What's the difference between pp and pe plastic pipes? Who can tell me?

ABS plastic?

English name: acrylic butadiene style?

Specific gravity: 1.05g/cm3, suitable for making general mechanical parts, wear-resistant parts, transmission parts and telecommunication parts.

Has the following properties:?

1, good comprehensive performance, high impact strength, good chemical stability and electrical properties.

2. It has good weldability with 372 plexiglass, can be made into two-color plastic parts, and the surface can be chrome-plated and painted.

3, high impact resistance, high heat resistance, flame retardant, reinforced and transparent. ?

4. the fluidity is a little worse than HIPS, better than PMMA and PC, and the flexibility is good. ?

PE plastic (polyethylene)?

English name: polyethylene?

Specific gravity: 0.94-0.96g/cm3?

Molding shrinkage: 1.5-3.6%?

Molding temperature: 140-220℃?

Drying conditions:-?

Material properties?

Excellent corrosion resistance and electrical insulation (especially high frequency insulation), which can be modified by chlorination and irradiation and reinforced by glass fiber. Low pressure polyethylene has high melting point, high rigidity, hardness and strength, low water absorption, good electrical properties and radiation resistance; High pressure polyethylene has good flexibility, elongation, impact strength and permeability; Ultra-high molecular weight polyethylene has high impact strength, fatigue resistance and wear resistance.

Low pressure polyethylene is suitable for making corrosion-resistant parts and insulating parts; High pressure polyethylene is suitable for making films, etc. Ultra-high molecular weight polyethylene is suitable for making shock absorption, wear resistance and transmission parts.

Molding performance?

Crystalline materials have low hygroscopicity, do not need to be fully dried, and have good fluidity. Liquidity is sensitive to pressure, so high pressure should be used for molding, and the material temperature should be uniform, the filling speed should be fast, and the pressure should be fully maintained. The sprue should not be used to prevent uneven shrinkage and increase internal stress. Pay attention to the selection of gate position to prevent shrinkage and deformation.

2. The shrinkage amplitude and shrinkage value are large, the directionality is obvious, and it is easy to deform and warp. The cooling speed should be slow, and the mold is equipped with a cold cavity and a cooling system.

3. The heating time should not be too long, otherwise it will decompose and burn.

4. When the soft plastic parts have shallow side grooves, they can be forcibly demoulded.

5. The melt may crack, so it is not suitable to contact with organic solvents to prevent cracking.

PP plastic (polypropylene)?

English name: polypropylene?

Specific gravity: 0.9-0.9 1g/cm3?

Molding shrinkage: 1.0-2.5%?

Molding temperature: 160-220℃?

Drying conditions:-?

Material properties?

Low density, strength, rigidity, hardness and heat resistance are better than those of low-pressure polyethylene, and it can be used around 100 degrees. Good electrical performance, high-frequency insulation, not affected by humidity, but brittle at low temperature, not mildew-proof, easy to age.

Suitable for making general mechanical parts, corrosion-resistant parts and insulating parts?

Molding performance?

Crystalline substance, with low hygroscopicity, is easy to melt, break and decompose after long-term contact with hot metal.

2. The fluidity is good, but the shrinkage range and shrinkage value are large, which is prone to shrinkage cavity, dent and deformation.

3. The cooling speed is fast. The cooling of gating system and cooling system should be slow, and the molding temperature should be controlled. The directionality is obvious at low temperature, especially at low temperature and high pressure. When the mold temperature is lower than 50 degrees, the plastic parts are not smooth, and it is easy to produce poor welding and traces, and it is easy to warp and deform above 90 degrees?

4. The plastic wall thickness should be uniform, avoiding lack of glue and sharp corners and preventing stress concentration.

Pvc？

The molecular weight and distribution of PVC were determined by general calibration method, using polystyrene standard, THF as mobile phase (note that your column should be used for THF) and differential refractive index detector. Most literatures give the K values and α values of various polymers at 25℃, but the K values and α values of polystyrene and PVC at 28℃ have not been found in reliable literatures at present. If it is not necessary to determine the molecular weight of PVC at 28℃, it can be determined at 25℃. At this time, k and a of PS and PVC are as follows: PS: K = 0.0 16, A = 0.706 pcv: K = 0.0 163, A = 0.766.

Definition and characteristics?

PVC roofing tile (UPVC lightweight roofing tile) is a new type of roofing waterproof material. PVC tile is made of rigid polyvinyl chloride (UPVC) as the main material, with heat stabilizer, lubricant, filler, sunscreen, ultraviolet absorber, foaming agent and so on. After three-layer mixing, plasticization and extrusion, and then three-layer foaming.

