9  EP 3 800 019 A1 10  ment represented by FIG. 11d from about 0.135 inch to about 0.570 inch. This particular abrasion was deter- mined to be reduced with larger radial knife extensions d$_{pos}$. FIG. 11 e represents what is believed to be an em- bodiment that retains the inward bevel of the clamp 26, butfurtherincludes a thickerclamp 26 and extendedknife position.Based on theseinvestigations itwas concluded that, depending on the configuration of the knife assem- blyused,a sufficientlylow rake-offangle  θ$_{r}$  isconsidered to be less than 23 degrees, more preferably less than 20 degrees, and most preferably about 17 degrees. 5 10 15 extensions ("d$_{pos}$") of about 0.0002 inch to 0.011 inch, and clamp set-back distances ("d $_{set}$")ofabout0.150 inch to 0.330 inch.Forexample,one approach was to reduce the knife angle  θ$_{h}$  (within the holder) from a conventional angle ofaboutfifteen degrees to as low as 11.25 degrees. In theory, as the rake-off angle  θ$_{r}$  approaches zero, the resultant stress in the sliced product should be reduced and the instancesofslice cracking willbedecreased and the slice quality should increase. However, in order to maintain the same relative radial knife extension d $_{pos}$, defined as adistance between the cutting edge48 ofthe knife 14 and a line ("L$_{holder}$") tangent to an inside radius of the trailing knife holder 27, and gap setting d $_{gap}$  at these extremely low angle configurations,itwasrequired to make extremely long lateral knife extensions ("d$_{ext}$") of about 0.1 to about 0.2 inch. Surprisingly, the compro- mises in knife position that these minimum knife angle configurations required did not resultin the expected im- provements in slice quality metrics. One embodiment combineda knife angle  θ$_{h}$  withinthe holderofabout12.5 degrees (knife angle 0$_{t}$ relative to the tangent of about 4.5 degrees), a rake-off angle  θ$_{r}$  of about 17 degrees, a radial knife extension d pos of about 0.011 inch and a clamp set-back d$_{set}$ of about 0.200 inch. 20 25 30 [0026] Furthermore, the knife 14 of FIG. 11e has a ground bevelthat isbiased to one side, preferably facing away from the impeller 10, to improve the slice quality. As used herein, a "biased bevel" refers to a knife edge that is not symmetrical, but instead has different bevels on its opposites sides in terms of angleand/or length,for example, as exemplified by the different biased bevels represented in FIG. 12. The knife tip geometries repre- sented in FIG.12 were investigated during development. As represented, knives with double (centered) bevels and biased (single or biased) bevels were evaluated, as were knives with differentbladewidths.The fundamental difference between the biased bevel knives in FIG. 12 is the angle of the primary (wider) bevel 54. Initial evalua- tions were conducted following prior art best practices with an 8.5 degree inward biased bevel(FIG.13b),mean- ing that the primary bevel 54 faces toward the center of the impeller10 atdifferentknife inclinations.Surprisingly, the performance with this orientation was poorer than expected. Following exhaustive analysis of the geome- try, the primary bevel 54 of the knife 14 was concluded to interfere with the path of the potato after slicing. The biased bevel knife 14 was then inverted (outward biased bevel in FIG. 13c) to minimize any interference with the unsliced portion ofthe potato.Data fromsubsequenttest- ing validated this approach, such that an outward biased bevel with the primary bevel 54 facing away from the center of the impeller 10 delivered improved slice thick- ness uniformity.Basedon the results ofthe investigation, primary bevels 54 of about 7 to 10 degrees are believed to be acceptable. One embodiment incorporates an 8.5 degree biased bevel with the primary bevel 54 facing away from the impeller 10. [0025] Several different clamps 26 with different ge- ometries were also evaluated in an effort to lower the rake-off angle  θ$_{r}$  and the probability that slice cracking would occur.Someofthese evaluations are represented in FIGS.11a through11e,whichinclude different(radially outward and inward) clamp bevels. FIG. 11a represents a priorartconfiguration including a knife 14 having a cor- rugated shape for making shaped cuts, a knife angle  θ$_{h}$ within the knife holder 27 of about 15 degrees, a radial knife extensiond $_{pos}$ ofabout0.070 inch,a clamp setback d$_{set}$ of about 0.260 inch, and a rake-off angle  θ$_{r}$  of about 21 degrees. FIG. 11b represents an experimental con- figuration in which theknife angle  θ$_{h}$  withintheknifehold- er27 was about15 degrees,aradialknife extensiond pos ofabout0.003 inch,a clamp setback d $_{set}$ of about 0.160 inch, and the rake-off angle  θ$_{r}$  is about 27 degrees. So- lutions to two immediate issues needed to be resolved: slice cracking and abrasion on the peaks of slices when attempting to produce slices having large amplitudes of 0.100 inch (about2.5 mm)orgreater.FIGS.11c and 11d represent subsequent steps in the investigation. In FIG. 11c, the fingers 50 of the clamp26 were beveled on their surfaces facing away from the impeller 10 to reduce the instances of abrasion on the peaks of the slice which contact the clamp 26. The bevel reduced the knife angle θ$_{h}$ , but resulted in a locally greater rake-off angle  θ$_{r}$  that increased slice cracking. The rake-off angle  θ$_{r}$  was then decreased further by moving the bevel to the radially in- ward side of the clamp 26 facing the impeller 10 (FIG. 11d), thereby maintaining a smooth transition for slices. In addition, the bend angle was reduced and the finger lengths shortened. In order to address abrasion on the peaks whichcontactthe inner sliding surface oftheshoe 22, knife extension values were explored using equip- 55 [0028] According to a preferred aspectofthe invention, an outward position of the knife bevel relative to the im- [0027] The knives 14 were initially positioned at "standard" position, in which the tips 14a of the knives 14 were positioned according to prior art practice a dis- tance ofabout0.003 inch (about75 micrometers)radially inward fromthe nominalinnerradiusofits shoe22,which meant different lateral knife positions for each different knife angle within the knife holder 27. During testing, lat- eral positions of the knife tips 14a were varied. In one embodiment, the knife tip 14a was located at a lateral distance of 0.195 inch (4.95mm) and a radial distance of 0.011 inch (0.28mm),resulting inthe configurationshown in FIG. 11e. 50 45 40 35 6