Method for irradiation crosslinking of sensitized polyester

Abstract

The invention relates to the field of high polymer materials, and discloses a sensitized polyester irradiation cross-linking method which comprises the following steps: drying polyester chips through drying equipment, putting the dried polyester chips into a double-screw extruder, adding polyethylene glycol, blending, extruding, cooling and granulating to prepare a radiation-sensitive agent-containing polyester functional master batch; taking another polyester chip, and carrying out pre-crystallization process and drying processing treatment on the polyester chip to obtain a treated object; the preparation method comprises the following steps: quantitatively conveying a radiation-sensitive agent-containing polyester functional master batch and a treated substance through an injection machine, and carrying out mixing granulation to prepare a radiation-sensitive additive-containing mixed slice; the mixed slices are subjected to forming treatment through forming equipment, and a formed product is prepared. The preparation method comprises the following steps: drying polyester chips, preparing sensitized master batches from the dried polyester chips and polyethylene glycol, pre-crystallizing and drying another polyester chip, quantitatively mixing and granulating the polyester chips and the sensitized master batches, performing tabletting, injection molding or spinning molding, and performing irradiation crosslinking in an inert gas atmosphere through electron beams or gamma rays to promote the crosslinking of polyester molecules.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer materials, and specifically relates to a method for irradiating and crosslinking sensitized polyester. Background Art

[0002] Due to its excellent comprehensive properties, such as high strength, good chemical stability, easy processability, etc., polyester materials are widely used in many fields, such as textiles, packaging, electronics and electrical appliances, aerospace, etc. With the continuous improvement of the material performance requirements in various industries, modifying polyester materials to further improve their performance has become a research hotspot. As an efficient and environmentally friendly material modification method, the irradiation crosslinking technology can form a crosslinked structure between polyester molecular chains through radiation without adding a large amount of chemical crosslinking agents, thereby improving the mechanical properties, thermal properties, chemical resistance, etc. of polyester, and has broad application prospects in the field of polyester material modification.

[0003] Currently, in traditional sensitized polyester irradiation crosslinking, the common method is to reduce the dose required for crosslinking through an irradiation sensitizer (radiation sensitizer), thereby reducing the cracking of the material during irradiation and the resulting performance deterioration. Commonly used radiation sensitizers include TAIC, trimethylolpropane triacrylate (TMPTA), etc., but these radiation sensitizers have relatively small molecular weights and are prone to volatilization at higher processing temperatures, which is not conducive to the modification processing of materials, especially not suitable for polyester. Summary of the Invention

[0004] Aiming at the deficiencies of the prior art, the present invention provides a method for irradiating and crosslinking sensitized polyester, which solves the problem that in traditional sensitized polyester irradiation crosslinking, the radiation sensitizer has a relatively small molecular weight and is prone to volatilization at higher processing temperatures, which is not conducive to the modification processing of materials, especially not suitable for polyester.

[0005] To achieve the above objectives, the present invention is realized through the following technical solutions: A method for irradiating and crosslinking sensitized polyester includes the following steps: S1. Dry the polyester chips through a drying device, then put them into a twin-screw extruder, add polyethylene glycol, and through blending, extrusion, cooling, and pelletizing, make a polyester functional masterbatch containing a radiation sensitizer; S2. Take another polyester chip, perform a pre-crystallization process and drying processing on it to obtain a processed product; S3. Quantitatively transport the polyester functional masterbatch containing a radiation sensitizer and the processed product through an injection machine for mixing and pelletizing to obtain a mixed chip containing a radiation sensitization aid; S4. Perform a forming process on the mixed chip through a forming device to obtain a formed product; S5. Irradiate the formed product with an electron beam or γ-ray to generate crosslinking inside it.

