Thermal cleaning in the fiber industry

Cleaning of spin packs, spinnerets

The gentle and repeatable cleaning of complete spin packs and spinnerets / spin nozzles is an important factor for fiber production, as this not only ensures a proper production process, but also a long lifetime for these key production tools.

 

Depending on the type of polymer (PE, PA, PP) and the design of the spin pack, the spin pack can be cleaned without requiring disassembly. Polymers are removed in a single step. Complete spin packs can be easily removed after cleaning. Inorganic remnants are removed using a select after-treatment method such as ultrasound.

 

The INNOVACLEAN cleaning system, for example, needs three to six hours to complete the cleaning process at temperatures between 450 °C and 480 °C. INNOVACLEAN can be used with most nozzle geometries and even with critical capillary sizes. The cleaning system eliminates any risk of thermal or mechanical damage to the spin nozzles.

 

Spin pack (assembled) before cleaning
Photo: Spin pack (mounted) before cleaning
Spin pack (dis-assembled) after cleaning
Photo: Spin pack (removed) after cleaning
Spin pack before / after cleaning
Photo: Spin pack before / after cleaning

Cleaning of melt blown dies, melt blown die blocks

Melt blown die before
Photo: Melt blown die before
Melt blown die after thermal cleaning
Photo: Melt blown die after thermal cleaning

Liquid polymer under high pressure comes out of a spinning beam (die beam, die block) in the melt blown process (spinning fleece process) and will be blown and spun through high speed hot air and cold air into fine fibres (micro fibres), which will be collected by a takeup mesh and carried away. Nonwoven micro fibre fleece fabrics are produced by this method, which, depending on the application, could be produced in different densities, thicknesses, absorptivity, strengths and merged into several layers. Besides of the well-known fleece shirts and fleece jackets, other typical products are extremely light but high efficient respiratory filters, cabin filters and fuel filters, and also large absorption and isolating stuff, such as diapers, cushion fleece, or isolating mats. Single use clothes or vacuum cleaner bags are also manufactured out of micro fibres fleece.

 

The cleaning of these spinning beams or die beams, which are frequently several meters long, requires a very delicate cleaning process, due to the extremely fine die holes and geometries. The fully automatically working thermal cleaning system VACUCLEAN by SCHWING heats up the tools slowly and gently, whereas a big portion of the cold polymer inside and outside will melt and flow out. The proper cleaning of the spinning beam will take place at approximately 450 °C within 8 to 14 hours, depending on the size and geometry of the tool, by means of controlled pyrolysis and oxidation under a vacuum atmosphere. By this method any thermal or mechanical damage is excluded and a perfect cleaning quality without carbon remains is always assured.

CLEANING OF SPIN PUMPS

Spin pump (assembled) before cleaning
Photo: Spin pump (mounted) before cleaning
Spin pump (dis-asembled) after cleaning
Photo: Spin pump (removed) after cleaning

The gentle and repeatable cleaning of complete spin pumps is an important factor for fiber production and ensures a long lifetime for these machine components.

The spin pumps can be cleaned without requiring disassembly. Polymers are removed in a single step. Complete spin pumps can be easily removed after cleaning. Inorganic remnants are removed using a select after-treatment method such as ultrasound.

 

The INNOVACLEAN cleaning system, for example, needs three to six hours to complete the cleaning process at temperatures between 450 °C and 480 °C. INNOVACLEAN and VACUCLEAN can be used with most melt pumps – from small spin pumps to large booster pumps. The cleaning system eliminates any risk of thermal or mechanical damage to the pumps.

Cleaning of melt lines

Proper melt distribution in spinning systems is critical, as the pipes are often several meters long and have complicated geometries. The already difficult maintenance and servicing of these components, which are important for the quality of the product, is made even more difficult when integrated, static mixers are used.

 

The MAXICLEAN thermal cleaning systems made by SCHWING, featuring customer-specific cleaning chamber sizes and integrated afterburning, are just as efficient as they are effective. Polymers and their decomposition products are removed in a single step during the thermal cleaning process. Inorganic remnants are removed using a select after-treatment method. A thermally cleaned melt line is just like new in terms of its flow properties.

Of course, other components in the fiber production facility such as extrusion screws, melt pumps, etc. can also be cleaned with the MAXICLEAN cleaning system. The fluidized bed system INNOVACLEAN or the vacuum system VACUCLEAN are used for spin packs and nozzles guaranteeing optimal cleaning even with very critical capillary sizes or geometries.


To enable us to respond to your questions or specific cleaning demands with custom-tailored information we ask you to please answer the interactive configuration questionnaire on the SCHWING homepage. Please use the inquiry form "Thermal Cleaning" for preparation and especially urgent requests.

Info Icon   Please do not hesitate to contact our specialists with any questions you may have. We would be pleased to assist you.