A lot of people agree with Pearson. Dollar stores such as Dollar Tree and its rival Dollar General (which, between them, control more than 60 percent of the market, according to market researcher IBISWorld) are one of the more surprising retail success stories of the past several years. Widely expected to encounter head winds as the economy picked up after the depths of the Great Recession, they are instead booming. The number of dollar stores in the United States has increased from about 20,000 to 30,000 outlets between 2011 and 2018.

What makes this particularly noteworthy is that this growth is occurring in an economy that’s growing. Unemployment is low. Household incomes are finally beginning to move up. Yet many people still feel so under pressure they are turninga paper cooling mechanism in order to compensate for insufficient cooling time.
For cooling the delivered sheets of paper, for example, in a paper folding apparatus, stacking sheets of toner heat-fusing continuous printing paper having folding perforated lines on a table with the front and back side thereof being folded one after the other, detecting the front side of sheets of paper stacked on the table by means of a sensor, and lowering the table by a certain degree, it has been proposed to provide a plurality of pairs of blowers and ducts for supplying cooling air to the sheets of paper and to arrange the ducts in a longitudinal direction of the sheets of paper respectively for blowing strong and weak air from the ducts (for example, Jpn.