Flaxseed - Chapter 11 | Official Grain Grading Guide

Determination of dockage

Definitions

Dockage is assessed and recorded to the nearest 0.1%.

Dockage is defined under the Canada Grain Act as "any material intermixed with a parcel of grain, other than kernels of grain of a standard of quality fixed by or under this Act for a grade of that grain, that must and can be separated from the parcel of grain before that grade can be assigned to the grain." Dockage is removed by the following cleaning procedures described in this chapter.

The sample as it arrives is referred to as the uncleaned or dirty sample. Its weight is the gross weight of the sample. Dockage is assessed on the gross weight of the sample.

Dockage is assessed in two stages.

  1. Follow Normal cleaning procedures, using the Carter dockage tester.
  2. Follow procedures for Cleaning for grade improvement. This cleaning can be done at any time after the cleaning assessment has been completed.

Dockage not reported

Important:

Dockage is not reported for samples graded

  • Flaxseed, Sample CW/CE Account Fireburnt
  • Flaxseed, Sample Salvage
  • Flaxseed, Sample Condemned

Normal cleaning procedures

Important:

Wear gloves and a mask to handle any samples that you suspect may contain hazardous substances.

1. Set up the Carter dockage tester as follows:

Feed control #4
Air control #3
Riddle No. 000
Top sieve Blank tray
Centre sieve None
Bottom sieve None
Sieve cleaner control Off

2. You need the No. 4.5 round-hole sieve, and one wire sieve, depending on the size of the flaxseed or solin and the nature of the material to be removed.

Round-hole sieves Wire sieves
No. 4.5 No. 4x14
  No. 3x16

3. Using a Boerner-type divider, divide the uncleaned sample to obtain a representative portion.

  • Official samples shall be at least 1 kg.
  • Unofficial samples shall be at least 1 kg.

4. For hand sieving use approximately 250 g per sievin

  1. Sieve each portion over the appropriate wire sieve until maximum cleanout has been achieved.
  2. Handpick seed clusters and return the seeds to the cleaned sample.
  3. Sieve each portion over the No. 4.5 RH sieve until maximum cleanout has been achieved.

5. Combine the separated 250-g portions.

6. Turn on the Carter dockage tester.

7. Pour the entire working sample into the hopper.

8. After the sample has passed through the machine, turn off the machine.

9. Lightly snap the retainer rod of the aspiration pan to loosen material gathered on the air screen.

10. Using a Boerner-type divider, divide not less than 20 g from the cleaned working sample.

11. From the 20-g portion, determine the percentage by weight of inseparable material.

12. Determine dockage, using the list under Composition of dockage.

Composition of dockage

Dockage includes

  • Material remaining on top of the wire sieve, except flaxseed clusters and whole flaxseed that are put back into the sample
  • Material that passes through the No. 4.5 round-hole sieve
  • Material removed by aspiration
  • Material that passes over the No. 000 riddle
  • Soft earth pellets handpicked from the cleaned sample
  • Inseparable material up to established grade tolerances handpicked from the clean sample
  • Material removed by Cleaning for grade improvement

Primary samples, commercially clean

Primary samples are commercially clean when the net dockage does not exceed 2.5% of the sample weight. Commercially clean primary samples can have up to 0.5% for broken and reasonably sound flaxseed deducted from the gross weight of the dockage.

Primary samples, not commercially clean

In not commercially clean primary samples there is no allowance for broken and reasonably sound flaxseed.

Sample grades

In sample grades, inseparable admixture is not added to dockage. Where the inseparable material exceeds 2.0% of the sample by weight, the admixture becomes a reason for the sample grade and is recorded in remarks.

Rejected account stones

In samples that grade Rejected (basic grade) Account Stones, dockage includes inseparable material handpicked from the clean sample up to the tolerance.

Cleaning for grade improvement

If the grade of a delivery can be improved by additional cleaning, perform the cleaning and add the additional material to dockage. Cleaning for grade improvement can be done at any time after the cleaning assessment has been completed.

  1. After the cleaning assessment has been completed, examine the material to be removed and select your equipment according to the material you want to remove. See the table Cleaning for grade improvement - Flaxseed for the list of equipment.
  2. Sieve the material by hand or pass it through the Carter dockage tester, depending on the material.
    Important: When you use a hand sieve, move the sieve from left to right 30 times, using a sifting motion. One time is one complete motion from the centre, to one side, to the other side, and back to the centre. The total distance from left to right is 20 cm, or about eight inches.
  3. Weigh the additional dockage and add it to the original dockage.
Cleaning for grade improvement - Flaxseed
Material to be removed Equipment Effect on composition of dockage
Inseparable material No. 5 round-hole hand sieve The material passing through the sieve is included in the dockage.
Not more than 5.0% of sound flaxseed may be removed for each single grade improvement achieved.
Lightweight material Carter dockage tester, with Feed control at #4 and air control at #4.5
Note: The material originally removed by aspiration is to be reconstituted back into the sample prior to cleaning for improvement.
The material removed, including damaged seed, is included in the dockage.
Not more than 5.0% of sound flaxseed may be removed from the cleaned sample for each single grade improvement achieved.

Optional analysis

Where a shipper requests special cleaning of a carlot of grain at a terminal elevator, and the elevator manager agrees, dockage material will be analyzed for the presence of grain. The percentage and grade of any grain contained in the dockage will be reported.

Procedures

  1. Analyze the official sample.
  2. Record the following on inspection records:
    • The percentage by gross weight to the nearest 0.1% and the grade of flaxseed.
    • The percentage by gross weight to the nearest 0.1% and the grade of grain separable from dockage.
    • The percentage of dockage.
Example:

95.0% Flaxseed, No. 1 CW

4.0% Barley No. 1 CW

1.0% dockage