I. Appearance quality
Appearance quality refers to the defects that can be observed by naked eyes, such as dust, holes, pinholes, transparent spots, wrinkles, folds, stripes, screen prints, wool marks, spots, serous pimples, clouds, cracks, color and luster.
2. Mechanical Properties
Mechanical properties, also known as mechanical properties or strength properties, are divided into static strength and dynamic strength.
1. Static strength is the most acceptable strength of paper under the condition of slow stress, also known as the ultimate strength. It includes the following quality indicators: tensile strength, burst resistance, tear strength, flexure resistance, stiffness and so on.
2. Dynamic strength refers to the strength of paper that can withstand instantaneous impact. It reflects the dynamic state of instantaneous diffusion of paper after being stressed. Dynamic strength mainly includes the following indicators: breakdown strength, ring compression strength, compaction strength, etc., which is the most important quality indicators for packaging paper and cardboard.
3. Fundamental Physical Properties
Fundamental physical properties include the most common properties of paper, such as quantity, thickness, tightness, smoothness, hardness, softness, compactness, absorbability and so on.
IV. CHEMICAL PROPERTIES
The chemical properties of paper include its chemical composition, moisture absorption, ash content, sizing degree, acidity and alkalinity, and durability.
V. Optical Properties
Optical properties refer to whiteness (brightness), color, gloss, transparency, opacity, etc. For printed paper, the optical properties of paper are very important, which directly affects the quality of printed matter.