Current Status And Development of Plastic Modification Technology

Current Status And Development of Plastic Modification Technology

Modified materials emerged in the 1990s, and their development over the past 30 years has endowed them with advantages such as replacing steel, copper, wood, other plastics, and heavier materials with lighter ones. They have been widely applied across various industries including home appliances, automotive, high-speed rail, subway, aerospace, ships, office equipment, communication devices, machinery, and construction.

Data from the National Bureau of Statistics shows that by 2020, the demand for modified plastics in China reached 22.5 million tons, with a modification rate increasing to 21.7%. Among this, the proportion of application in home appliances was as high as 34%, automotive applications accounted for 19%, and other fields made up 47%. By the end of 2022, the output of modified plastics in China was 28.84 million tons, with a total value exceeding 415.2 billion yuan, making China's modified plastics industry gradually become the world's largest market for demand and a source of growth momentum.

Modified plastics have become a strategic emerging industry and a research hotspot in the field of petrochemical polymer materials in China. Therefore, studying the principles of plastic modification, equipment and processes, raw materials, formulations, key preparation technology challenges, and applications is of great significance for promoting the development of the entire plastic industry.

I. Plastic Modification Technology and Characteristics

Plastic modification technology refers to the process of obtaining new materials with desired properties by employing physical modification methods such as filling, reinforcing, and blending, chemical modification methods like block copolymerization and radiation crosslinking, or other modification methods including foaming, stretching, and compounding during the processing of polymer resins into plastic products. This technology significantly enhances the properties of plastics, including flame retardancy, thermal conductivity, mechanical strength, wear resistance, and electromagnetic shielding. However, it may also reduce certain inherent characteristics of the original plastic, such as insulation performance, corrosion resistance, and gloss. Technicians can use appropriate formulations and measures to minimize these adverse changes in properties.

II. Key Aspects of Plastic Modification Molding Technology

Polymer modification involves the mixing and compounding of base resin and various modifying agents using initial mixing equipment, batch-type melting mixing equipment, continuous rotor (FCM) mixers, reciprocating screw compounding extruders, and other molding equipment.

In the modification and molding process, formulation design and preparation technology are particularly crucial. Formulation design includes the selection and principles of the base resin pellets and the form, amount, and combination of modifiers. Preparation technology involves determining a reasonable modification process, selecting the appropriate molding equipment, and drying the plastic pellets. Both aspects can significantly prevent crosslinking or degradation, thereby improving the performance and quality of the products. Additionally, non-destructive testing technology is applied, using physical methods to assess the internal and external structure of modified plastics without compromising the integrity and performance of the material. This ensures product quality, safety, reliability, and leads to process improvements and product lifespan extension.

1. Key Points of Plastic Modification Formulation

1.1 Selection of Base Resin:

The resin should be chosen for its proximity to the desired properties such as wear resistance and heat resistance. the selection of resin brands and types should be made accordingly. Resins with similar viscosities ensure consistent flow characteristics, which is essential for processing. The required flow properties for different production methods and modification needs may vary.

1.2 Selection of Additives:

The principles for selecting additives should aim for synergy, counteraction, processability, environmental friendliness, cost-effectiveness, and minimal or no negative impact.

The form of the additive greatly influences the modification. For instance, fiber-shaped additives provide excellent reinforcement, while spherical additives offer good toughness, flowability, and high gloss. The smaller the particle size of the additive, the better the mechanical properties, coloring power, and conductivity, although it may lead to a decrease in single dispersion. A comprehensive consideration of the additive's form is necessary to determine the amount of additive to be added and the method of surface treatment.

2. Key Points of Plastic Modification Process Technology

2.1 Drying Treatment

The moisture and volatile low molecular weight compounds contained in plastic pellets can lead to crosslinking or degradation during high-temperature molding, resulting in defects such as silver streaks and bubbles in the products, which affect product quality. It is necessary to preheat and dry the plastic. The temperature, time, and thickness of the material layer can affect the drying effect. In actual production, the choice between direct and indirect drying methods should be determined based on the hydrophilic properties, melting point, dew point, humidity, thermal conductivity, and production batch size of the plastic. The combination of these two methods is an effective way to dry the materials.

