CLENZED™ is Radical Materials’ range of integrated antimicrobial technologies for plastics, silicone and rubber. Available as additives, masterbatches and fully compounded materials, CLENZED technologies provide long-lasting protection against the growth of bacteria, mould and other microorganisms.
With more than 20 years of antimicrobial polymer development experience, we formulate and manufacture CLENZED materials in-house, tailoring the technology to the polymer, manufacturing process, application and regulatory requirements.
CLENZED™ combines proven antimicrobial technologies with Radical Materials’ in-house expertise in polymer formulation, compounding, manufacturing and material testing.
We work closely with customers to develop solutions tailored to the polymer, manufacturing process, application and regulatory requirements. The aim is to achieve effective antimicrobial performance while maintaining material properties, processability, appearance and cost efficiency.
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We work with a range of established antimicrobial technologies, including silver-based inorganic systems and organic anti-mould additives. The optimum solution depends on the polymer, target microorganisms, processing conditions and intended application.
Rather than applying a single antimicrobial chemistry to every project, we select and optimise the active technology to deliver the required performance while maintaining compatibility with the base material and minimising unwanted effects on colour, processing or mechanical properties.
Radical Materials has more than two decades of experience developing antimicrobial plastics, masterbatches and compounds for demanding industrial applications.
That experience extends beyond simply incorporating an antimicrobial additive. We understand how polymer chemistry, carrier selection, processing temperature, additive interactions and end-use conditions can influence efficacy. This allows us to identify potential formulation problems early and develop materials around the requirements of the finished component rather than treating antimicrobial performance in isolation.
Antimicrobial materials may be subject to different regulatory requirements depending on the active substance, finished product, intended claim and market in which the product will be sold.
We can develop formulations using antimicrobial technologies with appropriate regulatory support and help customers select solutions suited to applications including food-contact materials, healthcare products, consumer goods and article protection.
Regulatory status (including European Biocidal Product Regulations, UK Biocidal Product Regulations, FDA & EPA) is considered alongside efficacy and material performance from the outset of development rather than being addressed only after a formulation has been completed.
Our antimicrobial masterbatches and compounds are formulated and manufactured in-house, giving us direct control over raw-material selection, dispersion, processing conditions and product consistency.
With multiple extrusion lines, we can manufacture development quantities from 1 kg through to commercial production at up to approximately one tonne per day. This allows new formulations to be trialled quickly, adjusted where necessary and then scaled into routine production without transferring the project between unrelated development and manufacturing partners.
Not every antimicrobial project can be satisfied with a standard off-the-shelf masterbatch. Polymer grade, processing method, target organism, colour, operating environment and regulatory requirements can all influence the optimum formulation.
Our flexible development and manufacturing capability allows us to quickly produce small trial batches, evaluate performance and make formulation changes, before progressing to larger-scale production. This is particularly valuable for specialist polymers, new applications and projects where customers need to validate antimicrobial performance before committing to significant production volumes.
Antimicrobial functionality can be combined with other material properties within the same polymer compound or masterbatch system.
Depending on the application, we can develop materials incorporating combinations of CLENZED™ antimicrobial protection, SCOPIC metal and X-ray detectability, KONDUCT antistatic performance, Airsential malodour & VOC capture, UV stability, colour and other functional properties.
For example, a food-processing component might require a bright colour for visual identification, antimicrobial efficacy to inhibit bacterial growth and X-ray detectability to support foreign-body control. Developing these functions together allows the complete material system to be optimised for processing and performance rather than treating each additive independently.
CLENZED™ formulations can be independently tested against bacteria, fungi, mould and other microorganisms relevant to the intended application.
ISO 22196:2011 is widely used to quantify the antibacterial activity of treated plastics and other non-porous surfaces. Testing commonly uses Staphylococcus aureus and Escherichia coli, but formulations can also be challenged with application-relevant organisms including Listeria, Salmonella, Pseudomonas and Klebsiella.
Comparing treated samples with an untreated control provides a quantitative measure of antibacterial efficacy over a defined contact period.
