Offset blanket is a vital press part. It brings multiple benefits to the press. It acts as shock absorber. It is also receptive to both water and ink, without the two getting mixed. The blanket does not swell. It transfers ink both as a dot and as a solid. The transfer is sharp and clean without any streaks. It can act as an impression cylinder while printing blanket to another blanket.
Functional compressibility of any blanket is between five percent and seven percent. Try for a six percent compressibility blanket. Blankets below five percent have insufficient smash resistance. Over seven percent means un-sharp dot printing.
Every blanket must conform to these conditions while it gets soaked from its face and the back with water and the solvents without the material coming apart. Every blanket should compulsorily perform these functions when they are at high speeds. A blanket comes to contact with a number of papers, plates and also inks. It is frequently saddled with wrong packing heights. Paper lint accumulates after longer use periods.
The modern offset blanket is a marvel of innovation. High-quality fabrics make up the carcass. The fabrics are laminated together. The rubber compounds are resistant to solvent on machinery. All such factors make for a comparatively long functional life. A few blankets reach about 16 million impressions prior to being discarded from the job. The majority of blankets get replaced due to the damage which occurs from web breaks.
Same blankets in a single unit
A number of blanket surfaces are available in the market. They can be buffed, coated and caste surface. All of them can be used on the newspaper presses. It should be kept in mind that these varieties must not be mixed on any unit or multiple units feeding into the same folder. All blankets in any given machine must not only be of the same type but also must be from the same manufacturer.
Majority of the newspaper blankets have compressible layer integrated into a carcass. The compressible layer is fundamentally air trapped inside rubber layer. Such constructions fall into either one of two types: closed cell or the open cell. The open cell category is like a sponge, with cells connecting to each other. Closed cells are individual cells. Even though both cells can be used, the closed cell type provides the advantage of retaining smash resistance and compressibility over an extended time period.