Wednesday, 29 June 2016

Pexa’s Response to Brexit – Positive About the Future

Pexa’s business is international and our HQ has always been in the UK. Following the UK referendum on EU membership we make the following commitments.
  • We support democracy and respect its outcomes
  • We will remain vigilant to developments and make sure Pexa fully understands the political and economic situation, making the right decisions based on the facts
  • We will continue to invest in all the  measures required to ensure the continued growth of our business in the EU, UK and around the World
  • We embrace the future, rise to its challenges and have the vision, energy and know-how to excel in the dynamic global economy
  • We will protect the interests of our stakeholders and encourage them to engage with us and rely on our capabilities

Monday, 25 April 2016

Erosion Protection of Aircraft Radomes and Leading Edges

Protect Your Asset and Your Image

Aircraft leading edges suffer erosion from water droplets and solid particles which strike at high speed in flight and can cause unsightly damage as well as the potential for more serious structural problems.

Causes of erosion

Aircraft travel at speeds well in excess of 200mph through all varieties of climate. Small water droplets striking the surface at this very high speed deform on impact and transfer a lot of energy into the surface. This energy typically travels in waves through the substrate (often a painted surface) and can cause delamination or splitting of a paint system at one of the interfaces between layers. Solid particles such as dust entrapped within water droplets, ice or dry particles of sand/salt etc. also strike the surface and cause a different mode of erosion, wearing away the surface or “blasting” material from the upper layer of the eroding surface.


The effects of erosion are many. Firstly from a decorative aspect many aircraft nose radomes exhibit signs of wear which detracts from their appearance. These effects may also be present on wing leading edges and other prominent surfaces such as fairings.

The protective coating may eventually break through and more damage can occur. Erosion of the composite itself is possible, which can cause more severe damage requiring repair or replacement. Moisture ingress can be damaging to the resin matrix of the composite. Freezing and thawing of moisture exacerbates such damage and can eventually result in a failure of the composite. High levels of moisture in the composite can also impair radar transparency.

When paint or substrate edges are exposed by erosion, accelerated lifting of the edges can occur creating even more exposure of the composite.



Increasing the thickness of the first layer to be impacted by erosion is a good step as this increases the distance that energy imparted by droplet strike must travel within the film and reduces that energy before it reaches any of the interfaces between layers. There is an additional benefit for solid particle erosion as this also increases the amount of material which must be eroded away before any substrate is exposed.

Other technical characteristics of the coating can be modified, such as increasing its elastomeric properties, this allows energy to dissipate and also permits recovery of the deformation at the surface. In addition, improving the compatibility between layers is helpful to maximise the adhesion of the different interfaces.


So, a thicker layer of more elastomeric material is a good solution. There are various ways in which this can be accomplished. The “old school” method is to apply several layers of additional paint to add ≥250µ of additional elastomeric polyurethane coating. This is very effective at preventing erosion and can be applied in either a clear “over layer” or as a coloured finish to match the rest of the aircraft. It is time consuming to apply, as the layers need to be built up over time to allow solvents to evaporate. As a multi-day process this is much more suitable for an OEM application. The desired mode of failure is gradual erosion, whilst paint is easily applied to a 3 dimensional shape such as a radome.

In an MRO application the application of a polyurethane film is a much quicker solution and offers at least an equal performance. PM Research has created a clear polyurethane film matched to the exact dimensions of the radomes of >350 aircraft types in service today. Pexa is the authorised stockist and distributor of these products in Europe.

Commonly called radome masks or “boots”, as they fit like a boot over the 3D surface. The film has excellent elastomeric properties. It is a completely clear, non-yellowing polyurethane film of thickness 300µ. Tested and certified with very high peel strength, resistance to aviation chemicals and offering 500% elongation before breaking. The film functions well in the full range of temperatures in which aircraft operate. It is practically invisible to the eye and to radar. This approach mimics the elastomeric paint solution but without the additional down time.

PM Research has manufactured these products at its Wellsville, New York facility since 1973. The product range includes preformed boots for all sizes of aircraft from the smallest general aviation models right up to the largest commercial passenger jets. In addition to plain erosion resistant tapes for application to wing leading edges.

