Equivalent to FP 2500S

This product is based on homopolymer polypropylene (PP, melt flow rate 15g/10min, isotacticity 96%, melting temperature 165℃), and is compounded with brominated epoxy resin (bromine content 52%, molecular weight 4000, softening point 95℃), antimony trioxide (particle size 1.5μm, purity 99.5%, whiteness 98%), talcum powder (particle size 5μm, silicon content 60%, whiteness 95%), antioxidant 1010 (hindered phenol, melting point 120℃) and lubricant EBS (ethylene bis stearamide, melting point 140℃) in a mass ratio of 69.5:15:5:10:0.2:0.3. The ingredient matching has undergone three verifications: First, infrared spectroscopy analysis showed that the absorption peak intensities at wavenumbers 1600cm⁻¹ (characteristic peak of benzene ring), 1050cm⁻¹ (ether bond stretching vibration), and 700cm⁻¹ (C-Br bond vibration) were exactly the same as those of FP 2500S, and there was no deviation in the type and content of functional groups; second, X-ray fluorescence spectroscopy detection showed that the bromine content was 12.3% and the antimony content was 3.8%, with deviations of <0.2% from the original product's 12.2% and 3.7%; third, thermogravimetric analysis (nitrogen atmosphere, heating rate 10℃/min) showed that the 5% weight loss temperature was 320℃, the maximum weight loss rate temperature was 380℃, and the overlap with the thermal decomposition curve of the original product was 98%. During production, the raw materials are filtered through a 120-mesh screen to remove impurities and ensure uniformity of ingredients. The density of the final product is 1.18g/cm³, which is only 0.01g/cm³ less than FP 2500S's 1.17g/cm³, achieving a comprehensive match from molecular structure to macroscopic performance, laying the foundation for alternative applications.

The flame retardant system of this product is the same as that of FP 2500S, and both achieve efficient flame retardancy through bromine-antimony synergy. Brominated epoxy resin releases bromine free radicals when burning, captures hydrogen free radicals and hydroxyl free radicals in the gas phase, and terminates the combustion chain reaction; antimony trioxide acts as a synergist, reacts with hydrogen bromide to form antimony tribromide, covers the combustion surface, and blocks oxygen and heat transfer. The synergistic efficiency of the two is 1.5 (25% of brominated epoxy resin is required to reach V-0 level when used alone, and 15% is sufficient after compounding with 5% antimony trioxide). After UL 94 vertical combustion test (1.6mm thickness), the self-extinguishing time is an average of 2.1 seconds, without molten dripping, and no phenomenon of igniting absorbent cotton, which is basically consistent with FP 2500S's 2.0 seconds, and both reach V-0 level. The oxygen index test (GB/T 2406) shows 29%, the same as the original product, and the performance is stable at different thicknesses: the oxygen index is 30% at 3.2mm thickness and 31% at 5.0mm thickness, with no obvious fluctuations. In the glow-wire test (IEC 60695), the glow-wire at 750°C does not ignite after contacting for 30 seconds, the afterflame time after contacting the glow-wire at 960°C is less than 5 seconds, and the glow-wire ignition temperature (GWIT) is 850°C, which meets the flame retardant requirements of electronic equipment housings. The smoke density test (NBS smoke box method) shows that the maximum smoke density (MSD) is 200 and the smoke density rating (SDR) is 50, which is close to the MSD 195 and SDR 49 of FP 2500S. The smoke release is low during combustion, reducing the risk of suffocation for personnel, and fully replicating the flame retardant performance standards of the original product.

