Fuel System Manufacturing
Fuel System Manufacturing: a clean and efficient process
Plastic fuel systems manufacturing, based on extrusion blow-molding process, requires 5 major steps:
- Extrusion: Plastic raw material (in pellets) is being heated and melted using an extrusion screw. As it is pushed through an extrusion head, it forms a large plastic tube called parison.
- Blow-molding: The parison goes down between the two shells of a mold. Mold is closed and gas injected into the mold. The plastic material, due to the pressure, is projected on the surface of the mold to take its complex form. At the end of the process, the mold opens and tank shell comes out. Excess material is cut and regrind to be reused in the extrusion process.
- Cooling: Tank shell has to cool down before assembly of the components. Post-cooling devices can be used for this step to accelerate this part of the process.
- Finishing: Tank shell goes through a machining center to cut necessary openings and weld required components (such as valves, clips and sometimes filler pipe) onto the tank. Special finishing centers have been developed to optimize and robotize this part of the process.
- Assembly: Finished tanks are equipped with complementary components such as fuel delivery module, fuel lines or straps. Those complete Fuel Systems are then being delivered to vehicle assembly line, sometimes in sequence, to be mounted on the car.
Plastic material commonly used for automotive plastic fuel tanks is a special grade of HDPE (High Density PolyEthylene). Particularly suitable for the extrusion blow molding process, it confers to the tanks a real advantage in terms of performance: ability to manufacture complex shapes to embark a maximum of useable fuel in tight space, excellent behavior during crash, light weight and optimized cost for the function.
The fluorination process consists in treating monolayer HDPE parts using a mix of fluorine and nitrogen to lower the permeability of these parts to hydrocarbon.
- Without fluorination, H and C molecules are spaced out. With fluorination, H molecules are replaced by F molecules; F and C molecules are tightened.
- Fluorination increases the quality of the barrier properties of the part to fuel and makes the polyethylene less permeable to gasoline fuel by modifying the polymer surface.
Lean Manufacturing: IPS, the Production System of the Auto Inergy division
Industrial quality enhancement is part of Plastic Omnium’s business philosophy in the path to excellence.
The Auto Inergy division decided to build and deploy its own Production System, IPS: implemented in all factories and advanced supply sites of the division, IPS was also the way to progress towards an optimized production standard and contributes to enhance industrial performance levels, as well as safety and quality.
Benchmarking the other well known production systems, IPS is not only a "tool box", it is a complete system, mix of philosophy, best practices, discipline, continuous improvement, based on the involvement of all associates.
The "kaizen workshop" on the shop floor, is the easy way to involve everybody and gather all improvement ideas.
All sites are managing workshops such as 5S, Hoshin, TMP, SMED, VSM.
From these foundations, Plastic Omnium goes on increasing sophistication of tools while Lean Maturity is progressing.
The use of Kanban system allows as well a good flexibility meaning the ability to follow fluctuation of customer demand without loss of productivity.
IPS deployment is still progressing by pushing Lean principles upstream, inside the process design, to do it right first time, taking into account the economical and technical expertise conditions of the country where the plant is established.
IPS pulls the operational excellence of the Auto Inergy division, including safety & quality, to the highest level.