Metro Fastener MCU Pad Line Upgrade in China

Illustration notice. Process illustrations are not verified photographs of this installation.

Project reference basis. Figures and configuration details are reported in the supplied project brief. They are reference values for the stated application, rather than verified acceptance results or a guarantee for another installation. Confirm the source records, material, tooling, operating schedule and test method when assessing a comparable project.

Project brief for review. The supplied document describes this configuration and reports the outcomes below. Original acceptance records, test reports and media are not attached to this import; attribution and outcomes require verification before publication.

The supplied brief describes the following project context.

A leading railway fastener manufacturing enterprise in Southern China deployed Haifeng’s high-pressure microcellular polyurethane (MCU) molding line to modernize its elastomeric rail pad manufacturing workshop. The project was commissioned to supply high-performance damping pads for a new 160 km/h urban express metro line.

Prior to the upgrade, the facility utilized manual low-pressure casting and solvent-blown polyurethane formulations. The resulting open-pour pads exhibited coarse, non-uniform cell structures (averaging 150 µm in diameter) and high dynamic stiffening ratios exceeding 1.65. During laboratory testing under cyclic loads, the pads suffered structural collapse and plastic fatigue failure after just 1.2 million cycles, failing strict EN 13146 requirements. Furthermore, heavy flash and lengthy 18-minute mold residence times bottlenecked factory delivery.

Haifeng designed and commissioned an automated MCU production cell centered on the HF-MCU120-HP system. Combining 18 MPa water-blown impingement mixing with multi-station vacuum-assisted hydraulic mold carousels, the upgraded facility achieved ultra-fine 30– 50 µm microcellular foam distribution, passing 3 million cyclic fatigue tests with less than 5% stiffness drift.

Review point: EN 13146 part, specimen, load history and stiffness method require original reports. Fatigue, cell size and dynamic stiffness are material/component results, not machine certification. Mold vacuum -0.08 MPa is a gauge-pressure reference.

Reported equipment configuration from the supplied brief:

Haifeng delivered an automated, closed-loop microcellular polyurethane pad manufacturing cell. Polyether polyols, extenders, and green water-blowing additives are mixed in twin 150 L stainless steel day tanks with closed-loop thermal regulation holding material temperatures at 40°C.

High-pressure axial piston pumps displace components at 17.5 MPa under Coriolis mass flow measurement, keeping stoichiometric ratios within ±0.2%. Chemical streams meet inside an automated 18 MPa impingement mixing head that injects 75 grams of reactive formulation into multi-cavity aluminum molds within 1.0 second.

Before injection, the four-station hydraulic mold clamp evacuates the cavity to -0.08 MPa. The tool maintains tight temperature control at 55°C ± 1°C via multi-zone tempered water circulation. The water-blown formulation expands uniformly into fine closed-cell pores without requiring volatile physical solvents. Following a 6-minute cure, automated pneumatic pins demold the finished pads onto a cooling transfer belt with controlled flash.

EN 13146 part, specimen, load history and stiffness method require original reports. Fatigue, cell size and dynamic stiffness are material/component results, not machine certification. Mold vacuum -0.08 MPa is a gauge-pressure reference.