Starwheel or Pocketed Disc

The starwheel or pocketed disc is a critical component within a bottle unscrambler machine. It is a rotating disc machined with multiple pockets or cavities, each shaped to hold a single bottle in a specific orientation. As the disc rotates, it receives randomly oriented bottles from the infeed, aligns them into the correct upright position within its pockets, and transfers them in a controlled, singularized stream to the downstream conveyor or filling station. The disc is typically manufactured from stainless steel (e.g., 304, 316), engineering plastics (e.g., acetal, UHMW-PE), or cast aluminum, depending on the application requirements such as wear resistance, chemical compatibility, and weight. Key parameters include disc diameter (200–800 mm), pocket count (6–48), pocket diameter (20–120 mm), pocket depth (10–60 mm), rotational speed (5–60 rpm), positioning accuracy (±0.05 mm), surface roughness (Ra 0.8–1.6 μm), material hardness (50–60 HRC for stainless steel), operating temperature (-10 to 60 °C), and weight (5–50 kg). These values are reference ranges and must be confirmed for the specific model and application. The starwheel is designed to handle bottles of various sizes, with pocket dimensions matched to the bottle body diameter and height. Proper selection of materials and surface finish reduces friction and wear on bottles. The disc's rotational speed and pocket count determine throughput, while positioning accuracy ensures reliable transfer to downstream stations. For stainless steel versions, hardness in the range of 50–60 HRC improves wear resistance. Operating temperature limits are specified to avoid material degradation. The weight of the disc affects handling and installation, requiring adequate support structures. Always verify model-specific values and standards with the legal manufacturer or supplier before procurement.

The disc rotates at a controlled speed. Randomly oriented bottles are fed onto or near the disc. The pockets on the disc are designed to only accept bottles in the correct orientation (typically upright). Bottles falling into the pockets are carried by the disc's rotation. Incorrectly oriented bottles are rejected and recirculated. The rotation presents each pocket, now containing a correctly oriented bottle, to a discharge point where the bottle is released onto a conveyor.