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Photopolymer Plate Making and Its Use in Flexography
Flexography is the process of using flexible and often photographic plates, sometimes referred to as photopolymer plates, to transfer images onto a substrate. The process involves the application of a liquid photo-chemical to the surface which hardens when exposed to light, forming a flexible plate. This plate is used to transfer a print directly onto a variety of substrates including paper, card, vinyl, foil, film and board.
Photopolymer plate making is a process that requires specialized equipment and expertise to produce quality plate results. The process starts with a digital file which the printer must convert into a negative. This process utilizes an exposure unit and a flat, light-sensitive film typically between 8-24 inches. The negative image is exposed onto the light-sensitive film which is then developed and laminated to a flexible substrate to form a photopolymer plate.
Once created, the flexographic plate is typically mounted onto the print press cylinder. The mounting adhesive used to affix the plate must be strong enough to hold the plate securely during printing, yet still allow for easy and quick plate removal if needed. An additional process may be necessary depending on the desired plate life and substrate being printed. This process, often referred to as “treat and print”, can be used to improve the quality of flexographic prints by allowing the substrate to accept the ink more readily when printed.
Flexography is often used for certification labels, such as UL and CE certifications, that require a flexible and durable substrate. Since the plates are thin, flexible and strong, they are able to withstand the elements and retain a clear and concise statement of certification. Photopolymer plates are also easy to clean, allowing them to be reused or recycled over a long period of time.
Photopolymer plates are also commonly used for printing on garments, such as for shirt tags, labels, neck tags and many others. The process requires the use of a rigid plate to ensure accurate ink and substrate transfer. By using photopolymer plates rather than traditional etching plates, the printer can be assured that some of the most common issues with etching plates, such as weak edges, will not occur. Additionally, the transfer of ink on a photopolymer plate allows for more accurate registration, providing superior results compared to traditional methods.
In conclusion, photopolymer plate making is a specialized form of printing that provides superior results compared to traditional methods. The plates are flexible, strong, and can be easily cleaned and reused. Additionally, the use of photopolymer plates in flexography makes it ideal for use in printing of certification labels on a variety of substrates and garments.