[0006] By adopting the above technical solutions, polyethylene glycol is used as a radiation sensitizer to replace traditional small-molecule radiation sensitizers, and combined with the process control of each step, the stable introduction of the radiation sensitizer in the high-temperature processing system of polyester is realized, the crosslinking reaction of polyester is promoted, the crosslinking effect and comprehensive performance of the polyester material are improved, and the problem in the traditional radiation crosslinking of sensitized polyester is solved. That is, the molecular weight of the radiation sensitizer is small, and it is easy to volatilize at a relatively high processing temperature, which is not conducive to the modification processing of the material, especially not suitable for polyester. The application range of polyester materials in the high-performance field is expanded.

[0007] Preferably, the drying equipment includes a hot air circulation drying oven, a vacuum drying oven, and a rotary flash dryer. The polyester chips are one or more of PET chips, PBT chips, and PTT chips. The screw speed of the twin-screw extruder is 200 - 500 r / min, and the length-diameter ratio is 20 - 40.

[0008] Preferably, the drying is carried out at a temperature of 105 - 135 °C until the moisture content reaches 300 ppm. The molecular weight of the polyethylene glycol is 8000 - 60000, and the addition ratio is 20% - 30% of the total weight of the polyester chips and polyethylene glycol.

[0009] Preferably, the pre-crystallization process is to heat another polyester chip to a temperature range above the glass transition temperature and below the melting point, so that the polyester molecular chains are arranged in an orderly manner to form tiny crystalline regions.

[0010] Preferably, the drying and processing treatment is to dry another polyester chip after the pre-crystallization process through the drying equipment until its moisture content reaches 300 ppm.

[0011] Preferably, one or more of an antioxidant, a light stabilizer, and a dispersant are added during the mixing and granulation, and the content of the radiation sensitization auxiliary agent in the mixed chips is 0.5 - 10 wt%.

[0012] Preferably, the molding equipment includes a tablet press, an injection molding machine, and a spinning machine. The molding treatment is carried out at 260 - 290 °C for tablet pressing, injection molding, or spinning.

[0013] Preferably, the irradiation dose of the electron beam or γ-ray is 5 - 200 kGy, and the irradiation is carried out in an inert gas atmosphere. The inert gas includes nitrogen and argon.

[0014] The present invention provides a method for radiation crosslinking of sensitized polyester. It has the following beneficial effects: 1. After drying the polyester chips, a sensitizing masterbatch is prepared by mixing them with polyethylene glycol. Another portion of polyester chips is pre-crystallized and dried, and then the two are quantitatively mixed and granulated. After that, they are formed by pressing, injection molding, or spinning, and irradiated and crosslinked by electron beam or γ-ray in an inert gas atmosphere to promote the crosslinking of polyester molecules, thereby constructing a stable crosslinked structure inside the polyester and comprehensively improving the material properties, enabling effective resistance to high-temperature deformation and combustion dripping.

[0015] 2. By standardizing each step such as drying, pre-crystallization, mixing and granulation, forming, and irradiation, controlling the moisture content in the drying step, setting the temperature range in the pre-crystallization process, controlling parameters such as temperature and screw speed during mixing and granulation and forming, and specifying the dose and atmosphere requirements during irradiation, the material properties fluctuate little during the entire production process, and the production stability is high, which is conducive to large-scale industrial production.

[0016] 3. The present invention is applicable to various common polyester chip raw materials such as PET, PBT, and PTT. Whether it is a single polyester chip or a combination of multiple polyester chips, good sensitizing irradiation crosslinking effects can be achieved by adjusting the corresponding parameters, providing rich raw material selection possibilities for different application scenarios and broadening the application scope of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a process flow chart of a method for sensitizing polyester irradiation crosslinking proposed by the present invention; Figure 2 is a comparative schematic diagram of the sensitizing polyester irradiation crosslinking effect of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0018] The technical solutions of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0019] Please refer to the attached Figure 1 - attached Figure 2 , an embodiment of the present invention provides a method for sensitizing polyester irradiation crosslinking, including the following steps: S1. Dry the polyester chips through a drying device, then put them into a twin-screw extruder, add polyethylene glycol, and through blending, extrusion, cooling, and pelletizing, produce a polyester functional masterbatch containing a radiation sensitizer. The drying device includes a hot air circulation drying oven, a vacuum drying oven, and a rotary flash dryer. The polyester chips are one or more of PET chips, PBT chips, and PTT chips. The screw speed of the twin-screw extruder is 200 - 500 r / min, and the length-diameter ratio is 20 - 40. The drying is carried out at a temperature of 105 - 135 °C until the moisture content reaches 300 ppm. The molecular weight of the polyethylene glycol is 8000 - 60000, and the addition ratio is 20% - 30% of the total weight of the polyester chips and polyethylene glycol.

