Preparation method and application of degradable PET (Polyethylene Terephthalate) fiber

Abstract

The invention relates to the field of new materials. The preparation method of the degradable PET fiber comprises the following steps: fusing the degradable slices through a screw extruder, conveying the degradable slices to a filter, forming tows through a spinning box and a spinneret plate, and carrying out subsequent winding, drafting, curling and heat setting to obtain the degradable PET fiber. According to the invention, the PET fiber with physical and chemical properties of the polyester fiber and degradability of the fiber-forming material is prepared.

Description

Technical Field

[0001] The invention relates to the field of new materials, in particular to degradable polyester fibers. Background Art

[0002] With the rapid development of science and technology and the continuous improvement of people's living standards, textiles are no longer just for the purpose of protecting the human body and maintaining body temperature, but have gradually developed into products that combine low-carbon environmental protection, comfort, functionality, fashion and intelligence. However, the problem of white pollution has not been fully solved. The output of chemical fibers, led by PET, is increasing. The production and use of polyester fibers in my country are very large, and the accumulation of waste after use has caused environmental problems. Many ministries and commissions have issued plastic restriction orders. Under the background of the "dual carbon" strategy, it has become an urgent need to reduce the white pollution caused by petrochemical plastics that are not easily degradable and to find degradable materials.

[0003] Degradable means that the fiber material can be naturally decomposed under certain environmental conditions after use, thereby reducing pollution to the environment. At present, biodegradable polymers such as polylactic acid (PLA) and polyhydroxyalkanoates (PHA) are representatives of degradable fibers. However, domestic degradable PET fibers are still in the research stage, there are not many methods for making degradable PET fibers, and most of the processes are in the experimental stage, so it is very necessary to explore a practical method for making degradable PET fibers. Summary of the invention

[0004] The object of the present invention is to provide a method for preparing degradable PET fiber to solve the above technical problems.

[0005] Preparation method of degradable PET fiber: the degradable chips are melted by a screw extruder and conveyed to a filter, formed into filament bundles by a spinning box and a spinneret, and then the degradable PET fiber is obtained by subsequent winding, drawing, curling and heat setting.

[0006] The preparation method of degradable PET fiber comprises the following steps:

[0007] Step (1), adding a tackifier: fully mixing the epoxy tackifier and the degradable chips in a mass ratio of 0.5-1.5:98.5-99.5, and then melting and mixing through a screw extruder;

[0008] Step (2), adjusting the spinning temperature: the screw temperature is controlled at 286-310°C during spinning.

[0009] Step (3), filter element screening: select 80-120μ filter element.

[0010] Step (4), increasing the side blowing wind speed: during cooling and forming, the side blowing wind temperature is controlled at 21-23° C., and the center wind speed is 8.5-9 m / s.

[0011] Step (5), controlling the drafting ratio: the hot drafting ratio is in the range of 2.5-3.0, and the drafting oil bath temperature is in the range of 66-70°C.

[0012] Preferably, in step (1), the screw temperature is 286-310° C., and the winding speed is 1000-1100 m / min.

[0013] Preferably, in step (1), the degradable slices include PLA slices and degradable PET slices, and the PLA slices and the degradable PET slices are melt-mixed in a mass ratio of 50:50 through different screw extruders and extruded in parallel through a composite spinneret.

[0014] More preferably, the screw temperature of PLA is 220-235°C, and the screw temperature of PET is 288-308°C.

[0015] More preferably, the difference between the viscosity of the degradable PET slice and the viscosity of the PLA slice is 0.1-0.5. The different orientations and crystallization behaviors between components with different viscosities are utilized to generate elastic curling and form a spring-like structure.

[0016] Preferably, in step (1), a functional composite powder is further added, and the functional composite powder is prepared by the following steps: preparing a 0.02 mol / L titanyl sulfate solution and a 25% ammonia solution, then adding 4-5 g diatomaceous earth powder, stirring and mixing evenly, and then dropping 98% concentrated sulfuric acid, keeping the pH value of the solution at about 1.5; heating the mixed solution to 60-70 degrees and stirring, cooling to room temperature, filtering, washing, drying, and then baking in a muffle furnace at 500°C to prepare diatomaceous earth composite powder. Functional composite powder can give fiber antibacterial, formaldehyde removal and other functionalities.

[0017] The application of biodegradable PET fiber can be used as home textile fiber to make home textile quilt cores, pillow cores, mattresses or sets and other products.

[0018] Beneficial effects:

[0019] (1) The present invention repeatedly screened and optimized the preparation process of degradable PET fiber. The degradable slices had a low viscosity, which resulted in great difficulty in spinning and poor fiber roll shape. The above problems were solved by increasing the melt viscosity, adjusting the spinning method, spinning temperature, wind speed, winding process, etc., and the degradable PET fiber was successfully produced, meeting the desired quality requirements, and greatly improving the spinnability of the fiber.

