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 […]
Machinery
16 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 […]
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 […]
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 […]
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 […]
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 […]
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 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 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 […]
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 […]
During extrusion, the plastic is heated from the ambient temperature level to an elevated temperature level (usually >180 °C) so that the materials melts and becomes plastically deformable. After forming the product (film, tube, profile, rod, etc.), the product is cooled down to ambient temperature to achieve dimensional stability. Thus, […]
Collapsing of pipe ends is one of the most common problems in the extrusion of pipes and occurs especially when high production speeds areused on the production lines. The reasons for the geometric shape deformations are internal stresses. The reduction of the problem is often possible with simple means. […]
Different extrusion tool concepts can be used for the extrusion of rotationally symmetrical semi-finished product geometries (e.g. pipes, hoses, jackets, blown films, blow molds). Typical applications are the use of spiderleg dies, screenpack dies, heart curve but also the use of spiral mandrel distributors. From a price point of view, […]