What is the function of rubber blanket? Rubber blanket is used for image transfer. The role of rubber blanket in printing work cannot be ignored. In the printing process, the main function of rubber blanket is to resist pressure.

The rubber cloth itself has the characteristics of compression resistance, strong adhesion, and fast recovery, which can ensure a more stable ink transfer network or full plate.

Rubber blanket can be divided into the following categories: full air cushion rubber blanket, air cushion rubber blanket, three in one rubber blanket, general air cushion rubber blanket, traditional rubber blanket, UV specific rubber blanket, partially polished rubber blanket, metal printed 2PSC rubber blanket, friction resistant rubber blanket, paper cup specific rubber blanket, UV self-adhesive rubber blanket, Dunlop report machine self-adhesive rubber blanket, and various aluminum strip rubber blanket.

In the printing process, the use of rubber cloth plays a pivotal role. Without rubber cloth, it can be considered that the printing work cannot be completed.

Because during the printing process, the rubber cloth plays a compressive role and has strong adhesion, fast recovery, and no adhesive material left behind. The unique smooth surface and fabric layer of the rubber blanket ensure more stable ink transfer dots or full plates, providing stable ink transfer operations.

Offset rubber is one of the most important elements in offset printing technology. It is the final contact medium between the printing machine and the printed material. Its function is to transfer the inked images and text from the printing plate to the paper in their original form without any distortion.

Therefore, one of the key factors in obtaining the best printing quality is to choose the appropriate rubber blanket according to different printing needs. The use of low-quality rubber or inadequate installation of rubber can lead to downtime losses and quality issues, increase printing costs, and ultimately result in the loss of valuable customers.

Rubber blanket refers to the packaging material of the transfer drum on an offset press; The components of the lining. Rubber blanket is a composite product composed of rubber coating and substrate, which is used in indirect lithography to transfer ink from the printing plate to the substrate.

In addition to providing printing pressure for offset printing, rubber cloth should also have the ability to transfer ink from the image and text parts of the printing plate to the surface of the substrate under the influence of printing force, that is, the ability to receive and release ink. However, the aging of rubber cloth can change the ability of this ink transfer and also lead to the phenomenon of ink color distortion.

One of the main reasons for printing ink that is not solid is the decline in the performance of printing rubber cloth. To reduce the problem of printing ink that is not solid in offset printing technology, we should also start with rubber cloth.

How to choose rubber blanket? When selecting rubber blanket, the following technical indicators should be considered:

1. Appropriate hardness: A suitable hardness results in clear dots and uniform ink color in printed materials. Generally, a 70-80 degree (Schottky) rubber cloth is used;

2. Small compression deformation: To prevent a decrease in thickness, elasticity, and hardness of the rubber cloth during the printing process, it is advisable to choose rubber cloth with small compression deformation;

3. Excellent transmission performance: As an intermediate medium for transferring graphic and text dots, rubber cloth must have good ink adsorption capacity, ink transmission capacity, and strong hydrophobicity. Otherwise, it cannot transfer enough ink required for printing and cannot achieve the desired color tone for printing. At the same time, the surface adhesive layer of the rubber blanket should have a certain roughness, and the surface should be fine and clean without impurities;

4. Good surface oil resistance and solvent resistance: The rubber cloth cannot expand due to contact with chemicals during the printing process, which will damage its application performance;

5. The thickness should be uniform: the flatness error of the rubber cloth should be within 0.04mm, otherwise the printing pressure will be uneven, and the ink color of the product will be significantly uneven, seriously affecting the quality of the printed product;

6. Appropriate elongation: The smaller the elongation of the rubber cloth, the better, which can ensure accurate printing, complete dots, and clear graphics and text during the printing process.

The physical properties of rubber blanket are mainly as follows:

1. Tensile strength

The tensile strength is a measurement index of the fracture limit of rubber blanket, and it is also the main characteristic of the woven layer of rubber blanket. The design of the woven layer will affect the tensile strength of rubber blanket.

2. Thickness

The thickness of offset rubber cloth should be uniform, especially for rubber cloth with a width less than 42mm and after cutting, the range of thickness variation should not exceed 0.001mm.

3. Ink transferability

Ink transferability refers to the ability of an eraser to transfer ink, including the ability to accept ink and the ability to transfer ink. The higher the ink transfer rate, the better the ink transfer performance of the rubber cloth. Usually expressed as ink transfer rate, i.e. ink transfer rate=(amount of transferred ink/amount of adsorbed ink) x 100%.

4. Elongation rate

Elongation refers to the amount of rubber cloth that exceeds its original length under a certain tension.

The elongation of rubber blanket depends on the strength of the base fabric. Rubber cloth with high elongation is prone to stretching, resulting in a thinner adhesive layer and reduced elasticity. Therefore, the smaller the elongation of rubber cloth, the better.

5. Elasticity

Elasticity refers to the ability of an offset rubber cloth to recover deformation after removing external forces that cause deformation. Offset rubber cloth requires it to immediately recover deformation at the moment of release from pressure, so it must have high elasticity.

6. Oil adhesion of surface adhesive layer

The oil adhesion of the surface adhesive layer refers to the ability of the rubber cloth surface adhesive layer to resist the penetration of oil and certain solvents. Rubber blanket with poor oil and solvent resistance is prone to swelling when in contact with ink and solvents. Offset printing ink not only requires good oil and solvent resistance, but also requires the surface adhesive layer of the rubber blanket to have appropriate lipophilicity, which can effectively adsorb and transfer ink.

7. Compression deformation

Compression deformation refers to the plastic deformation caused by compression fatigue of rubber cloth after multiple compressions. Plastic deformation can make the rubber cloth thinner, elastic attenuation, and even unusable. Therefore, the smaller the compression deformation of rubber cloth, the better.

8. Flatness

Flatness refers to the uniformity of the thickness of the rubber blanket, usually expressed as flatness error. It is generally required that the flatness error of the rubber blanket does not exceed 0.04mm, otherwise, it will cause uneven ink color and severe dot deformation in the printed product.