Several characteristics of the blanket

Blanket's ink absorbency: refers to the performance of the blanket's surface adsorbing ink under the effect of printing pressure. The ink absorption of the blanket is the primary condition for the transfer of the graphic and text information by the blanket. The fineness of the blanket is good, and the amount of ink on the surface of the graphic blot is sufficient, and the quality and effect of the printing are good, and vice versa.

The ability of the surface of the blanket to absorb the ink depends on the surface condition of the blanket and the printing conditions. The blanket needs to be ground after processing to form a certain amount of sand on the surface, resulting in a velvet surface state. Strong ink absorption. However, after the printing blanket has been used for a period of time, the ability to absorb ink will decrease when the surface edge is smooth and a glossy film appears. At this time, the ink transfer rate will decrease with the decrease of the amount of absorbed ink. The imprinting will result in the lack of ink, dew, etc. At this time, the film must be wiped off to ensure the original ink-absorbing performance of the blanket.

The peelability of the blanket: refers to the peeling performance of the blanket and the paper under the effect of printing pressure. In actual use, the main factors affecting the peeling performance of the blanket are the chemical composition of the surface glue, the hardness and the smoothness and electrical properties of the surface, the physical properties of the ink, the surface state of the paper, and the size of the solid area on the printed matter. Other factors also have a greater relationship. When the paper completes a printing cycle during the peeling process, the paper peeled off from the blanket will be subjected to a large peeling force due to peeling at a high speed, often causing the paper to stretch or wrinkle, pull the hair, and severely peel off the paper. Fault failure. This not only increases the scrap rate, but also causes paper wool, paper dust to accumulate on the blanket or on the plate, causing problems such as stencils or heap plates.

Tensile deformability of rubber blanket: Refers to the deformation of rubber blanket under the action of tensile force. This deformation is manifested in three aspects: that is, the length of the blanket in the force direction increases; the lateral dimension is shortened and the thickness is reduced. The change in thickness caused by the tensile deformation of the blanket has an effect on the elasticity and hardness of the blanket. Therefore, in the operation of the blanket, it is not possible to perform tension only at the tip end of the blanket, but to apply pressure on the mouthpiece portion and the trailing portion of the blanket in order to make the blanket uniform on the roller. The degree of tightening, so as to ensure that the blanket in the high-speed operation does not occur relative position movement and changes.

Resilience of rubber blanket: refers to the ability of the blanket to return to its original state immediately after the pressure is removed from the printing job. Also known as instant recovery. The transfer process of lithographic offset printing is to use the high elastic energy of the blanket to complete the transfer of the graphic imprint with the minimum pressure and friction coefficient, to achieve a clear graphic, full ink, and a rich level of print quality. If the elasticity of the blanket is poor and plastic deformation occurs, the elastic state cannot be restored, and the blanket and the plate cylinder and the impression cylinder cannot fully contact with each other to maintain the original line pressure, and ink absorption will occur. Instability in ink transfer, ink failures occur before and after unevenness.

The ink-transmitting property of the rubber blanket refers to the performance of the blanket to transfer the ink on its surface to the surface of the substrate under the effect of the printing pressure. Not only does the blanket need to have good ink absorption, but it must also have good ink-transfer properties so that the ink on the surface can be transferred to the surface of the paper to form a graphic print that meets the requirements of the printing reproduction standard. If the blanket has poor ink transfer properties, the amount of ink transferred to the surface of the substrate is insufficient, which not only affects the color density of the printed matter, but also causes the ink on the surface of the blanket to accumulate, resulting in printing defects such as stencil printing.