licensed engineer, director of diamat Maschinenbau (Germany)
German company diamat Maschinenbau GmbH has found an optimal solution for production of rigid film from all types of polymers on one extrusion installation
Having developed in 2007 a line with a single screw extruder for production of thermoforming film from the main types of polymers (PP, PS, PET and polylactides), diamat company has approached establishment of most flexible production complying with market demands and not requiring a 100% loading with one type of polymer raw material.
The installation offered gives an opportunity to readjust the line for other type of raw material for a short period without any serious modifying operations and parts replacement. With the help of auxiliary software solutions full automation of the process is possible, so that the machine itself will set up parameters necessary for processing of the next type of polymer.
New approach to crystallization and drying process
diamat company has also designed entirely new crystallization and drying equipment complementing the given extrusion line and developing the flexible production concept. Drying stations are specially designed for processing of water absorbing materials with various viscosity and humidity degrees into rigid film packaging material.
Mechanical arrangement of the crystallizer is so that it is perfectly suited to processing of regranulate, domestic wastes, sheet die cutting and flakes with high dust content, which is typical for wastes of thermoforming production. Besides all types of PET this equipment is also successfully applied for crystallization and drying of other water absorbing materials - such as polylactides and regrind of PET and PE composites.
Crystallization system can be controlled independently from the extrusion line. That means that processing of such materials as, for example, PP and PS, becomes considerably cheaper - in comparison with processing of polyolefins and styrene in a twin-screw extruder. Therefore diamat flexible production concept is of particular interest nowadays.
Drying equipment is also notable for low energy consumption and shorter runtime, which enables to spend less time on process control and promptly react to deviations from its normal run.
General purpose extrusion
Extrusion line, consisting of one or several single screw extruders, is a coextrusion system able to satisfy all possible processor requirements.
The manufactured film has a three-layer structure (the so called aba-sandwich), where the mid layer is completely made of secondary raw material (production rejects, waste bottle flakes, domestic plastic wastes) and the outer layers are made of primary raw material. Such a structure ensures correspondence to sanitary and hygienic standards, enables to cut down expenses on blocking additives and masterbatches as well as provides an opportunity to apply gloss coating on styrene compounds and even to produce multicolour multilayer compounds. As for processing of polypropylene, usually used for single-layer film manufacture, a coextruder is applied here to increase the carrying capacity, which also brings about fast payback of equipment outlays.
Lines with production capacity 500 kg/h, manufacturing film 750 to 2000 mm wide, can have a central slitting unit for simultaneous production of several film flows. In this case it is recommended to use fully automatic systems for simultaneous winding of several rolls - these devices, allowing to spare production facilities, have been for many years now presented in the market by diamat company.
In extrusion lines advanced and highly efficient filter technologies are applied; thanks to them processing of highly contaminated materials is also possible.
The installations are equipped with all necessary devices: special systems for applying liquid antistatic agents, a film thickness measuring system (it can be combined with automatic dosing extruder head), pumping equipment for melt feeding, multi-component charge system, as well as three roller polishing machines with highly efficient cooling system.
If required, it is possible to install auxiliary devices for polishing film after cooling or for sealing film laminating, as well as cutting equipment.
Latest servo motors, fast transmission systems, communication systems and parameter checkout, remove control function - all these automation components are quite applicable to general-purpose diamat installations. All data can be transferred via auxiliary equipment to external control systems, then be printed and stored.
As all equipment is produced taking into consideration customer requirements, a line can be entirely manufactured for a certain customer. Closeness to a customer is provided by the company's multidivisional structure.
Extrusion installations diamat for production of rigid thermoforming packaging film enable a customer to process all most common types of polymers into high quality film using one line with fast readjustment, thus providing beneficial price and yield correlation. Flexibility and production capacity of these installations allow to comply with various customer needs, promptly and accurately responding to ever changing world market conditions.