PET blow molders encompass a variety of PET bottle-producing machines. The main classes of PET blow molders include single-stage and two-stage machines. The single-stage machines are similar to injection blow molding machines. The preform is made and subsequently blown into a finished product all within the same PET blow molding machine. This type of machine is highly suited for low volumes and short runs. Since the pre-form is never released, parameters such as heating, and air flow can be calibrated to provide for uniform wall thickness in non-round finished products. Typical products made on these machines include personal care bottles up to 8 oz and pharmaceutical bottles. Machinery Center offers top-name manufacturers such as Aoki and Nissei.\n\n In two-stage PET blow molders, the preforms are first injection molded on a separate injection molding machine. They are then fed into the blow molders to be reheated, stretched and blown into their final shape. This process involves core rods and cooled molds similar to previous processes discussed. Advantages to two-stage machines are that they are capable of very high-volume output and with the use of interchangeable molds, there is little restriction on bottle design. Machinery Center offers used PET blow molders for sale from brands including Sipa and Sidel. Note that preforms are made on their own injection molders of the likes of Husky and Milacron.