Photopolymer
Encyclopedia
A photopolymer is a polymer
that changes its properties when exposed to light, often in the ultraviolet
spectrum. These polymers are useful in dentistry
for fillings
and in rapid prototyping
in the stereolithography
and 3D printing
processes. This material is also used in the creation of ADA compliant Architectural Signage. This material also used as a relief plate for flexographic printing, mainly used in flexible packaging, plastics, paper, labels and corrugated boxes. Some commercial brands worldwide include DuPont Cyrel, BASF Nyloflex, Novacryl, Elaslon, McDermid and Soleflex Exaprint. The basic material is soft and light sensitive, then is applied a selective exposure to UV lamps, then it is developed and then cured.
The photopolymerized element can then be detackified by exposing the element to U.V. radiation emitting a wavelength in the range of 254 nm. To ensure final plate hardening and photopolymerization, the printing element can be further post-exposed to radiation emitting at wavelengths in the range of 365 nm.
Current platemaking processes utilize various sources of radiation for developing relief images and maximizing plate hardening. For example, actinic radiation from a variety of sources can be used, including commercial ultraviolet fluorescent tubes, medium, high, and low pressure mercury vapor lamps, argon glow lamps, photographic flood lamps, pulsed xenon lamps, carbon arc lamps, etc. Called photopolymeric flexographic relief printing plates in the flexographic printing plate industry because maximum consistent print quality will be obtained using plates with reduced shrinkage.
Polymer
A polymer is a large molecule composed of repeating structural units. These subunits are typically connected by covalent chemical bonds...
that changes its properties when exposed to light, often in the ultraviolet
Ultraviolet
Ultraviolet light is electromagnetic radiation with a wavelength shorter than that of visible light, but longer than X-rays, in the range 10 nm to 400 nm, and energies from 3 eV to 124 eV...
spectrum. These polymers are useful in dentistry
Dentistry
Dentistry is the branch of medicine that is involved in the study, diagnosis, prevention, and treatment of diseases, disorders and conditions of the oral cavity, maxillofacial area and the adjacent and associated structures and their impact on the human body. Dentistry is widely considered...
for fillings
Dental fillings
This page is about types of dental restorative materials. For dental fillings see dental restorationsDental restorative materials are specially fabricated materials, designed for use as dental restorations , which are used to restore tooth structure loss, usually resulting from but not limited to...
and in rapid prototyping
Rapid prototyping
Rapid prototyping is the automatic construction of physical objects using additive manufacturing technology. The first techniques for rapid prototyping became available in the late 1980s and were used to produce models and prototype parts. Today, they are used for a much wider range of applications...
in the stereolithography
Stereolithography
Stereolithography is an additive manufacturing technology for producing models, prototypes, patterns, and in some cases, production parts.-Technology description:...
and 3D printing
3D printing
3D printing is a form of additive manufacturing technology where a three dimensional object is created by laying down successive layers of material. 3D printers are generally faster, more affordable, and easier to use than other additive manufacturing technologies. However, the term 3D printing is...
processes. This material is also used in the creation of ADA compliant Architectural Signage. This material also used as a relief plate for flexographic printing, mainly used in flexible packaging, plastics, paper, labels and corrugated boxes. Some commercial brands worldwide include DuPont Cyrel, BASF Nyloflex, Novacryl, Elaslon, McDermid and Soleflex Exaprint. The basic material is soft and light sensitive, then is applied a selective exposure to UV lamps, then it is developed and then cured.
Process
- exposing imagewise a photopolymerizable element to actinic radiation emitting a wavelength in the range of 365 nm.
- removing the unexposed or unpolymerized areas of the plate with solvent.
- drying the resulting plate.
The photopolymerized element can then be detackified by exposing the element to U.V. radiation emitting a wavelength in the range of 254 nm. To ensure final plate hardening and photopolymerization, the printing element can be further post-exposed to radiation emitting at wavelengths in the range of 365 nm.
Current platemaking processes utilize various sources of radiation for developing relief images and maximizing plate hardening. For example, actinic radiation from a variety of sources can be used, including commercial ultraviolet fluorescent tubes, medium, high, and low pressure mercury vapor lamps, argon glow lamps, photographic flood lamps, pulsed xenon lamps, carbon arc lamps, etc. Called photopolymeric flexographic relief printing plates in the flexographic printing plate industry because maximum consistent print quality will be obtained using plates with reduced shrinkage.