PPS Plastic(Polysulfide)
English name:Phenylene sulfide
Specific gravity:1.36g/cm3
Molding Shrinkage:0.7%
Molding temperature:300-330℃.
PPS is a sulfur-containing aromatic polymers, linear PPS crosslinked above 350 ℃ into thermosetting plastics, branched chain structure PPS for thermoplastics, PPS is the United States Phillip's company in 1971, the first to achieve industrial production, the expiration of the patent, the Japanese companies also began to develop and produce. After the expiration of the patent, the Japanese companies also began to research and development and production. Japanese enterprises are more typical of Japan's Toray, Japan's production has been greater than the United States at this stage of production. Some other manufacturers are also mainly concentrated in the United States and Japan, Western European countries are now not producing PPS. 2000, the production of PPS can reach 50,000t / a. PPS demand for Japan accounted for 33% of the large, North America accounted for 32% of the Western Europe accounted for 19% of the Asia-Pacific accounted for 16%.
First, the material properties
1, Electrical insulation (especially high-frequency insulation) is excellent, white, hard and brittle, falling to the ground with a metallic ringing sound, light transmittance is second only to plexiglass, coloring resistance, water resistance, good chemical stability. Excellent flame retardant, non-combustible plastic.
2, General strength, rigidity is very good, but brittle, easy to produce stress cracking, intolerance. Gasoline and other organic solvents. Long-term use of temperature up to 260 degrees, in 400 degrees of air or nitrogen to maintain stability. Through the addition of glass fiber or other reinforcing materials modified, the impact strength can be greatly improved, heat resistance and other mechanical properties have also been improved, the density increased to 1.6-1.9, molding shrinkage is smaller to 0.15-0.25% suitable for making heat-resistant parts. Insulation parts and chemical instruments. Optical instruments and other parts.
Second, molding performance
1. Amorphous material, moisture absorption is small, but should be dried after molding.
2, Mobility between ABS and PC, fast solidification, small shrinkage, easy to decompose, choose a higher injection pressure and injection speed. Mold temperature of 100-150 degrees. Mainstream taper should be large, the runner should be short. Scope of application generally can be applied to the manufacture of PPS pipe, PPS sheet and other materials, mostly used in construction, home.
PPS characteristics and applications
I. Characteristics
(1) General properties: PPS is a white appearance, high crystallinity, hard and brittle polymer, pure PPS relative density of 1.3, but after modification will increase.PPS has a very small water absorption, generally only 0.03% or so.PPS has a good flame retardant, its oxygen index of up to 44% or more; compared to other plastics, it is a high flame retardant material in plastics (pure PVC oxygen index of 47%), PSF is 30%, PSF is 30%, and PPS is a high flame retardant material in plastics. , PSF is 30%, PA66 is 29%, MPPO is 28%, PC is 25%).
(2) Mechanical properties: the mechanical properties of pure PPS is not high, especially the impact strength is relatively low. To glass fiber reinforced will substantially improve the impact strength, from 27J/m to 76J/m, an increase of 3 times; tensile strength from 6Mpa to 137Mpa, an increase of 1 times. the rigidity of PPS is very high, rare in engineering plastics. Pure PPS bending modulus up to 3.8Gpa, inorganic filler modification can reach 12.6Gpa, an increase of 5 times more. And the rigidity of the famous PPO is only 2.55Gpa, PC is only 2.1Gpa. PPS under load creep resistance, high hardness; high wear resistance, the amount of abrasion of its 1,000 rpm is only 0.04g, filled with F4 and molybdenum disulfide will further improve; PPS also has a certain degree of self-lubricating properties. mechanical properties of PPS temperature sensitivity can be small.
(3) Thermal properties: PPS has excellent thermal properties, short-term resistance of 260 ℃, and can be used for a long time at 200 ~ 240 ℃; its heat resistance is comparable to PI, second only to F4 plastic, which is not common in thermosetting plastics.
(4) Electrical properties: the electrical properties of PPS is very outstanding, compared with other engineering plastics, its dielectric constant and dielectric loss angle tangent value is relatively low, and in a larger frequency, temperature and temperature range of change is not large; PPS arc resistance is good, comparable to thermoset plastics. pps is commonly used in electrical
Insulation Materials, its dosage can be accounted for about 30%.
(5) Environmental performance: one of the big features of PPS is good chemical resistance, its chemical stability is second only to F4; PPS is stable to most acids, esters, ketones, aldehydes, phenols and aliphatic hydrocarbons, aromatic hydrocarbons, chlorinated hydrocarbons, etc., and is not resistant to chlorinated and oxidizing acids, oxidizing agents, concentrated, concentrated nitric acid, aqua regia, and sodium hypochlorite, etc. PPS is good for radiation resistance.