What's the difference between polyethylene, PVC, polystyrene and polypropylene?

When uncolored, it is milky white and translucent wax-like; Touching the product by hand feels greasy, soft and tough; Slightly scalable. Generally, low density polyethylene is soft and transparent; High density polyethylene is very hard. ?

Common products: handbags, water pipes, oil drums, beverage bottles (calcium milk bottles), daily necessities, etc. ?

Polypropylene PP?

When uncolored, it is white, translucent and waxy; Lighter than polyethylene. Transparency is also better than polyethylene, and rigidity is also greater than polyethylene. ?

Common products: pots, barrels, furniture, films, woven bags, bottle caps, car bumpers, etc. ?

Polystyrene PS

Transparent when colorless. When the product falls to the ground or knocks, it has a metallic crisp sound, good luster and transparency, similar to glass, fragile and easy to break, and can be used to mark the surface of the product with nails. Modified polystyrene is opaque. ?

Common products: stationery, cups, food containers, household appliance shells, electrical accessories, etc?

PVC？

Natural color is yellowish, translucent and shiny. Transparency is better than polyethylene and polystyrene, but worse than polystyrene. With the different dosage of additives, it can be divided into soft PVC and hard PVC. Soft-packed products are soft and tough and sticky to the touch. The hardness of hard products is higher than that of low density polyethylene, but lower than that of polypropylene, and whitening will occur at the bending point. ?

Common products: plates, pipes, soles, toys, doors and windows, wire sheaths, stationery, etc?

Polyethylene terephthalate PET?

Good transparency, better strength and toughness than polystyrene and PVC, and not easy to break. ?

Common products: regular bottle products such as cola and mineral water bottles?

Polyethylene waste?

Polyethylene is the most abundant and widely used thermoplastic in plastics. It is a partially crystalline material polymerized from ethylene and can be processed by general thermoplastic molding methods. Polyethylene can be divided into three categories: high density polyethylene, low density polyethylene and linear low density polyethylene. ?

The density of high density polyethylene is generally higher than 0.94g/, while the density of low density polyethylene and linear low density polyethylene is between 0.9 1 ~ 0.94 g/cm. There are two main sources of waste polyethylene film:?

Waste, defective products, etc. Made in film production. These wastes are clean and clear in variety, and can be directly sent to the extruder for granulation after crushing and compression, and the recovery process is simple. ?

2. Waste films from chemical industry, electrical industry, food and consumer goods industry. These waste films have been polluted, some have been colored and printed with trademarks, and some still contain impurities such as sand, sawdust or shredded paper. ?

Polyethylene is widely used because of its low price, easy availability and wide application, but the most used is packaging products, which is estimated to be above 60%. High density polyethylene is mainly used for packaging films, bottles and hollow containers; The main uses of low density polyethylene are packaging film and agricultural film; Linear low density polyethylene is mainly used in films, film plastic parts, pipelines and wires and cables. ?

PVC waste?

Polyvinyl chloride used to be the most used plastic in history, but now it is replaced by polyethylene and PET in some fields, but it is still widely used, and its consumption is second only to polyethylene and polypropylene. There are many forms of PVC products, which can be divided into three categories: hard PVC, soft PVC and PVC paste. Rigid PVC is mainly used for extruded products such as pipes, door and window profiles and sheets, as well as injection-molded parts and bottle products such as pipe joints and electrical parts by extrusion blow molding, accounting for more than 65% of PVC consumption. Soft PVC is mainly used in calendered sheets, automobile interior accessories, handbags, films, labels, wires and cables, medical supplies and so on. PVC paste accounts for about 10% of PVC products, and the main products are plastic-lined products. ?

Polymethyl methacrylate waste?

Polymethyl methacrylate (PMMA) is commonly known as plexiglass. PMMA has unique properties that other plastics do not have: excellent transparency (close to glass); Toughness, chemical resistance and weather resistance are all good. Therefore, it is widely used in automobiles, medical equipment, indoor swimming pools and other places. With the development of automobile and other related industries, the amount of PMMA is increasing. There are three main types of PMMA products: sheets made by casting or extrusion; Specific products that already contain additives (such as modifiers and pigments); Paints and coatings. ?

Polystyrene waste polystyrene is a homopolymer of styrene, which is a kind of thermoplastic general plastic, and its output is second only to polyethylene, polypropylene and polyvinyl chloride. Polystyrene has a wide range of uses. It can be roughly divided into the following four aspects:

General purpose polystyrene: products are widely used in household appliances, computers, medical care and other daily necessities and transparent products. ?

High impact polystyrene: the impact strength and elongation at break are greatly improved, and the products are widely used in electrical accessories, household appliance shells, food containers and so on.