Paper whiteness and brightness revolution

Editor's Note: Through this article, we can understand the development of paper classification and the latest changes, but also understand what is called the "whiteness in the brightness revolution" in the true sense.

Paper upgrade

Due to the competition in the domestic papermaking industry and the pressure from foreign paper imports, papermakers in North America are actively improving the brightness, opacity and whiteness of coated and uncoated papers. The brightness standards required by the paper quality products, primary products, and secondary products that we are talking about have now reached a higher level, but prices have not increased as a result. For many years, the brightness standard and the paper rating have corresponded to each other, but due to the influence of the following changes, this situation also has to change:

* More and more imported paper enters the North American market

* More and more manufacturers in North America are using fluorescent brighteners (FWAs)

* The emergence of new technologies

First initiated reforming of coated paper

The rating of coated paper first changed the standard of brightness level. In the past two years, papermakers have classified the former grade standard for first-class products as first-grade goods, and the first-grade goods have been classified as second-grade goods. As far as the form is concerned, it is clear that the old grading standards have been invalidated. Therefore, the Standards Development Committee Grade Finders has collected the latest product information from the larger North American manufacturers. In 2004, Grade Finders incorporated some new standards into the 2004/2005 Competitive Grade Finder and the 2005/2006 Paper Purchase Encyclopedia.

Driven by the technology of Vision-Innovation-Paper (VIP Technologies), the United States International Paper Company, uncoated paper grades have also undergone the same change. Domtar, Weyerhaeuser and several other paper makers also produced higher brightness papers driven by IP. In collaboration with these manufacturers and other manufacturers, Grade Finders has revised the hierarchical structure of uncoated paper. The new standards and subsequent changes you can see in the North American version of the 2005/2006 Competitive Grade Finder.

Are you using the current standard?

Whether you are in business, in the printing industry, in a government department, college or university, an advertising agency or a publisher, you will obviously feel the impact of changes in standards. If the paper sorter uses a different brightness level standard, the resulting error is certainly a headache. Imagine the printer specifying that a certain print job requires the use of No. 1 offset paper. If he/she uses the old version of the industry standard, the brightness of the paper is 87-89. However, if the customer is using a new version of the standard, then the brightness of the paper that customers expect is between 91-93.9. If he/she delivers to the customer the price is high and ultimately not the product that the customer expects, this will bring a lot of problems to the printing factory.

Although many state and regional government agencies have used the new version of Competitive Grade Finder to develop their own bid standards. For example, Ohio and Virginia stated in their bid notes that only those listed in the 39th edition of the Comprehensive Grade Finder (2005/06) and paper purchases that are also accepted by the Grade Finders and will be subsequently revised The specifications added in the guide will be adopted. For production that is not included in the current version of the standard, a copy of Grade Finders approval must be issued.

Paper quality dominates the final price of the print. In order to be able to avoid mistakes in communication, each of us, including paper sorters, needs to understand the changes in the current paper grade.

Confusing paper characteristics

Many countries use whiteness when describing paper properties, but in North America, people prefer to use brightness when talking about paper properties.
The whiteness of the paper is measured using the entire visible spectrum, and the brightness is measured only at the blue end (short wavelength) of the visible spectrum.

From a technical point of view, whiteness is only a single indicator of relative whiteness. Our commonly used whiteness indicator, called CIE Whiteness, was developed by the France-based Intl Lighting Committee.

Brightness is determined by measuring the amount of light reflected through the surface of the paper. Although paper and pulp brightness values ​​are divided into 0-100 grades in the papermaking process, paper mills often add additives to increase the brightness of the paper. Technical Assn, a subsidiary of the Technical Association of the Pulp and Paper Industry (TAPPI) and ISO Standards International, have established industry standards for brightness measurement. The current situation is clear, North American manufacturers use TAPPI grade standards (sometimes called GE brightness), and foreign manufacturers usually use the ISO measurement system.

Although TAPPI and ISO standards help ensure consistency in the brightness measurement methods, these two standards use different measurement methods to measure the reflectivity of paper in the blue light band. Therefore, these two criteria cannot be used interchangeably.

The debate about whiteness and brightness

U.S. International Paper Company has recently developed a new technology, Vision-Innovation-Paper (VIP Technologies), which has now obtained U.S. patent rights. It is said that this technology can increase paper whiteness. IP company claims that whiteness is the best describing parameter for paper properties because the whiteness value is the result of measuring the entire chromatogram. IP paper companies have always believed that the initial purpose of GE Whiteness was to quantify the degree of pulp bleaching and was used to measure the brightness of paper without other measuring instruments. According to news released by the IP company to the media, brightness is no longer the first choice for measuring paper worldwide. It has been replaced by CIE Whiteness. The CIE whiteness measurement is more in line with human visual effects. According to IP company, this company's new technology will be able to produce a higher brightness product, the brightness value can be raised from the GE brightness range of 84 to 92, but if you start from the CIE white level, then the whiteness of the paper Can fly over to 135-145 to achieve unprecedented consistency in paper color.

The development of paper grading

In the 1960s, Bill Subers was a supplier to Remington Rand (now Unisys). Subers realizes that his client has no way to determine the quality level of the paper, but he also failed to walk in front of other businesses because he did not have a measurement tool to determine the paper grade, until Subers got a thorough understanding from IBM when he cooperated with IBM. Computer knowledge therefore has the ability to fill this gap. In 1967 he founded Grade Finders and founded the first phase of the Comparative Grade Finder.

Paper grade to see the price

Subers contacted some people in the industry who also complained about SD Warren, and found that the paper's rating standards were very good. But the real problem is that paper grade standards are based on price rather than on measurement parameters. For example, a grade of paper is priced at $38 per jin, then graded as first-grade offset paper; if the price is $35 per jin, then it is set as a second grade, and so on.

Grade Finders cannot afford a lawsuit and therefore reluctantly removes the SD Warren rating from its own book. A few years later, another paper maker, Consolidated Paper, also stuck with Grade Ratings.

But afterwards, things have changed surprisingly and SD Warren has withdrawn its initial request. Subsequently, Consolidated Paper's name also returned to the Grade Finders grading standard. Other paper companies also strengthened their cooperation. Best of all, Grade Finders saw that many states are using the Competitive Grade Finder to develop bids, and they will no longer accept papers that have not been calibrated using the Competitive Grade Finder. University, college, government, and printing company procurement personnel have found that only using this level of standards published by Grade Finders will have more benefits. In the next ten years, Grade Finders will continue to receive support from everyone and will make more improvements to publications. People have begun to use Grade Finders books as the Bible for paper procurement.

Author: Raymond Young V .. Source: net win