Paper material progressing refers to a set of industrial processes used to upgrade base paper into functional packaging materials by applying coatings, laminations, or composite layers. Through these processes, ordinary paper gains critical performance characteristics such as moisture resistance, grease resistance, heat sealability, mechanical strength, and chemical stability.
In modern packaging supply chains—especially food service, food packaging, and industrial wrapping—paper material progressing plays a central role in balancing performance, cost, regulatory compliance, and sustainability. This article provides a structured, engineering-oriented overview of how coated and laminated paper materials work, what materials are involved, how to evaluate key technical specifications, and how procurement professionals can make informed sourcing decisions.
Quick Definition
Paper Material Progressing = Base Paper + Functional Surface Treatment
From a manufacturing perspective, paper material progressing means combining a fibrous paper substrate with one or more functional layers through coating or lamination technologies.
Common functional layers include:
①Extrusion coatings (PE, PLA, PP, PET)
②Plastic film lamination
③Aluminum foil lamination
④Aqueous coatings
Extrusion Coating
Extrusion coating involves applying molten polymer directly onto paper. After cooling and solidification, the coated layer provides:
①Water and moisture resistance
②Oil and grease resistance
③Heat sealability
④Strong adhesion between polymer and paper fibers
This method is widely used for cup stock paper, food wrapping paper, and liquid packaging materials.
Lamination bonds a pre-formed film or foil to paper. The main objectives include:
①Barrier protection (water, oil, gas, aroma)
②Improved mechanical strength and stiffness
③Heat sealing capability
④Surface protection for printed graphics
⑤Enhanced scratch resistance and slip control
Lamination
How Coated Paper Works
Extrusion coated paper is produced using an extrusion coating line, where polymer and paper are combined in a continuous process.
Working Principle
Molten plastic—most commonly LDPE, HDPE, or PP—is extruded through a flat die and pressed onto the paper web. The polymer penetrates the surface pores of the paper, creating mechanical anchoring and adhesion. A chill roll rapidly cools the coating, forming a dense, uniform functional layer.
Typical Process Flow
Unwinding – base paper is fed from parent rolls
Pre-heating – improves bonding strength
Extrusion coating – molten polymer applied evenly
Nip pressure & cooling – coating solidifies
Edge trimming – removes uneven edges
Rewinding – finished coated paper roll
Functional Outcomes
Continuous coating layer acts as a moisture and grease barrier
Enables direct heat sealing without additional adhesives
Cost-efficient for high-volume packaging applications
How Laminated Paper Works
Laminated paper uses a different principle: instead of extruding molten plastic, a solid film or foil is bonded to paper using adhesives or thermal lamination.
Barrier Mechanism
Barrier performance depends on:
①Film continuity (absence of pinholes)
②Film thickness
③Polymer polarity and hydrophobicity
For example:
①BOPP provides excellent moisture resistance
②PET (BOPET) offers higher tensile strength and heat resistance
③Aluminum foil delivers near-total oxygen and light barrier
Heat-Sealing Mechanism
Heat sealability is usually achieved through an inner thermoplastic layer (PE or PLA). Under controlled temperature and pressure, the thermoplastic softens and fuses, forming a sealed interface critical for packaging integrity.
Types of Laminated Paper
By Structure
①Single-side laminated paper
②Double-side laminated paper
③Single-layer vs multi-layer composites
④Paper–plastic composites
⑤Paper–aluminum foil composites
By Material
①PE coated paper – economical, widely used
②PLA coated paper – bio-based, industrially compostable
③PET laminated paper – high clarity, durability, heat resistance
④Aluminum foil laminated paper – maximum barrier protection
⑤Waxed paper – basic grease resistance with limited durability
By Process
Extrusion coating
Dry lamination
Solvent-free lamination
Aqueous coating
Each process affects cost structure, barrier performance, regulatory compliance, and recyclability.
