How Do You Ensure Good Adhesion To Your Part?

One of the most frequent questions we get asked when speaking to potential customers is ‘Will the foam stick to our part?’. The short answer is yes, but it may take some other processes before achieving a suitable adhesion. Some substrates have a natural adhesion and therefore don’t require additional interference. If there isn’t a natural adhesion then there’s usually something we can do to achieve it. In this blog post, we will discuss adhesion further and look at a previous example of when Robafoam has overcome difficulty with adhesion.

The adhesion of the Robafoam seals to a component’s surface is dependent on the surface energy of the material or the surface treatment in question, as well as any possible contamination of the surface. Different material surfaces exhibit different levels of natural adhesion depending on their surface energy. Surface energy is measured in Dyne/cm2 and the optimal value for adhesion with our foam products is 50 Dyne/cm2.

One way to change the surface energy, to ensure the adhesion of the foam, is through the application of ‘atmospheric plasma’. All our 6 axis robots are equipped with a plasma system to use with our Contract Gasketing customers. The application of plasma is part of the same process, carried out just before the foam bead is applied. Below is a table that shows how the use of plasma changes the adhesion to substrates that our foam doesn’t normally have a natural adhesion to.

Another way of increasing adhesion is by using liquid surface primers. By increasing the ‘wetting’ of the foam to the surface part, adhesion can be improved, however, this may compromise the height of the bead as the foam has an affinity with the surface and wants to spread.

Case Study – Airline smart trolley latch – Security seal

In 2016, a company that had developed a product to overcome security difficulties with airline trolleys approached us to apply a seal to their part. The part (as pictured below) was a complex double-faced, 3D part, made of polycarbonate material and was the outside case which enclosed a number of electrical components as well as a GPS system.

 

The airline trolleys (holding food and gifts) are usually delivered with a security tab attached to the opening latch, which is removed by airline staff when setting up the plane. After some testing, these tabs were found to be very easy to open by non-airline staff, who could change the contents and apply a new security tab. The ability to plant an item on these trolleys that don’t require to go through security measures obviously then compromises the safety of the aeroplane. A new product was developed which held a smart security seal, allowing the trolley to be connected to electronic keys held by airline staff and therefore ensuring others are unable to open the trolley.

The part was brought to us during the prototype stage and required a IP69K rating, which means that the seal needed to withstand being sprayed by high-pressure water at point-blank conditions. When applying the foam to the prototypes, there was a natural adhesion to the samples and the testing all went smoothly and achieved the required IP rating. The product then moved onto production, and we received the first production parts to seal, however, we found all the foam gaskets we applied began to peel off. After much discussion with the customer, we realised that a fire-retardant additive, which had been added by the injection moulding company to the final production parts but not the initial prototypes, was causing a change in the Dyne/cm2 value of the part and therefore affecting the adhesion. Once plasma was incorporated into the process of the seal, all was solved and the parts were retested and able to be used.

This instance is one of many examples where Robafoam have had to adjust its processing to ensure a suitable adhesion to a part we have received. Plastic parts in particular can be made of varying percentages of materials, which can all have an impact on the adhesion of our foam. Recyclable parts, for example, are often required to be made with recycled content too, all in varying percentages. If we don’t know the percentage of recycled content, the best way to overcome adhesion difficulties is for us to test it.
What the product is made of is only one element that can affect adhesion. As previously mentioned, the contamination of a part can also impact its levels of adhesion. Airborne contaminants, such as working in an oily environment, can mean the foam won’t stick to the part. Plasma has a cleaning effect to a degree and can improve adhesion, but there may need to be other processes implemented to provide an adequate seal.

Plasma also has less impact on other substrates, including glass and stainless steel. In these cases, other options may need to be considered. When using raw aluminium, anodising can be used as this has the ability to increase adhesion too.
In summary, our 30 years of experience in the sealing and adhesive industry means we have a range of options and solutions available to you and are here to help. If you require some advice or wish to work with us to help develop a seal on your part, please get in touch.

How can Robafoam’s foam seals benefit the Automotive Industry

Robafoam has been working with the automotive industry as a foam seal specialist since was established in the UK as CeraCon UK in 2013 and today around a third of our customers are part of the automotive industry. We have a wealth of experience in applying seals to a wide range of parts, for both interior and exterior components. These include door modules, external lighting and roof antennas, to name a few. Our foam is a unique material that performs well on a number of substrates and the application method is so effective that even complex geometries can be sealed quickly and to a high specification.

