Packaging materials and application examples

Packaging Materials Overview

Packaging materials include containers, transport packaging, printing, auxiliary materials, and bags. They are categorized by material type, physical properties, source, and function.

Material Types by Composition

Materials are divided into plastics, paper and cardboard, glass, metal, and composite materials. Paper and cardboard are derived from plant fibers, with cellulose, hemicellulose, and lignin as key components.

Plant Fiber Components in Papermaking

Cellulose, the main structural component of plant cell walls, makes up 30% to 60% of raw materials. It contributes to pulp ratio and paper strength. Hemicellulose, 10% to 30% of raw materials, improves hydration, absorbency, opacity, and mechanical strength. Lignin, 10% to 30%, binds fibers but causes yellowing when exposed to sunlight and is removed during pulping.

Material Classification by Physical Properties

Soft packaging materials include paper, aluminum foil, and natural fibers. Semi-hard materials include cardboard, plastic, and tiles. Hard materials include metals, hard plastics, and glass.

Material Classification by Source and Function

Materials are divided into natural and processed types. They are also classified as major packaging materials or auxiliary materials, such as inks, binders, and coatings used in packaging production.

Applications of Paper and Cardboard

Paper and cardboard are used in wrapping, container making, and protective packaging. They are suitable for applications requiring recyclability, lightweight structure, and cost-effective material use.