Automotive Leather Solvent-Free Retrofit 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.

A leading automotive interior leather manufacturer in Zhejiang partnered with Haifeng to upgrade an existing solvent-based synthetic leather line into an automated, 100% solids solvent-free polyurethane coating and lamination cell. The retrofit targeted the production of premium microfiber synthetic leather for new energy vehicle (NEV) seat upholstery and dashboard coverings.

Prior to the upgrade, the facility operated conventional solvent-borne dry lines utilizing dimethylformamide (DMF) and toluene. Residual solvents in the finished leather resulted in an unacceptable vehicle interior odor rating of Grade 4.0 and total volatile organic compounds (TVOC) exceeding 850 µg/m³. These emissions disqualified the client from major automotive OEM supply contracts and incurred steep operational costs for solvent distillation towers.

Haifeng supplied a solvent-free reaction coating module centered on the HF-SFL180-2K system. Featuring continuous vacuum thin-film degassing, dynamic micro-pin mixing, and precision three-roll reverse application, the revamped line was reported to reduce residual-solvent emissions and improve odor performance against the automotive industry's stringent VDA 270 interior air quality standards.

Concept illustration — not a photograph of delivered equipment or a customer installation.

Haifeng engineered and integrated a modular solvent-free coating section into the customer’s existing roll-to-roll handling framework. The process utilizes two dedicated 120 L stainless steel conditioning vessels where high-viscosity polyol and polyisocyanate prepolymers undergo continuous vacuum degassing at 0.08 kPa, stripping entrained micro-air that would otherwise cause pinholes.

Independent servo-driven metering pumps measure the chemicals via Coriolis mass flow feedback, delivering the formulation to a water-jacketed micro-pin dynamic mixing head. The head achieves molecular-level blending in fractions of a second while holding chemical temperatures below 55°C to manage reaction exotherm.

The homogeneous reactive resin discharges directly into a high-precision three-roll reverse coating station. Precision-ground chrome rolls apply a uniform 0.12 mm liquid layer onto textured release paper across the 1,450 mm web width with thickness variations held below 2 µm.

The moving wet film is immediately married to an island-type microfiber nonwoven substrate via pneumatic lamination rolls, followed by curing inside a compact 12-meter convection oven before automatic peel-off and rewinding.