Roth Composite Machinery know-how speeds LPG vessel production

The company has developed a fully-automated production line containing four winding stations having five spindles each. The high degree of automation of the production line is said to guarantee maximum productivity.

Bernd Fischer, sales director at Roth Composite Machinery, stated: “Having a cycle time of 43 seconds per vessel, it is the world’s most effective production line of this type at present. The advantages of fibre-reinforced plastics for LPG vessels are clear – they are significantly lighter than conventional materials and allow a realisation of complex product geometries with highest stability.”

Fibre-reinforced plastic tanks are increasingly used for the storage of fluids or gases. So, for instance, they are suitable for applications with hydrogen or nitrogen.

The production line for the manufacture of plastic vessels reinforced by glass fibres is set up as twin concept. Two independent winding stations are placed in one gantry. The time for loading and unloading is in parallel to the productive time. The loading and unloading of the vessels is carried out in a fully-automated way by using robots. An impregnating bath with shuttle table for the impregnation of the fibres ensures optimal efficiency. By this, the production interruption periods are reduced by about 80%.

A patented procedure for an automatic applying and cutting of the fibres being integrated in the fibre delivery carriage enables highest degrees of automation and efficiency. The control guarantees the exactly defined positioning of the fibres onto the vessel. A gantry combination provides for high precision between the spindles and the stiffness of the total system. The tolerance value of the composite material from spindle to spindle is less than two grams.

The machine builder is using special heavy-duty components at each stage of the production line. Besides a blow-moulding machine for the plastic liners, the designed system also comprises the liner pre-assembly station. At this, the boss part is welded onto the liner, the shaft is screwed in, the vessel is pressurised and the liner surface is activated for the winding process by means of flame treatment. The high degree of production accuracy is shown by the minor deviations as regards the bursting pressure of the vessels. An energy-efficient drying oven being especially designed for the LPG vessels ensures optimal product results. Furthermore, an end-of-line and a batch control as well as the assembly of the outer casing and the labelling are integrated. Four handling and assembly robots allow precise and fast production processes. The process data control is enabled via a central main computer. At different stations, individual item numbers of the vessels are read out and stored by means of QR codes. Thus, the process data of each single product are traceable and allow for an optimal production and quality control. Roth Composite Machinery offers a remote access service for this production line.

www.roth-composite-machinery.com