I. What is PPS Sheet Material?
PPS sheet material, short for polyphenylene sulfide sheet material, is a high-performance sheet-like polymer material made from polyphenylene sulfide (PPS) resin through a specific process. PPS is a special engineering plastic with excellent high-temperature resistance, chemical corrosion resistance, and mechanical properties, making it widely used in harsh industrial environments.
II. How are PPS Sheets Produced?
The production of PPS sheets involves two core steps: resin synthesis and sheet molding.
Resin Synthesis: Using p-dichlorobenzene and sodium sulfide (Na₂S) as the main monomers, PPS resin particles are generated through a polycondensation reaction in a polar solvent (such as N-methylpyrrolidone, NMP). The reaction requires strict temperature control (approximately 200-250℃) and anhydrous conditions to ensure the molecular chains are regular and improve resin performance.
Sheet Forming:
Extrusion: PPS granules are heated and melted (approximately 280-320℃), then extruded through an extruder die into continuous sheets. After cooling, traction, and cutting, sheets of standard thickness (5-100mm) are produced.
Compression Molding: PPS granules are pre-compressed into blanks, then pressed into shape under high temperature (approximately 300-350℃) and high pressure (5-20MPa). This method is suitable for thick plates or complex-shaped sheets.
Subsequent finishing processes such as polishing and punching may be used to improve surface quality.
III. Core Characteristics and Advantages of PPS Sheets (Polyphenylene Sulfide Sheet)
The competitiveness of PPS sheets stems from their "all-around" performance combination:
High Temperature Resistance: Long-term operating temperature 200℃ (short-term temperature resistance 230℃), heat distortion temperature (HDT, 1.8MPa) exceeding 260℃, superior to most general-purpose engineering plastics.
Chemical Corrosion Resistance: Soluble only in strong oxidizing agents such as concentrated nitric acid and concentrated sulfuric acid; resistant to acids (such as hydrochloric acid and sulfuric acid), alkalis (such as sodium hydroxide), salt solutions, and oils, suitable for highly corrosive environments such as chemical and electroplating industries.
High Strength and Rigidity: Unmodified PPS has a tensile strength >65MPa and a flexural modulus >4GPa; after glass fiber reinforcement, the tensile strength can reach 170MPa, with outstanding creep resistance and no deformation under long-term stress.
Flame Retardancy: Containing sulfur, it achieves UL94 V-0 rating without the addition of flame retardants, with extremely low smoke emission, meeting stringent fire protection standards.
Excellent electrical performance: dielectric constant ≈3.0 at high frequency (1MHz), loss factor <0.001, arc resistance >120s, making it an ideal choice for high-frequency insulating components.
IV. General Application Scenarios of PPS Plastic Sheet
Due to their comprehensive performance, PPS sheets are widely used in industrial fields requiring high reliability and operating under harsh conditions:
Electronics and Electrical: LED brackets, connectors, coil frames, high-temperature resistant insulating gaskets (such as inverter insulation layers);
Automotive Industry: Engine sensor housings, gears, oil pump components, turbocharger system seals (resistant to 200℃ engine oil/exhaust gas);
Industrial Equipment: Corrosion-resistant pump and valve housings, pipe flange linings, high-temperature filter components;
Environmental Protection and Energy: Chemical reactor linings, corrosion-resistant layers for waste gas treatment equipment, lithium battery separator coating substrates.
V. Precautions for Using PPS Sheets
Avoid strong oxidizing agents: Although resistant to most chemicals, prolonged contact with concentrated nitric acid (>90%) or concentrated sulfuric acid (>95%) may cause surface swelling or slow degradation.
Control internal stress: Thick plates or complex-formed sheets may have residual internal stress. Annealing (180-200℃ for 2 hours) is necessary to reduce the risk of cracking (especially for dynamic load scenarios).
Dust protection during processing: PPS powder has an ignition point of approximately 490℃. Dust collection equipment must be used during processing (such as cutting and grinding), and the material should be kept away from heat sources to prevent dust explosions.
VI. Storage Methods for PPS Sheets
Environmental Control: Store in a dry, ventilated, and dark warehouse. Temperature < 30℃, humidity < 60% (PPS has extremely low hygroscopicity, but prolonged high humidity may affect surface coating or adhesion performance).
Stacking and Fixing: Lay flat or upright to avoid bending due to heavy pressure; secure the edges of roll sheets to prevent unwinding.
Isolation from Contamination: Store separately from corrosive chemicals and oil stains. Avoid direct contact with organic solvents (such as acetone) to prevent swelling.
VII. Comparison of PPS Sheets with Other Engineering Plastic Sheets (e.g., PEEK Sheet, PI Sheet)
Advantages: Cost is only 1/3-1/5 of PEEK; chemical resistance and flame retardancy are superior to PI (polyimide); processing is easy (no special equipment required).
Disadvantages: Long-term operating temperature is slightly lower than PEEK; pure PPS has lower toughness than some modified PI (but this can be approached after glass fiber reinforcement). More suitable for cost-sensitive industrial applications requiring high temperature and corrosion resistance.
Summary: PPS sheets represent "high performance + high cost-effectiveness" industrial materials. With proper use, standardized processing, and scientific storage, they can operate stably in harsh environments for extended periods, making them a key basic material in electronics, automotive, and chemical industries.