[0020] Specifically, put the selected polyester chips (such as PET chips) into the hot air circulation drying oven, set the temperature to 120 °C, and adjust the drying time according to the initial moisture content of the chips and the performance of the drying oven, generally 4 - 6 hours, until the moisture content reaches 300 ppm. The reason for choosing 120 °C for drying is that at this temperature, it can ensure the effective evaporation of moisture without causing adverse changes such as thermal degradation of the polyester chips due to excessive temperature. Then, weigh polyethylene glycol with a molecular weight of 20000 according to 25% of the total weight of the polyester chips and polyethylene glycol. Add the dried polyester chips and polyethylene glycol into the twin-screw extruder, set the screw speed to 350 r / min, the length-diameter ratio to 30, and the extrusion temperature to 270 °C. A screw speed of 350 r / min can ensure sufficient shear and mixing effects of the material in the screw, a length-diameter ratio of 30 can ensure sufficient mixing and plasticization of the material in the extruder, and an extrusion temperature of 270 °C can make the polyester chips and polyethylene glycol melt well and mix evenly. After sufficient blending and extrusion, cool through water cooling, and then use a pelletizer to pelletize to obtain a polyester functional masterbatch containing a radiation sensitizer. The prepared masterbatch can be effectively dispersed in subsequent processing, providing a uniform sensitizing source for subsequent cross-linking reactions, which is beneficial to improving the consistency of the final product performance.

[0021] S2. Take another polyester chip, carry out a pre-crystallization process and drying and processing treatment on it to obtain a treated product. The pre-crystallization process is to heat another polyester chip to a temperature range above the glass transition temperature and below the melting point, so that the polyester molecular chains are arranged orderly to form tiny crystalline regions. The drying and processing treatment is to dry another polyester chip after the pre-crystallization process through a drying device to make its moisture content reach 300 ppm.

[0022] Specifically, if PBT chips are selected for processing, they are first placed in a heating device for pre-crystallization. By referring to relevant materials, it is known that the glass transition temperature of PBT is about 22°C and the melting point is about 225°C. The temperature of the heating device is set at 150°C and maintained for 30 minutes to make the polyester molecular chains arrange orderly to form tiny crystalline regions. 150°C is between the glass transition temperature and the melting point, which can promote the molecular chains to have sufficient activity to arrange orderly at this temperature, and 30 minutes can ensure the full formation of the crystalline regions without excessive crystallization affecting the subsequent processing performance. After pre-crystallization, the chips are transferred to a vacuum drying oven, the temperature is set at 130°C, and dried for 2 - 3 hours until the moisture content reaches 300 ppm to obtain the processed product. The vacuum drying oven can remove moisture more efficiently at a lower temperature, avoiding the damage of high temperature to the pre-crystallized structure. The temperature of 130°C can maintain the stability of the pre-crystallized structure while ensuring the drying efficiency, making the performance of the processed chips more stable and reducing the quality fluctuation in subsequent processing.

[0023] S3. Quantitatively convey the radiation-sensitive agent-containing polyester functional masterbatch and the processed product through an injection machine for mixing and granulation to obtain a mixed chip containing a radiation-sensitive auxiliary agent; when mixing and granulating, add one or more of an antioxidant, a light stabilizer, and a dispersant, and the content of the radiation-sensitive auxiliary agent in the mixed chip is 0.5 - 10 wt%.

