Board, boards fibre

The production of MDF from allylated wood fibres has also been reported (Ogawa and Ohkoshi, 1997). The IBS of the 4 mm thick boards was superior to control boards (unmodified fibres bonded with PF resin), provided that the temperature of the allylation reaction and board density was sufficiently high. The MOR was markedly inferior to that of control boards in all cases (c. 10 MPa for allylated compared with c. 60 MPa for controls, at a board density of 800 kg m ). Blending of the allylated fibres with acetylated fibres caused a decrease in IBS, but did not affect MOR. It is perhaps significant that no free-radical initiator was used during hot-pressing in either study, which may account for the lack of reactivity of the allylated surfaces. 

Forss, K., and Fuhrmann, A. (1976). KARATEX—the lignin-based adhesive for plywood, particle board and fibre board. Pap. Puu 58, 817-824. 

Although the uses of ceramic fibres in composite structures lie mainly in ceramic-matrix and metal-matrix composites, where their outstanding chemical and thermal resistance are important, there are a few applications in organic polymers. Their relevant properties are low thermal expansion, low electrical conductivity, low dielectric constant, high stiffness, good compressive strength, and in most cases complete resistance to combustion. On the other hand they are very brittle, hard to process, and mostly considerably more expensive than carbon and para-aramid fibres. They have, for example, been used in hybrid structures with carbon and para-aramid and in electronic circuit boards. The fibres available or potentially available include alumina, combinations of alumina with... 

Despite their relatively high cost, epoxies are now firmly established in a number of important industrial applications. The largest single use is for surface coatings, which account for about 50% of current epoxy resin output. Other applications include laminated circuit boards, carbon fibre composites, electronic component encapsulations and adhesives. 

For some uses, the anisotropy of timber and its variability due to knots and other defects are particularly undesirable. Greater uniformity is possible by converting the timber into board such as laminated plywood, chipboard and fibre-building board. 

The markets for polyetherimides arise to an extent from stricter regulations concerning flammability and smoke evolution coupled with such features as high strength, toughness and heat resistance. Application areas include car under-the-bonnet uses, microwave equipment, printed circuit boards and aerospace (including carbon-fibre-reinforced laminated materials). The polymer is also of interest in flim, fibre and wire insulation form. 

About half of epoxide resin production is used for surface coating applications, with the rest divided approximately equally between electronic applications (particularly for printed circuit boards and encapsulation), the building sector and miscellaneous uses. In tonnage terms consumption of epoxide-fibre laminates is only about one-tenth that of polyester laminates, but in terms of value it is much greater. 

Epoxide resins reinforced with carbon and Aramid fibres have been used in small boats, where it is claimed that products of equal stiffness and more useable space may be produced with a 40% saving in weight over traditional polyester/ glass fibre composites. Aramid fibre-reinforced epoxide resins have been developed in the United States to replace steel helmets for military purposes. Printed circuit board bases also provide a substantial outlet for epoxide resins. One recent survey indicates that over one-quarter of epoxide resin production in Western Europe is used for this application. The laminates also find some use in chermical engineering plant and in tooling. 

European Norm EN 321, Wood fibre panels — cycle tests under humid conditions, 1994. European Norm EN 622-2, Wood fibre panels — Specification requirements for hitrd-board, 1998. 

Abstract Paper for recycling is the most important fibre raw material of the German paper industry. 16.3 Mio t of paper for recycling was utilised in 2010 corresponding to 72% of the total fibre raw material input for paper and board production. In comparison to the used virgin fibre-based chemical and mechanical pulp, the utilised amount of paper for recycling is about 2.6 times higher. 

Substitution of recycled fibre-based board by virgin fibre-based board. 

Obviously, the first measure to think about could be the substitution of recycled fibre-based boxboard for foodstuff by virgin fibre-based material. The required amount of recycled fibre-based boxboard for foodstuff equals to 700,000 t/year in Germany [7]. For the substitution of the recycled fibre-based boxboard, it is simply assumed that the required virgin fibre-based board is produced totally from mechanical spruce pulp with a process yield of 97%. This would require in total additionally about 1.68 Mio m3 wood per year. The inventory study of the carbon balance of the German forests [8] indicates an average yearly wood growth of... 

Kraftliner corrugated Difference to medium kraftliner Virgin fibre-based board Recycled board to virgin fibre-based... 

A total import of all required virgin fibre-based paper and board grades from other European countries to cover the German demand or from outside Europe to cover the European demand would currently fail due to unavailable capacities. 

Replace 1.02 by high-quality 2a, b, c (2a) Virgin fibre in folding box board only... 

The substitution of recycled fibre-based boxboard for foodstuff and from corrugated boxes as transport packaging to virgin fibre-based products is impossible due to insufficient availability of fibres and of paper and board production capacity. 

Deutch notes on BAT for paper and board from recycle fibres (1996) Ministry of Transport, Public Works and Water Management, Directorate-General for Public Works and Water Management and RIZA. Contact W.J. Luttmer, RIZA, P.O. Box 17, 8200 AA Lelystad, The Netherlands... 

In addition to fibre obtained directly from plant sources by chemical or mechanical treatment (virgin fibre), recycled fibre is also used and to an increasing extent for paper and board production. A breakdown of world fibre usage is given in Table 1.2 and the subject... 

Table 1.2 The source of fibre world-wide for paper and board production.

Year World pulp production from virgin fibre (million tonnes) World paper and board consumption (million tonnes) Recycled fibre usage (million tonnes) Recycled fibre usage (%)... 

The remarkable property of cellulose fibres which gives rise to their widespread use in paper and board products is their ability, when dried in contact with each other from water, to form a strong bond. Perhaps more importantly, this bond can be completely disrupted by the re-addition of water and this is the essential property which allows cellulosic fibres to be relatively easily recycled. 

Source Adapted from A.M. Scallan, in Fibre—Water Interactions in Paper Making , in Trans. 6th Fundamental Research Symp. , Technical Division of British Paper and Board Federation, London, 1977). 

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