SW JANUARY 2021 JOOMAG | Page 48

PRE-TREATMENT , SURFACE PREPARATION , DEGREASING & CLEANING

Simple switch for a safer solvent

Graham Fraser , MD of Fraser Technologies , discusses how an aerospace customer has made the change to a safer solvent .
Due to legislation around the safe use of nPB , any business still using this solvent in its cleaning and degreasing process must find a replacement .
Short for normal Propyl Bromide , nPB ( also known as solvent 1-bromopropane ), is a solvent commonly used in the cleaning and degreasing process for the aerospace , precision engineering , medical , optical and electronic industries and it is a hazardous substance that can damage fertility and harm unborn children .
nPB has been registered as a Substance of Very High Concern ( SVHC ) under REACH ( Registration , Evaluation , Authorisation and Restriction of Chemicals ), which regulates the supply and use of chemicals in Europe . As such , nPB was placed on Annex XIV , and its use was officially banned in July 2020 , unless an authorisation has been granted and the business has a permit for a specific use .
In 2017 , we worked with leading Aerospace manufacturer , BAE Systems , to replace the nPB that they were using with a safer solvent .
The challenge
BAE Systems approached us to assess their existing process to see how they could use an alternative solvent which would be safer , at which point we also discussed additional benefits including efficiency and cost saving .
To assess their existing cleaning processes , we arranged a site visit to inspect the Solvac Systems at two of their facilities . We performed a full system inspection to ascertain the suitability of the systems for conversion to Opteon™ SF79 ® . Opteon™ SF79 ® was chosen because of its cleaning performance ; ultralow GWP *; recyclability and reusability ; safety ; and ease of use .
As part of the process , our objectives were to test the equipment for suitability and compatibility for use with SF79 ® , as well as the general condition of the equipment and any opportunities to reduce solvent usage . The customer found that their solvent usage was very high and they were aware that reductions would improve their environmental impact , as well as save costs .
Before using nPb , both of BAE ’ s systems were originally supplied for use with Trichloroethylene ( Trike ) to flush pipework , so they were long narrow tanks specifically suited to this application . They each had a flushing rig and filtration , and originally had Carbon Absorption Deabsorption systems fitted .
The existing Solvac systems used more than 1 tonne of solvent per year , meaning they both required a permit from the local authority for continued use , further increasing costs for the company .
Due to the legislation around the safe use of Trike and nPB , these systems were fitted with over tank canopies and safety interlocks to ensure operators were not exposed to solvent vapours . One of the systems also had a PPM meter fitted , which restricted the front door from opening until the level of solvent had dropped below a specified level . This , as well as additional safety features , protected operators and reduced emissions .
The results
While there were minor issues with the system , these could be addressed and it was determined that Opteon™ SF79 ® was a suitable replacement . This has now been fully implemented at two of the locations , while the third is currently transitioning to the new product .
Since moving to Opteon™ SF79 ® , BAE has achieved the cleaning performance they expect , while also significantly reducing their environmental footprint . As SF79 ® does not have the acidity issues that nPB does , the customer ’ s usage was significantly reduced simply because fewer clean outs were required . And importantly , it is safe and easy for operators to use .
Speaking about the results of the change to SF79 ® , the customer ’ s Engineering & Governance Lead said : “ The transition from nPB to SF79 ® was relatively straightforward and quick , and communication was good throughout . Fraser Technologies also had a much stronger relationship with the manufacturer than we did , which was especially helpful during the process .
“ Due to a reduction in manufacturing throughput , we cannot confirm an exact reduction in annual usage , and therefore cost savings and environmental footprint . However , emissions monitoring that we undertook following the introduction of SF79 ® showed a reduction in volatile organic compounds to atmosphere compared with the previous solvent . The product ’ s lower GWP will also contribute to reducing the environmental impact of our site operations .
“ Overall , changing to SF79 ® has been a positive experience and it has helped us to achieve our safety , health and environmental objectives .”
* Global warming is a gradual increase in the overall temperature of the earth ’ s atmosphere , generally attributed to the greenhouse effect , caused by increased levels of carbon dioxide , CFCs , and other pollutants . GWP is used to represent the equivalent of C02 being released into the atmosphere . So 1kg of C02 = a GWP of 1 .
Telephone : 01506 443 058 Visit : www . frasertech . co . uk
46 JANUARY 2021 twitter : @ surfaceworldmag