[0024] Specifically, taking the preparation of a mixed chip containing an antioxidant and a dispersant as an example, the previously prepared radiation-sensitive agent-containing polyester functional masterbatch and the processed product are quantitatively conveyed to a mixing device through an injection machine. At the same time, 0.2 wt% of antioxidant 1010 and 0.5 wt% of dispersant zinc stearate are added, and after mixing evenly, granulation is carried out. Antioxidant 1010 can effectively inhibit the oxidative degradation of polyester during processing and subsequent use. The addition amount of 0.2 wt% can provide sufficient antioxidant protection without affecting other properties of the material due to excessive addition. Dispersant zinc stearate can promote the uniform mixing of the masterbatch and the processed product. The addition amount of 0.5 wt% can make each component fully disperse during the mixing process and avoid agglomeration. During the granulation process, control the temperature of the granulator at 230 - 250°C and the screw speed at 200 - 300 r / min to obtain a mixed chip with a radiation-sensitive auxiliary agent content of 3 wt%. The granulation temperature of 230 - 250°C can ensure good fluidity and plasticization effect of the material, and the screw speed of 200 - 300 r / min can make the material fully mixed and extruded into shape in the granulator. The radiation-sensitive auxiliary agent content of 3 wt% can ensure the crosslinking effect without affecting the mechanical properties of the material due to excessive content. The obtained mixed chip has good stability and uniformity, providing quality assurance for subsequent forming processing.

[0025] S4. The mixed chips are processed into a formed product by a forming device; the forming device includes a tablet press, an injection molding machine, and a spinning machine, and the forming process is carried out by tableting, injection molding or spinning at 260-290 °C.

[0026] Specifically, if the spinning forming method is adopted, the mixed chips are added into the spinning machine barrel, the barrel temperature is set at 280 °C, the spinning component temperature is set at 285 °C, and the spinning speed is 3000 m / min. The chips are extruded through a spinneret to form filaments. The barrel temperature of 280 °C and the spinning component temperature of 285 °C can fully melt the mixed chips and extrude them at a suitable viscosity, ensuring the forming quality of the filaments. The spinning speed of 3000 m / min can form a good orientation structure during the stretching process of the filaments while ensuring production efficiency. The filaments are cooled and solidified through a cooling air window, the cooling air temperature is controlled at 20-25 °C, and the wind speed is 0.4-0.6 m / s. Then, stretching is carried out, and the stretching ratio is 3-4 times. Finally, the formed polyester fiber is obtained. The cooling air temperature of 20-25 °C can quickly cool and solidify the filaments, and the wind speed of 0.4-0.6 m / s can ensure cooling uniformity. The stretching ratio of 3-4 times can effectively improve the strength and orientation degree of the fiber, making the fiber have better mechanical properties. The obtained polyester fiber has high strength and a uniform structure, meeting the usage requirements of subsequent products.

[0027] S5. The formed product is irradiated with an electron beam or γ-ray to generate crosslinking inside. The irradiation dose of the electron beam or γ-ray is 5-200 kGy, and the irradiation is carried out in an inert gas atmosphere. The inert gas includes nitrogen and argon.

[0028] Specifically, the formed polyester fiber is placed in an irradiation device, electron beam irradiation is selected, the irradiation dose is set at 80 kGy, and the irradiation time is adjusted according to the electron beam power and product dose requirements. The irradiation dose of 80 kGy can effectively promote the crosslinking reaction while avoiding fiber degradation or performance deterioration caused by too high a dose. During the irradiation process, nitrogen is filled into the irradiation chamber as a protective gas, and the nitrogen flow rate is controlled at 5-10 L / min, so that the polyester fiber completes irradiation crosslinking in an inert gas atmosphere. Nitrogen as a protective gas can effectively isolate oxygen and prevent the fiber from undergoing an oxidation reaction during irradiation. The flow rate of 5-10 L / min can fully replace the air in the irradiation chamber, ensuring the protection effect. After irradiation crosslinking, the crosslinking degree of the polyester fiber is improved, and its tensile strength, thermal stability, anti-dripping performance, etc. are significantly enhanced, better meeting the performance requirements in practical applications.