Robafoams Automotive benefits

Robafoam’s foam material uses

Our foam is often used within the industry as a barrier for water ingress and to prevent dirt or other particles from entering the components. However, can also be used to reduce noise and vibration within vehicles. The seals are directly bonded to the parts to make sure that the pad will not move out of place which creates a perfect gasket or cushion application.

IP rating

One of the qualities that makes our foam material suitable for the automotive industry is its ability to provide a high Ingress Protection level (IP rating). By varying the compression, foam hardness and bead size, Robafoam can offer a seal that withstands contact with water ranging from water spray to deeper immersion.

Testing

Robafoam’s foam has been subjected to vigorous testing during its development and continues to be tested to ensure its compliance with a variety of standards. One of these is the ASTM D1003 standard test method for haze and clarity which means that it can be used effectively within the lighting sector of the automotive industry.

We understand that no two application designs are the same. We can use our expertise in working with the automotive industry to support designers, adapt designs as necessary and seal accordingly, all to achieve the standards required for the specific application. Each part can have the seal customised in size, hardness and design to ensure that specifications from the customer are met.

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If you have any further questions or think that Robafoam might be able to assist in a particular application, then please don’t hesitate to get in touch.

How Can Robafoam’s Foam Seals Benefit The Lighting Industry

Since our establishment, our work within the lighting industry has progressively grown and exposed us to some very interesting projects.

Initially, we marketed our sealing technology to complement the UK government’s initiatives to convert to LED systems. The majority of applications were related to either diffuser sealing on glass or plastic substrates, or seals required for the main access cover components; these generally being powdered coated aluminium parts.

In nearly all cases these first applications were introduced to remove manually fitted cord seals. The conversion to FIPFG, improved productivity and reduced the quality issues regularly seen with manually fitted seals. It is increasing IP rating performance and improved service requirements due to the adhesion of our foam to the part surface.

Current Applications

Our foam can be currently found in a range of different lighting applications around the country. Main light seals on street lighting include foam on the diffuser, access covers, body seals and heat sinks. We also do applications for NEMA/Node unit sealing, solar charging units on the streetlights themselves, illuminated street light signage, bollard diffuser sealing and BEV/HEV charging point connections (located within the base of the lamp post).

Sealing requirements for public lighting

Testing

Robafoam foam material has been subjected to vigorous testing during its development and continues to be tested to ensure its compliance with a variety of standards, including some of which makes it perfectly suited to the Lighting industry’s requirements. One of these is the ASTM D1003 standard test method for haze and clarity. Our material was initially approved against the ASTM D1003 standard for our automotive lighting applications, however, this is of course a factor for the lighting industry as a whole.

We understand that no two application designs are the same and we can use our expertise to support designers, adapt designs as necessary and seal accordingly, all to achieve the standards required for the specific application.

IP Ratings

One of the qualities of Robafoam foam material that makes it so suitable for the lighting industry is its ability to provide a high Ingress Protection level (IP rating). By varying the compression, foam hardness and bead size, we can produce a seal that withstands contact with water ranging from water spray to deeper immersion.

Over the past few years, our customer base within the lighting industry has continued to grow which has meant we have taken on a variety of different sealing applications. Our technology is beginning to be known in the industry and our attendance at different exhibitions has helped to increase the awareness of what we do. The flexibility of the foam and its application means that we are able to work with a range of different parts and still produce high quality, high-performance foam bead.

If you work within the Lighting sector and are interested in some more information on foam sealing systems and foam sealing materials, please don’t hesitate to get in touch.

When is a streetlight not a streetlight? 

Perhaps not such a daft question. Nowadays it’s probably better to consider these as a potential national resource, with an evolving requirement. 

I am not talking about the familiar uses, as a convenient fixing point for public road signs, or even a canine public convenience. I would prefer to focusing on more technical matters.