Second, the scope of application
(1) Automotive industry: PPS used in the automotive industry accounted for about 45%, mainly used for automotive functional parts; such as instead of metal production of exhaust cylinder circulating valves and pump impellers, pneumatic signal mediator.
(2) Electronic and electrical appliances: PPS is used in the electronic and electrical appliances industry, accounting for 30% of the total. It is suitable for high-temperature electrical components with ambient temperatures higher than 200℃; it can be used to manufacture generators and engines with shabu-shabu, electric shabu brackets, starter coils, shielding and blades, etc.; it can be used for high-voltage housings and sockets, terminal posts and terminal boards on televisions; it is also used in the electronics industry for the manufacture of transformers, choke coils and relays, integrated circuit carriers and housings. and shells, integrated circuit carriers; the use of high-frequency performance, the manufacture of H-class winding frame and trimmer capacitors.
(3) Machinery industry: used for shells, structural components, wear parts and sealing materials, specifically the pump body, valves, bearings, bearing brackets, piston rings and gears. Edit PPS processing methods
I. Processing characteristics
Resin manufacturers provide PPS for a relatively low quality (4000 ~ 5000), high crystallinity (75%) of the white powder, this pure PPS can not be directly plasticized molding, can only be used for spraying. Used for plasticizing molding of PPS, must be crosslinking modification treatment, so that the viscosity of the melt rises. General crosslinking after the melt index of 10 ~ 20 appropriate; glass fiber reinforced PPS melt index can be larger, but not greater than 200.
PPS cross-linking method has thermal cross-linking and chemical cross-linking of two kinds, the current hot cross-linking-based. Thermal cross-linking of the cross-linking temperature of 150 ~ 350 ℃, below 150 ℃ does not cross-linking, higher than 350 ℃ occurs a high degree of cross-linking, but lead to processing difficulties. Chemical crosslinking need to add crosslinking promoter, specific varieties of zinc oxide, lead oxide, magnesium oxide, cobalt oxide, etc., as well as phenolic compounds, hexamethoxymethyltricyanoamide,, alkali metal or alkaline earth metal hypochlorite. PPS although crosslinking, but the fluidity of the decline is not much; therefore, the waste can be reused three times; PPS itself has a mold release, can not have to join the mold release agent; PPS after heat treatment can improve the degree of crystallinity and the heat distortion temperature, post-treatment conditions are: temperature 204 ℃, time 30min.
II. Processing methods
(1) Injection molding: general-purpose injection molding machine can be used, glass fiber reinforced PPS melt index of 50 is appropriate. Injection molding process conditions are: barrel temperature, pure PPS 280 ~ 330 ℃, 40% GFPPS 300 -350 ℃; nozzle temperature, pure PPS 305 ℃, 40% GFPPS 330 ℃; mold temperature 120-180 ℃; injection pressure, 50-130 MPA.
(2) Extrusion: using exhaust extruder, the process is: charging section temperature is less than 200 ℃; barrel temperature 300-340 ℃, the temperature of the connecting body 320-340 ℃, the temperature of the mouth mold 300-320 ℃.
(3) Molding: suitable for large products, using two compression, first cooling, then hot pressing. Hot pressing preheating temperature of pure PPS for about 360 ℃ for 15min, GFPPS for about 380 ℃ for 20min; molding pressure of 10 ~ 30Mpa, cooling to 150 ℃ demolding.
(4) Spray molding: the use of suspension spraying method and suspension spraying and dry powder thermal spraying hybrid method, are PPS sprayed onto the metal surface, and then after plasticizing, quenching treatment and get the coating; PPS coating treatment temperature of 300 ℃ or more, heat preservation for 30min.
HONY Plastic provide the following model :
1, 20% glass fiber reinforced PPS (PPS + 20% GF): high temperature resistance, high gloss, high flow;
2, 30% glass fiber reinforced PPS (PPS + 30% GF): high temperature resistance, standard grade;
3, 30% glass fiber reinforced PPS (PPS + 30% GF toughened): high toughness, high gloss, high flow, low temperature and cold resistance;
4, 40% glass fiber reinforced PPS (PPS + 40% GF): high temperature resistance, standard grade;
5, 40% glass fiber reinforced PPS (PPS + 40% GF toughened): high toughness, high gloss, high flow, low temperature and cold resistance;
6, 65% glass fiber / mineral reinforced filled PPS (PPS + glass fiber / mineral): high electrical performance, low cost;
7, 30% glass fiber reinforced PPS + Teflon (PPS + 30% GF + PTFE): self-lubricating, low friction, high wear resistance;
8, 40% glass fiber reinforced PPS + Teflon + graphite (PPS + GF + PTFE + graphite): self-lubricating, super wear-resistant;
9, 20% glass fiber + 20% carbon fiber + Teflon (PPS + GF + CF + PTFE)
10, 20% molybdenum disulfide + Teflon (PPS + MOS2 + PTFE)
