SM Milling Rolls Test

The new rolls were tested in 1998 in a 180 Tons / 24 h soft wheat mill in Poznan.

The tests were carried out in passages C2 – C3 and C5 as there were complete benches for each passage. Standard rolls (hardness 430 – 470 HB) were installed on one side and two SM self-matting rolls were installed on the other side.

 SM self-matting smooth rolls

During the tests, the basic parameters were analyzed in the wheat mill along with the products obtained, over a period of more than three weeks.


1. Intensification of the milling process

During the same period on both sides the SM self-milling rolls, produced slightly more flour.

Taking B1 value as 100%, the increase obtained was C2=2.1%, C3=1.8% and C5=1.3% with the self-matting rolls . Compared to normal rolls, 14%, 18% and 23% more flour was obtained, respectively. Considering the slightly coarser fraction of 200 the increase was higher (30%, 34% and 37% respectively).

This clearly shows that the milling process has been intensified.

The grinding results could be maintained by increasing the mill load. In this way by placing SM rolls in existing mills the capacity can be increased. It is also possible to make a shorter diaphragm and make better use of the roll banks. Capacity and extraction levels were monitored over a two-year test period (1997-1998).

Traditional cylinders were used in 1997. Trials were conducted in early 1998. In February 1998 all the traditional smooth rolls were replaced with SM self-matting rolls.

The quality of the grain being processed during the entire period was very uniform. The milling process, the equipment installed and the market situation were also similar during both periods.

The introduction of SM self-matting rolls was the only major change made at Molino in 1998. The results obtained during this year showed that flour extraction was 2.42% higher than in 1997 and mill capacity increased from 180 t/24hs to 200 t/24hs.

Even if we assume that some of the increases in extraction and capacity were the result of other factors, there is little doubt that the introduction of the new SM self-matting rolls produced a notable increase in both parameters.

2. Improved flour quality

The flour produced improved. The results were as follows:

  • The level of sedimentation (gluten quality) increased by 3-5 points.
  • The water absorption in the flour increased by 3-5 points.
  • The water absorption in the flour increased by 0.8-1.4%.
  • The water absorption in the flour increased by 0.8-1.4%.
  • The activity of alpha-amylase did not change.
  • Experiments conducted in 1998 in Canada showed that the protein level increased by approximately 0.25% and the flour cake was noticeably less spotted (ash) and brighter in color.
  • In the Poznan trials, despite the 10% increase in mill capacity, the change in ash content was virtually non-existent. In tests in Canada, they showed that with a constant mill capacity, the ash content dropped by 0.16%.

3. Lower electrical power consumption

The power consumption of SM self-matting rolls, in the different roll banks, compared to normal rolls, was lower by 2.5% – 5.7%.

Overall this showed that the smaller the particle size of the ground product, the greater the energy savings in grinding.

4. Lower the grinding temperature.

One of the characteristics of soft rolls, working on compression passages, is the relatively high working temperature of the rolls.

With the SM self-milling cylinders, the working temperature of the cylinders was lower by 3.6 – 5.7 C (6-10F).

Which in turn lowered the product temperature by 2.5-3.4 C (2.5-3.4F).

5. Lower maintenance cost.

During the last two years the SM self-matting cylinders installed in 1998 have required no maintenance, retaining a sandblast finish (May 2000). The results obtained show no noticeable deterioration.

During the last two years 1999-2000 more than 1000 Prillwitz SM self-mattens rolls of various lengths and diameters have been installed in mills in Poland, Germany, Holland, Italy, England, Canada, USA and Colombia.

As of the date of this technical report, the information received from all the mills where they are installed confirms the benefits of the SM self-matting rolls in the grinding process and their superiority over other mills in the world.

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