Ratio-Pak Piston (Self-Vented) / MDPE / 200ml - 7661404

Product Name

Nordson Ratio-Pak Piston (Self-Vented) / MDPE / 200ml - 7661404

Brief Description

This product is a 200ml, self-vented piston made from Medium-Density Polyethylene (MDPE), specifically designed for use within Nordson EFD Ratio-Pak dual cartridge dispensing systems. It plays a critical role in ensuring accurate and consistent dispensing of two-part materials by preventing air entrapment and facilitating smooth material flow.

Popular Applications & Uses

- Dispensing two-part adhesives, sealants, foams, and coatings.- Packaging and application of potting compounds.- Ensuring precise, on-ratio dispensing in multi-ratio cartridge systems.- Preventing air tunneling in high-viscosity materials.- Eliminating suck-back and dripping in low-viscosity fluids.- Reducing material waste and residue within syringe barrels.

Industries that Commonly Use It

- Aerospace/Defense- Automotive Service/Repair- Cabinet & Woodworking- Chemical Industry- Construction/ Building Services- Furniture- General Manufacturing- LED/Electronics- Marine- Medical Device/ Prosthetics- Metal Fabrication- Mold Making/ Casting- Packaging Services or Contractor- Plastic Fabrication- Transportation/ Specialty Vehicle

Special and Unique Features

- Self-Vented Design: Features a unique plug that automatically closes once all air is removed during filling, ensuring an airtight, leakproof seal and eliminating the need for shims or bleed plugs.- MDPE Material: Constructed from Medium-Density Polyethylene, offering good impact and stress cracking resistance.- Optimized for Ratio-Pak Systems: Specifically designed to integrate with Nordson EFD Ratio-Pak snap-together dual cartridge systems, allowing for versatile mix ratios from 1:1 up to 25:1.- Consistent Dispensing: Applies uniform force on the fluid column, preventing tunneling in thick pastes and suck-back in thin fluids, leading to accurate and consistent deposits.- Reduced Waste: Wipes the cartridge edges clean as fluid is dispensed, minimizing material residue and waste.

Key Properties

- Material: Medium-Density Polyethylene (MDPE).- Volume: 200ml.- Density (MDPE): Typically 0.926–0.940 g/cm³.- Impact Resistance (MDPE): Good shock and drop resistance.- Stress Cracking Resistance (MDPE): Better than HDPE.- Chemical Compatibility: Excellent chemical compatibility for a wide range of adhesives and sealants.- Operating Temperature (MDPE): Resistant from -50°C to +90°C (general MDPE property).- Melting Point (MDPE): Range between 125°C and 135°C (general MDPE property).

Surface Compatibility

The piston itself is made of MDPE. Its compatibility is primarily with the two-part materials it dispenses (adhesives, sealants, coatings, potting compounds) and the polypropylene (PP) or nylon cartridges it operates within. MDPE is known for its chemical resistance, making it suitable for various fluid types.

Known backups / known substitutes

- Non-vented pistons: These are alternative pistons for Ratio-Pak systems, but they require shims or other methods to bleed air during insertion.- Multi-Seal with Integral Center Bleed Plug Pistons: These pistons also bleed air during insertion without a shim, offering an alternative to the self-vented design.- Solid Multi-Seal Pistons: These require a shim for air bleeding during insertion.- Other Nordson EFD piston types: Nordson EFD offers various pistons tailored for different fluid viscosities and dispensing challenges, such as Optimum pistons for syringe barrels.- Pistons from other dispensing system manufacturers: Depending on the cartridge system, pistons from other brands might serve a similar function, but direct compatibility with Nordson Ratio-Pak is specific.

Comparison Note

The Nordson Ratio-Pak Self-Vented MDPE Piston (7661404) stands out from non-vented or solid pistons by significantly simplifying the filling process and improving dispensing accuracy. Its self-venting mechanism automatically releases trapped air, eliminating the need for manual bleeding steps like shims or bleed plugs, which saves time and reduces potential errors during packaging and dispensing. This feature ensures consistent, on-ratio dispensing and extends the shelf life of packaged materials by preventing air-related degradation. While other pistons exist, the self-vented design offers a distinct advantage in ease of use and process reliability for two-component material applications.