[0029] When preparing the radiation - sensitive agent - containing polyester functional masterbatch, polyethylene glycol is fully blended with polyester chips and evenly dispersed in the polyester system, enhancing its stability during high - temperature processing; another polyester chip is pre - crystallized and dried to provide good conditions for subsequent mixing and cross - linking reactions; in the mixing and granulation process, the proportion of each component is precisely controlled to ensure the uniform distribution of the radiation - sensitive auxiliary agent; through specific forming equipment and processes, the material is given the required shape; finally, cross - linking is achieved by irradiating with electron beams or γ - rays.

[0030] It realizes the stable introduction of the radiation - sensitive agent in the high - temperature processing environment of polyester, promotes the cross - linking reaction of polyester, and significantly improves the performance of polyester materials. After treatment, the cross - linking degree of polyester is significantly increased, the gel content is increased, and key performance indicators such as tensile strength and thermal stability are significantly improved. It solves the problem that in traditional radiation cross - linking of sensitized polyester, the molecular weight of the radiation - sensitive agent is small and it is easy to volatilize at higher processing temperatures, which is not conducive to the modification processing of materials, especially not suitable for polyester. This enables polyester materials to better meet the high - performance requirements in high - end fields and expands the application range of polyester materials.

[0031] The following is a further introduction in combination with specific embodiments: Example 1 Preparation of sensitized masterbatch: PET chips are dried at 120 °C until the moisture content reaches 300 ppm, and polyethylene glycol is mixed in at a ratio of 25% by weight as the radiation - sensitive agent, and then mixed and extruded at a temperature of about 270 °C in a twin - screw extruder to obtain a polyester functional masterbatch containing polyethylene glycol; Melt spinning: PET chips are pre - crystallized at 120 °C and dried at 140 °C until the moisture content reaches 300 ppm; the functional masterbatch is dried at 140 °C until the moisture content reaches 300 ppm. The dried functional masterbatch is quantitatively added to PET chips by an injection machine using volume measurement, so that the content of polyethylene glycol in PET is 3% by weight, and conventional polyester spinning equipment and processes are used to spin 150 d / 24 f polyester full - drawn yarns; Radiation cross - linking: The polyester full - drawn yarns containing polyethylene glycol are irradiated with an electron beam, the atmosphere is nitrogen, and the radiation dose is 60 kGy.

[0032] Example 2 Preparation of sensitized masterbatch: PBT chips are dried at 120 °C until the moisture content reaches 300 ppm, and polyethylene glycol is mixed in at a ratio of 25% by weight as the radiation - sensitive agent, and then mixed and extruded at a temperature of about 270 °C in a twin - screw extruder to obtain a polyester functional masterbatch containing polyethylene glycol; Melt spinning: The PBT chips are pre-crystallized at 120 °C and dried at 140 °C to make the moisture content reach 300 ppm; the functional masterbatch is dried at 140 °C to make the moisture content reach 300 ppm. The dried functional masterbatch is quantitatively added to the PBT chips by an injection machine using volume measurement, so that the content of polyethylene glycol in PBT is 2% by weight. Spinning 150 d / 24 f PBT fully drawn yarn; Radiation crosslinking: The PBT fully drawn yarn containing polyethylene glycol is irradiated by an electron beam, the atmosphere is nitrogen, and the radiation dose is 40 kGy.

[0033] Example 3 Preparation of sensitizing masterbatch: The PTT chips are dried at 120 °C to make the moisture content reach 300 ppm, and polyethylene glycol is mixed in at a ratio of 25% by weight as a radiation sensitizer, and then mixed and extruded in a twin-screw extruder at a temperature of about 270 °C to obtain a polyester functional masterbatch containing polyethylene glycol; Melt spinning: The PTT chips are pre-crystallized at 120 °C and dried at 140 °C to make the moisture content reach 300 ppm; the functional masterbatch is dried at 140 °C to make the moisture content reach 300 ppm. The dried functional masterbatch is quantitatively added to the PTT chips by an injection machine using volume measurement, so that the content of polyethylene glycol in PTT is 1% by weight. Spinning 150 d / 24 f PTT fully drawn yarn; Radiation crosslinking: The PTT fully drawn yarn containing polyethylene glycol is irradiated by an electron beam, the atmosphere is nitrogen, and the radiation dose is 20 kGy.

