Questions and answers

QUESTIONS AND ANSWERS

How is paper divided by grade and application?

How is paper divided by grade and application?

In accordance with the requirements of the national standard of the Russian Federation GOST R 57641-2017 “Xerographic paper for office equipment. General specifications”, office paper, depending on its application and set of quality indicators, must be produced in one of three grades:

• A-grade paper is suited for single-sided and double-sided printing at any speed of copying and printing machines.

• B-grade paper is suited for single-sided and double-sided printing at speeds up to 100 copies per minute.

• C-grade paper is suited for single-sided and double-sided printing at speeds up to 50 copies per minute.

In international practices, there is no unified classification and unified standard for office papers. There are no absolutely clear criteria for dividing into grades/classes of office paper; each manufacturer establishes its own classification (A, A++, B, C+ etc) in its regulatory documents. 

What are the main technical characteristics of paper?

What are the main technical characteristics of paper?

Grammage is the weight of paper expressed in grams per square meter (g/m²). The weight of 1 m2 of paper can be defined as the ratio between the weight of paper in grams and its area in square meters and is defined by ISO 536-76 standard and is determined on technical scales, cut from canvas according to a template of a stated size.

Caliper is the thickness of paper expressed in microns. 

Porosity is the number of air spaces in paper. The greater the porosity, the better paper absorbs paint.

Stiffness is the ability of paper to retain its shape after deformation. Paper stiffness depends on the raw material used to make paper and also on manufacturing process.

Opacity is the quality of paper that does not allow light to pass through it. Opacity is defined by ISO 2471 and is measured as a percentage.

Whiteness is a color characteristic of the paper surface. This characteristic is measured as a percentage and is determined by the level of reflected light of the paper surface relative to the standard white color. The higher the whiteness percentage, the whiter paper will appear. The criterion is a certain ideal whiteness of a reference plate, to which the whiteness of the test paper sample is compared photoelectrically. 

Paper smoothness/roughness is a characteristic showing the uniformity of the paper surface. According to Bekk, paper smoothness depends on the shape, total volume and distribution of uneven areas formed between the surface of paper and the ideal plane under given conditions of contact between them. The time required to extract a specified amount of air at a given pressure difference from the area between the paper surface and the polished glass surface is measured.

Paper dirt spots count is the number of specks visible to the naked eye per 1 m2. It is determined by counting specks on 2 samples with the area of 250x250 mm using a template. The unit of measurement is the number of specks per 1 m(specks/m2).

Paper humidity is the water content in paper. The determination method consists of weighing the sample at the time of sampling and after drying it to a constant weight. It is defined by ISO 287-85 standard and is measured as a percentage.

Paper brightness shows how brightly white paper glows when illuminated. This characteristic is also measured as a percentage. The higher the brightness, the more luminous paper will appear. Optical brightness is commonly used in papermaking to ensure the printing of high-quality images as it helps in achieving vibrant and rich colors.

Paper sizes are common standard paper sizes (e.g., A4, A3) that can be used for various tasks.


Why does Projecta paper have optimal performance?

Why does Projecta paper have optimal performance?

The production of high-quality papers in Russia has traditionally been associated with JSC Syktyvkarskiy LPK; and quality improvement has always been a priority for the company’s development.

Projecta paper is produced on the most modern equipment, high-quality raw materials and necessary components.

Strict quality control of the entire technological chain, a high level of technical specialists’ competence, constant development of technology and quality improvement, with environmental aspects taken into account, give our company the opportunity to produce paper for office equipment that meets international quality standards.

Projecta paper is solely produced of virgin pulp fibers which ensures high light fastness and long-term protection against fading.

Projecta paper is absolutely universal; it is designed for printing on laser, inkjet printers, copiers, and MFPs.


How does paper protect equipment and extend its service life?

How does paper protect equipment and extend its service life?

Projecta office paper is produced with surface sizing (polymer coating).

Binders are used to increase the bonding forces between fibers and increase the strength of paper.

By bonding the fibers together, these substances increase the internal strength of paper and eliminate dusting and plucking of individual fibers.

Surface sizing improves the physical, mechanical, adsorption and printing properties of paper.

In addition, the maximum service life of your office equipment is guaranteed by the use of high-quality raw materials in the production of Projecta paper, as well as the control over the content of resins and other inclusions.


How many sheets are in a ream?

How many sheets are in a ream?

In sheet production, paper is packaged in reams of 500 sheets. In some reams the number of sheets is 498 due to the fact that paper is cut from 6 mother rolls on two production lines. Consequently, the number of sheets in a pack will be a multiple of 6.

If you check more reams, you will find that the number of sheets in other reams is 504. Thus, the number of sheets in reams of office paper may be 498, 500 or 504.


What is important
to know about bleaching
of paper using
ECF technology?

What is important
to know about bleaching
of paper using
ECF technology?

Bleaching of softwood and hardwood pulp at our mill is carried out using ECF (Elemental Chlorine Free) technology.

Bleaching is a multi-step process of refining and brightening raw pulp.

The introduction of ECF technology for pulp bleaching is primarily aimed at improving the environmental aspects of paper production:

- Reduction of highly toxic compounds (chlorine dioxide) in wastewater.

- Increasing the overall industrial safety of the enterprise and nearby communities.

- Production of cardboard and paper products based on strict international environmental standards existing in the global practice of the pulp and paper industry.

- Significant reduction in fresh water consumption.