Silica Gel Crystal

White Silica Gel Crystal Pouches and Sachets

White Silica Gel Crystal Pouches and Sachets are precision-dosed, non-indicating unit desiccants containing high-purity amorphous silicon dioxide (SiO₂ ≥ 98.5%). Unlike conventional spherical beads that roll and slide under continuous movement, these desiccants utilize irregular, multi-faceted crystalline aggregates that mechanically interlock within the pouch. This interlocking geometry stabilizes the internal desiccant bed, eliminating internal granule shifting, media settling, and friction-induced dusting during high-vibration transport.

The active crystal media operates via physical capillary condensation, drawing water vapor directly into its sub-nanometer internal pore network without undergoing chemical transformation or liquefaction. Even when saturated to its maximum adsorption capacity, the crystalline desiccant remains chemically neutral and completely dry to the touch, preventing moisture runoff, packet sweating, or staining of packaged items. All sachets are manufactured on automated form-fill-seal machinery and are 100% free of Dimethyl Fumarate (DMF), cobalt salts, and hazardous biocides.

Structural & Substrate Architecture

1. Internal Media Architecture

• Mechanical Interlocking Matrix: The irregular, fractured faces of the crystals nest into one another when packaged. This mechanical interlock immobilizes the granules inside the sachet, preventing the media from grinding against itself or abrading the packaging envelope under high transit vibration.
• Nanoporous Capillary Network: The internal framework contains an interconnected microporous network with an average pore diameter of 2.0 to 3.0 nm. This micro-architecture creates a specific surface area of 650 to 800 m²/g, enabling high water vapor capture kinetics.
• Static Load Resistance: The crystals feature high structural crush resistance (≥ 95 N static load), preventing particle fragmentation and bed collapse when placed under heavy packaged assemblies.

2. Substrate & Outer Envelope Architecture

The performance of the sachet relies on pairing high water-vapor transmission rates (WVTR) with tear resistance:

• DuPont™ Tyvek®: Spunbonded high-density polyethylene micro-fibers forming a tortuous barrier. Dust-proof, lint-free, puncture-resistant, and liquid water-impermeable, yet highly permeable to moisture vapor. Ideal for pharmaceuticals, medical diagnostic kits, cleanrooms, and sensitive electronics.
• Composite Aihua / Micro-Perforated Filter Paper: Semi-translucent, high-tensile food-grade paper with micro-perforations. Delivers rapid vapor ingress at an economical cost for consumer goods, footwear, and dry dietary supplements.
• Spunbond Non-Woven Fabric (SMS/Ultrasonic): Multi-layer poly fabric engineered for high burst and tensile strength. Ultrasonic heat-bonded seams eliminate fiber shedding, making it suitable for automotive components, export master cartons, and machinery parts.
• Heavy Cotton Fabric with Suspension Strings (250g to 1kg): Heavy-gauge, tightly stitched woven cotton equipped with suspension eyelets and tie cords for hanging directly inside wooden machinery crates, transformer housings, and electrical cubicles.

3. Seal Engineering & Manufacturing

• All sachets are dosed and sealed on automated vertical form-fill-seal (VFFS) machinery to eliminate manual handling and ensure consistent weight tolerances.
• Packets feature hermetic ultrasonic or multi-track heat-sealed seams that achieve a burst seam strength exceeding 35 N/15 mm, preventing rupture under transit compression.

Technical Data Sheet (TDS)

1. Chemical & Physical Baseline

2. Moisture Adsorption Capacity (Equilibrium at 25°C)

3. Standard Sachet Sizing Matrix (0.5g to 1kg)