OUR COMPANY PHILOSOPHY
Flexible – safe – innovative: FENOTEC GmbH manufactures products from flexible materials and has set itself the goal of being just as flexible in responding to customer requirements. Our claim to be innovative on a daily basis includes on the one hand developing new products, on the other hand improving almost mature products and making them more user-friendly. Our numerous patented solutions prove this and have been developed to increase customer satisfaction.
The products we have been manufacturing for over 50 years are safe – safe for the environment, safe to use and safe for the operator.
A guarantee for the safety of our products is the approval by the DIBt (Deutsches Institut für Bautechnik). We also work closely with TÜV, BAM (Bundesanstalt für Materialforschung) and PTB (Physikalisch Technische Bundesanstalt) and have been awarded by BG RCI (Berufsgenossenschaft Rohstoffe und Chemische Industrie) for the occupational safety of our products.
Hot wedge welding is used as a continuous joining technique for the overlapping joining of plastic sheets (e.g. made of PE, PP) or coated fabric tarpaulins (e.g. PVC) above a film thickness of 0.3 mm. The hot wedge moves along the plastic foils or the coated fabric tarpaulins and welds the fixed sheets. The choice of the welding temperature, the pressure and the time at which the hot wedge exerts this pressure is of great importance. Through numerous tractor tests and storage tests, we have determined the optimum parameters for all the films we use. This enables us to ensure that the joining surfaces are uniformly plasticized.
At the beginning of the joining process, thin metal rails, which are provided with a non-stick layer (usually PTFE), are subjected to a short but high current pulse, during which they heat up. The heat is brought to the joint by means of heat conduction through the foil. While the temperature profile in the parts to be joined is symmetrical due to the arrangement of the heating tapes in heat pulse welding on both sides, it is asymmetrical in the one-sided process variant and is mainly used for very thin films.
In the ultrasonic process, the electrical oscillations generated by an ultrasonic generator are converted by the ultrasonic transducer into mechanical oscillations of the same frequency and transmitted to the weld metal via a transformation intermediate piece and the sonotrode. The generator and the so-called oscillating structure work in resonance. Due to the reflection of the mechanical vibrations at the sound-radiating end surface of the sonotrode, a standing wave is formed which transfers energy into the weld metal.
The mechanical vibrations applied to the workpieces under a certain contact pressure are absorbed and reflected at the interface. The resulting molecular and interfacial friction generates heat. The plastic begins to soften and a sound barrier forms in the area of the joining zone due to the plasticized and strongly damping plastic layer, which leads to a very intensive melting of the plastic, i.e. the reaction accelerates by itself, since an increasing proportion of the vibration energy is converted into heat.
So welding takes place by inner friction. After a certain holding or cooling time while maintaining the contact force, the welded joint is created. This process is used in our factory especially for thinner foils.
High-frequency welding is regarded as the highest quality process for joining thermoplastic materials. In contrast to processes in which heat is added from the outside or in applications in which the heat required for welding is generated by mechanical movement, in the case of high-frequency energy the heating takes place dielectrically in the material itself. In high-frequency welding, the welding heat is generated by molecular vibrations directly in the material.
Thermoplastic materials that achieve
sufficient plastification and melt flow by heating are
suitable for this process. In our production we process soft PVC foils, polyurethane foils (TPU) and TPU coated textile fabrics. The selection of the materials to be processed depends on the technical and practical requirements for the finished product.
Joined parts are bonded together by means of adhesive. The adhesion-forming interactions between the adhesive and the surface of the parts to be joined have an extremely short range of less than 1 nanometer. Therefore, a good wetting of the parts to be bonded by the not yet solidified, i.e. liquid adhesive, is a necessary prerequisite for the production of a high-quality bond. In addition to wettability, the adhesive and the part to be bonded must have matching molecular groups so that interaction between the adhesive and the surface of the part to be bonded can occur and thus adhesion. It is important to remove impurities before gluing. The rule of thumb applies here: Not as clean as possible, but as clean as necessary. This also applies to joining with swelling welding flux, which is the most frequently used method of bonding used by us.
Vulcanization is the term used to describe processes in which thermoplastic natural rubber or synthetic rubber is converted into elastomeric plastics. During vulcanization, covalent cross-links are formed between the macromolecules of the rubbers so that the molecules can no longer move freely against each other, resulting in elastic behavior. We use this process for our elastomeric plastics.
