Garments have shrunk due to fibres interlocking tightly after being washed in a washing machine generally through using the incorrect detergent for wool.
This also gives the appearance and feel of felt in woollens and can be referred to as felting.
This is not a problem caused by your washing machine and there is no fault with your washing machine if you see this issue.
Felting and shrinkage although different are closely linked. However, felting only occurs with woollens and is associated with wool appearing like felt after repeated washing and wearing. This is caused when woollen fibres interlock tightly so the fabric thickens, looses elasticity and becomes hard. The process is gradual and the fibres tightening also lead to shrinkage of the garment.
In effect shrinkage happens whenever any fibres tighten although the felt like appearance only occurs with woollens.
This process can be reduced by stretching the garment after washing to retain it's original size and drying flat.
Wash garments at the correct temperature and agitation in accordance with the fabric care label. Too high a temperature or using the incorrect agitation will cause shrinkage/felting. We recommend washing woollens in a delicate detergent such as Dreft.