Rubber expansion joints are mainly manufactured by manual wrapping of rubber sheets and fabric reinforced rubber sheets around a bellows-shaped product mandrel. Besides rubber and fabric, reinforced rubber and/or steel wires or metal rings are added for additional reinforcement. After the entire product is built up on the mandrel, it is covered with a winding of (nylon) peel ply to pressurize all layers together. Because of the labor-intensive production process, a large part of the production has moved to eastern Europe and Asian countries.