Competition between metal and polyester plates

Some printers would like to know if it is possible to save a certain amount of cost by replacing the metal plate with a polyester plate. Here, the main discussion is between the metal plate and the polyester plate, which can bring more benefits to the company.

Advantages: Metal Plates Today's competition in the printing market is becoming increasingly fierce. Printers need to continually innovate technology to obtain greater output and higher profits. However, when the printing plate technology developed into the metal plate, it seemed to stagnate, especially the aluminum plate. Years of experience show that the metal plate is currently the most efficient and lowest cost product.

In the United States, the aluminum version has a market share of about 90% of the total market. For a number of years, it has been widely used, mainly because he has the following properties: For the higher quality of long-lived energy transmission, Ink and printing adaptability, durability, easy handling and better product quality.

One trend in the printing industry is that more and more short-lived versions are available. As a result, printers may not need the benefits of aluminum plates, such as heat resistance and stretch-resistance of plates during printing. However, this does not mean that aluminum plates cannot be used for short-lived jobs. It turns out that aluminum plates can provide better quality whether they are used in short or long runs. Aluminium is a good choice when prints require fine details, bright images and full tone reproduction.

The main difference between plates is its surface. The surface of the aluminum plate is delicate, electrochemical, and full of particles. These physical properties allow the printer to have a large margin for handling water and ink balance. The balance of water and ink is directly related to the sharpness of the image, and it is also easy to operate. With an aluminum plate, the printer can perform secondary printing on the plate or by correctly controlling the amount of ink to solve the printing failures such as poor wetting and uneven coloration. Due to the lack of surface particles, the polyester version does not have the same water carrying capacity as the aluminum plate.

If one considers the ease of handling of the printing plate, the aluminum plate is the first to bear the brunt. It benefits the user both in terms of time and cost. The distortion that may occur on the polyester plate does not occur on aluminum plates. Aluminum version is lighter, more durable, and scratch resistant. Undoubtedly, the positioning will be more accurate, and it is necessary to use the aluminum version for businesses larger than 11 x 17 inches.

In addition, since a large amount of heat is generated in the high-speed printing process, the polyester plate tends to become soft and deformed after being stretched, resulting in inaccurate positioning and affecting the consistency of the product throughout the printing process.

Another criterion for measuring plate quality is dot resolution. For halftone, dot, and multicolor printing services that require 150- to 200-lpi network cable, it is necessary to use aluminum plates, which can generate dot sizes ranging from 1% to 98%.

With the increasing demand for digital printing, printers are continuously pushing forward the development of direct-to-plate (CTP) to get the maximum efficiency from the workflow. This trend of development makes it much more expensive to invest in aluminum plate manufacturers than to invest in CTP systems using film/polyester plates. At the same time, not all film imagesetters have the ability to process polyester plates. Since most film output machines are not originally designed for the platesetter, some issues regarding plate orientation, plate cutting, and image quality stability have been of concern. Some film imagesetter manufacturers have suggested that this part of the content will be added to future designs.

In the long run, the pressure of aluminum producers will increase, and those who consider using the polyester version of the market will be able to provide lower-cost printing solutions. The market rate of change in this area is very fast. In order to make effective decisions in the CTP system to meet the specific needs of the printer, it is necessary to maintain close contact with the supplier.

Due to the good printing performance of aluminum plate, the printer's familiarity with it, ease of use, and new technologies developed by suppliers to meet market demands and new applications, it will continue to occupy the plate market. .

Polyester imaging systems will continue to exist in their existing markets and are consistent with future market developments. The challenge for the growth of the polyester version market is to eliminate some long-standing printing performance issues and to take advantage of some of the benefits of the aluminum version – to improve color printing capabilities and consistency, and to maintain and expand the advantages of aluminum version systems in terms of cost and value. .

For small-format monochrome and spot color printing businesses, polyester versions are generally used, especially in images that do not involve dots. Advances in polyester plate technology will face the increasing challenges of digital imaging and color printing. Only by better meeting the characteristics of aluminum plates will the polyester version become an increasingly important part of the digital revolution. Otherwise, they will only maintain their original level.

Advantages: The choice of the prepress stage in the polyester version plays an important role in the final result. For example, if printing a six-color business with a resolution of 300 dpi, a metal plate is a must. However, if the fact communication is printed with the number of lines of 150 dpi, the use of a polyester version is profitable.

With the development of digital imaging, printers are forced to produce faster, cheaper and cleaner. Shorter-lived, shorter work cycles, higher quality translates into more benefits, and the use of polyester plates allows printers to better meet customer needs.

Although CTP technology continues to evolve, many printers are not yet ready to move to metal CTP systems. For those printers who want to use metal plates later, the CTP polyester system is a natural first step. Many imagesetters on the market are capable of outputting film and/or polyester plates, and some imagesetters go even further and are able to output metal plates, polyester plates and films.

How the polyester plate works The polyester plate was obtained after processing in developer and fixer. When a plate material is placed in the activator, the latent image of the image in the emulsion layer is decomposed and dissolved on the positive layer. The dissolved silver reacts with the physical development nuclei to form a lipophilic metal layer. Once the development is completed, the alkali on the printing plate is neutralized in the fixing solution. This ends the development process and reduces the pH of the silver image, making it suitable for printing. In order to achieve the best plate quality, chemicals must be mixed properly and the pH must be monitored.

With polyester printing, 5% to 10% more water is used than for metal printing, and many fountain solutions can be used for polyester plates as well as for metal plates.

With the continuous development of CTP technology, manufacturers have improved the technology so that it does not affect the quality of the image. The polyester version provides printers with another option for plates that are required for small-format printouts. The cost is greatly reduced.