Board & Packaging market
This segment of the industry has the broadest types and largest numbers of variations in production strategies of any of the market segments. Recycle fibre, mechanical fibre, bleached woodfree, and unbleached woodfree are all utilised and the finished product can be coated or uncoated. Substances vary between 100 and 400 gsm, but much higher substance laminated products are also produced (> 1000 gsm).
At a high level the board and packing sector can be spilt into two major sub-segments Container board and Carton board. Most container board grades do not use fillers today, but as global pressures on the fibre supply and environmental concerns increase, producers of linerboards may find themselves using fillers like Astrafil K more and more.
The majority of pigment used today in packaging grades is in the carton board sector. These applications include boxboard, liquid packaging, white lined chipboard (WLC) and solid bleached sulphate (SBS) to name a few. However, it should be noted that the nature and naming of packaging grades does vary from region to region. End uses in this sector also vary considerably requiring a wide range of different print processes to be utilised. These include sheet fed offset, heat set offset, rotogravure and flexography. Flexographic printing is considered to be the fastest growing method used, but often a given board will be printed by all of the above methods depending on its end use. This will also affect the print quality requirement. For example corrugated boxes for mass shipment will not require the quality that a perfume or hair colouring package sitting on the shelf hoping to catch the consumer’s eye might require.
Pigment use in this sector varies both regionally and by sub-segment. In North America the dominant pigment used is kaolin. This is because most unbleached boxboard mills have acid wet ends and a number are situated close to the kaolin reserves in Georgia. There are a variety of kaolin pigments used such as Contour Xtreme, Astra-Plate, Astra-Print GS, KCS, Premier, Astra-Sheen and calcined clay. The way they are used depends upon the grade and type of coating being applied. The finer pigments are usually used in top coat applications while the coarser and platier ones are used in precoating. The higher brightness bleached boxboard grades in N. America utilise calcium carbonate pigments like Carbital 90 and Carbital 95 together with kaolin.
In Europe pigment use in B&P can be split in to two broad categories. For virgin fibre based Boxboard applications, most grades are double coated and pigment use closely resembles that used in Coated woodfree apart from a greater use of kaolins such as Capim NP in precoating for improved coverage. Carbonate choice for precoating is often products like Carbital 60, Carbital 75 or Carbopaque 90. In the topcoat glossing kaolins like Astra-Sheen and finer carbonates such as Carbital 90, Carbital 95 or Carbilux are often used. Imerys also recommends its CarboFlex PCC/GCC concept for these applications as a cost effective way of generating gloss together with light scatter and optics. In recycled Boxboard or coated WLC, most grades are triple coated and optical coverage of the base board is a key requirement of the pigment system. Calcined clays, steep carbonates like Carbopaque 90 as well as hydrous kaolins such as Capim NP are all used in the pre and mid coats and can help to reduce expensive opacifiers like titanium dioxide. Topcoats are broadly similar to those used in virgin based box board.
In Asia, both Japanese and Chinese coated boxboard producers tend to use pigment recipes closer to European practice than North American. Although overall kaolin levels can be higher, the kaolin and carbonate types used are similar with the exception of more PCC used in Japan.
