PEEK (polyetheretherketone) sheets around 3mm thick, as a lightweight branch of high-performance engineering plastics, retain the core characteristics of PEEK (high temperature resistance, chemical corrosion resistance, high strength, and biocompatibility) while offering superior flexibility and lower unit weight, making them more suitable for weight-sensitive applications requiring complex molding or high-precision assembly. Their application primarily involves precision machining (laser cutting, CNC milling), hot bending, and ultrasonic welding, with the core logic being "achieving more advanced functional integration with thinner sheets."
Ⅰ.Can a 3mm PEEK sheet retain its original properties?
People might worry that thinner plastic sheets would affect their performance. However, in fact, 3mm PEEK sheets largely retain the core inherent characteristics of PEEK. While some mechanical properties (such as tensile strength and resistance to deformation) are slightly weakened due to the reduced thickness, a balance between lightweight and functionality is achieved through increased specific stiffness.
Ⅱ. 3mm PEEK Sheet: Retained Core Inherent Properties
The essential properties of PEEK (polyetheretherketone) are determined by its molecular structure (an aromatic semi-crystalline polymer). The 3mm sheet, as a "lightweight form" of PEEK, retains the molecular structure, thus preserving its core inherent properties, including:
High Temperature Resistance: Long-term operating temperature remains 250℃ (short-term up to 300℃), thermal decomposition temperature >500℃, suitable for high-temperature environments.
Chemical Corrosion Resistance: Resistant to most organic solvents (such as acetone and ethanol), acids and alkalis (such as hydrochloric acid and sodium hydroxide), and oils, except for strong oxidizing acids such as concentrated sulfuric acid (>95%) and concentrated nitric acid (>70%).
The corrosion rate depends primarily on the material itself, not its thickness.
Biocompatibility: Meets biocompatibility standards, exhibiting no cytotoxicity, sensitization, or genotoxicity, and can be used in medical implants (such as bone repair splints).
Low hygroscopicity: Water absorption rate <0.1% (at 23℃/50%RH), far lower than nylon, exhibiting good dimensional stability (thermal expansion coefficient ≈ 4.7 × 10⁻⁵/℃).
PEEK's molecular chain contains no hydrophilic groups, so the thickness of the sheet does not affect its hygroscopicity.
Self-lubricating and wear-resistant properties: Coefficient of friction approximately 0.1~0.3 (dry friction), low wear rate (<10⁻⁶ mm³/N·m), suitable for wear-resistant components such as bearings and guide rails.
Ⅲ. Reduced Properties of 3mm PEEK Sheets(Polyetheretherketone Sheet)
Due to the reduced thickness, the mechanical properties transmitted through the cross-sectional dimensions decrease slightly. The most significant reductions are:
1. Tensile Strength:
The tensile strength of a 3mm PEEK sheet drops to 90-100 MPa.
Reason: Tensile strength is positively correlated with the material's effective load-bearing area. Thinner sheets have a smaller cross-sectional area, resulting in a slightly weaker ability to withstand tensile forces.
2. Stiffness:
The flexural modulus of a 3mm sheet is approximately 3.2 GPa.
Performance: Under the same load, a 3mm sheet is more prone to slight bending.
3. Impact Strength:
The notched impact strength of a 3mm sheet is approximately 70 kJ/m².
Reason: The energy absorption path of a thinner sheet is shorter, making it more susceptible to fracture upon impact.
Ⅳ. Underlying Reasons for Property Variations
The performance variations of 3mm PEEK Plate follow a thickness-performance trade-off:
Retained properties: Intrinsic properties determined by molecular structure (e.g., high temperature resistance, chemical corrosion resistance), independent of thickness;
Reduced properties: Extrinsic properties determined by geometry (e.g., tensile strength, resistance to deformation), which decrease linearly with decreasing thickness;
Ⅴ. Performance Compensation Strategies in Practical Applications
Although the tensile strength and other mechanical properties of 3mm sheets are slightly reduced, this deficiency can be compensated for through design optimization:
Structural Reinforcement: Add reinforcing ribs to stress-bearing areas to improve overall load-bearing capacity;
Composite Application: Combine with metal inserts to utilize the strength of metal to compensate for the deficiencies of PEEK;
Process Optimization: Use hot pressing to increase the density of the thin sheet and enhance mechanical properties.
Ⅵ. Specific Application Scenarios and Typical Components
1. Aerospace and Defense: The Ultimate Balance Between Lightweight Design and Weather Resistance
Application Methods: Laser cutting (high precision), hot bending (softening and shaping at 350℃), ultrasonic welding (assembling multi-component modules).
Typical Components:
Lightweight Interior: Curved skin for drone fuselages (replacing metal to reduce weight);
Electronic Functional Components: Radar radomes (3mm thickness ensures signal penetration);
Sealing and Protection: Oil-resistant gaskets around engines (cut into irregular shapes to fit pipe interfaces).
2. Medical and Bioengineering: Combining Biocompatibility and Minimally Invasive Technology
Application Methods: CNC milling (machining complex shapes such as orthopedic guides), compression molding (fabricating implant splints), plasma cleaning (enhancing surface hydrophilicity).
Typical components: Minimally invasive surgical instruments: Orthopedic intramedullary nail positioning guide (precisely matches bone contour); Implants and rehabilitation: Lightweight sockets for prostheses (breathable and conforms to the residual limb); Medical devices: Dental implant abutments (promotes osseointegration).
3. Electronics and Semiconductors: Adapted for High Precision and Clean Environments
Application Methods: Laser cutting (burr-free), stamping (mass production of connectors), vacuum thermoforming (bonding circuit boards).
Typical Components:
High-Frequency Electronic Components: Thermally conductive insulating pads for IGBT modules (thin design improves heat dissipation efficiency);
Semiconductor Equipment: Plasma-resistant guide rails for wafer transfer robots;
Precision Connectors: Aging-resistant cable connectors for industrial robots.
4. Automotive and New Energy: Key Carriers for Electrification and Lightweighting
Application Methods: Thermoforming, welding (assembling motor components), injection molding inserts (composite with metal parts).
Typical Components:
Powertrain Systems: Stator slot wedges for new energy vehicle motors (fixing winding coils and high-temperature resistant);
Precision Transmission: Oil-resistant sensor housings (suitable for confined installation spaces);
Chassis and Safety: Wear-resistant bushings for suspension systems (reduced maintenance).
5. Chemicals & Energy: Flexible Solutions for Corrosion Resistance and High Pressure
Application Methods: Cutting, thermoforming, adhesive assembly.
Typical Components:
Pumps, Valves & Piping: Sealing gaskets for hydrochloric acid delivery pumps (3mm thin sheet cut into rings, resistant to strong acid penetration);
Oil Exploration: Downhole pressure sensor housings;
6. Machinery & Precision Instruments: Balancing High Wear Resistance and Precision
Application Methods: CNC milling, ultrasonic welding, polishing.
Typical Components:
Wear-resistant Moving Parts: Yarn guide plates for textile machinery (resistant to fiber abrasion);
Seals & Gaskets: Piston rod sealing support rings for hydraulic cylinders;
Robot Components: Aging-resistant cable sheath substrates for industrial robots.
