High Plansifter in Whole Wheat Flour Production: Keeping Bran and Germ

Whole wheat flour is made by keeping the bran, germ and endosperm together instead of separating them, so the sifting section is asked to do something different from a white flour line. The machine must still control particle size, but it must not discard the bran and germ streams it would normally route away. The value to watch is how much of the bran and germ stays in the finished flour while the particle size still meets the target the customer buys against.

What changes when the finished product is whole wheat

In a conventional mill the sifter splits ground stock into flour, semolina, middlings and bran, and each stream goes its own way. On a whole wheat line the bran and germ are recombined with the flour, so the sifter's task shifts from separation towards sizing. Oversize bran flakes that would feel gritty are reduced and re-sifted until they pass, while very fine dust is controlled so the flour does not become pale and dusty. Machine types and how they fit a mill are grouped under Flour Mill Machines, and the cleaning steps ahead of the mill sit under Grain Machines.

What decides how well the sifter holds bran and germ in the flour

Why germ makes sifting harder

Germ is soft and carries oil, so it tends to smear and blind fine screens, and it is easily lost to a stream you did not intend. Bran is flat and elastic, which makes it ride across a fine screen rather than pass through it. Both behaviours mean the sifter needs attention to screen cleaning and to how returns are handled, and neither is solved by simply fitting a coarser screen. The aim is to reduce oversize material until it passes, not to open the mesh so far that the flour loses the uniform texture the product is judged on.

Selection questions to put to any supplier

Ask which screen materials and cleaning devices the machine uses, and how they behave with an oily, sticky product. Ask how many returns the machine can handle and how those returns are re-introduced into the flow. Ask what grain types and products the unit has been used on, and whether spare frames and cloths stay available in the same dimensions. Ask for the drawings and inspection records that will ship with the machine, so the frame dimensions can be checked on arrival. A supplier that works through selection, matching and inspection rather than reading from a fixed catalogue can answer all of this before any order is placed.

Installation and commissioning checks

1. Check frame dimensions and screen tension against the packing list before lifting the machine into place.
2. Confirm the sifter is level and that its support or suspension is free to move.
3. Set the feed so that stock enters as an even curtain across the full width.
4. Run empty, then with product, and watch the return streams rather than only the flour outlet.
5. Take a flour sample and check both particle size and the visible bran and germ content before handover.

Routine maintenance and what wears out

The parts that age are the screen cloths, the suspension elements and the flexible connections. On a whole wheat line the screens demand the most attention, because oily germ and elastic bran shorten the period during which a cloth performs as intended. Keeping a sample of the flour from the day each screen was fitted gives you a reference, and drift against that reference is a better trigger for replacement than a fixed interval. The same logic applies to spare parts: order replacements on the dimensions recorded at commissioning, not from memory, which keeps the Flour Mill Parts you hold usable across the line.

Common problems and what to check first

1. Flour feels gritty: check for oversize bran passing without reduction, then look at the mesh and the returns.
2. Screens blind quickly: check the screen cleaning devices and the germ content reaching the machine.
3. Bran reappears as large flakes: check the re-grind and return path first.
4. Output drops while quality holds: check for a partly blinded screen before assuming a mechanical fault.
5. Dust in the sifting room: check cover gaskets and the flexible connections at inlet and outlets.
6. Flour looks too pale: check whether fine bran and germ are being lost to a waste stream rather than the flour.

FAQ

Why is a plansifter used in whole wheat flour production?

It controls particle size so the flour has an even texture, while the bran and germ streams are kept and recombined rather than removed from the product.

Does the same sifter make both white and whole wheat flour?

Often yes, but the settings differ. Mesh and return handling are retuned for the whole wheat product, which is why section count and spare frame availability matter at selection.

Why do my screens blind faster on whole wheat?

Germ carries oil and tends to smear on fine cloth. Screen cleaning devices and a feed rate matched to the load reduce the problem.

Can I just fit a coarser screen to stop blinding?

A coarser screen lets larger particles through and costs texture. The better route is to reduce oversize material and keep the screen clean.

How do I judge that the flour is still whole wheat?

Check the visible bran and germ content in a flour sample against what you agreed with the customer, alongside the particle size check.

What to send us for a precise answer

Send us your grain type, target capacity, the equipment already on your line and the part you are replacing. WUXI HASEN supplies machines, spare parts and full grain processing lines, including parts for equipment built by other suppliers. You can reach our team at amina@immyhitech.com.