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CORDIS

FRICTION OPTIMISATION OF SEALS THROUGH ADVANCED LASER SURFACE TEXTURING OF MOULDS

Periodic Reporting for period 3 - MouldTex (FRICTION OPTIMISATION OF SEALS THROUGH ADVANCED LASER SURFACE TEXTURING OF MOULDS)

Berichtszeitraum: 2020-05-01 bis 2021-04-30

MOULDTEX has developed cost-effective surface modifying methods for friction reduction in dynamic contacts, in particular in those in which one of the components is an elastomeric or plastic part manufactured by injection moulding or vulcanisation. These methods have been implemented in real production lines, supported by advanced product and process design modelling tools as well as online inspection and correction tools to prevent defect generation and propagation. The core of this approach lies in the texturing of the mould surface using lasers and transferring the texture to the rubber component surface during the moulding process. Direct surface texturing is used only once to create the inverted pattern on the mould surface, its costs depreciated across the thousands of components manufactured using that mould. The innovative production process represents a step change in the manufacture of textured seals as it allows for the first time the mass production of textured seals with improved friction and wear characteristics (>20% friction reduction and >50% extended life) and prices comparable to current mass production methods (<10% increase). This friction reduction and life enhancement will lead to dramatic energy consumption savings of 1-6% on average.
The project has developed and demonstrated a novel process for the design and high volume manufacture of surface-textured dynamic seals made of elastomer materials and tailored to the friction environment within which the component operates, achieving a friction reduction of >20% at a cost premium of <10%. The technology boasts the following key innovative features:
i. A holistic design software to enable ease of take-up and use by seal manufacturers to quickly and cheaply design high-value products with tailored friction reduction customised to the specific needs of the target application
ii. Modelling tool to optimise the texture parameters for a given set of operating conditions enabling >20% reduction in friction and >50% improvement in wear of dynamic seals without impacting on sealing performance and at a <10% price premium
iii. Process simulation workflow for the fine-tuning of the process conditions and of the texture geometry to be applied on the mould surface.
iv. Combination of laser-matter modelling with advanced adaptive optics enabling the controlled formation of tailored hierarchical micro-/nano- surface textures on different material substrates
v. 5-axis machine laser systems for free form mould tool surface functionalization enabling cost efficiency and ease of take-up by mould manufacturers
vi. In-line optical inspection
vii. Surface texturing of mould using energy efficient laser processes with zero requirement for additional chemicals or materials thereby enabling minimal environmental impact
During its 42 months, the following work has been performed:
Within WP1 “Friction Modelling”, advanced models for the prediction of the friction variation produced by a texture pattern (with respect to the untextured case) have been developed, as well as Reduced Order Models that are able to instantaneously predict the friction variation as a function of the parameters of influence. Experimental tests have been performed on a textured pneumatic U-cup rod seal in order to validate the simulation model and the ROM.
In WP2, a Holistic Design Software, called Mouldtex Optimizer, has been developed. It consists of a simple web platform with a real-time user-friendly visualization that allows users to analyse the effects of the micro-texture on a seal application, for different operational conditions, in terms of friction reduction and demoulding forces. It has an optimisation module which reveals the optimum texture which provides the highest friction reduction for a specific application and operational conditions in real-time. The tool has the capability of being expanded, easily adding different materials, geometries and/or applications.
Within WP3 “Laser Texturing”, we have improved the precision of mould texturing through pico-laser based techniques. The physical mechanisms underlying laser-matter interactions have been analysed, leading to the development of a multiscale computational code that is able to correlate the laser parameters with the surface pattern features. We have developed an adaptive optics configuration for the accurate and dynamic control of the pico-laser irradiation scheme and a prototype pico-laser system combining the modelling software and adaptive optics enabling reliable and accurate formation of the desired texture on the mould.
Within WP4 “Mould Tool”, a workflow has been defined in order to take into account the possible impact of both the moulding and demoulding processes after the best texture combination is defined with the holistic software. In addition, a highly effective sol-gel coating that enhances the demoulding process has been developed. Finally, a prototype of a 5-axis laser system with an innovative miniaturised head as well as other beyond-the-SOA features has been developed and optimised.
In WP 5, an innovative optical system for the in-line quality control of the seal texture has been developed. Mould etching and regeneration procedures have also been developed within this WP.
Finally, in WP6, three pilot lines have been set up for demo purposes: one for the production of surface textured moulds, another for the production of a V-ring rotational seal and a third one for the manufacturing of a U-ring translational seal.
Surface texturing for friction reduction is a known technology that has been analysed at theoretical and laboratory level, but its huge potential for mass production manufacturing of dynamic components has remained untapped so far. This project has shown the technical and economic viability of implementing this technological solution in an operational industrial environment.
The project has demonstrated that it is possible to improve the targeted functionalities of dynamic seals by at least 20%, with a cost increase below 10% with respect to the cost of conventional products. The uptake of this technology by seals and moulds manufacturers will help strengthen the global position of the European manufacturing industry through the intensive implementation of innovative and unconventional technologies.
The market share for European plastic and rubber producers of commoditized products is getting steadily reduced in favour of lower manufacturing costs from emerging countries. Maintaining margins in highly commoditized rubber and plastic products is getting very difficult for European enterprises, given the increased cost of raw materials and the increased price sensitivity of the end users. The only way for EU manufacturers to significantly reduce their manufacturing costs is moving to higher added value products. MouldTex will increase the competitiveness of seals and industrial equipment manufacturers across the full value chain in highly competitive markets such as: seal manufacturers, manufacturers of products / systems using textured seals, mould tool manufacturers and laser engravers.
Holistic design software developed in WP2
Moulding simulation performed in WP4
Validation of the ROM developed in WP1
Laser texturing machine prototype developed in WP4
Validation of the simulation model developed in WP