When manufacturing profiles (with hollow chamber structures), the design of the vacuum calibrations and the post-cooling represents a challenge. The number of calibrations, the geometry, the materials and coatings used, the vacuum control, the temperature control and much more must be optimally tailored to the product, the material and the […]
Extrusion
15 posts
When producing profiles and tubes with internal hollow chamber structures, so-called supporting air is often used. Here, a volume of air is blown through the die into the interior of the hollow chambers or lumens so that they do not collapse. The outer surfaces of the extrudates are usually drawn […]
In the field of material feeding to an extruder, there are a variety of different systems on the market. Starting from a central conveyor system or individual vacuum conveyors, the plastic granulate is stored in the simplest case only in a small storage tank – the hopper – so that […]
OPC UA – what exactly is that? To enable communication between different systems (e.g. a plastics processing machine / injection moulding machine / extruder) and a PC application (e.g. a virtual assistance system) or higher-level organisational systems (e.g. product control systems, MES, etc.) it is necessary to know in which […]
The processing behavior and the achievable product properties of plastics can change enormously depending on the residual moisture content of the polymer raw material. In most cases, too high residual moisture leads to problems, but in some cases quality problems or processing problems also occur due to too low residual […]
As already mentioned in the previous article, it is always advisable to optimally parameterize the temperatures of the extrusion cylinder to avoid production problems and to ensure economical and productive production. Optimizing cylinder temperatures while production is running is not an easy task and is therefore often avoided due to […]
Today’s extruders usually have several different heating (or heating/cooling) zones, which can be individually parameterised with regard to the desired temperature. The temperature control of the extruder is essential for the achievable product quality as well as for the productivity of the plant. Nevertheless, in practice it happens very often […]
Blocking of films is the most frequent cause of complaints about films. In some light cases, the problem is only a slight quality defect, but in more extreme cases it leads to large quantities of rejects, as entire rolls have to be disposed of on which blocking has occurred. […]
In the course of the current trends towards Industry 4.0 (smart factory), the availability of as much process information as possible is one of the first necessary steps. Process information, machine control parameter and sensor values are generally available to a large extent, but it is often not easily possible […]
In order to achieve a high product quality, additives are added to the raw materials, which cause a change or improvement of the product properties. Nowadays plastic products are often used in areas where the use of pure plastics would be unthinkable. After the melting zone of the extrusion screw […]
The term “assistance system” refers to electrical, information technology or mechatronic systems (e.g. a software, a car) that provide the user with assistance in a current real situation or even actively intervene in the operating process and carry out actions in the background. As virtual assistants (e.g. in the […]
In different extrusion processes, curvature (or bowing, sabre-running, katana effect, etc.) represents a major quality problem and is often difficult to get a grip on. The cause of the curvature is almost always an inhomogeneous thermal situation of the product during cooling and can often be greatly reduced or completely […]
In the processing of plastic, additives offer the possibility of changing the properties of polymers and adapting them to a corresponding task. A distinction is made between additives that have an influence on the process ability of the plastic and additives that have an influence on the product properties. Frequently […]
Identifying the “real” cause of a problem is usually the most important step if a sustainable solution is to be achieved. Often fundamental mistakes are made in this area and either “workarounds” are developed which merely help to avoid the problem or fake causes are eliminated. Various methods exist for […]
The extrusion of pipes, profiles, sheets, films, solid and hollow rods or other semi-finished products can cause a wide variety of problems that can impair the economic efficiency of the processes. These problems may concern the production itself, but may also have arisen from the market or external circumstances. We […]