MORE THAN 50 YEARS OF KNOW-HOW EXTRUSION DIE TECHNOLOGY SLOT DIES & COEXTRUSION FEED BLOCKS

EDITORIAL DI Dr. Friedrich Kastner CEO / Managing Partner COLLIN Lab & Pilot Solutions GmbH Corné Verstraten CSO / Joint Partner COLLIN Lab & Pilot Solutions GmbH Dear Readers, In 2022, we could look back on 5 decades of experience and know-how, the K 2022 was a great success and as group, we are strengthened for the next years. Founded as a sole proprietorship in 1972, COLLIN is now a globally established, medium-sized pioneer in the field of extrusion machine construction. Continuous optimisation and further development at all levels, our team of experts, the wide range of our product solutions...

COLLIN LAB & PILOT SOLUTIONS FULL OF VIGOUR FOR THE NEXT 50 YEARS In 1972 the company was founded as sole proprietorship. Today, COLLIN Lab & Pilot Solutions is a worldwide premium supplier of lab and pilot lines for the plastic processing and converting industry, medical device technology, pharmaceutical industry as well as for research and development institutes. With more than 135 employees and over 35 representative agencies worldwide and an export rate of 85%, the Bavarian company is well known as pioneer of extrusion. As member of NGA Group and headquarters in Germany as well as local subsidiaries...

4.1 Collin cast line at the end of the 70s 4.2 New head office in Maitenbeth since 2018 of our goals to push the company’s potentials and professional competences of the team together into the right path forward. As an example, our portfolio was focused into the five fields Pilot Line, Lab Line, Medical Line as well as Polytest Line and Teach Line. Furthermore, we started to establish a worldwide sales network with more than 35 local representatives and agencies along with our own subsidiaries in the U.S.A., Singapore as well as a recent addition in the Republic of India. We also focused on strengthening...

DIE TECHNOLOGY FROM & PILOT SOLUTIONSThe variety of extrusion products requires Author: Dr Ing- Franz Grajewskia variety of extrusion tools The variety of extruded strands at COLLIN Lab & Pilot Solutions consists of ► Tubes, outer diameter range <1 mm to >70 mm ► Blown films, lay flat width <50 mm to >800 mm ► Profiles ► Fibres and strands for e. g. 3D print or medical ► Hoses for medical applications applications (intravaginal rings) Besides the strand extrusion, the extrusion tools from COLLIN Lab & Pilot Solutions cover the complete range for flat films and sheets up to a width of 100 mm....

In previous years, the configuration was made purely empirically (very time-consuming), however, nowadays, modern calculation methods such as FEA (Finite Element Analysis) are available. These methods allow exact flow channel calculations and provide results for different final products very quickly. Due to an own tool manufacture at the affiliated company COMELT, COLLIN Lab & Pilot Solutions is a premium supplier of extrusion technology. Besides the dies for Collin, at COMELT, also production dies are offered and produced. As already mentioned above, the importance of the tool is decisive for...

The critical area in every coextrusion die is the area where two-layer flows are combined. Figure 7.1 schematically shows the connections and the resulting conclusions. v1, v2 different ► Results in distensions in the barrier layer ► Shear stress differences ► Both results in an instability in the barrier layer Potential influences, v1 = v2 ► Visc1 and Visc2 as equal es possible ► Gaps h1, h2 matched to each other ► Temperatures T1, T2 matched to each other ► Throughputs m1, m2 matched to each other (only possible to a very limited extent) 7.1 Processes in the combination of two melt layers Overview...

In 1973, the breakthrough in overcoming these problems came with the invention of the spiral mandrel distributor /3/. Depending on the geometry of the spiral supporting basic body, we distinguish Transition area ► Axial, cylindrical distributors ► Axial, conical distributors ► Radial distributors with spirals in one plane Turning area Outlet gap The principle of the spiral mandrel distributor (see Figure 8.1) is similar for all types, although due to the progressive development, there is a wide variety of details for the individual geometries. 8.1 : Design of a spiral mandrel distributor (Picture...

► Especially in case of high number of layers, between 9 and 13 layers, there is a space-saving arrangement of the platens ► Every platen is equipped with an individual heating belt, which allows an individual temperature for each platen. With insulations, which are arranged between the platens, temperature differences of up to approx. 40K can be achieved. Especially for the coextrusion of materials with widely different flow behaviours, this is an advantage. ► The number of layers of a blown film can easily be changed ► Quick disassembly and assembly at shortest cleaning times ► Cost-effective...

In the transition area from the large into the small channel, the melt is accelerated. Here, the molecular chains are stretched. But since they have the aim to return into the energetically more favourable structure namely into an „entangled “structure, this occurs at the outlet of the narrower channel and appears as swelling material. However, the elastic energy, which is stored in the material is reduced depending on time and temperature. That means, the longer the small channel and the higher the temperature, the smaller the swelling. These two influencing parameters are limited by the increased...

As a result, all information for the quality evaluation of an extrusion tool is available. The fact that elastic effects cannot be considered in these calculations must not be ignored. In the following, some examples of calculations are illustrated. As already explained above, the speed with which layers in coextrusion tools hit each other is decisive for the quality of the film. In Figure 11.1, the confluence of three layers with corresponding speed vectors and flow lines can be seen. It is clear, that there is a very good optimizing result. For the mechanical dimensioning of a tool, it essential...