ASTM G21 evaluates the resistance of synthetic polymeric materials to fungal growth under conditions favourable to mould development.
The organisms selected should reflect the intended application. These may include moulds such as Cladosporium, Aspergillus and Penicillium. Testing is particularly relevant where fungal growth could cause staining, odour, material deterioration or loss of product performance.
ISO 21702:2019 provides a method for measuring antiviral activity on treated plastics and other non-porous surfaces.
Antiviral efficacy should never be inferred from antibacterial performance alone: individual viruses can respond very differently to the same surface technology. Where antiviral properties are being investigated, testing can therefore be carried out against the relevant virus or, during development, an appropriate surrogate such as bacteriophage Phi6.
Any antiviral performance claim should be based on appropriate test evidence rather than the assumed behaviour of an antimicrobial additive.
Standard test methods provide valuable comparative data, but standard laboratory conditions do not always represent the environment in which a finished product will operate.
Where appropriate, we can evaluate antimicrobial formulations under application-relevant conditions, varying factors such as temperature, contact time, organism and ageing or environmental exposure.
For example, antimicrobial materials intended for refrigerated food-processing environments can be tested at 5°C against organisms such as E. coli, Listeria monocytogenes and Salmonella, providing a more meaningful indication of performance under real operating conditions.
Antimicrobial plastics contain active substances that are incorporated into the polymer during manufacture, typically through an antimicrobial masterbatch or fully compounded formulation. Rather than sitting only on the surface as a temporary coating, the antimicrobial technology is dispersed throughout the material and remains available at the surface as the component is used.
The exact mechanism depends on the antimicrobial technology. In silver-ion systems, small quantities of active silver ions become available at the polymer surface and interfere with several processes required for bacterial survival and reproduction. These can include disruption of cell membranes, interference with enzyme activity and inhibition of cellular replication. Because several mechanisms are involved simultaneously, silver-ion technology provides broad antibacterial activity rather than relying on a single biological target.
Different technologies may be required where mould or fungal control is also important, as strong antibacterial performance does not automatically mean that a material will provide equivalent antifungal efficacy.
The effectiveness of an antimicrobial plastic depends on more than the active ingredient alone. Polymer type, additive concentration, dispersion, surface characteristics, temperature, humidity and contact time can all influence performance. For this reason, Radical Materials develops antimicrobial formulations around the finished material and intended application, with efficacy verified using appropriate laboratory and, where necessary, application-specific testing.
Antimicrobial plastics should be considered an additional hygiene and material-protection measure, not a replacement for appropriate cleaning, disinfection or good manufacturing practice.
CLENZED antimicrobial technology can be incorporated into a wide range of thermoplastics, engineering polymers, silicone and rubber. Radical Materials develops polymer-specific formulations that take account of processing temperature, carrier compatibility, mechanical properties, colour, regulatory requirements and the intended application.
Polypropylene is one of the most versatile substrates for antimicrobial modification, combining low density, chemical resistance and straightforward processing. However, the optimum antimicrobial system still depends on the grade, processing conditions and finished application; the same additive should not simply be transferred between polymers without considering its effect on performance.
Antimicrobial technology can be incorporated into LDPE, LLDPE and HDPE for films, profiles and moulded products. The carrier system and additive concentration should be selected to achieve good dispersion while preserving the flexibility, toughness or rigidity required from the particular polyethylene grade.
Because PE applications range from thin films to substantial mouldings, a polymer-specific masterbatch is generally preferable to treating antimicrobial addition as a universal one-size-fits-all formulation.
TPU combines flexibility, abrasion resistance and toughness, making it attractive for seals, profiles, flexible components and hygiene-sensitive equipment such as food conveyor systems. Antimicrobial modification needs to consider the TPU chemistry, hardness, processing temperature and other functional additives already present in the material.
This is a good example of why functional polymer development should begin with the finished application: achieving antimicrobial efficacy is only useful if the TPU retains the flexibility and mechanical performance for which it was originally selected.
PVC is one of the more challenging polymers to make antimicrobial effectively. Plasticisers, stabilisers, pigments and other ingredients can influence both antimicrobial efficacy and appearance, while inappropriate carrier systems may cause haze, phase separation or discolouration.