2.2 Screw Combination and Feeding Technology

In the molding equipment for modified plastics, the screw structure is the core component. The molding cycle consists of stages such as feeding, melting, mixing, and degassing. Different materials, formulations, properties, molding processes, and process stages require different screw structures and local structural combinations to meet the needs, which necessitates systematic research and engineering practice validation.

2.3 Filler Surface Treatment Technology

During the plastic modification process, various polar inorganic fillers are added. However, their compatibility with non-polar organic materials is poor. Modification methods such as intercalation of powders, mechanical force, and chemical encapsulation are used to improve compatibility, in order to produce high-performance products.

2.4 Color Difference and Dimensional Appearance Control Technology

The combination of scientific instruments like computers and the experience of operators is used for color matching of pigments, testing whiteness and black spots, and employing filtration techniques to remove impurities, resulting in a wide range of high-quality products with rich colors.

III. Plastic Modification and Non-destructive Testing Technology and Their Applications

Entering the 21st century, harmonious coexistence between humans and nature is a global issue that humanity must face together. With technological innovation and changes in development models, various industries are moving towards green, energy-saving, environmentally friendly, recyclable, and recyclable development. High-performance material modification technologies are emerging continuously.

1. Graphene Modification Technology

Graphene, extracted and prepared from graphite by Nobel Prize winners in Physics Andre Geim and Konstantin Novoselov, is a new two-dimensional carbon crystal material composed of a single layer of carbon atoms. It is the thinnest material ever discovered, with a thickness of about 0.335nm. Polymer plastics modified with graphene technology have superior properties, such as high heat resistance, corrosion resistance, high hardness, barrier properties, and high mechanical and electrical performance. Some scholars have conducted in-depth research on the processing methods, performance, and non-destructive testing of graphene-modified plastics.

Moreover, some scholars believe that there are many challenges to be addressed in graphene modification technology, such as the controllability of layer folding, stacking, aggregation, good compatibility, and high quality, low cost, and other issues.

Kamboj, Saurabh, and other scholars have systematically summarized the latest research results of graphene technology, including the preparation methods of graphene-based composite materials and their development and application in photocatalysts, supercapacitors, and lithium-ion batteries.

After graphene forms composites, the performance of nano-metal oxide materials is significantly enhanced, effectively degrading organic pollutants in wastewater and finding broader application in photocatalysis. Graphene is also considered an excellent material for supercapacitors, offering great potential for the development of high-performance electric vehicles. Lithium-ion batteries made with graphene composite materials as anode materials have low self-discharge rates, high energy density, and good cycle life.

Graphene modification technology has also sparked the interest of researchers in energy storage, chemical sensors, electronics, and healthcare applications.

2. Carbon Fiber Modification Technology

Carbon fiber, known as the "black gold" of the 21st century, possesses excellent properties such as high modulus of elasticity, specific strength, creep resistance, and fatigue resistance to corrosion. It serves as a reinforcing material for modified resin matrices. Thermoplastic reinforced materials are characterized by their recyclability, fast molding, impact resistance, and ease of repair, and they hold promising application prospects in transportation, shipping, aerospace, and medical equipment fields.

The strength, modulus, interfacial bonding performance, and comprehensive properties of carbon fiber vary depending on the type. The surface of carbon fiber exhibits inert and non-polar characteristics, and the focus of research both domestically and internationally is to enhance its adhesion to the resin matrix through modification techniques, thereby improving performance and expanding its application areas.

Scholars like Zhan Yikai and Li Gang have summarized the surface modification techniques of carbon fiber, which are divided into chemical and physical methods.