Coating Materials Breakdown
Base Paper Substrates
①Ivory board (FBB) – folding cartons, food boxes
②Kraft paper (brown / white) – bags, wraps, industrial packaging
③Cup stock paper – hot and cold beverage cups
④Food-grade paper – controlled additives, low odor
⑤Recycled paper – restricted use due to food safety concerns
Recycled paper is generally not recommended for direct food contact unless separated by a certified functional barrier.
Coating Layers
①PE (LDPE / HDPE) – moisture barrier, heat sealability
②PLA – bio-based, compostable under industrial conditions
③Water-based barrier coatings – emerging plastic-reduction solutions
④Functional layers – EVOH (oxygen barrier), aluminum foil
Lamination Materials Breakdown
Paper Substrates
①Ivory board
②Coated cup stock
③Corrugated linerboard (non-direct food contact)
Film Layers
①BOPP – cost-effective moisture barrier
②BOPET (PET) – strength and temperature resistance
③PLA film – sustainability-driven applications
Adhesives
Solvent-based adhesives
Solvent-free adhesives
Water-based adhesives
Adhesive selection directly impacts odor, migration risk, and food-contact compliance.
Key Specs Explained
Physical Parameters
GSM (basis weight) – total weight including coating
Coating weight / film thickness (μm)
Functional Performance
Heat seal initiation temperature (SIT)
Heat seal window
Thermal resistance
Oil and water resistance
Content Compatibility
Hot beverages
Cold beverages
High-oil foods
Acidic products
Alcohol-containing products
Frozen and microwave-use scenarios
Printing & Converting
In most industrial setups, printing is done before lamination or coating, allowing the functional layer to protect ink from abrasion, moisture, and chemical exposure.
Lamination Common Applications
①Folding cartons
②Outer wraps
③Paper lids
④Spiral paper tubes
Typical Use Scenarios
①Moisture barrier packaging
②Grease-resistant food packaging
③Decorative and functional films (soft-touch, matte, holographic)
Food Safety & Compliance
Key Food Contact Considerations
①Odor and taste transfer
②Optical brightening agents (OBA)
③Solvent residue
④Chemical migration
United States
FDA 21 CFR compliance
Approved materials and additives
Supplier declarations of compliance
European Union
Framework Regulation (EC) No 1935/2004
GMP Regulation (EC) No 2023/2006
Plastics Regulation (EU) No 10/2011
Migration testing (overall and specific)
Recyclability & Sustainability
Why Paper–Plastic Composites Are Difficult to Recycle
①Fiber separation challenges
②Polymer-to-paper ratio
③Recycling facility limitations
Key Variables Affecting Recyclability
Coating thickness
Delaminability
Repulpability
Certification standards
PLA Compostability Boundaries
Industrial composting required
Controlled temperature and humidity
Not suitable for home composting
Sustainability claims must be carefully framed
Quality Standards & Inspection
Common Inspection Items
Basis weight and thickness
Coating uniformity
Heat seal strength
Cobb value
Grease resistance
Odor evaluation
Typical Defects
Pinholes
Orange peel texture
Fish eyes
Delamination
Uneven coating
Curling
Odor issues
Poor sealing performance
Buying Guide
Material Selection Logic
Sustainability-driven projects → PLA coated paper
Standard food packaging → PE or PP solutions
High-gloss, premium appearance → PET lamination
Logistics & Storage
Recommended shelf life: 12 months
Store in dry, temperature-controlled environments
Common Procurement Pitfalls
Evaluating GSM without considering coating thickness
Focusing on oil resistance while ignoring heat sealability
Overlooking storage and handling conditions
FAQ
Can laminated paper be used in a microwave?
BOPP laminated paper typically tolerates temperatures up to approximately 130 °C, but actual microwave performance depends on structure and exposure time.
Can laminated paper be used in an oven?
PET laminated paper may tolerate temperatures below 180 °C, but prolonged oven use is not recommended.