corporate training and planning 1 specialty plastics polyphenylene sulfide (pps)
TRANSCRIPT
CORPORATE TRAINING AND PLANNING
1
SPECIALTY PLASTICSPolyphenylene sulfide
(PPS)
CORPORATE TRAINING AND PLANNING
2
General DescriptionBenzene rings and sulfur atoms form the backbone of the symmetrical macromolecule and characterize the properties:
- high strength, stiffness and hardness,- high heat distortion temperature,- low moisture absorption,- favorable flow properties,- high dimensional stability,- high chemical resistance,- high weathering & radiation resistance - low flammability (without additives).
CORPORATE TRAINING AND PLANNING
3
Structure and General Properties PPS has a symmetrical structure and is only slightly branched
So it is highly crystalline; degree of crystallinity, and thus the properties of moldings, depend on the thermal history to a very great extent.
melting temperature is 285°C
toughness of the brittle basic material is improved by the addition of glass fiber and mineral fibers.
CORPORATE TRAINING AND PLANNING
4
AdditivesAmong the high temperature resistant additives, the most important are glass fiber, carbon fiber & mineral fillers such as chalk, iron oxide and others
– Carbon fiber reduces surface resistance & in special cases achieves a desired electrical conductivity
– Mineral fillers improve processability, reduce shrinkage (particularly anisotropic shrinkage) and improve surface gloss
– Graphite increases the stiffness of molded material
– PTFE improves the friction and wear characteristics.
CORPORATE TRAINING AND PLANNING
5
Availability
Four basic grades of PPS compounds are:• glass-reinforced • glass- & mineral filled • pigmented glass- & mineral filled and• carbon fiber-reinforced.
40% glass-reinforced material has lower density and higher mechanical strength than glass- and mineral filled compounds which offer a good balance of properties at a lower cost & the pigmented glass- & mineral filled grade offers competitive properties & attractive colour at an intermediate cost.
CORPORATE TRAINING AND PLANNING
6
Thermal Properties
• No appreciable weight loss in filled PPS below 500oC in N2 or air.
• Coefficient of linear expansion is comparable to that of aluminium.
• Water absorption of PPS is low. After immersion in water for 31 days at 100 °C, the increase in weight was only 1.01 %.
• Good Heat ageing resistance - UL long-term temperature indices of 170 °C for 40% w/w glass reinforced PPS & 200 °C for 40% w/w glass- and mineral filled PPS
CORPORATE TRAINING AND PLANNING
7
Resistance to Chemicals
• Excellent chemical resistance, better than other advanced engineering plastics
• No known solvents below 200°C
• Inert to steam, strong bases, fuels and acids
• Minimal moisture absorption
• Very low coefficient of linear thermal expansion
• Stress-relieving manufacturing
• PPS ideally suited for precise tolerance machined components
CORPORATE TRAINING AND PLANNING
8
Resistance to Chemicals
At room temperature PPS is resistant to• dilute mineral acids,• alkaline solutions, • aliphatic and aromatic hydrocarbons, • ketones, • alcohols • chlorinated hydrocarbons, • oils, • fats, • water and hydrolysis
CORPORATE TRAINING AND PLANNING
9
Flammability
• PPS exhibits excellent fire retardancy (LOI = 53)
• When exposed to a flame, molded PPS extinguishes only after removal of the ignition source & then chars forming
shiny black crust there is slight expansion
• It burns with a yellowish-orange flame giving
off grey smoke with black traces and a smell
of rotten eggs
• It does not drip.
CORPORATE TRAINING AND PLANNING
10
Processing
• PPS is injection and compression molded.
• Non-stick coatings are applied to metal parts by fluidized bed dipping or electrostatic spraying.
• Mold cavities should be well ventilated as air inclusions lead to weak flow lines.
CORPORATE TRAINING AND PLANNING
11
Processing
Pre-drying• The glass fiber reinforced grades
require drying only when stored in poor conditions.
• It is recommended that the mineral-filled grades are dried for 6 hours at 160°C.
• Regrind must be pre-dried. The excellent thermal stability of the material enables the proportion of regrind to be as high as 35%.
CORPORATE TRAINING AND PLANNING
12
Processing
• Melt temperature is 340 to 370°C
• Mold temperature 25 to 200°C. At 120°C, molding surfaces become smooth and shiny. The toughest moldings are obtained at 40°C
• Molding shrinkage is 1 % for unreinforced & 0.2% for glass fiber reinforced material
• Metal inserts cause stress cracking which can be avoided by selecting special purpose grades
CORPORATE TRAINING AND PLANNING
13
Joining
• Moldings can be joined by screws. Vibration welding provides higher strength joins than ultrasonic welding.
