Polyimide (PI) is a high-performance engineering plastic based on imide monomers, with short-term use temperature above 400°C, long-term temperature range from -269°C to 300°C, some with no obvious melting point, high insulation performance, low dielectric constant and other characteristics.
Dalian Allstar’s production process is: first, dianhydride and diamine undergo condensation reaction in solvent to generate polyamic acid (PAA) solution, then PAA is dehydrated and cyclized to form polyimide through thermal imidization method. After years of verification, our production process is mature and can provide stable quality polyimide.
The polyimide produced by Dalian Allstar has obvious advantages and can replace traditional metals, glass, and even ceramic materials, suitable for extreme environments.
Our engineers, through years of R&D and case feedback, will analyze the properties and characteristics of polyimide materials from the following aspects, including thermal stability, mechanical properties, friction properties, electrical insulation properties, chemical resistance, etc.
Ultra-wide operating temperature range: short-term use temperature above 400°C, long-term temperature range from -269°C to 300°C. Within this operating range, polyimide can guarantee high strength and no creep. Extremely high heat deflection temperature: can still maintain shape stability in 470°C environment for short periods.
High strength: Within the operating temperature range, polyimide can achieve tensile strength of 116MPa and flexural strength of 170MPa, belonging to high-strength engineering plastics. Dimensional stability: Thermal expansion (linear thermal expansion coefficient) 4.3 (unit 10-51/K) temperature range 50-200°C standard DIN 53 752. Thermal expansion (linear thermal expansion coefficient) 5.3 (unit 10-51/K), temperature range 200-300°C, standard DIN 53 752
Surface resistivity value 10¹⁵Ω, 23°C, standard DIN IEC 60093
Polyimide can resist corrosion from various chemicals, making it an ideal material for laboratory tools.
Lower friction coefficient and wear rate
Polyimide (PI) materials can be classified into thermoplastic PI, thermosetting PI, pure PI, and filled reinforced PI according to different processing methods and application scenarios.
Thermoplastic PI, as the name suggests, is a type of polyimide obtained through heating. This material can be repeatedly heated, and the material can be reused.
Its characteristics are: reprocessable, good toughness, good heat resistance.
Mainly applied to high-precision, complex-shaped components, such as aircraft interior parts, electrical connectors, medical devices, etc.
Thermoplastic PI, as the name suggests, is a type of polyimide obtained through heating. This material can be repeatedly heated, and the material can be reused.
Its characteristics are: reprocessable, good toughness, good heat resistance.
Mainly applied to high-precision, complex-shaped components, such as aircraft interior parts, electrical connectors, medical devices, etc.
In 2016, we collaborated with a Chinese smartphone accessories factory. To save space and achieve curved connections between the motherboard, camera, and display, they needed us to develop an ultra-thin, bendable, and high temperature-resistant circuit board. With our deep understanding of pure polyimide materials' characteristics of high temperature resistance, electrical insulation, and flexibility, we recommended our flexible circuit board to the factory, which fully met the customer's requirements.
High-Temperature Ovens We learned that the customer's bearings operate at temperatures of 200-400 degrees Celsius and need to transport materials, so the conveyor belt bearings must withstand continuous high temperatures while maintaining smooth operation. We recommended our patented product A-PI-3S (bearing grade specialty material) to the customer, and their problem was solved perfectly.
We have large inventory of PI sheets in various thicknesses. These sheets can be processed into PI washers, PI insulators, PI bearing seats, etc.
Thickness: 0.5-105mm
Width: Maximum 520mm
Length: 1000-3000mm
You can purchase PI rods for turning and machining, which can be processed into PI bearings, PI bushings, PI seals, PI shafts and other products. This is very friendly for small quantity component needs and sample stages, without waiting for mold opening time and cost. However, it is not very cost-effective for batch products.
PI tubes have high strength and heat resistance, making them very suitable for manufacturing sleeves, insulators and other components.
