Skip to main content Skip to navigation

Success Story Assetbank

Show all news items

Warden Plastics reduces materials while maintaining effectiveness of biological random filter media product


Established in 1957, Warden Plastics specialises in plastic injection moulding and extrusion, serving a diverse range of industries including automotive, electronics, medical, construction, and defence. Warden's initial area of activity was the chipping and selling of re-granulated plastics, but it soon expanded its operations to include the design and production of plastic extrusions. Warden Biomedia is the trading name for Warden Plastics’ own product range, enabling Warden to manufacture and market their Biomedia range. Warden Biomedia specialises in the research and development of random filter media for aeration and biological wastewater treatment plants.


One of its Biomedia products is the Biomarble, with the principle of increased surface area, the eco-friendly biological filter media are injection moulded in recycled polypropylene with specific design features to increase the efficiency of the effluent treatment process. The excellent ventilation and high voidage performance of Biomarble media make them extremely effective in wastewater treatment applications. The Biomarble is a product currently on the market, and Warden’s management team were looking to see if they could optimise tooling and reduce the product weight. In doing this, they wanted to reduce the cost of production while maintaining the performance of the part. There is growing demand for Biomedia in biological wastewater treatment processes, and Warden Plastics is becoming a global supplier in the wastewater treatment industry.

If successful, Warden was also seeking to make similar cost and material savings for its next-generation spherical design product, which is still in development stages.


After initially meeting WMG's SME Group at a networking event, Warden reached out to us for support. After considering their challenge, we were able to provide pre-funded materials analysis and design support under our Digital Innovation for Manufacturing (DI4M) programme.

The Biomarble is plastic sphere with a surface area of 310m²/m³. The Biomarble media is used in attached growth systems where biologically active microorganisms remove carbon and ammonia from wastewater.

Fernando Murguia, Technology Transfer Engineer (TTE) in our SME Group, began by building a simulation of the plastic injection process for the existing product. The simulation was then evaluated and used to optimise the geometry of the product to minimise the volume of material while being just as effective. Further simulations were carried out to show the efficiency of the final design. Fernando was also able to offer advice on tooling solutions and design.

Picture shows WMG's Dr Fernando Murguia and Mark Barrett, Managing Director at Warden Plastics


  • Although the changes we made to the original Biomarble design were relatively small, they have had a big impact on cost, material usage and waste.
  • The optimised Biomarble design saved 0.39g of plastic material per product, approximately 10% of the overall product weight.
  • This translates to a 6% cost reduction in its manufacture. Based on last year’s sales, this equates to a saving of £ 42,000 per annum.
  • The new product is a new design and yet to go on the market. We are assisting Warden in improving the basic design and manufacturing process to maximise potential profits. In order for the new product to make it to the market, it must be lightweight and have high machine output “yield”. WMG is assisting Warden to achieve these goals. WMG has already helped reduce the raw material content by 18%, which will help ensure its commercial viability.
  • This saving enabled Warden to invest in new tooling for the Biomarble to keep ahead of demand for this product both for the home market and for export.

Mark Barrett, Managing Director at Warden Plastics, commented: “We’re always looking to make efficiencies and reduce waste to make our business more sustainable. The simulations Fernando created allowed us to see how we could reduce the quantity of material but keep the product effectiveness, so that we could make decisions prior to investing in new tooling. We hope to launch the new iteration of the Biomarble later this year.”

Dr Fernando Murguia added: “This is the kind of product that will enable an environmentally conscious future and, from our perspective, it was of the utmost importance to run a number of simulations to optimise the use of materials and ensure we were keeping the product effectiveness. Warden is a really dynamic team, and it was great to be able to help them become more sustainable and efficient.”

Thu 10 Feb 2022, 12:05 | Tags: Plastics SME Success Story