Fields of application

Polygraphy. Publishing Business.

Polygraphy has become a part of our life since earlier times. This is not only books and periodicals, but also numerous postcards, notebooks, diaries, forms, register books and so and so forth. Not every sphere of activity can afford its existence without polygraphic products.

Initially polygraphy appeared for multiple copying of texts and images. It made a long and hard way of development and growth. The first book known to the humanity was published in China in 868 A.D. The cover of the book and the tools of publishing with more than a thousand year history stepped far forward and had greatly changed.

But no mater which stage of publishing it was (let it be typesetting, reel-fed offset machine or all-round mechanization and automation in technological process) there were used glues.

One needs to use glues in after print process. This stage is very important because customers become more and more exacting to the quality of the finished product appearance.

The main fileds of use:

-sizing (fastening) of block of pages;

-side fastening of cover to the block of pages;

-insertion of blocks of a book on the automatic lines.

There are usually two types of fastening used in polygraphy : wire sewing (or paper-clipping) and glueing (non-sewing type).

When wire-sewing a booklet  is picked up sheet-by-sheet, then the whole block is creased and fastened with papar-clips. This type of fastening is economic, performed in one sitting and is applied mostly for polygraphic products with small amount of pages (up to 80). That is because thicker books and booklets don’t close. For this reason the glue fastening is used and helps to form the products of any banding.

In small circulations (which acquire more and more popularity) sheet-by-sheet method of binding has become widely spread. The picking up is made by single lists. They are collected in blocks, are put in the straight line, cut from the back and pasted up on the butt with glue. Here comes a block to which the cover then is added. This type is easy and takes little time.

The used glues are to meet special requirements. They must:

- have good adhesion and cohesion;

- supply firmness of butt with elasticity retention when opening a book;

- be quick-drying.

The quality of finished product often depends on quality and the right use of glue.

Different kinds of glues were used on various polygraphy stages: from the most simple vegetable (gluten) and animal glue to hot-melt glue and PUR-glue.

Nowadays 2 main types of glues are used: hot melt and cold-applied adhesive.

Cold-applied adhesive is known as PolyVinylAcetate (PVA). It, certainly, has its pluses, which are important for polygraphic products production: PVA produces a firm and elastic adhesive film, which pastes the polygraphic products together. Dispersion glues are also environmentally safe. But their functions are based on the water polymers dissolution and water evaporation follow-up. That’s why more time is needed for the process of drying. This fact is an obstacle for production of high-capasity equipment and achievement of high speed production. That was why new methods of pasting up (adhesion) appeared, that is: the use of hot melt adhesive and corresponding equipment.

Cold-applied adhesives, unlike hot melt ones, satisfy all 3 main glue requirements (reference on certain brands). Due to their physical properties (heating and cooling) they give an opportunity to speed up the production of any non-sewing fastening stuff allowing at all that to use high-capasity equipment.

There exist numerous variants of glue applying in polygraphy: combing and laminating paper and cardboard, thread binding (the combination of adhesion and mechanical joint) and so on. With all this they use various types of papers (with and without coating, with diverse porosity and mass). There doesn’t exist a glue that can paste any material with the needed strength. That’s why we select the type of glue and an appropriate application technology according to a specific case. The choice of glue solution depends on  the quality of finished product, conditions of production and materials.

Not the last place is given to the right choice of equipment.

Moreover, the applied equipment is important to be set in a proper way, otherwise any glue of good quality wont help to repair any defect. It’s necessary to keep an eye on temperature conditions and follow the rules of equipment exploitation, and perform preventive cleaning.

If the conditions are kept to then the use of modern glue and its technologies gives the maximum effect, increases productivity considerably and provides high quality of finished products.

The specialists of “MELTPAK” not only choose the glue solution for every task individually, but also provide the technical support for every company’s customer.

New opportunities of non-sewing fastening appeared thanks to the advantages of use in the production of polygrapgic stuff PUR-glues.

PUR-glues are the glues of high durability, excellent plasticity and good adhesion and cohesion with most of materials. Advanced durability of glue film, short time of drying, high temperature resistance are also typical for these glues.

PUR –glue is resistant to solvents, oils and sharp temperature jumps. The glue film is very elastic. The booklet can be opened to the angle of 180 degrees which is impossible when fastening with hot-melt adhesive is applied. This glue is very economic and reduces expences to 30-40 % in comparison with sewing fastening (reference is given to Forbo glue).