Radical Materials therefore develops antimicrobial PVC around the complete compound, with particular attention to compatibility, clarity and long-term stability.
POM is widely used for precision engineering components because of its stiffness, dimensional stability, low friction and excellent wear behaviour. Introducing antimicrobial functionality needs to preserve those characteristics rather than achieving efficacy at the expense of mechanical or processing performance.
As with other engineering polymers, additive compatibility, loading level and the requirements of the finished component should therefore be considered together during formulation.
PA6, PA66 and related polyamides offer excellent strength, toughness and wear resistance, but their relatively high processing temperatures place additional demands on antimicrobial additives and carrier systems. Technologies used in nylon must remain stable through processing while achieving the required efficacy without unnecessarily compromising the polymer’s engineering properties.
This makes antimicrobial nylon a good example of why processing temperature and base-polymer chemistry matter when selecting an antimicrobial additive.
ABS is frequently used in durable housings, controls and equipment where appearance and impact performance are important. Silver-ion systems can work effectively in these polymers, but grade selection, colour and operating temperature can have a significant effect on performance.
Our testing experience has shown that different ABS grades can produce markedly different antimicrobial results at low temperatures, even when the same antimicrobial technology and concentration are used.
PC/ABS blends combine the toughness and heat resistance of polycarbonate with the processing and surface characteristics of ABS. Antimicrobial modification must take account of both polymer phases, processing temperature and any colour or appearance requirements.
Polycarbonate is widely used where impact resistance, dimensional stability and appearance are important, including equipment housings, controls, glazing components and other durable moulded parts.
Antimicrobial modification requires careful attention to the grade, processing temperature, colour and optical requirements of the finished component. In transparent or translucent applications, the antimicrobial system must also be selected to minimise unwanted haze, discolouration or loss of clarity.
Radical Materials can develop antimicrobial polycarbonate formulations that balance efficacy, processing stability, appearance and mechanical performance, with testing tailored to the requirements of the finished application.
Polyketone combines low moisture absorption with excellent toughness, chemical resistance and wear performance, making it particularly attractive for food-processing, water and fluid-handling components. Radical Materials has developed a dedicated antimicrobial polyketone masterbatch using a PK carrier, avoiding the unnecessary introduction of a dissimilar polymer.
Our antimicrobial polyketone technology has also been evaluated at 5°C, providing performance data under conditions representative of chilled and refrigerated food-processing environments.
HIPS combines economical processing with useful impact performance and is widely used in appliance housings, liners and other moulded or thermoformed products. Antimicrobial formulations can be developed around the required surface finish, colour and operating environment.
Silicone can generally achieve excellent antimicrobial performance, but its cure chemistry creates some unusual formulation challenges. Certain antimicrobial actives can interact with catalysts, accelerators or pigments, causing yellowing or brown discolouration and potentially compromising efficacy.
Antimicrobial and anti-mould functionality can be incorporated into natural and synthetic elastomers for applications such as seals, gaskets and flexible components. The formulation approach depends on the rubber chemistry, cure system, processing method and target microorganisms, rather than simply transferring a thermoplastic masterbatch into an elastomer.
Where required, antimicrobial functionality can also be combined with other properties such as metal and X-ray detectability within the same silicone or rubber system.
Antimicrobial functionality can be incorporated into many other thermoplastics, thermosets, coatings and elastomeric materials beyond the polymers listed above.
The optimum approach depends on factors such as processing temperature, polarity, additive compatibility, colour, surface characteristics and the intended environment of use. Where a standard masterbatch is not suitable, Radical Materials can develop a custom formulation around the specific substrate and application.
CLENZED™ plastics can provide an additional hygiene measure for components used in food and beverage processing equipment, particularly where surfaces are repeatedly exposed to moisture, food residues or refrigerated conditions.
Typical applications include conveyor components, guides, fittings, handles, housings, seals and other moulded or extruded parts. Antimicrobial functionality can also be combined with metal and X-ray detectability where both microbial control and foreign-body detection are required. Antimicrobial materials complement appropriate cleaning and sanitation procedures rather than replacing them.
