Ratio-Pak Piston (Non-Vented) / MDPE / 250ml - 7661406

Product Name

Nordson Ratio-Pak Piston (Non-Vented) / MDPE / 250ml - 7661406

Brief Description

This product is a non-vented rear seal piston, specifically designed for use with Nordson Ratio-Pak 250ml dual cartridge systems. Made from Medium Density Polyethylene (MDPE), it is a critical component for the precise and consistent dispensing of two-part (2K) materials such as adhesives, sealants, foams, coatings, and potting compounds. The non-vented design is suited for specific fluid types to ensure optimal dispensing performance and prevent issues like piston bounce.

Popular Applications & Uses

- Dispensing two-component adhesives and sealants in assembly operations.- Packaging and application of potting compounds for electronic components.- Controlled application of foams and coatings.- Precision fluid dispensing in manufacturing processes requiring specific mix ratios.- Use in conjunction with industry-standard dispense guns for 2K materials.

Industries that Commonly Use It

- Aerospace/Defense (for high-performance bonding and sealing applications)- Automotive Service/Repair (for structural adhesives and sealants)- Chemical Industry (for packaging and dispensing specialized 2K formulations)- Construction/Building Services (for sealants, coatings, and repair compounds)- General Manufacturing (across various sectors for assembly and bonding)- LED/Electronics (for potting, encapsulation, and bonding sensitive components)- Marine (for sealing, bonding, and repair in harsh environments)- Medical Device/Prosthetics (for precision assembly and bonding of components)- Metal Fabrication (for bonding and sealing metal parts)- Packaging Services or Contractor (for filling and utilizing 2K cartridge systems)- Plastic Fabrication (for bonding and assembly of plastic components)

Special and Unique Features

- Non-vented design for specific fluid compatibility and consistent pressure.- Part of the Nordson Ratio-Pak system, allowing flexible combination with other cartridge sizes for various mix ratios (1:1 up to 25:1).- Made from MDPE, offering a balance of strength, flexibility, and chemical resistance.- Designed as a rear seal for secure containment of materials within the cartridge.- Compatible with industry-standard dispense guns for ease of use.

Key Properties

- Material: Medium Density Polyethylene (MDPE).- Density: 0.926–0.940 g/cm³.- Good shock and drop resistance.- Less notch sensitive than HDPE.- Better stress cracking resistance compared to HDPE.- High ductility and impact strength.- Low friction properties.- Resistance to acid and base attack.- Low water absorption capability.- Maximum operating temperature around 50°C.

Surface Compatibility

As a component of a dispensing system, the piston itself does not directly interact with external surfaces for adhesion. Its compatibility is with the two-part materials it helps dispense and the polypropylene (PP) or nylon cartridges it seals. MDPE is known for its chemical resistance, making it suitable for a wide range of chemical formulations.

Known backups / known substitutes

- Other Nordson EFD Ratio-Pak pistons (e.g., self-vented versions for different fluid viscosities or applications).- Pistons made from different materials (e.g., HDPE, PP) if chemical compatibility or mechanical properties require it, though this would depend on the specific Ratio-Pak cartridge design.- Alternative dispensing system pistons from other manufacturers, but these would likely require a complete change of the cartridge and dispensing gun system due to proprietary designs.

Comparison Note

This non-vented MDPE piston is specifically engineered for the Nordson Ratio-Pak 250ml cartridge system, offering a balance of material properties suitable for a broad range of two-part materials. Compared to vented pistons, non-vented pistons are typically chosen for applications where air entrapment needs to be minimized for specific fluid characteristics, ensuring a clean and consistent dispense without oozing or drooling. Its MDPE construction provides a good balance of flexibility, toughness, and chemical resistance, distinguishing it from pistons made of other polyethylenes like HDPE or LDPE which have different mechanical and thermal properties.