[0034] Comparative Example 1 Preparation of functional masterbatch: The PET chips are dried at 120 °C to make the moisture content reach 300 ppm, and triallyl isocyanurate is mixed in at a ratio of 25% by weight as a radiation sensitizer, and then mixed and extruded in a twin-screw extruder at a temperature of about 270 °C to obtain a polyester functional masterbatch containing triallyl isocyanurate; Melt spinning: The PET chips are pre-crystallized at 120 °C and dried at 140 °C to make the moisture content reach 300 ppm; the functional masterbatch is dried at 140 °C to make the moisture content reach 300 ppm. The dried functional masterbatch is quantitatively added to the PET chips by an injection machine using volume measurement, so that the content of triallyl isocyanurate in PET is 3% by weight, and 150 d / 24 f polyester fully drawn yarn is spun using conventional polyester spinning equipment and process.

[0035] Radiation crosslinking: The polyester fully drawn yarn containing triallyl isocyanurate is irradiated by an electron beam, the atmosphere is nitrogen, and the radiation dose is 60 kGy.

[0036] Comparative Example 2 Preparation of functional masterbatch: PBT chips are dried at a temperature of 120 °C until the moisture content reaches 300 ppm, and triallyl isocyanurate is mixed in at a ratio of 25% by weight. The mixture is melt-extruded in a twin-screw extruder at a temperature of 270 °C to obtain a polyester functional masterbatch containing triallyl isocyanurate; Melt spinning: PBT chips are dried at a temperature of 140 °C until the moisture content reaches 300 ppm; the functional masterbatch is dried at a temperature of 140 °C until the moisture content reaches 300 ppm. The dried functional masterbatch is quantitatively added to the PBT chips by an injection machine using volume measurement, so that the content of triallyl isocyanurate in the PBT chips is 2% by weight, and PBT filaments of 150 d / 24 f are spun.

[0037] Radiation crosslinking: The PBT fully drawn filaments containing triallyl isocyanurate are irradiated with an electron beam in a nitrogen atmosphere with a radiation dose of 40 kGy.

[0038] Comparative Example 3 Preparation of functional masterbatch: PTT chips are dried at 120 °C until the moisture content reaches 300 ppm, and diallyl phthalate is mixed in at a ratio of 25% by weight as a radiation sensitizer. The mixture is melt-extruded in a twin-screw extruder at a temperature of 250 °C to obtain a functional masterbatch containing diallyl phthalate; Melt spinning: PTT chips are dried at a temperature of 140 °C until the moisture content reaches 300 ppm; the functional masterbatch is dried at 140 °C until the moisture content reaches 300 ppm. The dried functional masterbatch is quantitatively added to the PTT chips by an injection machine using volume measurement, so that the content of diallyl phthalate in the PTT chips is 1% by weight, and PTT fully drawn filaments of 150 d / 24 f are spun.

[0039] Radiation crosslinking: The PTT fully drawn filaments containing diallyl phthalate are irradiated with an electron beam in a nitrogen atmosphere with a radiation dose of 20 kGy.

[0040] Example 4 The polyesters with different radiation sensitizers in Examples 1-3 and Comparative Examples 1-3 are irradiated, and then the gel content is tested to characterize the crosslinking effect. Accurately weigh 0.2 g of the sample, extract it with a mixed solvent of 98% phenol and 99% tetrachloroethane with a mass ratio of 1:1 at room temperature for 72 h, add fresh solvent every day, and continuously oscillate in an ultrasonic instrument. Then, it is thoroughly washed in absolute ethanol, the gel is filtered and separated, and the gel is placed in a vacuum oven and dried to a constant weight of W g. The gel fraction (g) is calculated according to the following formula.

