Spinneret seals from Wiremesh-ProTec – supporting the filament-forming element
If man-made fibers are to be produced, three different spinning processes come into question. Polyamide, polyester and viscose, for example, are processed in the form of a dissolved spinning mass to form fibers. Various spinnerets are used here, which have to withstand high temperatures, among other things. The focus here is also on other elements of the technical systems, such as the spinneret seals. Wiremesh-ProTec has suitable spinneret seals for every spinning process and for all spinnerets, which can be reliably integrated into the highly productive technology.
The spinning processes at a glance – Wiremesh-ProTec spinneret seals can be used here
In order to produce man-made fibers, the raw material must be dissolved or melted in a container. If the wet spinning process is used, the mass is spun in a chemical bath. Monofilaments can be created with just one nozzle opening, while multifilaments are created with several nozzle openings. A pump pushes the raw material through the spinneret, which in turn is sealed with spinneret seals so that no material escapes. In the wet spinning process, chemicals neutralize the solvent, allowing the fibres to solidify. After they emerge, they are stretched and wound up.
In the dry spinning process, the spinning mass is spun in a stream of hot air. This allows the volatile solvent to evaporate. The melt spinning process allows the molten mass to cool and solidify as it is pressed through the nozzle. Fibers made of polyamide and polyester, among others, are produced in this way.
Spinneret seals should have these properties
Both the spinneret and spinneret seals must be able to withstand high temperatures. At the same time, it is important that the components work reliably even under high pressure – this also requires clean assembly. If the spinneret seals are not precisely matched to the spinneret and the manufacturing process, they can have a negative impact on the fineness and cross-sectional shape of the resulting fibers. It is therefore all the more important that the spinneret seals are precisely processed elements.
The materials in question
The materials for spinneret seals must be adapted to the spinning process and the associated conditions. For example, nickel, tantalum, gold-platinum-iridium or glass are used for wet spinning. Stainless steel and tantalum, on the other hand, are suitable for dry spinning. Last but not least, stainless steel and platinum-rhodium are used in the melt spinning process. At Wiremesh-ProTec, we always make sure to provide the right elements for the respective process in order to ensure a smooth production process.
The background to the very first spinning processes
The first spinning process is said to have been described as early as 1842. This involved drawing glass fibers from a molten glass through fine openings. Over the years, attempts were made to use this method for the production of artificial silk: in 1908, an artificial silk manufacturer commissioned a watchmaker to develop special metal spinnerets, which were produced in the same year and patented shortly afterwards. Platinum was used for the first metal spinnerets because of its high resistance to corrosion. However, other alloys were soon available as an alternative, as platinum proved to be too expensive. The spinneret seals also soon became the focus of technical devices in order to achieve consistent fiber quality.