• PPS can be bonded to itself and most other materials including metals with epoxide resin adhesives, cyanoacrylate and reactive monomeric acrylate systems.
CORPORATE TRAINING AND PLANNING
14
Typical Applications
Pump Parts:Housings, impellers, bushings, ball valves, pump vanes, end plates, oil well valves , oil well sucker rod guides and heat shields
Electrical components: High voltage enclosures and sockets, coil bobbins, yokes and connectors, printed circuits for digital watches, relay housings, guides and switch relays, encapsulating of contacts and connectors.
CORPORATE TRAINING AND PLANNING
15
Typical Applications
valve & compressor parts
HPLC COMPONENTS
SOCKET ASSEMBLY
CORPORATE TRAINING AND PLANNING
16
New applications:• High pressure liquid chromatography
components, • Wafer retaining rings for CMP polishing, • Hydrocarbon pump, valve & compressor
parts • Oil field parts, • Aerospace components• Medical and diagnostic device parts• Electronic device encapsulation,• Microwave cookware, • Thick-walled mechanical parts, • High arc resistance, • High modulus anti-friction devices.
CORPORATE TRAINING AND PLANNING
17
Typical Applications
• PPS is also used in the coatings industry.
• Slurry coatings can be applied by a spraying and baking operation.
• Release coatings are formulated from PPS along with small amounts of PTFE and appropriate pigments and applied by slurry techniques.
CORPORATE TRAINING AND PLANNING
18
MANUFACTURERS
Celstran® (Ticona)Comshield® (A. Schulman Inc.)Larton (LATI S.P.A.)NOVAPPS® (Mitsubishi Engineering-Plastics Corp)RTP Compounds (RTP Company)Ryton® (Chevron Phillips Chemical Co.)SUPEC* (GE Advanced Materials Asia Pacific)Techtron® (Quadrant Engineering Plastic Products)TEDUR® (Albis Plastics Corporation)Thermotuf* (LNP Engineering Plastics Inc.)Torelina® Alloy (Toray Resin Company)TOYOBO (TOYOBO America, Inc.)Xtel(TM) (Chevron Phillips Chemical Co.)
CORPORATE TRAINING AND PLANNING
19
Further Reading
1. BRYDSON J.A, Plastics Material, Butterworth Heinemann, oxford, New Delhi (2005)
2. DOMININGHAUS H., Plastics for Engineering, Hanser publishers, Munich, New York (1998)
3. CHARLESS A . HARPER, Modern Plastics Hand Book McGraw –Hill, New York (1999)
4. MARGOLIS J. M., Engineering Thermoplastics, Marcel-Dekker, New York (1985)
CORPORATE TRAINING AND PLANNING
20
Table –I Guide values of properties of PPSProperties Units PPS R 4 R10Density g/cm3 1.67 1.60 1.90Water absorption (23°C, 24h) % - 0.05 0.03Tensile strength N/mm2 121 116 83
Elongation at break % 0.9 0.5
Tensile modulus of elasticity N/mm2 114700 12400
Impact strength (Izod) J/m 69 175 132
Impact strength (Charpy) kJ/m2 12.8 6.1
Notched impact strength J/m 5.8 53
Notched impact strength kJ/m2 6.6 4.2
Rockwell hardness scale R 123 R123 R 120
Melting Point °C 285
Service temperaturein air without mechanical loading long-term °C 200 200
Glass transition temperature 93 88 88
Heat deflection temperature °C 260
CORPORATE TRAINING AND PLANNING
21
Table –I Guide values of properties of PPSProperties Units PPS R 4 R10
Vicat ISO Method A °C 243 245
Coefficient of linear expansion mm/mm/°C 2.9x105 22.10-6 22.10-6
Thermal conductivity W/mK 0.25 0.25
Volume resistivity cm 4.6.1016
Surface resistance 4.5.1016 2.1015
Dielectric constant 106 Hz 3.8 3.8 4.8-6.1
Dissipation factor 50 Hz 0.0014 0.01-0.08
Dielectric strength kV/mm 17.2
Power Factor 0.0014
Fire performance to UL 94 class V-0 V-0
CORPORATE TRAINING AND PLANNING
22
CORPORATE TRAINING AND PLANNING
23
CORPORATE TRAINING AND PLANNING
24
CORPORATE TRAINING AND PLANNING
25
CORPORATE TRAINING AND PLANNING
26
CORPORATE TRAINING AND PLANNING
27
CORPORATE TRAINING AND PLANNING
28