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Useful Information

Information about cardboard products

  • Cardboard is made from papers being produced from cellulose fibers. Cardboard is made by gluing a wave-corrugating named waved part with astar-named two plates each other in the middle of such plates. Cardboard useable for package of different products is a box designed for products protection, transportation and delivery to a customer.
  • A cardboard product produced from joining three layers is more durable as compared with one-layer cardboard products. Besides this, corrugating availability provides cardboard firmness  and solidity.
  • Air absence in cardboard waves plays the heat change-proved role.

 

Cardboard production

The cardboard-producing structural composition consists of papers sorted “Liner” applicable for outside and “Fluting” applicable for corrugating. Liner-named papers are grayish, white or colored “Kraft Liner”, “Test Liner” and “Schrenz” papers. And the papers applicable for corrugating are “NSSC Fluting”, “Saman Fluting” and “Schrenz”.

The weight, sort and characteristics of papers applicable for outside, inside, intermediate layers to be used for cardboard production are very important with respect to the use field of the box.

The sort and type of applicable papers, glue, admixture are to be selected in accordance with the purpose. For example, grey and dark-colored krafts shouldn’t be used for the boxes to be brightly colored, and the  low-weight weak-fluted boxes shouldn’t be applied for the boxes to be kept in humid environment.

Cardboard sub-products production

  • Cardboard production is started from receiving line rand fluting papers at the applicable rate and sort from paper warehouse and its putting to cardboard-producing equipment. The “single facer” group (corrugating machine) being the most important part as a “tear” of cardboard-producing equipment to be applicable for single-waved cardboard production consists of many parts. Fluting paper being softened by heat and vapor is passed through corrugating bathes and shaped as waves and corrugating. As such shape is made starch-based glue is put on the top of waves and sticking on the liner papers made by heating in the heating appliances is provided by pressing them.
  • Obtained single-facer papers are collected on the “bridge”. There are two single-facer group – goffer presses in the machines manufacturing two types wavy cardboards and there are three single-facer group – goffer presses in the machines manufacturing three waves. The second important part in the “wet” type of the equipment manufacturing cardboard is obtained in the group “double facer” (drying) group and in  this case the cardboard layer having single wave is obtained by sticking liners heated in the front heaters on the single-facer layer got sticky by the wave tops on the other side. In case when couple wave is required, the second single-facer is added and cardboard of couple waves is manufactured by layer paper. Though that the glue used in manufacturing of cardboard equipments dries very quickly, first of all cardboard is dried on heating pans, then it gets cold by giving up humidity in the felts.
  • Afterwards, the trims of the cardboard available in the “dry” part of the equipment of cardboard manufacturing are cut, cutting according length in relation to the row number is carried out as it is planned and the folding parts being vertical against waves are established when it is required. Then cutting across of the cardboard is carried out, cardboards of the same size and sometimes of the different size are obtained and they are put one on another and used according to destination.

 
Paper applied in cardboard manufacturing

            Characters of cardboard are defined according to its type, papers used in manufacturing and the auxiliary means. We shall be aware of the paper that the cardboard is made from is order to investigate characters of cardboard. Inasmuch as, raw materials and manufacturing styles used in manufacture have specifications distinguishing from each other. Selection of those specifications according to the purpose plays an important role in manufacturing of the relevant box. 

Papers used in manufacturing of cardboard: papers obtained from wood, chaff and the other alike plants, once used papers (refusal papers) and as well as alaf used in different volume according to its kind, water, additional substances and the styles of paper manufacturing is used in the process.

Alaf – is a fine part looking like cord available on the body of tree and plant. Alaf of wood and plant is considered of the first sort and alaf obtained in recycling period is called the second sort. Resistance of papers increases when alaf grows up. Length of alaf of mellow trees is 4-6 mm and length of alaf of firm trees is 1-2 mm. 

            It is necessary to state that all kinds of tree can’t be applied in cardboard manufacturing. Starch and coloring substances can be used in order to improve mechanical specifications of paper, to increase resistance against humidity and oil and to provide flatness of the surface.

  Papers applied in cardboard manufacturing are used in the internal, external covers and intermediate layers. Fluting papers where liners, goffer is used are divided into two principal groups:

  • KRAFT LINER
  • TEST LINE

Papers called as SCHRENZ or recycled paper and used in the industry can be used both liner and fluting paper according to their sorts. Liners are classified by bursting values (BST) changing among 1.5 and 1 and measured by kPa and flutings are classified by horizontal crumbling values (CMT) measured by N (Newton).

  • NSSC

This kind of paper manufactured from firm trees having short alaf (for example: eucalyptus) and via mechanical and chemical ways are used in manufacturing of goffer layer in the cardboards. Such kinds of papers safeguard the form obtained under influence of humidity and heat because of their characters.  These papers called by the sigils of the words “Neutral Sulfite Semi Chemical” showing manufacturing style can be manufactured as 85-200 gr\m2. Their mostly used weight is 112-127 gr\m2. Alaf of the second sort turing may be changed between 10-50
% according to the countries that they are manufactured by.

  • Schrenz

These are papers manufactured using alaf of every type of old papers, mainly having grey color and becoming liner or fluting papers by being colored when it is required and having weak resistance. Its bursting value is under 2 kPa and weight changes between 100-350 85 gr\m2.

