D was obtained. Then, ordinary polyester yarn was used as the plush yarn and the recycled polyester sound-absorbing fiber was used as the base yarn to weave a sound-absorbing tapestry on a double-needle-bar Raschel warp knitting machine.

[0061] Example 6: Preparation of recycled polyester fiber-based sound-absorbing tapestry

[0062] The regenerated polyester hollow fiber with a linear density of 10D prepared in Example 3 was selected as the core yarn. The regenerated polyester hollow fiber was blended with a sheath-core type thermal bonding fiber with a linear density of 4.1D (commercially available, sheath-core type low-melting point polyester yarn, melting point 110°C) in a mass ratio of 6:4 to form a composite yarn. The composite yarn was then hot-air consolidated at a pressure of 1 MPa, a temperature of 125°C, and a time of 80 minutes. After stretching, a regenerated polyester sound-absorbing fiber with a linear density of 10D was obtained. Then, ordinary polyester yarn was used as the plush yarn and the regenerated polyester sound-absorbing fiber was used as the base yarn to weave a sound-absorbing tapestry on a double-needle-bar Raschel warp knitting machine.

[0063] Example 7: Preparation of recycled polyester fiber-based sound-absorbing tapestry

[0064] The regenerated polyester hollow fiber with a linear density of 15D prepared in Example 3 was selected as the core yarn. The regenerated polyester hollow fiber was blended with a sheath-core type thermal bonding fiber with a linear density of 4.1D (commercially available, sheath-core type low-melting point polyester yarn, melting point 110°C) in a mass ratio of 6:4 to form a composite yarn. The composite yarn was then hot-air consolidated at a pressure of 1 MPa, a temperature of 130°C, and a time of 80 minutes. After stretching, a regenerated polyester sound-absorbing fiber with a linear density of 15D was obtained. The sound-absorbing tapestry was then woven on a double-needle-bar Raschel warp knitting machine using ordinary polyester yarn as the plush yarn and the regenerated polyester sound-absorbing fiber as the base yarn.

[0065] Example 8: Preparation of recycled polyester fiber-based sound-absorbing tapestry

[0066] The regenerated polyester hollow fiber with a linear density of 20D prepared in Example 3 was selected as the core yarn. The regenerated polyester hollow fiber was blended with a sheath-core type thermal bonding fiber with a linear density of 4.1D (commercially available, sheath-core type low-melting point polyester yarn, melting point 110°C) in a mass ratio of 6:4 to form a composite yarn. The composite yarn was then hot-air consolidated at a pressure of 1 MPa, a temperature of 125°C, and a time of 80 minutes. After stretching, a regenerated polyester sound-absorbing fiber with a linear density of 20D was obtained. Then, ordinary polyester yarn was used as the plush yarn and the regenerated polyester sound-absorbing fiber was used as the base yarn to weave a sound-absorbing tapestry on a double-needle-bar Raschel warp knitting machine.

[0067] Example 9: Preparation of recycled polyester fiber-based sound-absorbing tapestry

[0068] The difference between this embodiment and embodiment 8 is that the regenerated polyester hollow fiber and the sheath-core thermal bonding fiber with a linear density of 4.1D (commercially available) are blended in a mass ratio of 4:6 to form a composite yarn.

[0069] Example 10: Preparation of recycled polyester fiber-based sound-absorbing tapestry

[0070] The difference between this embodiment and embodiment 8 is that the regenerated polyester hollow fiber and the sheath-core thermal bonding fiber with a linear density of 4.1D (commercially available) are blended in a mass ratio of 5:5 to form a composite yarn.

[0071] Comparative Example 1

[0072] Ordinary recycled polyester fiber with a linear density of 4D was used as a control.

[0073] Comparative Example 2

[0074] Ordinary recycled polyester fiber with a linear density of 8D was used as a control.

[0075] The following table shows the raw material specifications and sound absorption coefficients of recycled polyester sound-absorbing fibers in the embodiments of the present invention.

[0076] .

Claims

1. A method for preparing a recycled polyester porous fiber-based sound-absorbing tapestry, characterized in that: The following steps are involved: (1) Preparation of recycled polyester materials The waste polyester materials are sorted, crushed, cleaned and dehydrated to obtain clean bottle flakes; then the clean flakes are pre-crystallized, dried at high temperature and extruded into granules to obtain recycled polyester granules; (2) Preparation of recycled polyester hollow fibers Recycled polyester particles and water-soluble polyester are used as the raw materials for the sheath layer, and water-soluble polyester is used as the raw material for the core layer. Composite melt spinning is carried out, and after being extruded through a composite spinning circular spinneret, side-blown air cooling is carried out, and the fibers are bundled and oiled. Then, two-stage drafting, relaxation and heat setting treatment are carried out, and then winding is carried out. Finally, alkaline solution treatment is carried out to completely decompose the water-soluble polyester in the sheath layer and the core layer to form recycled polyester hollow fibers. (3) Preparation of recycled polyester sound-absorbing fiber Recycled polyester hollow fibers of different specifications are blended with core-sheath thermal bonding fibers in a certain mass ratio to form composite yarns, which are then hot-air consolidated under constant pressure and stretched to obtain recycled polyester sound-absorbing fibers. (4) Preparation of recycled polyester fiber-based sound-absorbing tapestry The sound-absorbing tapestry is woven on a double-needle-bar Raschel warp knitting machine using ordinary polyester yarn as the plush yarn and recycled polyester sound-absorbing fiber as the base yarn.

2. The preparation method according to claim 1, characterized in that In step (1), the high temperature drying temperature is 90-100°C and the time is 6-8 hours.

3. The preparation method according to claim 1, characterized in that In step (2), the mass percentage composition of the components of the cortex raw material is: 75-90% recycled polyester particles, 10-25% water-soluble polyester.

4. The preparation method according to claim 1, characterized in that In step (2), the cortex of the recycled polyester hollow fiber accounts for 60-90wt%, and the core layer accounts for 10-40wt%.

5. The preparation method according to claim 1, characterized in that In step (2), in the two-stage drawing, the drawing temperature of the first-stage drawing is 75-90°C, and the drawing ratio is 2-4 times; the drawing temperature of the second-stage drawing is 95-100°C, and the drawing ratio is 1-2 times.

6. The preparation method according to claim 1, characterized in that In step (2), the temperature of the relaxation heat setting is 100-140°C and the time is 40-100 minutes.

7. The preparation method according to claim 1, characterized in that In step (2), the alkaline solution treatment conditions are: sodium hydroxide alkaline solution concentration is 1-5 g / L, temperature is 95-100° C., and treatment time is 5-40 min.

8. The preparation method according to claim 1, characterized in that In step (3), the constant pressure is 0.8 MPa-1.2 MPa.

9. The preparation method according to claim 1, characterized in that In step (3), the temperature of hot air consolidation is set to 120°C-135°C, and the consolidation time is 70-90 minutes.

10. The preparation method according to claim 1, characterized in that In step (3), the mass percentages of the recycled polyester hollow fiber and the sheath-core thermal bonding fiber are: 55% to 65% of the recycled polyester hollow fiber and 35% to 45% of the sheath-core thermal bonding fiber.