Waste polyester fiber/waste polyethylene composite material and preparation method thereof
Technical Field
The invention belongs to the technical field of material preparation, and particularly relates to a preparation method of a waste polyester fiber/waste polyethylene composite material.
Background
The plastic has light weight, low cost and excellent performance, and is developed and widely applied in the field of materials once being invented. With the rapid development of social economy, the development of the packaging industry is changing day by day, and the demand for packaging materials is greatly increased. While in many packaging materials, the plastic is used in an amount of about 25%. Worldwide annual production of plastics has been reported to be as high as 2 billion or more tons, with the amount of packaging accounting for about 30% of that. The invention and the use of the plastic greatly facilitate our lives, but a great deal of plastic waste and the difficult degradability thereof undoubtedly bring great pressure to our living environment. The data show that only 2019 years of China can produce 6300 million tons of waste plastics.
Polyethylene (PE) is currently one of the most popular plastics in the world with the greatest yield due to its multiple advantages of low cost, excellent properties, and easy processing. The development of modern production and the rise of the packaging industry have increased the demand for PE materials, and the large amount of waste generated therewith has increased. Therefore, how to realize recycling of waste plastics and increase the value of renewable resources is the focus and focus of current research. The method of re-melting the recycled waste plastics and preparing the recycled waste plastics into recycled particles by means of extrusion and the like is an important waste plastics recycling method. However, the plastic is aged in the processes of primary use, secondary melting granulation and secondary molding, so that the strength of the regenerated material is far inferior to that of a new material, and the application range is greatly limited. Therefore, the strength of the reclaimed material is generally improved by adding a certain proportion of virgin material or by means of modification and reinforcement.
The polyester fiber has a series of excellent properties, such as high breaking strength and elastic modulus, moderate rebound resilience, good heat resistance and light resistance, a melting point of about 255 ℃ and a glass transition temperature of about 70 ℃, is one of synthetic fiber varieties with the fastest development speed and the highest yield, is widely applied to textile industry and fillings of bedding and clothing, but has lower recycling rate of waste polyester fiber. The polyester fibers filled in the waste throw pillows are used as a reinforcing material, the modified waste polyethylene and the maleic anhydride grafted linear low density polyethylene (LLDPE-g-MAH) are used as a compatibilizer, the interfacial bonding force between the polyester fibers and the polyethylene is improved, the strength of the polyethylene reclaimed material is finally improved, and the modification and use cost of the polyethylene reclaimed material is reduced.
Disclosure of Invention
The invention aims to provide a preparation method of a waste polyester fiber/waste polyethylene composite material, which realizes the recycling of waste polyester fibers and waste polyethylene and improves the performance and the utilization value of recycled plastics.
In order to achieve the purpose, the technical scheme adopted by the invention is as follows:
a preparation method of a waste polyester fiber/waste polyethylene composite material is implemented according to the following steps:
step 1: weighing the following ingredients in percentage by mass: waste polyester fiber, regenerated polyethylene and LLDPE-g-MAH;
step 2: setting the sectional temperature of the extruder to be one to eight heating zones respectively, setting the temperature of a machine head, and preheating the extruder for at least 1 hour after setting parameters;
and step 3: blending and extruding, namely stirring and mixing the waste polyester fiber, the regenerated polyethylene and LLDPE-g-MAH which are weighed according to a certain proportion uniformly, cleaning a machine once by using pure waste polyethylene before extruding to clean residual substances in the machine, then adjusting the rotating speed of a feeding machine and the rotating speed of a screw, putting the mixture of the waste polyester fiber, the regenerated polyethylene and the LLDPE-g-MAH into an extruder, and stably extruding a sample strip at a constant speed;
and 4, step 4: water-cooling the extruded sample strips, and then cutting the sample strips into granules by using a granulator to obtain waste polyester fiber/polyethylene composite material particles;
and 5: and laying the waste polyester fiber/polyethylene composite material particles cut into granules horizontally into an air drying box for drying, and finally obtaining the dried waste polyester fiber/polyethylene composite material particles.
Further, the following components are weighed in the step 1 according to the mass percentage: 5-25% of waste polyester fiber, 70-93% of regenerated polyethylene and 2-10% of LLDPE-g-MAH, wherein the sum of the mass percentages of the components is 100%.
Further, the temperature of each zone in the step 2 is as follows: the first heating zone to the eighth heating zone are respectively 165 ℃, 170 ℃, 174-.
Further, in the step 3, the rotating speed of the feeder is 5-15rpm, and the rotating speed of the screw is 20-30 rpm.
Further, the temperature of the forced air drying oven in the step 5 is 70 ℃, and the drying time is 1 hour.
A waste polyester fiber/waste polyethylene composite material prepared by the method as described herein.
The invention has the beneficial effects that: the invention utilizes the recycled waste polyester fiber and polyethylene reclaimed material as raw materials, adopts a double-screw extrusion method to prepare the waste polyester fiber/waste polyethylene composite material, opens up a new way for recycling the waste polyester fiber, improves the strength of the polyethylene reclaimed product so as to improve the application value of the polyethylene reclaimed material, provides a new method for changing waste polymers into valuables, and relieves the problem of environmental pollution caused by the waste polymers.
Drawings
FIG. 1 is a scanning electron microscope image of a cross-section of a waste polyester fiber/polyethylene composite prepared in example 1 of the present invention.
FIG. 2 is a graph of mechanical property data of the recycled polyethylene material and the composite materials obtained in examples 1, 2 and 3 of the present invention.
Detailed Description
The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.