The boots are supplied on a 3D plastic support which makes it easy to apply them directly to the surface. Application can be achieved in a very short time frame and has little effect on aircraft down time.

Pexa supplies PM Research boots to radome OEMS, repair stations and aircraft maintenance facilities.

© Jim Rowbotham Pexa Ltd 2016

Monday, 18 April 2016

Pexa invests for growth in France

For several years Pexa has provided an excellent service to the aerospace industry in France. Pexa supplies surface coatings and treatments to aerospace, defence and other high tech industries including oil & gas and electronics. Pexa has decided to expand its team in France and has recruited Mr Christophe Mondou to represent its business and to provide technical service and support to customers in the Southern half of France. Christophe has many years’ experience in technical sales roles and has an excellent track record in supplying the aerospace manufacturing sector.

Jean-Paul De Almeida, head of Pexa’s business in France said “With the appointment of Christophe we can provide our customers in France with a much more frequent and dedicated service. I will continue to take care of our customers in the North from our offices in Paris while Christophe will be available to provide a responsive and personal service in the South. Both our customers and suppliers will benefit from this investment. In addition we will be able to provide a better service to neighbouring French speaking countries such as Morocco”.

Friday, 18 December 2015

Dalic, leader in selective metal plating partners with Pexa for its UK & Ireland Distribution

Dalic has been a leader in selective electroplating of metals since 1937. They produce an array of metal plating solutions for anodising with chromic and sulphuric acids and plating with zinc, nickel and cadmium. These can be applied using Dalic’s portable electroplating equipment including the Dalistick Station which allows plating to be carried out in situ at any industrial premises. This allows for the restoration of metal plating in maintenance and repair situations and in the OEM situation when large scale electroplating tanks are not available. Dalic has approvals from most of the major aerospace design authorities and several automotive manufacturers.

Pexa is the leading distributor of surface coatings and treatments to the aerospace industry. From its new facilities in West Yorkshire UK Pexa’s team delivers a complete range of surface finishing materials and equipment to its many customers in the aerospace and other high tech industries.

Dalic has entered into an exclusive distribution agreement with Pexa for the supply of its product range in the UK & Ireland. The new deal has a great synergy as the two companies both specialise in surface treatment materials with a strong position in aerospace industry. Dalic has an excellent technology base with an impressive list of approvals for its products whilst Pexa has a great reputation and an infrastructure that can support the sales, distribution and technical support of the Dalic product range. The new agreement will allow companies throughout the UK & Ireland to access Dalic’s class leading solutions. The new arrangement goes live on the 4th January 2016.

For further details please contact Jim Rowbotham, Managing Director of Pexa Ltd

Friday, 24 July 2015

First UK Aerospace Coatings and REACh Seminar takes off

Delegates from several of the World’s leading aerospace and defence companies including BAE Systems, Boeing, Rolls-Royce and Thales, together with other key members of the UK’s aerospace surface finishing supply chain gathered in Manchester yesterday for the first “Aerospace Coatings and REACh Seminar” held in the UK.

Organised by Pexa and AkzoNobel Aerospace Coatings and held at the Concorde Visitor centre at Manchester Airport, the seminar brought around 50 attendees up to date with the impact of the EU Regulation for the registration and authorisation of chemicals “REACh”. The aerospace industry makes significant use of chromate containing pigments for the corrosion protection of aircraft and the use of these substances will be significantly impacted by REACh. Pexa and AkzoNobel are developing a position as industry leaders in the management of this issue and the provision of solutions.

Speakers Maurizio Pulcini and Hans Polak of AkzoNobel and Jim Rowbotham of Pexa interpreted and presented the current status of REACh, how it will be implemented and the authorisation path for hexavalent chromates in the surface coating process. It is Pexa and AkzoNobel’s intention to provide all the necessary support to companies using chromates to enable them to do so within an authorisation and, at the same time, to provide “best in class” alternatives to chromate containing primers to allow the industry to minimise their use.

A healthy question and answer workshop took place, where important concerns were discussed. Pexa and AkzoNobel will hold more such events, as this important issue evolves, and will try to maintain a key user group of companies involved in this process so that information is shared and discussed within the industry.

Delegates were able to take a guided tour of the Concorde G-BOAC which is housed at the venue at Manchester airport, an interesting case study in aerospace materials.