Greaseproof Paper for Food Packaging: Characteristics, Applications, and Maintenance

Introduction to Greaseproof Paper

Greaseproof paper is a specialized packaging material designed to resist oil and grease penetration while maintaining food safety standards. This paper is manufactured through a highly refined pulping process that compacts cellulose fibers to create a dense, non-porous surface structure. The typical basis weight ranges from 30 gsm (grams per square meter) to 100 gsm, with thickness varying between 40 to 150 microns. Its grease resistance is measured by the Kit test (TAPPI T559 standard), where high-quality greaseproof paper can withstand ≥1200 seconds before oil penetration occurs.

Key Characteristics with Technical Data

Applications in Food Packaging

The unique properties of greaseproof paper make it indispensable across multiple food industry segments:

• Fast Food Packaging: Used for wrapping burgers, sandwiches, and fried foods, where it prevents grease stains while maintaining food temperature. The typical usage involves 40-60 gsm paper with silicone coating for enhanced release properties.

• Bakery Products: Ideal for lining baking trays and wrapping pastries, withstanding oven temperatures up to 220°C for 20-30 minutes. The paper's low surface energy (30-40 dynes/cm) prevents dough adhesion.

• Confectionery Packaging: Protects chocolate and candy products from oil migration, with specialized grades offering oxygen transmission rates below 100 cc/m²/24h to preserve freshness.

• Frozen Food Packaging: Used as inner liners for frozen products, maintaining integrity at temperatures as low as -40°C (-40°F) with minimal embrittlement.

• Butcher Paper: Heavy-duty versions (70-100 gsm) wrap fresh meats, absorbing surface moisture while preventing grease leakage, with moisture absorption rates below 5% by weight.

Maintenance and Storage Guidelines

Proper handling ensures optimal performance of greaseproof paper throughout its lifecycle:

Storage Conditions:

• Maintain ambient temperature between 15-25°C (59-77°F) with relative humidity at 45-55% RH

• Store rolls vertically to prevent deformation, with maximum stack height of 1.5 meters for sheet formats

• Protect from direct sunlight, as UV exposure can reduce tensile strength by up to 20% over six months

Handling Precautions:

• Use clean, dry hands or gloves to prevent oil transfer from skin (human sebum has surface energy of 22-25 mN/m, which can compromise the paper's barrier properties)

• For printing applications, use food-grade inks with surface tension below 38 dynes/cm to ensure proper adhesion

• When die-cutting, maintain tool clearance of 0.05-0.1mm to prevent edge feathering

Usage Best Practices:

• For baking applications, pre-heat paper with the oven to minimize thermal shock (coefficient of thermal expansion is 8-12 μm/m·°C)

• In microwave use, limit power to 800W maximum for durations under 2 minutes to prevent charring

• For oil-rich foods, change wrapping every 4-6 hours as the barrier effectiveness decreases after absorbing 3-5% its weight in oil

Environmental Considerations

Modern greaseproof paper aligns with sustainability requirements:

• Biodegradability: 90-95% decomposition within 45-90 days under industrial composting conditions (ASTM D6400)

• Recyclability: Compatible with standard paper recycling streams when free from food contamination

• Carbon footprint: Production emits 0.8-1.2 kg CO₂ equivalent per kg of paper, compared to 2.5-3.5 kg for plastic alternatives