A preparation method of a waste polyester fiber/waste polyethylene composite material is implemented according to the following steps:
step 1: weighing 1000g of required ingredients, wherein the proportion of each component is as follows: 5-25% of waste polyester fiber, 70-93% of regenerated polyethylene and 2-10% of LLDPE-g-MAH, wherein the sum of the mass percentages of the components is 100%;
step 2: setting the temperature of each section of the extruder as 165 ℃, 170 ℃, 174-;
and step 3: blending and extruding, namely stirring and mixing the waste polyester fiber, the regenerated polyethylene and the LLDPE-g-MAH which are weighed according to a certain proportion uniformly, cleaning a machine once by using pure waste polyethylene before extruding to clean residual substances in the machine, then adjusting the rotating speed of a feeding machine to be 5-15rpm and the rotating speed of a screw to be 20-30rpm, putting the mixture of the waste polyester fiber, the regenerated polyethylene and the LLDPE-g-MAH into an extruder, and stably extruding a sample strip at a constant speed;
and 4, step 4: water-cooling the extruded sample strips, and then cutting the sample strips into granules by using a granulator to obtain waste polyester fiber/polyethylene composite material particles;
and 5: and laying the waste polyester fiber/polyethylene composite material particles cut into granules in an air drying oven at 70 ℃, and drying for 1 hour to finally obtain the dried waste polyester fiber/polyethylene composite material particles.
The components and the processing mode act as follows:
the total amount of the ingredients used in this experiment to prepare the waste polyester fiber/waste polyethylene composite was 1000 g. Waste polyethylene regenerated particles are selected as a matrix material, waste polyester fibers are selected as a reinforcing material, polyester fiber fillers in waste throw pillows are taken, the length of the fibers is cut short by scissors, the final length is about 3-10mm, and LLDPE-g-MAH is used as a compatibilizer to improve the interface bonding force of the polyethylene matrix and the polyester fibers.
Example 1
Respectively weighing 50g of polyester fiber, 930g of polyethylene and 20g of LLDPE-g-MAH, and uniformly mixing. The temperature of each zone of the extruder is set as follows: the first to eighth zones were preheated for 1 hour at 165 ℃, 170 ℃, 174 ℃, 174 ℃, 176 ℃, 176 ℃, 178 ℃, 178 ℃ and 185 ℃ respectively. The feeding speed is adjusted to 15rpm, the screw rotating speed is 25rpm, the machine is cleaned once by 500g of pure waste polyethylene reclaimed material, and residual substances in the machine are cleaned. Then adjusting the feeding speed to 15rpm and the screw speed to 20rpm, extruding and blending the mixture, soaking a sample strip in water for cooling, and then cutting the mixture into particles by using a granulator. And finally, drying the particles in an air drying oven at 70 ℃ for 1 hour to obtain the waste polyester fiber/waste polyethylene composite material particles.
Fig. 1 is a scanning electron microscope image of a cross section of the waste polyester fiber/polyethylene composite material prepared in example 1, and it can be seen from the structure of the cross section that the waste polyester fiber is uniformly distributed in the polyethylene reclaimed material without obvious agglomeration, and the waste polyester fiber and the polyethylene reclaimed material are tightly combined without obvious gaps and bubbles in the material matrix.
Example 2
100g of polyester fiber, 850g of polyethylene and 50g of LLDPE-g-MAH are respectively weighed and mixed uniformly. The temperature of each zone of the extruder is set as follows: the first to eighth zones are respectively 165 ℃, 170 ℃, 176 ℃, 176 ℃, 178 ℃, 178 ℃, 180 ℃, 180 ℃ and 190 ℃ of the head temperature, and are preheated for 1 hour. The feeding speed is adjusted to 15rpm, the screw rotating speed is 25rpm, the machine is cleaned once by 500g of pure waste polyethylene reclaimed material, and residual substances in the machine are cleaned. Then adjusting the feeding speed to 10rpm and the screw speed to 25rpm, extruding and blending the mixture, soaking a sample strip in water for cooling, and then cutting the mixture into particles by using a granulator. And finally, drying the particles in an air drying oven at 70 ℃ for 1 hour to obtain the waste polyester fiber/waste polyethylene composite material particles.
Example 3
Respectively weighing 200g of polyester fiber, 700g of polyethylene and 100g of LLDPE-g-MAH, and uniformly mixing. The temperature of each zone of the extruder is set as follows: the first to eighth zones are respectively 165 ℃, 170 ℃, 178 ℃, 178 ℃, 180 ℃, 180 ℃, 182 ℃, 182 ℃ and 195 ℃ of the head temperature, and are preheated for 1 hour. The feeding speed is adjusted to 15rpm, the screw rotating speed is 25rpm, the machine is cleaned once by 500g of pure waste polyethylene reclaimed material, and residual substances in the machine are cleaned. Then adjusting the feeding speed to 5rpm and the screw speed to 30rpm, extruding and blending the mixture, soaking a sample strip in water for cooling, and then cutting the mixture into particles by using a granulator. And finally, drying the particles in an air drying oven at 70 ℃ for 1 hour to obtain the waste polyester fiber/waste polyethylene composite material particles.
The technology of the invention adopts a double-screw extrusion method, and the waste polyester fiber/waste polyethylene composite material is prepared by taking the most common recyclable waste plastic polyethylene as a raw material and the polyester fiber in the waste throw pillow as a reinforcing material. As can be seen from the data in FIG. 2, the tensile strength and flexural modulus of the waste polyester fiber/waste polyethylene composite material prepared by adding the waste polyester fiber are both obviously improved, and a new way is opened for improving the performance of the recycled plastic.
While specific embodiments of the invention have been described above, it will be appreciated by those skilled in the art that this is by way of example only, and that the scope of the invention is defined by the appended claims. Various changes and modifications to these embodiments may be made by those skilled in the art without departing from the spirit and scope of the invention, and these changes and modifications are within the scope of the invention.