New cleaning method, apparatus and use

[0115]Examples A to D in Table 1 all incorporate a particulate inorganic filler having a D50 particle size of less than 10 microns and a D90 particle size of less than 40 microns. It was shown that as the wt % of this smaller particle size filler approached and extended above 60 wt % the particle shape / size characteristics of the resulting cleaning particles became less optimal for laundry applications. In particular, these cleaning particles exhibited some degree of defects including: snake skinning, tails, cutting edges and particle to particle non-uniformity in shape and size and showed shapes which were far from the desired smooth ellipsoidal shape. As the weight incorporation of the filler increased the aspect ratio soon became undesirably higher than 1.2, indicating that the particles were becoming more cylindrical and less ellipsoidal. It was noted that the cleaning particles with undesirable shape characteristics using Blanc® Fixe N also demonstrated significant variations in

[0116]Examples E to H in Table 2 all incorporate a particulate inorganic filler having a D50 particle size of at least 10 microns and having a D90 particle size of at least 40 microns. In addition to the desirable density results in Table 1 it was surprisingly possible to obtain cleaning particles with wt % incorporation of the particulate inorganic filler which approached or exceeded 60 wt % and which had excellent shape characteristics. That is to say Examples E to H had smooth ellipsoidal shapes which were substantially free from snake skinning, tails, cutting edges and were uniform in shape and size. The improved ellipsoidal shape is evident from the improved aspect ratios of the cleaning particles which are all <=1.2. Thus, particles having the more desired shape and density characteristics for laundry applications were even better achieved.

[0117]Example I in Table 2 incorporates a particulate inorganic filler having a D50 particle size of at least 10 micron and having a D90 particle size of less than 40 microns. As can be seen the particle shape characteristics are intermediate between those of Examples A to D in Table 1 and those of Examples E to H in Table 2.

2 Cleaning

2.1 Cleaning Examples and Methods

[0118]The following cleaning particles as prepared in part 1 above were selected for cleaning experiments: Comparative Example A and Example G.

[0119]The cleaning experiments were triplicated for each cleaning particle using a Xeros washing apparatus as described in PCT patent publication WO 2011 / 098815 with a recommended dry laundry loading of 25 kg. The washing cycle was carried out using 20 kgs of a cotton flatware ballast. The washing cycle was run for 60 minutes at a temperature of 20° C. or 70 minutes at a temperature of 40° C. and using an 250 gms of Pack 1 cleaning formulation supplied by Xeros Ltd. 69 m2 of surfa