Streetlights nowadays are considerably smarter and hugely more efficient than their old sodium bulb predecessors. The light source is now generally LED based giving much cleaner and brighter illumination with all the safety benefits this brings, with significant improvement in reliability and reduced servicing costs. Also, they now have sophisticated control mechanisms allowing variable/programmable start and stop times with dimming facility also results in much reduced operational costs and ecological benefits. These control units are called Nema’s or light nodes, usually visible as a small protrusion on the top of the light.

Moving on from the improvements in the street light unit itself, this kerb-based pole is seeing new opportunities for multifunctionality.

How many of us have had the conversation about the UK’s ongoing conversion to fully electric vehicles? 

Considering the current price increases in conventional fuels, I expect it’s becoming more widely discussed.  This inevitably includes a debate, about how people who don’t have a driveway, are expected to charge their vehicle in the street. How do we avoid millions of extensions leads crossing pavements with the ensuing trip hazard claims? What’s needed a national grid of street-based charging points. To consider this as a “new” dedicated infra-structure would make the HS2 investment seem reasonably priced. 

Ultimately, what’s needed is an existing curbside matrix of places to plug your EV into. Now you see where this is going. Companies are already working on methods of adapting the current lamp-post access doors to take an EV connection point, with trials taking place in various council districts.

The next offering to highlight in support of an increasing need to enhance public and vehicular safety, or for the more skeptical among us another step forward to an Orwellian state. This being the integration of CCTV systems within the actual light unit or as an independent unit using the elevation and power source to its benefit.

The one thing, virtually all of the above evolution has in common, is the need to keep the weather from the increasing complex electronics and electrical supply within. As you can imaging the connecting interfaces of these parts, can be complex 3D profiles. Also with component designers need to make things as aesthetically pleasing as possible; even more capability is needed from the material and process used to ensure the seal and longevity of this assemblies. 

Robafoam’s robotic foam sealing process is already widely used on the light unit with diffusers, covers/body’s and nema components within the traditional lighting requirements. However, being at the forefront of high IP rated seals, the Contract Gasketing service Robafoam offers in the UK, as well selling the foam systems we use. We offer a real resource into the increasing evolution of the not-so humble street-light. For more information visit www.robafoam.com   

How Robafoam supports new customers

How Robafoam supports new customers

Robafoam is a specialist engineering company that has over 30 years of experience in robotically applying foam seals directly to parts. We support customers from the initial design concept right through to production sign off across multiple services such as sub contract services, lighting sealing solutions, automotive sealing solutions and more. Below are some key stages that Robafoam offer support with.

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Initial evaluation of joint design.

Whether it’s a new part in the early design phase or an existing product that is wanting an improved IP rating, the first step would be to evaluate the joint design. Understanding what the joint design is, as well as the assembled gap size, is crucial to deciding the gasket specification. For the majority of IP ratings, the gasket must be compressed to a minimum of 50% and no further than 70%. Controlling the compression is an important factor to ensure the serviceability of the part, if the gasket is over-compressed, the cell structure within the foam material can become damaged and therefore unable to return to the original height.

Our design guide can help designers optimise the joint design to ensure they can achieve the required IP rating. https://www.robafoam.com/wp-content/uploads/2021/07/Robafoam-Design-Guide_Download.pdf

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Sample prototype

Once the joint design has been optimised, Robafoam offers free sample processing which allows designers to see what our technology is capable of. We have a dedicated lab facility that uses a 4600 6-axis ABB robot and has the capability of processing parts up to 2m x 3m in size. We are able to apply our gasket direct to any substrate whether it be a type of metal, plastic, or a 3D printed SLA prototype. The only characteristic the substrate must have is thermal stability at 80 degrees due to the gasket being a heat cure material.

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Costings and preliminary testing

From the prototype or sample trial, a cycle time and foam weight (gasket weight) will be generated. These two factors are what our costings are based upon. A quote will be issued to the customer at this stage.

At this stage, Robafoam is able to perform some unofficial testing on the sample to ensure the sample gasket is suitable for the application.

Specification refinement

Initial testing can be carried out on the prototype sample. It is important to evaluate how the part assembles with the gasket as well as carrying out IP ratings. Robafoam’s technology has the capability of changing the foam hardness by increasing or decreasing the amount of air entrained within the PU material. Therefore, if the part does not pass the required IP test, we would recommend hardening the foam to increase the compressive force of the gasket. Alternatively, if there are some assembly issues due to the gasket being too hard then we can increase the foam ratio to compensate for this.