Length: Customized (according to customer requirements)
The polyimide film produced by our company has excellent flexibility, thermal stability and dielectric strength, and is widely used in FPC, insulation layers and other products.
In 2021, we collaborated with a semiconductor wafer production factory in Shenzhen, Guangdong, China. Their requirement was to produce fixtures and combs for handling their products. The specific requirements were as follows:
1. Protect wafer circuits
2. High cleanliness (low outgassing)
3. Chemical corrosion resistance We recommended our antistatic product.
A-PI-F modified polyimide to the customer, and the customer was very satisfied with our product.
Polyimide bearings are one of our company’s superior products. After years of research and development and practical application, our product quality is very stable.
In 2019, we collaborated with a new energy vehicle parts factory. The polyimide bearings were applied in the E-Drive System. The motors of new energy vehicles generate “shaft voltage” at both ends of the motor spindle when driven by high-frequency PWM (Pulse Width Modulation) inverters. When this voltage reaches a certain level, it breaks down the lubricating oil film of traditional metal bearings, forming electric arcs that cause electrical corrosion on the bearing raceways and rolling elements, producing abnormal noise and ultimately leading to premature bearing failure. We provided improved polyimide bearings (A-PI-3S) that solved the electrical corrosion problem for the customer, and the customer was very satisfied.
When we need a wear-resistant product, we try adding different amounts of graphite to polyimide materials. After multiple repeated experiments, we believe that materials with 50% graphite added are very suitable for applications requiring high temperature resistance, high thermal conductivity, and low friction. We can use them to process thrust washers, valve seats, bearings, bushings, etc. Specific performance data can be found in the table.
| Test Item | Environmental Conditions | Test Method / Standard | Unit | Test Results (Molding Method H) | Test Results (Molding Method L) |
|---|---|---|---|---|---|
| Color | / | / | / | Black | Black |
| Rockwell Hardness | 23℃, 50%RH | GB/T 3398.2-2008 | HRE | ≥8 | ≥65 HRL |
| Unnotched Impact Strength | 23℃, 50%RH | GB/T 1043.1-2008 | kJ/m² | ≥15 | ≥8 |
| Tensile Strength | 23℃, 50%RH | GB/T 1040.1-2008 | MPa | ≥50 | ≥30 |
| Elongation at Break | 23℃, 50%RH | GB/T 1040.1-2008 | % | ≥3.0 | ≥2.5 |
| Flexural Strength | 23℃, 50%RH | GB/T 9341-2008 | MPa | ≥60 | ≥50 |
| Flexural Modulus | 23℃, 50%RH | GB/T 9341-2008 | MPa | ≥6000 | ≥3800 |
| Density | 23℃, 50%RH | GB/T 1033.1-2008 | g/cm³ | 1.7 | 1.6 |
| Coefficient of Friction | 23℃, 50%RH | GB/T 3960-2016 | / | 0.28 | — |
| Wear Mass | 23℃, 50%RH | GB/T 3960-2016 | mg | 2.1 | — |
| Linear Thermal Expansion Coefficient | 23℃, 50%RH | GB/T 1036-2008 | 10⁻⁶°C⁻¹ | 51.3 | — |
In equipment such as engines, pumps, and valves, materials need to provide reliable sealing and resistance to high temperature, high pressure, and chemical corrosion, which are exactly the advantages of PI.
| The natural color is typically amber or golden yellow, with transparent colorless varieties also available. |
| Yes, polyimide materials are suitable for laser cutting, providing smooth cutting edges and high precision. |
| Not flammable, polyimide has excellent flame-resistant properties and is classified as a flame-retardant material. |
Absolutely. We have application engineers who have seen most problems and provide serious consultation, detailed support, and production project guidance for projects.
Over 15 years of material production experience with deep understanding of material properties
Focus on combining technological R&D with practical applications
Guarantee that all shipped products undergo strict testing, ensuring the principle of no defective products shipped
Years of export packaging experience, ensuring materials are not easily damaged during transportation