In the course of the digitalization of production plants, more and more process parameters are being collected, stored and made available for analysis. For a detailed analysis of production parameters, however, it is essential to know the prevailing situation in production, as otherwise it is very difficult to meaningfully evaluate […]
Basics
33 posts
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 […]
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 […]
In many companies there are situations in which the production capacity utilisation is extremely reduced, whether due to economic or seasonal fluctuations or extraordinary events. In such times, it is advisable to get things done that often cannot be done in the normal production routine due to time constraints and […]
In the extrusion of pipes, cables, profiles and many other semi-finished products, immersion cooling tanks or spray cooling tanks are used in which the hot extrudate is introduced and cooled with cooled water. Both the immersion cooling tank – in which the extrudate is completely submerged in a water bath […]
The choice of the right extruder size is based on many different factors and can have a decisive influence on the achievable product quality and also on the achievable productivity of the production. General statements are often not correct and must therefore be thoroughly questioned before they are implemented in […]
Every optimization, regardless of whether it is a technological, process engineering or a organizational measure, usually requires an adaptation of behavior patterns. Adapting behaviour patterns, especially when the behaviour to be changed has been practised for years, is often not easy and in many cases represents a hurdle, the overcoming […]
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 […]
Spiral mandrel distributors are among the most powerful extrusion tools for the production of pipes, films, hoses and bottles and are available in a wide range of variants on the market. Spiral mandrel distributors can be used for various production processes and a good design of the spiral mandrel distributor […]
Extrusion dies should ideally be designed and coated in such a way that production can be carried out without any interruption for cleaning. This aspect is already taken into account in the design of the flow paths, in the selection of steels and coatings as well as in the selection […]
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 […]
In plastics processing, quality problems are often caused by the presence of angel hair, impurities or dust. Angel hair can be recognized as very fine, hair-like plastic threads that can be formed during material transport. Dusts are fine solid particles of different sizes and can be made of plastic, but […]
When extruding profiles, the maximum production speed is one of the most important factors for the calculation af a quotation. If the production speed is assumed to be higher than the real production can be in practice, this can mean high losses for the extrusion plant and represents a high […]
Extrusion cylinders are generally divided into smooth barrel extruders (conventional extruders) and grooved extrusion cylinders (grooved barrel extruders, helibars, etc.). The differences between the different systems lie, as the name suggests, in the design of the extruder barrel. While the conventional extruder has a completely smooth cylinder, a grooved system […]
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 […]
The screw of an extruder is considered as the “heart” of the machine and can have a significant influence on the achievable product quality, the achievable maximum throughput and the efficiency of the production plant. There are different basic concepts of screw design, which have different advantages and disadvantages. In […]
Due to the poor thermal conductivity of thermoplastics, residual stresses (tensile and compressive residual stresses) are build up in the walls of the product during cooling processes after extrusion. Deformations and distortion of the products often result from the residual stresses, whereby the presence of the residual stresses becomes visible. […]
In addition to the width of a film and the profile tolerance, the flatness is considered as one of the most important quality criterions. Good flatness refers to film products with a high planarity, also a low tendency for sagging areas or bulges. The flatness of a film is an […]
In extrusion, plastic granulate is plasticized by converting mechanical energy into thermal energy. The mechanical energy required for this (torque and rotation of the screw) is generated with the aid of electric motors, i.e. from electrical energy. The additional heaters often only contribute a small part to the overall energy […]
Voids/blowholes/vacuoles are frequent quality problems that can occur especially in the manufacture of thick-walled products. Although the cause of this problem is well known, it is often difficult and time-consuming to avoid it. When cooling plastics from melt temperature to ambient temperature, the specific volume or density of the plastic […]