Anti-blocking Silica | Precipitated Silica for Plastic Film Opening High-purity amorphous precipitated silica designed as efficient anti-blocking additive for polyolefin films. It creates micro-protrusions on film surface to separate film layers, effectively eliminating blocking without damaging optical properties. Certified with ISO 22000, HALAL, KOSHER and REACH compliant, suitable for global plastic film & masterbatch manufacturers. Ideal for BOPP, PE, PP and PET packaging film formulations. Product Information Shandong Zhonglian Chemical Co., Ltd. is a China-based professional manufacturer of functional precipitated silica for plastic additives. Our anti-blocking silica for film opening is engineered to solve film sticking issues during winding and unwinding. It delivers reliable opening performance while keeping low haze and high clarity of finished films. Every batch is produced under strict GMP management, with full traceability from raw material to finished powder. We supply complete technical documentation including TDS, MSDS, COA and formulation test reports, supporting customers' masterbatch development and global regulatory registration. Our anti-blocking silica is widely adopted by film producers across Europe, North America and Southeast Asia. Customized particle size and oil absorption available, we support bulk shipment for multinational film enterprises and regional masterbatch factories. Anti-blocking Silica Parameters Item Specification SiO₂ Content (Ignited Basis) ≥ 97.5% Loss on Ignition (1000℃, 1h) ≤ 8.0% Moisture (As Packed, 105℃, 2h) 3.0 – 5.5% pH (5% Water Suspension) 6.5 – 7.3 Bulk Density 0.20 – 0.28 g/cm³ DBP Oil Absorption 80 – 120 cm³/100g Median Particle Size (D50) 3 – 7 μm BET Surface Area 100 – 140 m²/g Whiteness (CIE L*) ≥ 97.5 Heavy Metal Limits Arsenic ≤ 1 ppm, Lead ≤ 2 ppm, Mercury ≤ 0.5 ppm Total Aerobic Plate Count ≤ 50 cfu/g Core Material Amorphous precipitated hydrated silica Primary Application Film anti-blocking / opening agent, plastic masterbatch additive Export Certification ISO 22000, GMP, HALAL, KOSHER, REACH Standard Packaging 10 / 15 / 20 kg export-standard waterproof kraft paper bag Trade Terms FOB Qingdao / CIF destination port / DDP Qualifications and Honors •REACH Registration Compliance •ISO 22000:2018 Food Safety Management System •GMP Certified for Polymer Additives •ISO 9001:2015 Quality Management System •SHC HALAL Certification •OU KOSHER Certification •FDA Food Contact Material Approval •8 Patents for Precipitated Silica Production Technology •National High-Tech Enterprise of China •Plastic Additive Raw Material Supplier Certification Product Features Controlled Particle Morphology. Narrow particle size distribution with uniform spherical particles. Builds micro-roughness on film surface to separate contact layers, achieving stable anti-blocking effect while maintaining low haze. High Whiteness & Low Impurity. Ultra-high whiteness (L* ≥ 97.5) and low heavy metal content, will not cause yellowing or speckles in transparent films. Good Resin Compatibility. Chemically inert, compatible with PP, PE, PET and most polymer matrix. No negative impact on tensile strength, elongation and heat-sealing performance. Consistent Batch Quality. Online particle size & physical index monitoring, stable performance batch by batch, reducing formulation adjustment work for masterbatch and film manufacturers. Core Advantages •Specialized film opening grade, outstanding anti-blocking efficiency •Strict heavy metal & microbial control, compliant with food contact packaging regulations •Customizable D50 and oil absorption for different film thickness & clarity requirements •Full technical package to support customer formulation validation •Large stable bulk supply capacity for continuous film & masterbatch production Usage Instructions 1.Recommended addition ratio: 0.1 – 0.5% in finished film; or 3 – 8% inside opening masterbatch, adjust according to film thickness and anti-block target. 2.Can be used alone or blended with slip agents to balance opening and sliding property. 3.Add during twin-screw extrusion masterbatch compounding stage, fully dispersed in polymer melt. 4.To avoid film haze and fish eyes, ensure good dispersion and prevent silica agglomeration. 5.Store sealed in dry warehouse, keep away from moisture and dust contamination. Application Scenarios •BOPP Packaging Film — for food packaging BOPP films, solves roll blocking during high-speed production, maintains high transparency. •PE / PP Blown & Cast Film — suitable for cast polypropylene, LDPE packaging film, agricultural mulch film and shopping bag film. •PET Polyester Film — for PET packaging and lamination films, meets strict optical requirements. •Anti-blocking Masterbatch OEM & ODM — perfect for masterbatch producers, stable quality and complete certifications to support multiple product SKUs.