Furthermore, the technology has the capability of changing the gasket height in specific areas of a part. If your design has a small out of flat condition in areas, or you require a greater level of compression between fixing points, we can increase the gasket height within these areas. A simple change in robot speed is all that is required.

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Design sign off

Once the customer is satisfied with the gasket specification and has completed all the required testing, the design will be signed off and ready for production. Bot ISIR and reference samples will be produced at this stage. Small batch runs are also performed to ensure the production process is refined.

Foam sealing technology

Robafoam Technology – Robafoam Foam Sealing System

Robafoam are specialists in the field of 1K foam sealing. Using our expertise, we design and manufacture entire foam sealing systems, tailoring these for a range of applications including automotive sealinglighting sealing and more.

The 1K foam sealing technology converts a single part polyurethane (PU) material into a closed cell liquid foam. This is achieved by mechanically entertaining air (or chosen gas) into the material. The chosen level of air entrainment enables a wide range of hardness to be selected.

Designed to work with many materials, to create closed-cell foam. Our technology produces a liquid foam seal that is applied directly to customer components. This unique system requires no in-process purging and has been measured at over 98% availability.

We would like to introduce you the Robafoam Technology.

Foam Sealing

 

Pump unit single-component sealing material:

The pump unit is a drum where the raw material is stored (20lts pail – 200lts drum). The material can be stored at room temperature and does not require heating prior to the air entrainment. Due to the material requiring 80 degrees to cure, the shelf life is months as the material does not react without the required heat.

The raw material is pumped from the 200kg drum into the Foam unit where the entertainment of air occurs.

Foam creation equipment:

The process takes the raw material from the pump unit and converts it to foam by accurately introducing a measured quantity of compressed air. The amount of air used in this process defines the foam hardness. The more air added, the softer the foam will be. This can be adjusted to create a wide range of shore hardness, depending on the requirements of the customer- We refer to this as foam ratio.

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Dispensing valve:

Our 6 axis robot system can apply a gasket to any substrate including plastics, metals, and glass. The level of natural adhesion the foam has to the substrate depends on the dyne value. If there is no natural adhesion, we can use plasma pr-treatment to increase it. Using 6 axis robot, we have the capability of applying a bead to simple flat parts and complex 3D profiles as well as double face applications.

Oven system:

Whether requiring our material for bonding or foam sealing, the PU cures rapidly at temperature 80ᵒC or above. The material itself will cure within seconds at the required temperature, however, what defines the curing time is the heat sink properties of the part. The last section of material to cure is the one that is in direct contact with the part and therefore this face much reach 80ᵒC. The average curing time can be between 3-8 minutes. During the initial enquiry and sample phase of working with a customer, the requirements of the part curing can be adjusted to find the optimal curing time needed for each part.

The flexibility of Robafoam’s oven systems means that they can be customised to work for any requirement or production environment. Ambient to 220ᵒC, our industrial ovens and thermal systems are suitable for material curing, drying, tempering, preheating, and cooling.

What is Foam Sealing?

Liquid foam sealing and formed-in-place foam gaskets have been used for decades across a range of industries. Simply put, they are a liquid applied substance that then hardens to form the seal.

There are a few different methods of generating these high specification foam seals, Robafoam specialises in a single component foam system which we will focus on as an example. We believe our product and process gives you the best sealant on the market, and in this piece, we are going to discuss some of the benefits of foam sealing and what makes foam sealing so good.

What is foam sealing, foam gasketing, formed-in-place gasketing and formed-in-place foam gasketing?

The standard definition of a foam formed in place gasket or seal is that the seal material being applied is a liquid; this way it can flow into the groove or intimately mate with the surface it has been applied to. Because of this, formed in place foam gaskets can be applied to a wide range of surface finishes, part geometries and can vary in size and shape as it’s applied depending on the flow rate and dispensing rate of the material.

Once on the surface, the liquid then has to undergo some form of curing; this can be heat cured, a two-component chemical reaction or air-cured.

Most of the foam materials being applied (and non-foamed materials) are either thixotropic or have high viscosities which stops them from losing their shape when sat on the surface.

What is the aim of a Foam Gasket?

