, and may transition to a loose equilibrium, the price will fall. However, if the production of high-pressure hose is not ideal this year, the tension balance will be in short supply and the price may rise again. Therefore, this year's high-pressure hose price trend is largely due to the gathering of many suppliers, buyers and manufacturers here. The steel wire braided high-pressure hose structure consists of a liquid-resistant synthetic rubber inner rubber layer, a steel wire reinforced layer and a weather-resistant synthetic rubber outer rubber layer. Uses: mainly used in aircraft fuel, mine hydraulic support, oil field exploitation and construction machinery.
For the China market. Characteristics and uses of polystyrene (ps) 1. Features 1. The characteristics of gpps GPPS are colorless, odorless, tasteless, shiny and transparent.
Polystyrene (ps) is polymerized from styrene monomer (sm) and can be polymerized by various synthetic methods. At present, bulk polymerization and suspension polymerization are important methods in industry. The English name of polystyrene is polystyrene, abbreviated as ps (hereinafter referred to as ps). Ps is a thermoplastic amorphous resin, which can be divided into general polystyrene (gpps), impact polystyrene (hips) and expanded polystyrene (eps).
Ps polystyrene includes: gpps transparent polystyrene, commonly known as rubber. The raw materials are fully transparent particles, and the general products of gpps are: sheets, daily necessities, electrical housings, decorations, stationery, bottles and so on. Gpps is brittle, high gloss, hard rubber, and will drop when there is sound. The raw materials are completely transparent particles. Specific gravity 1. 05- 1。 07 g /mm3, immersed in water, burning yellow flame accompanied by thick black smoke, the burning mouth is smooth, with styrene smell, and very brittle filaments can be pulled out.
As early as 1930, polystyrene was first industrialized by German company i.g.farben, and commercial production began in the United States from 1937. At present, the output of polystyrene ranks fourth among the thermoplastic resins in the world, second only to polyethylene, polyvinyl chloride and polypropylene. At present, there are 30~40 kinds of styrene series resins in the world, with nearly 100 brands and more than 400 brands. Output 1 1 10,000 tons/year, and ps accounts for about 65%.
Polystyle, ps for short (ps for short). Ps is a thermoplastic amorphous resin, which can be divided into general polystyrene (gpps), impact polystyrene (hips) and expanded polystyrene (eps). As early as 1930, polystyrene was first industrialized by German company i.g.farben, and commercial production began in the United States from 1937. At present, the output of polystyrene ranks fourth among the thermoplastic resins in the world, second only to polyethylene, polyvinyl chloride and polypropylene. At present, styrene series trees in the world
Because of its simple production process and rich raw materials, polystyrene is currently produced in most countries and regions around the world.
China's polystyrene is mainly produced by subsidiaries such as Sinopec, PetroChina, CNOOC, etc., which introduce equipment and technology from foreign companies, and joint ventures or wholly-owned enterprises of important foreign manufacturers in China, which is of great significance to the China market.
Characteristics and uses of polystyrene (ps)
I. Characteristics
1.gpps function
Gpps are colorless, odorless, tasteless and glossy transparent particles. Light weight, low price, low water absorption, good coloring, good dimensional stability, good electrical properties, transparent products and easy processing.
Gpps is soluble in aromatic hydrocarbons, chlorinated hydrocarbons, aliphatic ketones and esters, but it can only swell in acetone. Resistant to some mineral oils, organic acids, alkalis, salts, lower alcohols and their aqueous solutions. The water absorption rate is low, and its mechanical properties and dimensional stability can still be maintained in humid environment. Excellent electrical performance, high volume resistance and surface resistance, not affected by temperature and humidity changes, nor by corona discharge. The radiation resistance is also very good.
The important disadvantages of gpps are fragile and easy to crack, low impact strength, poor heat resistance, unable to withstand boiling water, and can only be applied at low temperature and low load. Poor resistance to sunlight, flammable. When it burns, it turns black and has an extraordinary smell.
Use of ps
General polystyrene can be used in daily necessities, electrical appliances, instrument casings, toys, lamps, household appliances, stationery, cosmetic containers and rooms.
Internal and external decorations, fruit bowls, optical parts (such as prisms and lenses), lenses, window mirrors and molded products, car lamps, telecom accessories, electric frequency capacitor films, high-frequency insulating materials, containers such as televisions, waveguides, chemical containers, etc. Suspended polymeric resin can be made into foamed plastics with different densities, which can be used as heat insulation, sound insulation, shockproof, floating and packaging materials, cork substitutes, pre-foamed bodies can be used as water filtration media and lightweight concrete, and low foamed plastics can be made into synthetic wood for furniture.
High impact polystyrene (hips) can be injected or extruded into various products, which are suitable for household appliance casings, electrical appliances, instrument accessories, refrigerator linings, plates, TV sets, tape recorders, telephone casings, stationery, toys, packaging containers, daily necessities, furniture, tableware, trays, tableware, structural foam products and so on.
Forming technology of polystyrene
Polystyrene has good fluidity, good processability, easy coloring and good dimensional stability. It can be processed into various products by injection molding, extrusion molding, blow molding, foaming, thermoforming, bonding, coating, welding, machining and printing. It is especially suitable for injection molding, and the material can be directly applied in injection molding without drying. However, in order to improve the product quality, the pre-drying of 1~2h can be carried out in a blast oven at 55℃~70℃. The specific process conditions are as follows: barrel temperature is about 200℃, mold temperature is 60~80℃, injection temperature is 170 ~ 220℃, and injection pressure ratio is 1.6~4.0. Molded products should be treated at a constant temperature of 70℃ for 2 ~ 4 hours in an infrared lamp or a blast oven.