[0020] (2) The present invention prepares PET fibers that take into account both the physical and chemical properties of polyester fibers and the degradable properties of fiber-forming materials. DETAILED DESCRIPTION

[0021] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further described below.

[0022] Preparation method of degradable PET fiber: the degradable chips are melted by a screw extruder and conveyed to a filter, formed into filament bundles by a spinning box and a spinneret, and then the degradable PET fiber is obtained by subsequent winding, drawing, curling and heat setting. Specific embodiment 1

[0024] The preparation method of degradable PET fiber comprises the following steps:

[0025] Step (1), adding a tackifier: the epoxy tackifier and the degradable chips are mixed in a mass ratio of 0.5:99.5 and then melted through a screw extruder. The epoxy tackifier can increase the melt viscosity, thereby improving the spinnability. Preferably, the screw temperature is 288-308°C and the winding speed is 1000m / min, so as to prepare a three-dimensional hollow curly degradable PET fiber.

[0026] Step (2), adjusting the spinning temperature: the screw temperature during spinning should be 8°C lower than the normal temperature. Lowering the spinning temperature and shortening the melt residence time can solve the problem of low intrinsic viscosity of the biodegradable chips and increased spinning difficulty.

[0027] Step (3), screening filter element: the filter element of the filter is a 120μ filter element. The filter element of the melt filter cannot be too dense to reduce thermal degradation of the melt.

[0028] Step (4), increasing the wind speed of the side blowing: During the cooling and forming process, the temperature of the side blowing is controlled at 21° C., and the central wind speed is 8.5 m / s, which is 10% higher than the conventional wind speed, thereby improving the roll shape of the degradable PET fiber.

[0029] Step (5), control the drafting multiple: the hot drafting multiple is in the range of 2.6. If it is too small, the yarn will be stiff and the elasticity will be poor, and if it is too large, the yarn will be fuzzy. The drafting oil bath temperature is 67°C.

[0030] The properties of the degradable PET fiber obtained in Specific Example 1 are as follows:

[0031] Shrinkage rate 67%

[0032] Oil-water ratio: 8.5%

[0033] V1:102

[0034] V2: 25

[0035] Compression rebound E value: 82

[0036] Curl rate: 11%

[0037] Hollow rate: 18.6% Specific embodiment 2

[0039] The preparation method of degradable PET fiber comprises the following steps:

[0040] Step (1), adding a tackifier. The epoxy tackifier and the degradable slice are mixed in a mass ratio of 1.0:99.0, and then the functional composite powder and the mixed degradable slice are melt-mixed by a single screw extruder. The epoxy tackifier can increase the melt viscosity, thereby improving the spinnability. Alternatively, the mixture is first mixed and then melted by a screw extruder. Preferably, the screw temperature is 287-307°C and the winding speed is 1100m / min, so that a three-dimensional hollow curly degradable PET fiber is prepared. The functional composite powder is prepared by the following steps: a certain concentration of titanium oxysulfate solution and a 25% ammonia solution are prepared, and then an appropriate amount of diatomaceous earth powder is added, and concentrated sulfuric acid is added after stirring and mixing evenly; the mixed solution is heated and stirred, filtered after cooling, washed, dried, and then baked in a muffle furnace at 500°C to prepare diatomaceous earth composite powder. The functional composite powder can give the fiber functionality.

[0041] Step (2), adjusting the spinning temperature. The intrinsic viscosity of the biodegradable chips is relatively low, which increases the difficulty of spinning. The screw temperature during spinning should be 9°C lower than the normal temperature. In addition, the melt residence time should be shortened as much as possible.

[0042] Step (3), screening filter element. The filter element of the melt filter cannot be too dense, and a 100μ filter element is selected to reduce thermal degradation of the melt.

[0043] Step (4), increasing the wind speed of the side blowing air. During cooling and forming, the temperature of the side blowing air is controlled at 23°C, and the central wind speed is 9 m / s, which is 10% higher than the conventional wind speed, thereby improving the roll shape of the degradable PET fiber.

[0044] Step (5), control the drafting multiple. The hot drafting multiple is in the range of 2.8. If it is too small, the yarn will be stiff and the elasticity will be poor. If it is too large, the yarn will be fuzzy. The temperature of the drafting oil bath is 68°C.

