Popular science of ppe plastic bags

Popular science of ppe plastic bags

  PPE is a thermoplastic engineering plastic with excellent comprehensive properties, which is outstanding in electrical insulation and water resistance, and good dimensional stability.

1. Dielectric performance ranks first in engineering plastics: PPE resin has no strong polar groups in its molecular structure, and its electrical properties are stable, which can maintain good electrical properties in a wide range of temperature and frequency. Its dielectric constant and dielectric loss tangent are the smallest among engineering plastics, and are hardly affected by temperature, humidity and frequency. Its volume resistivity is the highest among engineering plastics. The excellent electrical properties of PPE make it widely used in the production of electrical products, especially high-voltage components, such as line output transformers (FBT) of color TVs.

2. Good mechanical and thermal properties: The PPE sub-chain contains a large number of aromatic ring structures, and the molecular chain has strong sensitivity.The resin has high mechanical strength, excellent creep resistance, and little effect of temperature changes. PPE has high heat resistance, the glass transition temperature is as high as 211℃, and the melting point is 268℃.

 3. Excellent water resistance: PPE is an amorphous resin. In the usual temperature range, there is little molecular motion, no large polar groups in the main chain, no polarization of the dipole moment, and very good water resistance. The species with the lowest water absorption among plastics. There is still little decrease in its physical properties after prolonged immersion in hot water.

4. Good flame retardancy and self-extinguishing: the oxygen index of PPE is 29, which is a self-extinguishing material, while the oxygen index of high-impact polystyrene is 17, which is a flammable material. The combination of the two is moderate Flammability: When manufacturing flame retardant grade PPE, it is not necessary to add halogen flame retardants. Adding phosphorus-containing flame retardants can reach the UL94 standard and reduce environmental pollution.

5. Low shrinkage, good dimensional stability; non-toxic, low density.

6. Media resistance and light resistance: PPE is basically not corroded by acids, alkalis and detergents. Under stress, mineral oil, ketones, and ester solvents will cause stress cracking; organic solvents such as aliphatic hydrocarbons will produce stress cracking. , halogenated aliphatic hydrocarbons and aromatic hydrocarbons will melt and dissolve. The weakness of PPE is that it has poor light resistance, discoloration and yellowing when used in sunlight or fluorescent lamps for a long time. The reason is that ultraviolet rays can split the chain of aromatic ethers. And how to improve the light resistance of PPE has become a problem.

Molding

PPE can be processed into various products by injection molding, extrusion and other processes:

1. Injection molding: Both plunger or screw injection molding machines can process PPE. Generally, a screw type injection molding machine is used, and the length-diameter ratio is required to be greater than 15:1, and the compression ratio is 1.7 to 4.0 (generally 2.5 to 3.5).

2. Extrusion: PPE can be processed into tubes, sheets, rods, blocks, etc. on an extruder. Extruder with vented type and large aspect ratio.

Author Rowling

E-mail: rowling@bowenpack.com

Phone Number:+86-15920713687 (whatsapp/wechat)