The aim of using a formed in place seal is to create a truly bespoke seal that is applied directly to the part. This means the sea is bonded onto the part either onto a flat surface or more often, into a groove which ensures that the most intimate seal can be formed and any surface imperfections such as sink within a moulded part or surface scratches on a metal part do not affect the seal performance as the seal will fill the gaps and not just sit on the surface.

Methods of applying foam seals

Depending on the level of accuracy and the performance requirements of the seal, you can apply these seals in two main ways:

Manually Applied Foam Seal Straight from the Cartridge

Foam can be applied straight from the canister, this is a cost-effective answer for many people who are looking for high resistance insulation for home projects. Manufacturers make foam sealing systems easy to use and accessible for this method of application as well, so it is a great solution that comes with an array of benefits. Here are some of the key factors to take into account:

Manually Applied Sealing Foam is Only as Good as the Operator

We have already discussed the great assets of polyurethane foam, and how its properties lend themselves to being a perfect solution for sealant needs. another great benefit is that it can be applied manually, on the other hand though, this means your foam seal is only as good as its operator. To have an effective barrier, you need to have the foam effectively applied to the required areas.

Manually Applied Foam Gaskets are Cheaper than other Solutions

The physical properties of foam types for sealing purposes are a great form of resistance at a lower cost; especially when manually applied. However, as previously mentioned, to get the best application generally you will need some experience.

Good Enough for Low to Mid IP Ratings

When a foam gasket is manually applied, it is good enough for low to mid IP ratings, good for NVH reduction, bonding, potting and cushioning.

Using Robafoam Technology to Robotically Apply Foam Components

Here at Robafoam, we have a tried and tested way to apply a foam gasket effectively compared to other application methods; hence, offering you the best resistance and insulation properties. Here are some key factors about our method:

More Reliable Resistance

For the best repeatability and accuracy, applying a seal by robot ensures the seal is the same every time. Using this method, you can control the seal very accurately, this can allow for tolerances to 1/10th mm which can be important for technical applications.

Better for Large Projects

Perfect for large projects where tooling can be manufactured, leading to high throughput of parts with low numbers of rejects and low downtime.

Top IP Ratings

With a higher degree of accuracy, this is the best way to get top IP ratings and the highest performance for NVH reduction, bonding, potting and cushioning.

Top 5 questions we’re asked about Foam Sealing Materials

What is Polyurethane Foam Sealant?

With less face to face meetings now, we understand that information can be harder to find, so we thought it would be a good time to investigate the sorts of questions we get asked about our unique foam sealing process.

Both the foam material itself and the process in which it is made and applied is unique within the sealing industry and offers many benefits for our customers. However, it also means that sometimes designers and manufacturers have questions about how it could work with their part. Below are the top five questions we get asked at Robafoam.

Top 5 questions we get asked by potential customers

Here are our most commonly asked questions regarding our foam sealant:

What is Polyurethane foam made of?

The material we apply to our customer’s parts is a single component polyurethane material. Launched in 2015, and developed by chemists in the UK, the material is regularly tested and reviewed to enhance its performance.

It is categorised as a 1K technology as it uses a single component that requires no additional chemicals or materials to apply the foam or for it to cure. The material is entrained with compressed air to create the foam and the amount of air used can be adjusted to create a wide range of foam hardness, depending on the requirements of the customer.

What level of IP rating can be achieved with Polyurethane foam?

This is one of the most common questions we are asked. And the answer is that our foam can achieve any IP rating required, as long as its incorporation is considered alongside the design of the part.

Achieving an IP rating is a balance between the compression, hardness, and width of the seal, working with the flexibility, span, and wall thickness of the part. It is therefore very helpful if we work with designers at the early stages of the development of the parts to ensure these requirements are considered.

How long do Polyurethane foams take to cure?

On its own, the material takes seconds to cure when subjected to heat above 80C. We generally use thermal ovens to cure the seals however they can also be moisture cured if required.

The length of time it takes to cure varies due to the substrate of the part and the size of the foam seal that has been applied. To ensure the whole of the seal is cured fully, the part that the seal has been applied to also needs to reach 80C. A metal part would reach this temperature easily due to its thermal conductivity, therefore, reducing the curing time, however, a plastic part takes longer. We refer to this as the heat-sink property of the part material. Generally, it can take anywhere between 2 and 7 minutes for the seal to fully cure.

