News for the plastics and rubber industry. Macplas
Technology Wednesday, 21 April 2021

Single-calender extrusion process for the production of waterproofing membranes

In the extrusion domain dedicated to thermoplastic PVC and TPO single or multilayer waterproofing membranes, Amut is able to design different tailor-made turn-key plants with either double or single calender. Such diversified systems may reach an overall production up to 15 million sq. m. and 8 million sqm of high quality membrane per year, respectively.


The single calender system is the result of the technological innovation conducted in over 40 years of experience and makes it possible to produce in one single step a co-extruded 3-layer membrane, adding the inner reinforcement (polyester, polypropylene, fiberglass) and the fleeceback scrim bonding for support. The end product is a finished membrane composed of up to five materials/layers coupled in a single step, offering to end-users a completely different proposal from those currently available on the market.


The single calender achievement was obtained thanks to constant studies and research in the extrusion process applied to sheets and rolls of thermoplastic material. The state-of-the art single calender line combined with reliable extrusion and laminating technology, allows Amut to offer a diversified production of membranes, minimizing the costs associated with two or three-step processing, material change and machine purging.


The high efficiency extrusion lines manufactured by Amut are fully automatic, to optimize the production cycle. In particular, a well-proven control software, designed and developed in-house, gives several supports to customer’s operators. A typical example is the automatic ramp procedure where the line is started at low speed to reduce the waste generated during the machine setup and then, by a simple input of ramp parameters, the line is automatically speeded-up to reach the target output. The whole management of all operation and control parameters makes the line ready for Industry 4.0 with sizeable benefits in terms of quality control and global integration with the production database of customers.


Moreover, the lines are equipped with automatic packing system for the rolls produced and features technology for dimensional control of the product and visual surface inspection, with detection of any aesthetic effects. An automatic process for direct in-line dosing of raw materials and flame retardants additives is also included in the plant.