[0041] , where 、 are the masses (g) of the polymer sample before and after extraction, respectively. The experiment is repeated three times and the average value is calculated.

[0042] The evaluation results are shown in the following table: As can be seen from the above table, for the polyester samples using polyethylene glycol as the radiation sensitizer in Examples 1-3, the gel contents after irradiation are 5.8%, 7.2%, and 6.5% respectively. This indicates that polyethylene glycol can effectively promote the cross-linking reaction of polyester during irradiation, forming a cross-linked structure inside the polyester. In Comparative Examples 1-3, for the polyester samples using different radiation sensitizers (such as triallyl isocyanurate, diallyl phthalate, etc.), the gel contents are all 0, indicating that these radiation sensitizers fail to cause cross-linking of the polyester under the same irradiation conditions. Thus, it can be seen that polyethylene glycol has unique advantages and good cross-linking promotion effects as a radiation sensitizer in the process of sensitizing the radiation cross-linking of polyester, achieving the purpose of effectively improving the cross-linking degree of polyester and improving the properties of polyester materials (such as thermal stability, mechanical properties, etc.) through a specific radiation sensitizer.

[0043] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for sensitized polyester radiation cross-linking, characterized in that: The following steps are involved: S1, drying the polyester chips by a drying device, and then putting them into a twin-screw extruder, adding polyethylene glycol, and preparing a functional polyester masterbatch containing a radiation sensitizer by blending, extruding, cooling, and granulating; S2, taking another polyester chip, and subjecting it to a pre-crystallization process and a drying process to obtain a processed product; S3, quantitatively conveying the polyester functional masterbatch containing the radiation sensitizer and the treated material through an injection machine, mixing and granulating, and preparing mixed slices containing the radiation sensitizer; S4, forming the mixed slices by a forming device to obtain a formed object; S5. Irradiate the molded product with electron beams or gamma rays to generate crosslinks inside the molded product.

2. The method for radiation crosslinking of sensitized polyester according to claim 1, characterized in that: The drying equipment includes a hot air circulation drying oven, a vacuum drying oven, and a rotary flash drying machine. The polyester chips are one or more of PET chips, PBT chips, and PTT chips. The screw speed of the twin-screw extruder is 200-500r / min, and the aspect ratio is 20-40.

3. The method for sensitized polyester radiation cross-linking according to claim 1, characterized in that: The drying is carried out at a temperature of 105-135° C. until the moisture content reaches 300 ppm. The molecular weight of the polyethylene glycol is 8000-60000, and the addition ratio is 20%-30% of the total weight of the polyester chips and the polyethylene glycol.

4. The method for radiation crosslinking of sensitized polyester according to claim 1, characterized in that: The pre-crystallization process is to heat another polyester chip to a temperature range above the glass transition temperature and below the melting point, so that the polyester molecular chains are arranged in an orderly manner to form tiny crystallized regions.

5. The method for radiation cross-linking of sensitized polyester according to claim 1, characterized in that: The drying process is to dry another polyester chip after the pre-crystallization process through a drying device so that its moisture content reaches 300ppm.

6. The method for radiation cross-linking of sensitized polyester according to claim 1, characterized in that: During the mixing and granulation, one or more of an antioxidant, a light stabilizer and a dispersant are added, and the content of the radiation-sensitive additive in the mixed slices is 0.5-10wt%.

7. The method for radiation crosslinking of sensitized polyester according to claim 1, characterized in that: The molding equipment includes a tablet press, an injection molding machine, and a spinning machine. The molding process is tablet pressing, injection molding, or spinning at 260-290°C.

8. The method for radiation cross-linking of sensitized polyester according to claim 1, characterized in that: The irradiation dose of the electron beam or gamma ray is 5-200 kGy, and the irradiation is performed under an inert gas atmosphere, wherein the inert gas includes nitrogen and argon.

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