Mattresses are bulky waste. Like the more general category of municipal solid waste, mattresses must also go through a selection process before they are ground. Selection involves removing material with greater added value that can be recycled from the remaining material that cannot be recycled and will be incinerated. As waste, mattresses are crushed, then the metal is separated for recycling while the rest goes with other materials to unsorted waste. There are many uses for old mattresses: the textiles are used to create thermal insulation for the construction industry; the springs become construction materials, while the cotton fibres are used in oil filters, mats and padding.