Anti-blocking Precipitated Silica | Film Opening Agent for BOPP PE PP PET Films Manufactured by Shandong Zhonglian Chemical Co., Ltd. Get reliable anti-blocking performance for plastic films with our high-purity precipitated silica. Engineered as a professional film opening additive, it effectively eliminates layer adhesion during winding, storage and unwinding, while preserving excellent optical clarity and mechanical properties of films. Ideal for packaging film producers, masterbatch manufacturers and OEM/ODM oral care & plastic enterprises. Get Latest Price · Contact Now for Samples Product Information The Anti-blocking Precipitated Silica from Shandong Zhonglian Chemical Co., Ltd. is a functional amorphous hydrated silica specially developed for the plastic film and masterbatch industry. It is designed to solve the common blocking problem of polyolefin and polyester films, providing a stable and efficient opening solution for high-speed film production lines. Inside the product, uniformly sized micro silica particles form regular micro-protrusions on the film surface during film forming, which physically separate the upper and lower film layers, reduce the contact area between films, and fundamentally prevent inter-layer adhesion caused by pressure and heat during winding. The soft particle morphology will not scratch the film surface or damage the gloss of the product. This opening silica adopts advanced precipitation process control, with ultra-high whiteness and extremely low heavy metal residue. It maintains chemical inertness in most polymer resin systems, does not react with active additives such as slip agents and antioxidants, and has no negative impact on the heat sealing performance, tensile strength and elongation of the finished film. Our production base operates under a strict GMP quality management system, and each batch of products has full traceability from raw ore mining to finished powder packaging. We provide a complete set of technical documents and regulatory certification materials to support customers' product formula development, factory audit and global market access. Product Appearance White amorphous powder with uniform particle size, no agglomeration and no impurities. It can be uniformly dispersed in polyolefin and polyester resin systems, and is suitable for twin-screw extrusion masterbatch making and direct film extrusion production. Product Parameters 表格 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 ≤1ppm, Lead ≤2ppm, Mercury ≤0.5ppm Total Aerobic Plate Count ≤ 50 cfu/g Core Material Amorphous precipitated hydrated silica Primary Application Film anti-blocking / opening agent, plastic masterbatch additive Product Features 1. Controlled Particle Morphology & Uniform Dispersion Adopting narrow particle size distribution control technology, the product has regular particle shape and uniform size. It can be uniformly dispersed in the resin matrix during extrusion processing, avoiding film defects such as fish eyes, crystal points and streaks caused by particle agglomeration. 2. High Purity & Low Haze Performance Ultra-high SiO₂ purity and low impurity content ensure minimal impact on film light transmittance and haze. The whiteness L* is as high as 97.5, which will not cause yellowing or color cast of transparent films, and maintains the original gloss and appearance of the product. 3. Excellent Resin Compatibility Chemically inert amorphous silica structure, compatible with PP, PE, BOPP, PET and other common polymer materials. It can be used together with slip agents, antioxidants and light stabilizers without affecting the efficacy of other additives. 4. Stable Batch-to-batch Consistency Full online monitoring of particle size, oil absorption and whiteness in the production process, strict quality control of each production link, to ensure that the performance of each batch of products is highly consistent, and reduce the repeated adjustment of customers' production formulas. 5. Food Contact Grade Safety Strictly control heavy metals and microbial indicators, in line with global food contact material safety standards. It is suitable for food packaging film production scenarios with high hygiene requirements. Core Advantages Reliable & Long-lasting Anti-blocking Effect The physical opening mechanism formed by micro-spacer particles is not affected by temperature and humidity changes. Even under the pressure of long-term storage and high-temperature transportation, it can still maintain stable anti-blocking performance, and solve the problem of difficult unwinding of film rolls. Versatility Across Film & Masterbatch Applications Whether it is BOPP biaxially oriented film, cast PP film, LDPE blown film, PET polyester film, or functional anti-blocking masterbatch production, this product can be well adapted. We support customized particle size and oil absorption indicators according to different film thicknesses, processes and performance requirements to meet diversified production needs. Usage & Storage Instructions 1.Recommended addition ratio: 0.1% – 0.5% in the finished film formula; 3% – 8% when used to prepare anti-blocking masterbatch. The specific dosage can be adjusted according to the target film thickness and anti-blocking grade. 2.It can be used alone, or blended with slip agent silica or other additives to balance the opening performance and sliding performance of the film. 3.It is recommended to add it in the dry powder mixing stage of masterbatch production, and fully disperse it with the carrier resin under twin-screw extrusion to ensure uniform distribution in the system. 4.To achieve the best anti-blocking effect, avoid particle moisture absorption and agglomeration during feeding and processing, and ensure good dispersion of the powder in the resin melt. 5.Storage requirements: Store in a cool, dry and ventilated warehouse, seal the packaging after opening, avoid moisture absorption and dust contamination, and the shelf life is 24 months under unopened conditions. Application Scenarios BOPP Food Packaging Film Suitable for various BOPP packaging films such as ordinary packaging film, heat-sealing film and cigarette packaging film, which solves the problem of roll sticking in high-speed production and meets the requirements of high transparency and food contact safety. PE / PP Blown & Cast Film Widely used in LDPE blown film, cast PP film, agricultural mulch film, shopping bag film and other fields, providing stable opening performance and good film surface quality. PET Polyester & Lamination Film Adapted to PET film and composite lamination film production, with low haze and high gloss characteristics, to meet the strict optical performance requirements of high-end packaging films. Anti-blocking Masterbatch Production Ideal for functional masterbatch manufacturers, with good dispersion and stable batch quality, supporting the production of various concentration of opening masterbatch products. Frequently Asked Questions Q1: What is anti-blocking silica and how does it work? A: Anti-blocking silica is an amorphous precipitated silica used as a film opening additive. It forms micro-protrusions on the film surface to physically separate film layers, preventing adhesion during winding and storage. Q2: Which types of films is this product suitable for? A: It is suitable for BOPP, cast PP, LDPE blown film and PET packaging film, and can also be used for the production of anti-blocking functional masterbatch. Q3: What certifications do you have for this silica? A: Our products have ISO 22000, GMP, HALAL, KOSHER, REACH certification and FDA food contact material approval, which can meet the regulatory requirements of most global markets. Q4: Can you customize product specifications? A: Yes. We can adjust D50 particle size, DBP oil absorption and other indicators according to customers' film formula and performance requirements. Q5: What is the recommended addition amount? A: 0.1% – 0.5% in the finished film; 3% – 8% in the anti-blocking masterbatch. The specific dosage can be adjusted according to actual test results. Q6: What technical documents can you provide? A: We can provide complete documents such as TDS, MSDS, COA, particle size distribution report and regulatory certification to support customers' product development and registration. Q7: What are the packaging and trade terms? A: Standard export packaging is 10/15/20kg waterproof kraft paper bags. Trade terms support FOB Qingdao, CIF destination port and DDP.