5 Key Points for Labeling with Different Material Labels
In the modern packaging and labeling industry, there is a wide variety of label materials. Each type of material has its own unique requirements for labeling. These requirements not only affect the aesthetic appeal of the label but also its functionality and durability in practical use. Below is a detailed introduction to the labeling requirements for several common types of label materials.

01 Paper Labels

Paper labels are the most common type of label, known for their low cost and wide adaptability for printing. Although the labeling requirements for paper labels are relatively simple, there are still some important points to note. First, paper labels have a smooth and flat surface, making them easy to print and cut. Therefore, labeling machines can usually handle them easily. By adjusting the labeling pressure and speed, the machine can ensure that the label adheres firmly and without bubbles. However, paper labels also have their limitations. They are not waterproof or oil-resistant and are prone to tearing. Therefore, their applicability is limited in environments that are humid or oily.
Common Types: Coated paper, writing paper, kraft paper, waterproof paper, etc.
Labeling Requirements:
1.  Adhesive Selection: Water-based acrylic adhesive or rubber-based adhesive is commonly used. For applications in humid environments (such as beverage bottles), waterproof adhesive should be selected.
2.  Surface Preparation: The surface of the object to be labeled should be dry and free of oil. Rough surfaces may cause the label to adhere poorly.
3.  Environmental Control: In high humidity environments, ordinary paper is prone to moisture absorption and deformation. It is recommended to control the workshop humidity at 40%–60%.
4.  Labeling Speed: When labeling at high speeds, attention should be paid to the tensile strength of the paper to avoid tearing.
5.  Application Scenarios: Cosmetics, outer boxes of food products, books, courier waybills, etc.

02 Synthetic Material Labels (Such as PP, PE, PET)

Film labels include a variety of materials such as PET, PE, PVC, BOPP, and PC. They are widely used in industries such as food, pharmaceuticals, and electronics due to their excellent water resistance, oil resistance, high-temperature resistance, and chemical corrosion resistance. When labeling these types of labels, the labeling machine is required to have high precision in material transmission and label adhesion. For example, PET labels have a smooth and hard surface. The labeling machine needs to have a strong label tension control system to prevent the label from bending or breaking during transmission. In addition, some film materials need to undergo corona treatment or coating treatment before labeling to enhance their adhesion to the adhesive.
Characteristics: Water-resistant, oil-resistant, chemical-resistant, and flexible.
Labeling Requirements:
1.  Adhesive Compatibility: Low surface energy plastics (such as PE and PP) are difficult to adhere to. Special adhesives designed for low surface energy materials (such as modified acrylic adhesives or hot-melt adhesives) must be used.
2.  Surface Pre-treatment: In some cases, the object to be labeled needs to be treated with corona or flame treatment to increase surface tension.
3.  Temperature Adaptability: Synthetic labels are often used in freezing or high-temperature environments (such as refrigerated food and automotive parts). It is necessary to ensure that the adhesive remains sticky under extreme temperatures.
4.  Labeling Tension Control: Due to the high elasticity of the material, the labeling machine needs to precisely control the tension to prevent wrinkling or retraction.
5.  Application Scenarios: Cosmetic bottles, pharmaceutical packaging, industrial parts, outdoor equipment, etc.

03 Thermal Paper Labels

Thermal paper labels are a special type of paper label. Their surface is coated with a thermosensitive layer. The label paper changes color when heated by the thermal printer head to display text, patterns, and other information. This type of label has the advantages of convenient printing, clear imaging, good preservation, low cost, and environmental friendliness. During the labeling process, due to the surface characteristics of thermal paper, it is required to avoid high temperatures and friction to prevent the information on the label from being affected.
Characteristics: No carbon ribbon required, color change through thermal print head, low cost, high efficiency.
Labeling Requirements:
1.  Light and Heat Avoidance: The thermosensitive layer will turn black when exposed to heat or ultraviolet light. The label should be stored away from light and avoid exposure to direct sunlight after labeling.
2.  No Lamination: Most thermal paper labels cannot be laminated with a protective film, as this will affect the printing effect.
3.  Adhesive Compatibility: Some thermal papers have a back coating that is sensitive to adhesives. It is necessary to test whether the adhesive will cause yellowing or failure.
4.  Limited Shelf Life: The information on thermal labels has a limited shelf life (usually 6 months to 2 years) and is not suitable for long-term traceability scenarios.
5.  Application Scenarios: Logistics waybills, supermarket price tags, temporary storage identification.

04 Metal Foil Labels

Metal foil labels have a unique metallic luster and strong gloss, with a strong visual impact. They also have excellent anti-counterfeiting and decorative properties. When labeling, due to the special nature of the material, the labeling machine needs to have precise control over the label position to avoid errors caused by the reflection of light. At the same time, metal foil labels have relatively poor flexibility. When labeling on irregular surfaces, it is necessary to carefully adjust the labeling pressure and speed to ensure that the label adheres smoothly.
Characteristics: High gloss, strong barrier properties, high-quality feel.
Labeling Requirements:
1.  Higher Rigidity: Metal foil is relatively hard and prone to lifting edges when labeling curved surfaces. It is recommended to use flexible backing paper or composite structure.
2.  Adhesive Heat Resistance: If used for high-temperature sterilization (such as canned food), adhesives with a thermal stability of more than 120°C should be used.
3.  Avoid Scratches: The labeling rollers should be smooth and burr-free to prevent scratching the metal surface.
4.  Static Electricity Issues: Metal materials are prone to static electricity, which can affect the precision of automatic labeling. It is recommended to equip with static elimination devices.
5.  Application Scenarios: High-end liquor, health care products, electronic component identification.

05 Labels for Special Environments

For special environments such as freezing, high temperature, and humidity, the choice of label material and labeling process is even more critical. For example, in freezing environments, labels such as Jinda Freezing Adhesive Non-adhesive material are used for frozen product labels (within -20°C). The material is paper-based and not waterproof. It should be applied at room temperature and then placed in the refrigerator after 24 hours. In high-temperature environments, all adhesives can withstand 80°C for short-term exposure (not exceeding 1 hour), and some acrylic adhesives can withstand 145°C. For long-term exposure (more than 1 hour), it is necessary to contact the sales representative for recommendations.
Labeling Points:
•  Removable Labels: Use adhesives with low initial tack and high cohesive strength to ensure no residue after removal. Suitable for promotional labels and trial packs.
•  Anti-counterfeiting Labels: Often contain holographic, thermochromic, microtext, and other technologies. During labeling, avoid high temperature and high pressure that may damage the functional layer.
•  RFID/NFC Labels: With built-in chips and antennas, avoid bending or puncturing during labeling, and stay away from metal surfaces (metal can shield signals).

In summary, each type of label material has its unique requirements for labeling. These requirements depend not only on the physical and chemical properties of the label itself but also on the surface characteristics of the object to be labeled, the usage environment, and the performance of the labeling equipment. Only by fully understanding and meeting these requirements can the label function properly in use, achieving an aesthetic, durable, and functional effect.