  • Recycled paper

This type of paper is manufactured by alaf of the second type and its resistance is low. Its resistance may be increased by applying different additional substances. Their weight is 85-220 gr\m2. Alaf of the second type, used old cardboard boxes, refusals of cardboard plants and used craft bags can be used as the raw materials of recycled papers. This kind of paper can be used in large scale as liner paper using different additional substances and different kind of alaf. Utilization of alaf of the second type causes to the following positive and negative factors:

Positive – decrease of pollution of environment, economical influence to price of paper;
Negative – horizontal crumbling of paper, decrease of such mechanical specifications as coming unstuck, bursting and etc., showing of qualitative differences relevant to used raw materials.

Chaff Fluting

This is fluting paper obtained by semi-chemical processing of chaff and adding 60% alaf of second sort to alaf of the first sort and having 112-160 gr/m2 volume. Notwithstanding the fact that its horizontal crumpling values are high, it is influenced by humidity and moisture very quickly.

Wave types of cardboard products
           
Cardboard product is manufactured by sticking corrugated paper between two flat layers. The waves establishing “spine” of cardboard  - look like columns of the point of vertical view and belts being the simplest and reliable way of conducting to every openness fro the point of horizontal view. Cardboard products can be cut and folded in every direction against to this strong structure.

 

Wave

  • Profile of cardboard product seen in upright cutting is called so. The waves are divided into groups. They are classified according to their length, height and number in 1 meter. Wave form causes to utilization of more paper in fluting layer of cardboard product in comparison with liner. Fluting amount used in connection with wave type against 1 meter liner is determined by take-up factor.

 

Wave type Height of wave
H		 Length of wave (b) Number of wave /m Goffer factor

A-large

4,0-4,8

8,0-9,5

105-125

1,48-1,53

B-fine

2,2-3,0

5,5-8,5

153-181

1,28-1,43

C-middle

3,2-4,0

6,8-8,0

125-147

1,42-150

E-micro

1,0-1,8

3,0-3,5

285-334

1,22-1,29

  Besides, there is F wave and K wave that is not widely used

  • F wave: H 0,8 mm, b 24 mm, wave number /m 420
  • K wave: H 7,0 mm, b 12,0 mm, wave number /m 90
  • N wave: H 0,6 mm, wave number /m 560
  • Different types of waves give different characters to cardboard products.

A wave

It provides perfect support thanks to its thick wall in connection with wave height, carrying out of vertical loads perfectly and easily crumpling on horizontal surface. This type doesn’t give correct pressure surface because of big interval between waves as its superficial crumpling is weak. These characters require utilization of A waves on the external surface in the paired wave combinations because of thinness and closeness of the other waves combined on the internal surface. Widely used in our state at the beginning A wave yielded to C wave being more useful from the point of view of utilization of paper and having better pressure surface.

B wave

  • It is very resistible against fragility in carrying of vertical loads because of thinness of walls and against superficial crumpling in connection with more closeness of waves. In connection with this character it gives perfect results in pressure. It is widely-used type.

C wave

  • This type of wave appeared after A and B waves and meeting positive characters of both waves is a perfect conductor and gives positive result in pressure. Contrary to long-term struggle against A wave its utilization is becoming wider.



E wave



1 Having wonderful superficial crumpling thanks to increase of number of waves in a meter E wave give the best results pressure in comparison with the other waves. Thanks to these characters E wave is widely used in cardboard boxes. Boxes without defects are made when E wave is combined with the other wave and it can be used as a carrying box independently. At the same time E wave is laminated to cardboards of offset pressure and is used as consumption package. 

  • E wave appeared for the same purpose is directed to this aim to. The last manufactured wave type wave, distinguished from E wave, being thinner and having 0.6 mm height in 1 meter and having 560 waves is N wave. This wave type which characters look like cardboard is very appropriate to lamination.

 Application spheres pf cardboard packages

  • Cardboard packages I quality of different type can be obtained by selection of different quality, weight and wave according to the utilization purpose. The principal cardboard package types having one wave are A, B, C and E according to the characters of waves. They are combines as E+B, B+A, B+C and establish cardboards having paired-wave and by combining as E+B+B, B+C+C, A+C+B, C+B+E the cardboards of three-wave are manufactured.
  • A wave: it is widely used in implementation of intermediate layers, in strengthening and etc. materials because of carrying out the duty of pillow in installation of storehouses and in packages not being conductor.
  • B wave: it is applied in packaging of every type of products, especially of the products being conductors and manufacturing of boxes having moulds.
  • C wave: it is applied in packaging of many products including wet vegetables and fruits.
  • E wave: It is quite fine wave. It is possible to pattern on it and it is widely used in consumption packaging production.
  • Paired-wave: it is appropriate to conducting of heavy loads and putting one on another thanks to its power. It is resistible against bursting and riddling. It is used in flower boxes, packaging of heavy, pouring products, citrus products and heaped products. It is praised as telescopic boxes.

 

  • Three wave: it is used as package of capacious and very heavy loads as it combines characters of different waves. Its thickness can be till 12 mm.
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  • Single-facer: It can be applied in lamination of single facer, offset papers consumed in different type of waves, for decorative purposes and as bandage.