Laboratory and life-science equipment frequently incorporates moulded polymer components that are repeatedly handled, exposed to moisture or used in environments where maintaining clean surfaces is important.
CLENZED™ addititves can be incorporated into equipment housings, instrument controls, racks, trays, sample-handling components and other durable plastic parts.
Formulations can be tailored to the required polymer, chemical resistance, colour and processing method, with antimicrobial efficacy tested against organisms relevant to the intended environment.
Ventilation and air-handling systems contain polymer components that may be exposed to condensation, humidity and accumulated organic contamination, creating conditions in which bacteria, fungi or mould can develop.
Components such as condensate trays, fan housings, duct fittings, vents, filters and other polymer parts can benefit from the use of CLENZED™ additives & plastics to help inhibit microbial growth and protect the material from staining, odour and deterioration.
Where mould resistance is particularly important, formulations can be developed and tested specifically for fungal performance rather than relying solely on antibacterial efficacy.
Frequently touched components in public and shared environments can act as persistent contact points for microbial contamination. CLENZED™ technology can be incorporated directly into durable plastic and elastomeric parts to provide continuous surface protection.
Typical applications include door push plates, light switches, lift controls, handrails, transit grab handles, ticketing equipment, seating components and other high-touch surfaces used in schools, transport systems, offices, healthcare facilities and other public buildings.
The antimicrobial formulation should be selected for the polymer, expected wear, cleaning regime and target microorganisms, with efficacy verified under conditions relevant to the finished application.
Every CLENZED™ project begins with the requirements of the finished application rather than with a predetermined additive. We consider the polymer, manufacturing process, target microorganisms, operating environment, regulatory requirements and any mechanical or aesthetic constraints before selecting the most appropriate antimicrobial technology.
Development can then progress through small-scale compounding, processing trials, antimicrobial testing and formulation optimisation before scale-up into commercial manufacture. Because the entire process is carried out in-house, development times can be significantly reduced. In many cases, we can formulate, compound and supply a new masterbatch for initial customer trials within 1–2 working days.
CLENZED™ technology can be supplied as a concentrated masterbatch, custom additive system or fully compounded antimicrobial polymer, depending on the application.
We start by understanding the finished application, polymer, manufacturing process, operating environment, target microorganisms and any regulatory or aesthetic requirements. Where appropriate, we can also review existing formulations, samples or test data.
We select the antimicrobial technology, carrier system and likely addition rate according to the polymer and application. Colour, processing temperature, mechanical properties, regulatory requirements and any additional functional additives are considered at the same stage.
Small development batches can be produced in-house for initial processing trials. Depending on the project, the material may be supplied as a concentrated masterbatch or as a fully compounded ready-to-process material. Polymer masterbatches & compounds are processed on our Thermo Fisher lab extruder, while silicone & rubber are mixed using our lab scale Winkworth Z-Blade.
The trial material is processed using conditions representative of production so that dispersion, colour, processability and component performance can be assessed before the formulation is finalised.
Formulations can be supported by antimicrobial efficacy testing against relevant microorganisms, alongside evaluation of properties such as tensile strength, impact performance, colour stability, UV resistance and processability. Testing conditions can also be adapted to better reflect the intended application, including low-temperature environments. Antimicrobial testing is conducted by independent laboratories. Comparative mechanical testing is done in-house, with an option to employ third party laboratories when appropriate.
Results from processing and laboratory testing are used to refine the formulation where required. The objective is to achieve the required antimicrobial performance while maintaining the mechanical, processing and aesthetic properties of the base material.
Once the formulation has been qualified, it can be transferred directly into routine manufacture. Because development and production are both carried out in-house, knowledge gained during trials is retained through commercial scale-up and ongoing supply.
During the COVID-19 pandemic, many materials were marketed as “antiviral” using technologies originally developed for antibacterial applications. Radical Materials invested extensively in independent antiviral testing, including evaluation of commercially available products, and found that antibacterial efficacy should not be assumed to translate into antiviral performance.