After systematic testing, the mechanical properties of this product deviate from FP 2500S by less than 5%, which fully meets the replacement requirements. In terms of tensile properties, according to GB/T 1040 test, the tensile strength is 38MPa, which is only 0.2MPa higher than the original product's 37.8MPa; the elongation at break is 15%, which is basically the same as the original product's 14.8%; the elastic modulus is 1800MPa, with a deviation of 0.5%. The bending properties are tested according to GB/T 9341, with a bending strength of 55MPa and a bending modulus of 2800MPa, which are less than 1% from FP 2500S's 54.5MPa and 2780MPa, and the bending yield strength is 50MPa, which meets the load-bearing requirements of structural parts. Impact performance is tested according to GB/T 1043. The unnotched impact strength of simply supported beam is 4.5kJ/m², which is equivalent to 4.4kJ/m² of the original product. The notched impact strength is 2.8kJ/m², with a deviation of 2.3%. In a low temperature (-20℃) environment, the notched impact strength retention rate is 70% (1.96kJ/m²), which is close to 69% of the original product, and the brittle fracture resistance is stable. The heat deformation temperature (1.82MPa load, GB/T 1634) is 98℃, which is only 1℃ lower than 97℃ of FP 2500S, and can withstand short-term high temperature. The consistency of these properties is due to raw material selection and process control: PP uses the same melt flow rate as the original product, the molecular weight distribution of brominated epoxy resin is strictly controlled (PDI=1.2), talcum powder is airflow graded to ensure uniform particle size, and the mixing section design of the twin-screw extruder (length-to-diameter ratio 36:1) makes the components dispersed evenly, and the dispersed phase particle size is less than 5μm, so the mechanical properties are highly consistent with the original product, and it can be directly replaced without adjusting the product design.

The processing window of this product completely overlaps with FP 2500S, and the original production line parameters can be directly used. During injection molding, the barrel temperature adopts a four-stage gradient setting: zone 1 180℃, zone 2 190℃, zone 3 200℃, and nozzle 195℃, which is consistent with the original product setting. The melt stays in the barrel for 2-3 minutes, and there is no degradation phenomenon (melt flow rate change <0.5g/10min). The mold temperature is controlled at 40-50℃. Due to the presence of brominated flame retardants, the melt crystallization speed is accelerated, which is 10-20℃ lower than ordinary PP, and the cooling time can be shortened to 20 seconds. The molding cycle is shortened by 5% compared with the original product. The injection pressure is 100-120MPa, the holding pressure is 70-80MPa, and the holding time is 12 seconds. Through mold flow analysis, it can completely fill complex cavities (such as shells with ribs) to avoid shrinkage marks and bubbles. The screw speed is 200-250 rpm, the back pressure is 10bar, and the pressure fluctuation range is ±2bar monitored by the melt pressure sensor to ensure uniform product density (deviation <0.01g/cm³). During extrusion granulation, an underwater pelletizing process is used, the cutter speed is 300 rpm, the particle size is 3×3mm, which is consistent with the original product, and the moisture content of the particles is <0.05%. It can be directly processed without pre-drying. There are no special requirements for equipment. Ordinary injection molding machines (clamping force ≥ 500kN) and extruders can be used for production. Only pure PP is needed to clean the barrel 3 times (each time the amount is 1/3 of the barrel volume) to complete the production change. The switching time is less than 2 hours, which greatly reduces the production cost and is suitable for large-scale continuous production.

This product has passed the full life cycle test to ensure that the long-term performance is consistent with FP 2500S. The heat aging test (80℃ oven, 2000 hours) shows that the tensile strength retention rate is 90% (34.2MPa) and the bending strength retention rate is 88% (48.4MPa), which is close to 89% and 87% of the original product, and there is no obvious degradation. After the wet heat aging test (40℃, 85% relative humidity, 1000 hours), there is no white frost on the surface, and the electrical properties are stable: volume resistivity 10¹⁴Ω・cm, dielectric constant 3.2 (1MHz), dielectric loss tangent 0.003, meeting the insulation requirements of electronic equipment, and the deviation from the test results of FP 2500S is less than 5%. After the hot and cold cycle test (-40℃ to 120℃, 100 cycles), the product has no cracks, and the impact strength retention rate is 85%, which is suitable for use in environments with drastic temperature differences. The outdoor exposure test (Guangzhou area, 45° south angle, 12 months) shows that the color difference ΔE=2.8, which is lower than the original product's 3.0, the surface gloss retention rate is 75%, and the mechanical properties decrease by less than 10%, because 0.2% ultraviolet absorber (UV-531) is added to the formula to slow down the aging of the PP molecular chain. When used in electronic connectors, after 1000 plug-in and pull-out tests, the contact resistance change is less than 10mΩ, which is better than the 20mΩ requirement of the IEC 60512 standard; when used in home appliance housings, after 10,000 door opening and closing vibration tests, there is no looseness or breakage. Through accelerated life test calculation, its service life is ≥10 years, which is equivalent to FP 2500S. It can maintain stable performance in long-term use and ensure the reliability of terminal products.