Chemical methods include surface oxidation and grafting, which offer the advantages of fast reaction rates and significant effects. They can increase surface roughness and microscopic characteristics, thereby improving interfacial bonding strength. However, the chemical modification process can easily damage the internal structure of the fiber, leading to a decrease in strength, which is a challenge that needs to be addressed.

Physical methods include coating and plasma treatment, which have the advantages of being flexible, easy to control, and pollution-free. However, they require high standards for production equipment and do not fundamentally enhance surface properties. They cannot be applied in situations that demand high surface performance, thus limiting the development of this technolog.

3. Non-destructive Testing Technology for Modified Plastics

The complexity and instability of manufacturing processes, as well as the impact of environmental changes during service, can lead to various types of damage such as delamination, porosity, fiber breakage, and wrinkles, which significantly affect the mechanical properties of the materials. Ultrasonic non-destructive testing technology, with its advantages of being portable, easy to operate, and having high detection efficiency, is widely used in the fields of product design, finished product damage detection, quality evaluation, and life assessment.

Scholars like Yang Hongjuan have systematically summarized ultrasonic non-destructive testing technologies based on bulk waves or guided waves, such as C-scan, phased array, laser ultrasound, air coupling, and fiber optic ultrasound, as well as damage diagnostic imaging algorithms to achieve damage morphology imaging. The appropriate non-destructive testing method is selected according to the density, thickness, elastic constants, and transducer parameters of the sample to be tested. Research prospects include the construction of array acoustic field models for carbon fiber-modified materials, damage imaging algorithms, intelligent monitoring imaging systems, quantitative assessment standards for damage, diagnostic evaluation, and life prediction.

IV. Recommendations for the Development of Modified Plastics and Non-destructive Testing Technology

(1) Improve the industrial system, standard system, and intellectual property rights system for modified plastics.

(2) The theoretical research and practical application research of plastic modification need to promote and improve each other. Currently, modified materials mainly focus on theoretical research and general product fields, while the application research involved in the production practice process, such as talent training, equipment manufacturing, formula design, and process development, still needs to be strengthened.

To further improve the conversion rate of scientific research results into intellectual property and guide actual production, it is necessary to strengthen the research and development and production processing of high-performance modifiers, new materials, and products. This will promote the development of China's plastic modification industry towards safety, green, environmental protection, lightweight functionality, and ecological intelligence.

(3) In terms of non-destructive testing technology and imaging algorithms, it is necessary to further construct array acoustic field models and damage imaging algorithms for carbon fiber-modified materials. Establish standards for quantitative assessment of damage, diagnostic evaluation, and life prediction, and develop intelligent monitoring imaging systems to make non-destructive testing equipment more portable, easier to operate, and more accurate and efficient.

V. Conclusion

The vigorous development of modified plastics provides strong technical support for the diverse development of industries such as home appliances, automobiles, aerospace, high-speed rail, ships, office equipment, power tools, and mechanical construction. However, these industries also set higher technical requirements for the formulation design and research and development, modification molding processes, and equipment of modified plastics. Therefore, the study of plastic modification molding technology is of positive significance for promoting the development and transformation and upgrading of the entire plastic industry.

With the rapid development of modified plastics and the growing technological needs of various industries, YINSU Flame Retardant Company is committed to advancing the field of flame retardancy in modified plastics. We recognize the importance of working with the industry to promote safe, green, environmentally friendly, lightweight functionality and eco-smart.

YINSU is committed to investing in research and development to create innovative flame retardant solutions that meet the stringent standards of modern applications. Our focus is on developing halogen-free, environmentally friendly flame retardants that enhance the performance of modified plastics without compromising safety and environmental sustainability.

By providing high performance flame retardant solutions, YINSU will make a significant contribution to the plastics modification industry and support the transition to more sustainable and efficient materials. Our commitment to innovation and excellence will drive us to develop products that not only meet but exceed the expectations of an evolving market.