Viruses behave very differently from bacteria and fungi, so antiviral claims should be supported by appropriate testing against the relevant virus or a recognised surrogate.
Effective virus reduction does not necessarily require a conventional antimicrobial biocide.
Radical Materials has investigated an alternative approach based on engineering the physical and chemical properties of the polymer surface. Selected additives and processing technologies can modify characteristics such as surface energy, wettability and interfacial behaviour, creating conditions that are less favourable to viral persistence.
The objective is not simply to add an “antiviral ingredient”, but to design a polymer surface whose properties contribute to faster loss of viral infectivity.
We do not assume antiviral performance from an additive’s chemistry, antibacterial efficacy or supplier claims. Any proposed virus-inhibiting material should be evaluated using an appropriate antiviral test method under conditions representative of its intended use.
Performance can depend on the virus, polymer formulation, surface properties, temperature, humidity and contact time.
Radical Materials can develop and evaluate polymer formulations intended to reduce viral persistence, with performance claims based on appropriate test evidence.
Virus-inhibiting surfaces should be regarded as an additional risk-reduction measure, not a replacement for appropriate cleaning, disinfection or infection-control procedures.
CLENZED™ is Radical Materials’ family of integrated antimicrobial technologies for plastics, silicone, rubber and other materials. Depending on the application, CLENZED formulations can be developed to inhibit bacteria, mould, fungi or other microorganisms and supplied as additives, masterbatches or fully compounded materials.
Rather than using one universal antimicrobial chemistry, the active technology, carrier system and addition rate are selected according to the polymer, manufacturing process, target microorganisms, required performance and applicable regulatory requirements.
An antimicrobial plastic is a polymer containing an active technology that inhibits the growth or survival of microorganisms on the material surface. The antimicrobial functionality is normally incorporated during manufacture using a masterbatch or fully compounded formulation, rather than applied as a temporary surface treatment.
Depending on the technology selected, antimicrobial plastics can be developed to target bacteria, mould, fungi or other microorganisms. They should be regarded as an additional hygiene or material-protection measure rather than a replacement for appropriate cleaning and disinfection.
The mechanism depends on the antimicrobial technology used. Inorganic silver-ion systems, for example, release small quantities of biologically active silver ions at the polymer surface. These interfere with several processes necessary for bacterial survival and reproduction, helping to inhibit growth and surface colonisation.
Other antimicrobial technologies operate through different mechanisms and may be more appropriate for controlling fungi or mould.
Performance depends not only on the active substance but also on the polymer, additive concentration, dispersion, surface characteristics and environmental conditions.
An antimicrobial masterbatch is a concentrated mixture of antimicrobial active substances dispersed in a polymer carrier. It is added to the base polymer during manufacturing processes such as injection moulding, extrusion or film production.
Using a suitable carrier polymer and correctly dispersing the active technology are important because these factors can influence processing, appearance, mechanical properties and antimicrobial efficacy.
Radical Materials develops polymer-specific antimicrobial masterbatches rather than assuming that one universal formulation is appropriate for every material or application.
Antimicrobial is the broadest term and refers to materials designed to inhibit microorganisms. Antibacterial describes activity specifically against bacteria, while anti-mould or antifungal materials are designed to inhibit fungi and mould.
A technology that performs very well against bacteria will not necessarily provide equivalent protection against mould, and vice versa. Where both are important, the formulation can incorporate appropriate technologies to provide the required spectrum of activity.
The microorganisms relevant to the finished application should therefore be identified before selecting an antimicrobial system.
Antimicrobial functionality can be incorporated into most commonly processed polymers and elastomers. These include polypropylene (PP), polyethylene (PE), nylon/polyamide (PA), POM/acetal, TPU, PVC, ABS, polycarbonate, PET, PBT and polyketone (PK/POK), as well as silicone and a range of natural and synthetic rubbers.
The optimum antimicrobial technology and masterbatch carrier depend on the polymer, processing temperature, manufacturing method, required efficacy, colour and finished application.
Materials can be developed for processes including injection moulding, extrusion, calendaring and compression moulding.
