Fish Processing Machinery

Fish arrives at the plant in a state no other protein does: whole, irregular, slippery and covered in a layer that has to come off before anything else can happen. The order the machines run in matters as much as which machines you buy, because each stage sets up the cut that follows it.

The line, stage by stage

A fish processing line is built around a fixed sequence. Product moves from the holding area through the stages below, and each stage changes what the next one can do.

• Descaling. Water under pressure lifts the scales without cutting into the flesh. Doing this first keeps scales out of the downstream cuts and out of the wash water.

• Gutting. Viscera are removed and the body cavity is cleared.

• Head and tail removal. Blades cut the head and tail off square, which fixes the length the rest of the line works with.

• Butterfly cutting. The belly or the back is opened so the fish lies flat for filleting.

• Filleting and bone removal. The spine is separated from the fillets. The better this stage performs, the less meat goes out with the frame.

• Skinning. The skin is peeled from the fillet.

• Slicing and cutting. Fillets are portioned to weight or to a fixed size.

• Meat recovery. Trimmings and frames go to a picker, which recovers the remaining meat as paste for surimi, fish balls and formed products.

Where the volume is there, some plants combine the first two stages into a single machine that descales and opens the belly in one pass.

What to check before you specify

Fish size range. Every machine in the line is rated by the height or length of fish it accepts. A machine rated to 150 mm will not take a fish of 250 mm, and the constraint runs through the whole line. Measure your smallest and largest fish, not the average.

Throughput per stage. The slowest machine sets the line rate. Head removal generally runs faster than bone removal, which is where lines usually bottleneck. Match the stages to the fish, not to the sum of the pieces.

Fresh, chilled or semi-thawed. Some stages work on fresh and semi-thawed product but not on hard-frozen blocks. Frozen fish is sawn, not cut on these machines.

Species. Scale type, skin thickness and bone structure differ between species. Machines are usually specified for a family — tilapia, carp, mackerel, squid, flatfish — rather than for everything.

Yield from the bone removal stage. This is the number that decides whether the line pays. A stage that leaves meat on the frame is a permanent loss, so ask for the yield figure and test it on your own fish.

Where it sits in the plant

A fish line usually starts after washing and ends at the freezer or the packing table. The three machines below are the ones most plants specify first, because they set the yield of everything downstream.

• High-pressure descaling: our QL-150 fish descaling machine takes fish up to 150 mm high at 40-50 fish per minute.

• Bone removal: our QG350 fish bone removal machine cuts along the spine into three pieces and returns over 85% yield after head removal.

• Meat recovery: our YCR150 fish meat picker turns frames and trimmings into paste for surimi and formed products.

FAQ

Do I need the whole line, or can I add stages one at a time?

Stages can be added over time, but the sequence is fixed. Buy in the order the fish moves, and size each machine to the peak rate the stage before it can deliver.

What fish sizes can a line handle?

It depends on the smallest machine in the sequence. Check the height or length rating of every stage against your product range before committing.

Can these machines run frozen fish?

No. These stages work on fresh, chilled or semi-thawed fish. Hard-frozen blocks are reduced with a frozen fish saw.

How many people does a fish line need?

That depends on how much of the line is automated and how much trimming is done by hand. Descaling, head removal and bone removal are the stages that remove most manual work.

Which stage matters most for profitability?

Bone removal. It is where meat is either recovered or lost to the frame, and the difference accumulates over every fish the line runs.