US 2016/0251602 Al  14  Sep.  1,  2016  meric particles for 1 minute (i.e. sample 4). This indicated that  it was the PET polymeric particles used that were an effective  cleaning component in the formulation.  [0187]  The data in Table 15 illustrates the results of XPS  analysis for the amounts of another impurity on the mild steel  sample surfaces, namely nitrogen and calcium. The mild steel  sample treated with the polymeric particles (i.e. mild steel  samples 4) indicated effective removal of nitrogen and cal› cium. In comparison, the controls (i.e. mild steel samples 1, 2  and 3) showed relatively high levels of these nitrogen and  calcium containing  impurities.  This  demonstrated an  improved cleaning efficiency for the mild steel samples  treated with the polymeric particles (i.e. sample 4) even for  low treatment periods of 1 minutes, which again indicated  that it was the polymeric particles used that were the essential  cleaning component.  [0185]  The data shown in Table 13 illustrates the results of  XPS analysis for the ratio of iron oxide to iron metal on the  mild steel surface following the various treatments. As shown  by the results for samples 4 (treatment with PET particles and  formulation for 1 minute), compared to control samples with› out PET particles there was demonstrated a decrease in the  iron oxide area(%) and an increase in the iron metal area(%),  shown by the higher iron/iron oxide ratio compared to the  controls. Thus the use of PET particles has demonstrated  removal of iron oxide from an uncoated mild steel surface. It  should be noted that the mild steel samples were not pre› corroded and were used immediately as supplied.  [0186]  The data shown in Table 14 illustrates the results of  XPS analysis for the amount of iron metal and carbon on the  mild steel surface following the various treatments. The  amount of carbon can serve as a surrogate measure for the  presence of contaminants (e.g. smut). A higher iron/carbon  ratio as indicated in Table 14 thus indicates that more iron is  present on the mild steel surface and that more carbon or  contaminant residue has been removed. The mild steel  sample treated with the polymeric particles for 1 minute (i.e.  sample 4) showed a significant increase in iron/carbon ratio of  compared to the controls (i.e. mild steel samples 1, 2 and 3)  demonstrating an improved cleaning efficiency. Indeed the  mild steel samples treated with the formulation without beads  for 1 minute (i.e. sample 3) showed a lower iron/carbon ratio  than the equivalent mild steel samples treated with the poly- [0188]  The ingredients were Mulan™ 200S (25.0 g), a  non-ionic surfactant supplied by Christeyns, Bradford, UK  and the citrate component consisted of trisodium citrate dihy› drate (500.0 g) supplied by VWR, Loughborough, UK. The  polymeric particles were Nylon 6,6 grade Technyl™XA1493  supplied by Solvay, Lyon, France in the form of beads. The  mass of the polymeric particles used in the apparatus was 10  kg. Uncoated 1 mm thick mild steel sheet was supplied by  Metals 4U Limited, Pontefract, UK and were pre-corroded by  immersion for 10 seconds in a mixture of 1 % w/w sulphuric  acid, 0.1 % w/w salt and 0.3% w/w hydrogen peroxide fol› lowed by washing with deionized water and isopropanol.  [0189]  XPS analysis was carried out with a Axis Ultra  DLD, using an Al ka monochromated radiation source. An  overall survey scan was taken initially, followed by detailed  scans of the main peaks for the elements identified, using a  pass energy of 160 eV and 20 eV respectively. The measured  data was fitted using Casa XPS (Casa Software Ltd, UK),  using relative sensitivity factors based upon the scheme  Experiment 5  Experiment to Investigate Iron Oxide Removal from  Mild Steel Using an Apparatus Fitted with Pumping  Means with Non-Ionic Surfactant and Nylon  Polymer Particles  TABLE 13-continued  TABLE 15  TABLE 14  XPS results for cleaning efficiency  Sample  Treatment  Mild steel 1  Control - No  Treatment  Mild steel 2  Control Treated  With Water Only  Mild steel 3  1 Minute Control  Treatment  Water45 kg+  Citrate 500 g +  Perlastan ON-60  25 g  +  Surfac B678 25 g  Mild steel 4  1 Minute Treatment  Water45 kg+  Citrate 500 g +  Perlastan ON-60  25 g  +  Surfac B678 25 g +  PET polymeric  particles 10 kg  Carbon  Iron Metal  Content  Content(%)  (%)  1.61  73.90  3.99  64.97  8.40  43.34  15.24  36.71  Iron/Carbon  Ratio  0.02  0.06  0.19  0.42  Sample  Mild steel 1  Mild steel 2  Mild steel 3  Mild steel 4  XPS results for cleaning efficiency  Treatment  Control - No Treatment  Control Treated With  Water Only  1 Minute Control Treatment  Water45 kg+  Citrate 500 g +  Perlastan ON-60 25 g +  Surfac B678 25 g  1 Minute Treatment  Water45 kg+  Citrate 500 g +  Perlastan ON-60 25 g +  Surfac B678 25 g +  PET polymeric particles  10 kg  Calcium  Content  (%)  0.55  0.71  1.73  0.00  Nitrogen  Content  (%)  0.00  0.81  1.31  0.00  XPS results for iron oxide removal  Sample  Mild steel 4  Treatment  1 Minute Treatment  Water45 kg+  Citrate 500 g +  Perlastan  TM ON-60 25 g +  Surfac TM B678 25 g +  PET polymeric particles  10kg  Iron/Iron Oxide  Ratio  0.16 