There is no universal addition rate for antimicrobial masterbatch. The required concentration depends on the antimicrobial technology, active loading within the masterbatch, polymer, processing method, target organisms and required level of efficacy.
Using more masterbatch than necessary can increase cost and may unnecessarily affect mechanical or aesthetic properties, while insufficient addition may compromise antimicrobial performance.
For this reason, Radical Materials determines appropriate addition rates through formulation experience and, where required, antimicrobial testing of the finished material rather than relying on a standard dosage for every application.
Any additive has the potential to alter the properties of a polymer, particularly when used at significant loading levels. Effects can include changes in impact strength, tensile properties, flexibility, colour, processing behaviour or surface finish.
Careful selection of the antimicrobial technology, carrier polymer and addition rate can substantially reduce these effects. Where necessary, the overall formulation can also be modified to compensate for changes caused by the antimicrobial additive.
Our approach is therefore to optimise antimicrobial efficacy and material performance together, rather than treating them as separate requirements.
Antimicrobial technology incorporated throughout a polymer can potentially remain effective for much of the useful life of the component because it is not simply a temporary surface coating.
Actual durability depends on the active technology, polymer, environmental conditions, surface wear, cleaning regime, UV exposure and other aspects of the application.
Where long-term antimicrobial performance is important, accelerated ageing or application-specific testing can be used to determine whether efficacy is maintained after exposure to representative conditions rather than assuming performance solely from an initial antimicrobial test.
Yes, antimicrobial plastics can be developed for food-contact applications, but regulatory compliance must be considered for the complete formulation and intended use.
The antimicrobial active substance must have appropriate regulatory status, but this alone does not automatically make the finished plastic suitable for food contact. The polymer, additives, concentrations, migration requirements, conditions of use and target market must also be considered.
Radical Materials can develop antimicrobial formulations using appropriately supported technologies and work with customers to address the regulatory requirements applicable to their finished component.
They can, but antimicrobial efficacy should not be assumed to remain unchanged as temperature falls. Temperature and humidity can significantly influence antimicrobial performance, making application-relevant testing particularly important for refrigerated food-processing environments.
Radical Materials has tested antimicrobial polyketone at 5°C against food-relevant organisms including Escherichia coli, Listeria monocytogenes and Salmonella, demonstrating greater than 99.999% antibacterial efficacy after 24 hours using an ISO 22196-based method.
Where low-temperature performance is important, formulations can be evaluated under conditions representative of their intended use.
Yes. Antimicrobial technology can be combined with other functional properties within the same masterbatch or polymer compound.
For food-processing applications, for example, a material can potentially incorporate antimicrobial protection together with metal and/or X-ray detectability, custom colour, antistatic properties or UV stabilisation.
Combining several functions requires careful formulation because each additive can influence processing and material properties, and additives may interact with one another. Developing the complete formulation as a system helps ensure that each required property is achieved without unnecessarily compromising the others.
Testing should be selected according to the microorganism, material and intended application.
For hard, non-porous plastic surfaces, ISO 22196 and the related JIS Z 2801 method are commonly used to assess antibacterial activity. Testing can be performed against organisms including Staphylococcus aureus, Escherichia coli, Listeria, Salmonella and others where relevant.
Fungal and mould resistance requires different methodologies, such as ASTM G21.
Standard laboratory conditions are not always representative of actual use, so temperature, humidity, contact time and other conditions may also need to be adapted for application-specific development work.
It is feasible to engineer polymer surfaces that reduce viral persistence, but antibacterial performance should never be assumed to imply antiviral efficacy. Viruses behave very differently from bacteria, and antiviral claims require appropriate testing against the relevant virus or recognised surrogate.
Our development work has also investigated approaches that modify the physical and chemical properties of the polymer surface using conventional additives or processing aids, creating conditions less favourable to viral persistence rather than relying on a conventional antimicrobial biocide.
Any proposed virus-inhibiting surface should be validated using appropriate antiviral testing, and should remain an additional risk-reduction measure rather than a substitute for cleaning or infection-control procedures.