[0045] The properties of the degradable PET fiber obtained in Specific Example 2 are as follows:

[0046] Shrinkage rate 71%

[0047] Oil-water ratio: 8.9%

[0048] V1: 110

[0049] V2: 28

[0050] Compression rebound E value: 84

[0051] Curl rate: 12.1%

[0052] Hollow rate: 19%

[0053] Formaldehyde removal rate: 90% Specific embodiment 3

[0055] The preparation method of degradable PET fiber comprises the following steps:

[0056] Step (1) adding a tackifier. The epoxy tackifier and the degradable PET slices are fully mixed in a mass ratio of 0.5:99.5. The mixed degradable PET slices and PLA slices are respectively passed through different screw extruders in a mass ratio of 50:50. Preferably, the mixed slices are melt-mixed by a screw extruder and extruded in parallel through a composite spinneret. Preferably, the PET screw temperature is 287-307°C, the winding speed is 1000m / min, and the screw temperature of PLA is 220-235°C. A three-dimensional hollow curled degradable PET / PLA composite fiber is prepared.

[0057] Step (2), adjusting the spinning temperature. The intrinsic viscosity of the biodegradable chips is relatively low, which increases the difficulty of spinning. The screw temperature during spinning should be 9°C lower than the normal temperature. In addition, the melt residence time should be shortened as much as possible.

[0058] Step (3), screening filter element: The filter element of the melt filter cannot be too dense, and a filter element of 80μ is selected to reduce thermal degradation of the melt.

[0059] Step (4), increasing the wind speed of the side blowing air. During cooling and forming, the temperature of the side blowing air is controlled at 23°C, and the central wind speed is 9 m / s, which is 10% higher than the conventional wind speed, thereby improving the roll shape of the degradable PET fiber.

[0060] Step (5), control the drafting multiple. The hot drafting multiple is in the range of 2.7. If it is too small, the yarn will be stiff and the elasticity will be poor. If it is too large, the yarn will be fuzzy. The temperature of the drafting oil bath is 66°C.

[0061] The properties of the degradable PET fiber obtained in Specific Example 3 are as follows:

[0062] Shrinkage rate 68%

[0063] Oil-water ratio: 8.3%

[0064] V1:106

[0065] V2: 28

[0066] Compression rebound E value: 89

[0067] Curl rate: 18%

[0068] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the present invention to be protected.

Claims

1. A method for preparing degradable PET fiber, characterized in that: The degradable chips are melted through a screw extruder and conveyed to a filter, formed into filament bundles through a spinning box and a spinneret, and then subjected to subsequent winding, drawing, curling and heat setting to obtain degradable PET fibers.

2. The method for preparing the degradable PET fiber according to claim 1, characterized in that: The steps include: Step (1), adding a tackifier: fully mixing the epoxy tackifier and the degradable chips in a mass ratio of 0.5-1.5:98.5-99.5, and then melting and mixing through a screw extruder; Step (2), adjusting the spinning temperature: the screw temperature is controlled at 286-310°C during spinning. Step (3), filter element screening: select 80-120μ filter element. Step (4), increasing the side blowing wind speed: during cooling and forming, the side blowing wind temperature is controlled at 21-23° C., and the center wind speed is 8.5-9 m / s. Step (5), controlling the drafting ratio: the hot drafting ratio is in the range of 2.5-3.0, and the drafting oil bath temperature is in the range of 66-70°C.

3. The method for preparing the degradable PET fiber according to claim 2, characterized in that: In step (1), the screw temperature is 286-310°C, and the winding speed is 1000-1100 m / min.

4. The method for preparing the degradable PET fiber according to claim 2, characterized in that: In step (1), the degradable slices include PLA slices and degradable PET slices, and the PLA slices and the degradable PET slices are melt-mixed in a mass ratio of 50:50 through different screw extruders and extruded in parallel through a composite spinneret.

5. The method for preparing the degradable PET fiber according to claim 4, characterized in that: The screw temperature of PLA is 220-235℃, and the screw temperature of PET is 288-308℃.

6. The method for preparing the degradable PET fiber according to claim 4, characterized in that: The difference between the viscosity of the degradable PET slice and the viscosity of the PLA slice is 0.1-0.

5.

7. The method for preparing the degradable PET fiber according to claim 4, characterized in that: Preferably, in step (1), a functional composite powder is also added, and the functional composite powder is prepared by the following steps: preparing a certain amount of titanium oxysulfate solution of 0.02 mol / L and a 25% ammonia solution, then adding 4-5 g of diatomaceous earth powder, stirring and mixing evenly, and then dropping 98% concentrated sulfuric acid, keeping the pH value of the solution at about 1.5; heating the mixed solution to 60-70 degrees and stirring, cooling to room temperature, filtering, washing, drying, and then placing in a muffle furnace and baking at 500°C to prepare diatomaceous earth composite powder.

8. Use of the degradable PET fiber prepared by the method for preparing the degradable PET fiber according to any one of claims 1 to 7, characterized in that: It can be used as home textile fiber to make home textile quilt cores, pillow cores, mattresses or sets.