How long does a polyurethane foam seal last?

Our foam seal has been rigorously tested to ensure it lasts the lifespan of the product that requires the seal. For example, a street lighting has a life span of around 10 years or a car’s warranty guarantees a time frame of around 7+ years.

Naturally, the dynamic forces to which the joint is subjected, along with exposure to more aggressive chemicals can have an impact on the longevity of the seal. Also, the greater level of service requirement (decompressing and recompressing the foam seal) will impact its seal performance over time. And those seals operating at the higher end of its thermal resistance will also play a factor.

Does it stick to all types of parts?

This is a trickier question to answer as it is very much dependent on the substrate that the foam is being applied to. The relationship between the foam material and part surface is key and, in particular, the Dyne value which measures the surface energy of the part surface.

It is not a simple matter of saying that we naturally bond to powder coat surface, for example. As there are many types of coatings with one category.  However, if we find through testing, the material is unable to stick to the substrate, all is not lost. Using atmospheric plasma; more often than not, we are able to change the parts surface energy.

Naturally, not all customers require adhesion and this is something we would consider in our evaluation of a new application. All our robot cells have a plasma system incorporated, meaning this option is never an issue for our customers. Below is a table giving a general “rule of thumb” regarding adhesion to different material types.

Other Frequently Asked Questions

Here are a few more questions that people often ask:

Is Polyurethane foam good insulation?

Polyurethane foam is often used as a foam sealant, the application process means it can be applied to tricky surfaces and areas easily as it takes the form of the environment it’s applied to. As a result, construction has implemented insulating foam sealants as an alternative to traditional sealants. Here are some of the things polyurethane foam can protect against:

Heat Insulation

Polyurethane foam is a great form of thermal insulation. It can easily fill gaps and cracks as the foam will fill any area it is applied to. The spread of the foam will seal any seals and help keep heat in.

Sound Insulation

With spray foams, and their ability to mould to a shape or area, they also insulate against sound. They can help prevent vibration between two surfaces and as a result, can help eliminate unwanted noise.

Water insulation

Again, since polyurethane foam fills gaps and cracks so well, it can be the perfect barrier for water as it stops even the slightest bit of moisture from getting through joints.

Are Polyurethane Foams flammable?

Polyurethane foam is not flammable; however, like most seals, it can only withstand certain levels of heat. For most jobs though, this is no issue as the foam is great for heat insulation.

Big changes for CeraCon UK

As we start a New Year, we wanted to look back on 2020, what it has brought for CeraCon UK and the changes that have been made during the year. Despite the difficulties that coronavirus has brought to companies across the UK, CeraCon have been lucky in weathering the storm and we continue to grow our customer base and develop the sealing options we can offer our customers.

Some of the main highlights of 2020 include exhibiting early in the year at both Southern Manufacturing at the Farnborough Exhibition Centre and at Engineering Solutions Live in Gaydon, the development and installation of our R&D cell for sealing battery-electric-vehicles and being featured in the Nov/Dec double issue of the Lighting Journal.

Ceracon Building

 

However, the most exciting change from the year has been something that has been going on behind the scenes. In December CeraCon UK completed a management buyout and became a fully independent UK owned business! The MBO was led by Managing Director Robert Jones, who has run the business since its establishment in 2013. Our thanks to Lloyds Bank for supporting the necessary funding process.

Robert said “We are thrilled to be able to take the business forward independently, developing new markets and customers in the UK, whilst still being supported by CeraCon Gmbh.  I have to thank the Coventry and Warwickshire Enterprise Partnership, Lloyds Bank and my business advisers for the help and support, in that satisfactory completion of this acquisition.”

Despite becoming independent, CeraCon UK will continue to work closely with CeraCon GmbH; operating as the exclusive agent for CeraCon products and technology within the UK and Ireland, including the CeraPUR foam material.

CeraCon UK would also like to thank our solicitor, Oliver Hughes of Hughes Legal and Steven Mugglestone of accountants, Michael Harwood & Co. for all their assistance throughout the process.

We look forward to the new challenges that 2021 will bring and want to thank our customers for their continued support throughout the past year.