For both household applications and future-mobility systems, composite liners form the core of high-performance solutions. At Kautex, extrusion blow molding is leveraged to produce seamless, multi-layer thermoplastic liners that serve as inner seals in composite vessels. These liners are engineered with precise wall thickness, barrier properties, complex features (like integrated bosses and testing points), and co-extrusion options to meet rigorous technical and safety requirements.

In domestic systems (such as LPG cylinders, water filter housings, and other gas/liquid containment), these liners ensure leak-tight, durable performance while allowing efficient production and reliable quality control. In mobility applications — for CNG, hydrogen, and other high-pressure use cases — our liners must meet extreme conditions: pressures up to 700 bar, wide temperature ranges (from –60 °C to +120 °C), and minimal gas diffusion. Kautex has pioneered a polyamide liner of 320 litres volume (approx. 500 mm diameter, >2 m length) for hydrogen pressure vessels — a world first for blow-molded liners of this size.

These liners act as robust inner cores in overwrapped fiber composite vessels: in addition to the blow-molded liner, they include threaded or flanged boss parts for valves and fittings, and are wrapped in composite materials for mechanical strength. The outcome is lighter, more resistant, and cost-efficient tanks compared to welded or rotationally moulded alternatives.

At every step — from material selection and simulation through liner blow molding, in-line testing, and integration into vessel systems — Kautex ensures full-service support to meet both current standards and future demands.