Reversible printing blanket

Details Reversible printing blanket Reversible printing blanket

1999-03-16

2001-03-27

Funk, Stephen R. (Department: 2854)

Printing

Printing members

Rolling contact

C428S909000

Reexamination Certificate

active

06205922

ABSTRACT:

This application is a 35 USC 371 national application of PCT/FR 97/00831 filed May 9,1997.
FIELD OF THE INVENTION
This invention pertains to a reversible printing blanket to be used with offset printing machines.
BACKGROUND OF THE INVENTION
Many types of printing blankets have long been used. These blankets consist essentially of a layer of compressible material such as cellular rubber to which a lithographic layer capable of producing an impression on a surface, for example, paper, is attached.
These designs present a number of drawbacks, among which we should note sagging due to loss of resiliency, blanket overheating during the printing process, the risk of destabilizing the offset balance during the process, paper flow control problems and vibrations in rapid rotary press machines.
Furthermore, the blankets currently in use are too specialized and can only be used under optimal quality control conditions to the extent that one often needs to use as many different types of printing blankets as there are types of printing to produce
The goal then of this device is to eliminate the aforementioned drawbacks by providing a reversible printing blanket whose structural symmetry allows it to reduce or eliminate the problems of sagging, overheating, paper flow control and vibration.
BRIEF DESCRIPTION OF THE INVENTION
So, this invention consists of an offset printing blanket characterized by at least one layer of compressible material sandwiched between two external lithographic layers which render the blanket reversible.
Another characteristic of this invention is that the blanket consists of two layers of compressible material. These layers are either both isotropic, both anisotropic or one layer is isotropic while the other is anisotropic.
It is thus understood that such a reversible blanket allows impressions to be made by both sides of the blanket in such a way as to permit two separate, unique printing jobs, each of which produces a high quality impression on a surface, such as paper. This procedure is always better than using only one single blanket with compromising structural properties which does not always yield satisfactory results.
A unique reinforcing layer is inserted between the blanket's two compressible layers, marking yet another property of the invention.
Furthermore, this blanket can include a control layer to control the flow of paper for printing. This layer is located between the compressible material and one of the two lithographic layers.
So, a characteristic of this blanket is that a paper flow control layer is inserted between one of the layers of compressible material and its associated lithographic layer while a second paper flow control layer is inserted between the other layer of compressible material and its respective lithographic layer.
Additionally, in the case of a single layer of compressible material, the layer will either be isotropic with a Young elasticity modulus of between 0.2 and 50 MPa or an anisotropic layer with a Young elasticity modulus of between 20 and 1000 MPa in the direction parallel to the blanket's orientation and between 0.2 and 50 MPa in the direction perpendicular to the blanket's orientation.
The Young elasticity modulus is preferably between 1.5 and 15 MPa if one layer of material is isotropic while the Young elasticity modulus for the layer of anisotropic material is between 200 and 500 MPa in the direction parallel to the blanket's orientation and between 1.5 and 15 MPa in the direction perpendicular to the blanket's orientation.
Furthermore, another characteristic of the blanket described here is that at least one of the two layers of isotropic compressible material has a Young elasticity modulus of between 0.2 and 50 MPa or that at least one of the two layers of anisotropic compressible material has a Young elasticity modulus of between 20 and 1000 MPa in the direction parallel to the blanket's orientation and between 0.2 and 50 MPa in the direction perpendicular to the blanket's orientation.
The Young elasticity modulus is preferably between 1.5 and 15 MPa for the layer or layers of isotropic material while the Young elasticity modulus for the layer or layers of anisotropic material is preferably between 200 and 500 MPa in the direction parallel to the blanket's orientation and between 1.5 and 15 MPa in the direction perpendicular to the blanket's orientation.
It should also be specified here that the layers of compressible material are between 0.2 and 0.8 millimeters thick.
The Young elasticity modulus of the two lithographic layers, whether they are the same or different, is between 1.5 and 50 MPa. They may be of the same or different thickness, but in either case their thickness shall be between 0.05 and 0.4 millimeters.
The aforementioned single reinforcement layer has a Young elasticity modulus of between 500 and 10,000 MPa in the direction parallel to the blanket's orientation while its thickness is between approximately 0.05 and 0.8 millimeters.
Furthermore, the aforementioned single reinforcement layer shall be made of a textile grid or a plastic polymer film. The plastic polymer film can be either single layered or multi-layered.
Additionally, the paper flow control layer or layers incorporated into this blanket shall have a Young elasticity modulus of between approximately 200 and 1000 MPa in the direction parallel to the blanket's orientation and a thickness of between approximately 0.05 and 0.4 millimeters.
It should also be noted that the paper flow control layer or layers shall be made of a fiber-reinforced elastomer.
The layers of compressible material are made of cellular rubber whose fibers are preferably oriented in the same direction as the blanket for the anisotropic layers.


REFERENCES:
patent: 668919 (1901-02-01), Hill et al.
patent: 3652376 (1972-03-01), Bowden, III
patent: 5006400 (1991-04-01), Pinkston et al.
patent: 5347927 (1994-09-01), Berna et al.
patent: 5352507 (1994-10-01), Bresson et al.
patent: 5366799 (1994-11-01), Pinkston et al.
patent: 5456171 (1995-10-01), Biava et al.
patent: 2244765 (1974-03-01), None
patent: 154089 (1981-11-01), None

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