Sewing is a very good way to reinforce a seam. We combine this process with other joining processes and use it in particular for our sewn nonwovens and for the outer shells of missiles.
We process plastic films, both thermoplastics and elastomers. Thermoplastics are plastics that are deformed at higher temperatures and elastomers under mechanical stress.
As the temperature rises, the binding forces of the thermoplastics’ chain molecules are reduced so that the molecule chains can move freely and the plastic behaves elastically. If the temperature continues to rise, the thermoplastic material enters the plastic state in which it is deformed. The material is then cooled and retains its shape. This process can be repeated without affecting the properties of the material as long as the temperature at which the macromolecules are chemically degraded or destroyed is not exceeded. This behaviour makes thermoplastics meltable, weldable, swellable and soluble.
At room temperature, elastomers usually have a fully reversible deformation behaviour under mechanical stress (tensile and compressive stress). Due to the strength of the cross-linkages of the chain molecules, the molecular threads are very conditionally mobile and therefore elastomers are neither meltable nor soluble.
A combination of both plastics is also possible: thermoplastic elastomers (TPE). The advantage of TPE is that it has the elastic and dynamic properties of elastomers and the weldability of thermoplastics.
We also offer various COEX films (coextruded films) on customer request. These are multifaceted films that are produced from different or identical starting materials. This enables the combination of several positive properties, e.g. processability or tightness.
PVC film, soft
Polyvinyl chloride (PVC) is a thermoplastic material that is one of the most widely used plastics together with PP and PE. This can be explained by its very good mechanical properties, its chemical resistance and its resistance to oxidation, even under stress conditions, e.g. under pressure or in long-term contact with chemicals.
It is produced by chain polymerisation from the monomer vinyl chloride. PVC plastics can be found on the market as hard PCV for e.g. window or raw profiles or as soft PVC for applications such as hoses or roof seals. We use soft PVC in the manufacture of our sleeves to give them the required flexibility for installation in the tank.
Polyethylene is the most widely used thermoplastic in the world. It is produced by chain polymerization from the monomer ethylene. PE can be found as HDPE (high density PE) or as LDPE (low density PE). HDPE is mainly used in construction and LDPE in the packaging industry.
Due to their good chemical resistance, especially to bases and acids, and their good mechanical properties, our PE films are very suitable for use as inner liners.
Polypropylene (PP) is one of the most widely used thermoplastics due to its extensive properties. It is produced by chain polymerisation from the monomer ethene. The production of PP is very flexible. This can be modified specifically, for example, by adding additives that can change the properties of the PP. As a result of this variability, this plastic can be found in many applications, especially in packaging, electrical appliances and in the automotive industry.
We process and trade different PP films, which have a good chemical resistance against bases and acids and which at the same time show good mechanical switching, outweigh fatigue resistance and impact strength.
Polytetrafluoroethylene (PTFE) is a thermoplastic consisting of carbon and corduroy. The connections C-F are very strong. In addition, the fluorine atoms are larger than the carbon atoms. For this reason, the fluorine atoms form a protective layer over the weaker C-C compounds. Due to these two properties, chemical reactions are strongly prevented. PTFE is distinguished by its exceptional chemical resistance and therefore it is of great importance in the chemical industry.
Thermoplastic polyurethane (TPU) is a thermoplastic elastomer (TPE). TPU is produced by a polyaddition reaction of diols. The good elastic and at the same time dynamic properties of TPU make it possible to use this excellent film as an inner cover.
Rubber is an elastomer produced from rubber and latex by vulcanization. This elastomer has very good elasticity, elongation, low temperature flexibility and tensile strength. Depending on the application, rubber can be made to measure by selecting the starting products and molecular structure. The most important applications of rubber are car and truck tyres. It can also be processed into foam rubber for use as mouthpieces for instruments, for example.
2. Fabric-reinforced materials
The reinforcement of plastics with fabric material allows the use of these materials for applications requiring higher robustness. These materials are used, for example, in swimming technology.
Geotextiles are plastics which consist of natural or artificial fibres and which are used in the building industry, e.g. for separating, filtering, protecting or draining in landfills or in hydraulic engineering.
Nonwovens are geotextiles made of fibres or filaments, which are usually produced by mechanical needling or thermal fusion. The raw materials and production methods are very broad and therefore the application possibilities are also very large. We process nonwovens from various fibres and filaments for the installation of our leak protection linings.