Micro-flute corrugated is a relatively new product. It has exceptional properties which allow for a wide variety of end uses in packaging.
The micro-flute segment comprises roughly 7-9 percent of total corrugated market in North America. Recent studies report an annual growth rate of microflute applications between 12 and 15 percent. While the largest share of production continues to belong to E- and F-flutes, the introduction of N- and G-flutes may change statistics in the years to come. The general rule of thumb holds that E-flute has approximately 90 flutes; F-flute, about 128 flutes per foot; and G- and N-flutes count 178 per foot.
Printing offset direct onto a range of micro-flutes has today become of age and has obvious advantages with better quality than flexography and more intricate detail– than screen such as (source, KBA):
- Improved print quality with perfect register and colour consistency
- Much finer screens and halftones
- Lower production times
- Lower plate making cost
- Ideally suited for both long runs and shorter promotional specials
Short-grain material must be used for micro-flute printing. The flutes then lie in the direction of travel, offering greater stability. The blanket is the key parameter for micro-flute printing since it must be able to ensure good ink transfer even at low pressures. Therefore, inks that transfer well, even at the lowest of pressures, should be selected.
Moisture has many detrimental effects on the properties of micro-flute corrugated. It creates an overall weakening of the fibers, which in turn reduces the overall strength of the corrugate Corrugated board loses about 50 percent of its compression strength when it is exposed to at or above 50 percent relative humidity. Also, the starch-based adhesive used to hold the linerboard and micro-flute together does not tolerate high levels of moisture. The adhesive loses its strength when exposed to high humidity conditions. Expansion occurs when corrugated takes on water, and it shrinks when it is dried.
Micro-flutes advantages over solid board include the fact that less raw material is required to achieve a given level of stability. Micro-flute packaging also has better stacking and flexural strength and weighs less. Its superior insulating properties also make it ideal for deep-freeze fast-food packaging.