The purpose of plastic blending modification

1. Improve some physical and mechanical properties of plastics and expand the scope of application

(1) Improve the comprehensive performance of plastics. Utilize the properties of each polymer component, learn from each other's strengths and complement each other's shortcomings, eliminate the shortcomings in the performance of each single polymer component, maintain their respective advantages, and obtain polymer materials with excellent comprehensive properties. For example, the blending of polypropylene and polyethylene not only maintains the advantages of high tensile strength and compressive strength of polypropylene and high impact strength of polyethylene, but also overcomes the shortcomings of poor impact strength and stress cracking resistance of polypropylene.

(2) Improve plastic toughness (improve impact resistance). A small amount of one polymer can be used as a modifier for another polymer to obtain significant modification effects. Rubber toughened plastic is the most typical example. For example, PVC/rubber, PP/rubber and other blend systems have good impact resistance; another example is PA/PE blend system, which greatly reduces the hygroscopicity of PA and improves the impact strength at low temperature.

(3) Improve the heat resistance of plastics. The heat distortion temperature of most plastics is not high, and for some parts that work at a certain temperature, general-purpose plastics are incompetent. By blending with plastics with good heat resistance, its heat resistance can be improved.

(4) Reduce the water absorption rate and improve the dimensional stability of the product. If the water absorption of PA is large, it is easy to cause the dimensional change of the product. The PA/PE blend system greatly reduces the water absorption of PA.

(5) Improve stress cracking performance. Such as modified PC with PE, modified PC with ABS, etc.

(6) Improve other physical and mechanical properties. Such as wear resistance, air tightness, weather resistance, chemical resistance (solvent resistance), damping, adhesion, biocompatibility, etc.

2. Improve melt fluidity and improve molding performance

For example, the field of aerospace science needs high-temperature-resistant plastics, and many high-temperature-resistant plastics are difficult to form and process due to their high melting point and poor melt fluidity. Blending technology can solve this problem. For example, polyimide (PI) is insoluble and insoluble, and it can be easily injected by blending it with polyphenylene sulfide (PPS) with good fluidity.

Since both plastics have good heat resistance, their blends are still excellent high temperature materials. Mixing PS into polyphenylene ether (PPO) and mixing ABS into PC can improve fluidity and processability. For rigid PVC, it is often necessary to incorporate CPE, ACR and other resins to improve its processability. In addition, the crystallization behavior of the crystalline polymer can also be controlled by blending.

3. Endow plastic with some special properties to prepare new plastic alloy materials

Preparation of flame-retardant plastic alloys, which can be blended with halogen-containing and other flame-retardant polymers. For example, adding PS, ABS, polyoxymethylene, etc. to PVC, chlorinated PE, polyphenylene ether, and polyphenylene sulfide can improve its flame resistance. Plastics have low electrical conductivity, for some materials that require conductive and anti-static, they can be blended with conductive polymers to make plastic materials with anti-static, conductive and electromagnetic shielding functions to meet the requirements of electronics, home appliances, communications, military and other industries.

In order to prepare decorative plastics with pearl luster, different polymers with different optical properties can be blended. For example, adding polymethyl methacrylate to PC can get pearl luster products. Using the lubricity of silicone resin, it can be blended with many polymers to obtain polymer materials with good self-lubrication.

Two resins with different tensile strengths and poor miscibility are blended and foamed, which can be made into multi-layer and porous materials with beautiful natural wood grain, which can be used as a substitute for wood.

4. Reduce the cost of materials and improve economic benefits

For some engineering plastics with excellent performance but expensive, it can be blended with low-cost general-purpose plastics. Without affecting the use conditions, it not only reduces the cost of materials, but also improves the molding processability. For example, adding ABS and SAN to PC and PSF can improve performance and reduce material cost.

5. Recycling waste polymer materials to reduce environmental pollution

Blending technology can also be used for the recycling of waste plastics, saving resources and reducing environmental pollution. In a word, the comprehensive properties of plastics can be improved by blending modification. In the case of relatively low investment, increase the variety of plastics, expand the use of plastics, reduce the cost of plastics, realize the high performance, functionalization, specialization and serialization of plastics, and promote the development of the plastics industry and the polymer material industry. At the same time, it has also promoted the development of high-tech industries such as automobiles, electronics, electrical appliances, home appliances, communications, military, and aerospace.

Nanjing Haisi Extrusion supply plastic blending modification machine, any interest please feel free to contact us!