The provision of a liquid nitrogen dewar is outside the scope of this procurement. However, the mill must be supplied with a properly specified inlet connection capable of accepting a standard cryogenic transfer hose from an external dewar. The connection must allow direct metering and control of liquid nitrogen into the mill chamber for temperature regulation. The system must include proper venting and safety features to safely handle, prevent over-pressurization and vent gaseous nitrogen that results from the flashing or evaporation of liquid nitrogen during the cooling process. Equipment can be benchtop style or free-standing. If benchtop, the footprint should be no greater then 35” x 48”. If free standing, unit should be no greater then 72” x 72”. The exhaust/vent system must be designed for connection to existing building air-handling infrastructure to ensure proper capture and dispersion of gaseous nitrogen. The vendor must specify the design airflow rate and connection parameters (e.g., duct size, static pressure limits, flow requirements) of the exhaust/vent system to enable integration with the facility’s ventilation system. The operating area will be equipped with oxygen deficiency monitoring, and bidders must provide any necessary specifications to ensure compatibility with such monitoring and safe operation. The system must include all components necessary for cryogenic milling of flexible plastic films, including but not limited to: Milling vessels or chambers Cutting or impact rotors or blades Liquid nitrogen delivery and control interface Cyclones or collection systems for separation of gaseous nitrogen and collection of milled materials Feed and discharge mechanisms suitable for continuous operation Exhaust or vent system for safe removal of evaporated nitrogen gas Demonstration and Evaluation Period To ensure compliance with performance requirements, the bidding period will remain open for two weeks to allow bidders to: Request and receive plastic bag samples for milling evaluation Specify the amount (by mass) of plastic bags required for their milling demonstration Pre-process the plastic bags if necessary before milling, with all pre-processing steps documented in the final bid documentation Demonstrate milling capabilities using the provided sample(s) Prepare a brief report in bid documentation detailing: The milling process and parameters Any pre-processing performed Cooling control approach (including temperature setpoints, nitrogen metering method, and venting design) Results of milling performance and outlet temperature control
