摘要:
A mixture of a high molecular weight EPDM rubber with a low molecular weight (liquid) EPDM rubber provides a highly useful laser-ablatable flexographic printing plate precursor formulation. This formulation is sensitive to infrared radiation by the incorporation of an IR absorbing compound such as a carbon black. The inclusion of the liquid EPDM rubber avoids the need for plasticizers such as process oils during manufacturing, and provides improved image sensitivity, print quality, and run length. Both flexographic printing plates and printing sleeves can be made using the mixture of EPDM rubbers.
摘要:
An imageable element can be imaged using non-ablative processes. This element has a non-silicone, non-crosslinked layer contiguous to and under an ink-repelling crosslinked silicone rubber layer. These elements can be used for providing lithographic printing plates useful for waterless printing (no fountain solution). Processing after imaging is relatively simple with either water or an aqueous solution consisting essentially of a surfactant or mechanical means to remove the crosslinked silicone rubber layer and a minor portion of the non-silicone, non- crosslinked layer in the imaged regions.
摘要:
An apparatus and a method for straightening a surface of a flexible media (108) mounted on an imaging drum (104) of an imaging device (100), is presented. A flexible media is mounted on an imaging drum. The flexible media is scanned by an optical displacement sensor (ODS- 124) and is provided to a microprocessor (412) component which is part of the system controller (128). The microprocessor combines the data received from the ODS (404) with the data of the image to be imaged on the imaging device. The combined data is sent to the imaging head (120). The imaging head images the data on the flexible media.
摘要:
An imageable element can be imaged using non-ablative processes. This element has a non-silicone, non-crosslinked layer contiguous to and under an ink-repelling crosslinked silicone rubber layer. These elements can be used for providing lithographic printing plates useful for waterless printing (no fountain solution). Processing after imaging is relatively simple with either water or an aqueous solution consisting essentially of a surfactant or mechanical means to remove the crosslinked silicone rubber layer and a minor portion of the non-silicone, non- crosslinked layer in the imaged regions.
摘要:
A non-ablative negative-working imageable element has first and second polymeric layers under a crosslinked silicone rubber layer. These elements can be used in a simple method to provide lithographic printing plates useful for waterless printing (no fountain solution). Processing after imaging is relatively simple using either water or an aqueous solution containing very little organic solvent to remove the imaged regions. The crosslinked silicone rubber layer is ink-repelling and only the first layer that is closest to the substrate contains an infrared radiation absorbing compound to provide thermal sensitivity.
摘要:
A laser-engraveable composition comprises one or more elastomeric rubbers including at least 10 parts of one or more non-CLCB EPDM elastomeric rubbers, based on parts per hundred of the total weight of elastomeric rubbers (phr). The laser-engraveable composition further comprises 2-30 phr of a near-infrared radiation absorber and optionally 1-80 phr of an inorganic, non-infrared radiation absorber filler, as well as a vulcanizing composition that comprises a mixture of at least two peroxides. A first peroxide has a t 90 value of 1-6 minutes as measured at 160°C, and a second peroxide has a t 90 value of 8-40 minutes as measured at 160°C. This laser-engraveable composition can be used to form a laser-engraveable layer and to form various flexographic printing precursors.
摘要:
A flexographic printing precursor can be imaged and used for flexographic printing. This precursor has at least two laser-engraveable layers, in which the underlying non-printing laser-engraveable layer is more sensitive than the outennost non-metallic printing laser-engraveable layer. The non-printing layer-engraveable layer comprises (1) a first elastomer, (2) a polymer that is nitrocellulose, a polymer comprising a triazene group, a glycidyl azide polymer, or a polyvinyl nitrate), and (3) a first near-infrared radiation absorber. The outermost non-metallic printing laser-engraveable layer comprises a second elastomer and a second infrared radiation absorber.
摘要:
A laser-engraveable composition comprises one or more elastomeric rubbers including at least 10 parts of one or more CLCB EPDM elastomeric rubbers, based on parts per hundred of the total weight of elastomeric rubbers (phr). The laser- engraveable composition further comprises 2-30 phr of a near-infrared radiation absorber and either 1-80 phr of an inorganic, non-infrared radiation absorber filler, or a vulcanizing composition that comprises a mixture of at least two peroxides. One first peroxide has a t 90 value of 1-6 minutes as measured at 160°C, and a second peroxide has a t 90 value of 8-20 minutes as measured at 160°C. This laser- engraveable composition can be used to form various flexographic printing precursors that can be laser-engraved to provide relief images in flexographic printing plates, printing cylinders, or printing sleeves.