Industry // Agro-processing

Machine vision inspection for agro-processing lines

Camera checks for grain milling, sugar, animal feed, fruit and nut packing and dried goods.

Technical review: Frank GuoReviewed 24 September 2026

// Short answer

On agro-processing lines, camera checks usually confirm the bag label and date or batch code, check that a heat seal or stitch line looks complete, and look for foreign matter visible on the surface of product on a belt. Vision cannot see inside a bag or under the product, and a visible seal check is not a leak test. Dust, humidity, cleaning and vibration decide how the station is built.

// Where it fits

Inspection points on a bagging and packing line

A typical sequence for milled products, sugar, feed, nuts or dried fruit; your line may differ.

[Schematic]Process flow · not to scale

Swipe sideways to see the whole drawing →

[1] Foreign matter: visible objects on the product surface before filling.

[2] Seal / stitch: seal or stitch line present, complete and clean.

[3] Label & code: the right bag print, a readable and correct code.

[4] Bag count: every position in a pallet layer filled.

// Defect risks

What goes wrong at each step

Visible faults by step, and the application that checks for them.

Agro-processing production steps, visible faults and matching inspections
Production step	Typical visible faults	Inspection
Cleaning and sorting	Stones, husks, sticks, plastic or string on top of the product	Surface defect detection (visible surface only)
Bag filling	Product in the seal area; bag top folded	Fill level, cap & seal
Sealing and stitching	Open, creased or contaminated seals; missing stitch lines	Fill level, cap & seal
Coding and labelling	Missing, smudged or wrong codes; the wrong bag print after a changeover	OCR/OCV & date codes Label & print inspection
Palletising	Missing bags in a layer	Presence, absence & counting

// Inspections

Checks that apply on agro-processing lines

Label, code and seal checks can often share one station.

Label & print inspection

The right bag print or label for the product and pack size.

At: labeller or bag magazine

Label & print inspection

OCR/OCV & date codes

Dates and batch codes on paper, woven and film bags, checked against the run.

At: after the coder

OCR/OCV & date codes

Visible seal & stitch

Heat seal visibly complete, stitch line present. Not a leak test.

At: after the sealer or sewing head

Visible seal & stitch

Visible foreign matter

Objects that differ in colour or shape, on top of product on a belt.

At: inspection belt before filling

Visible foreign matter

// Application map

Agro-processing inspection scenarios by product

Typical products from South African mills, sugar plants, feed mills and packhouses, what a camera checks on each, and the application page with the detail. The method in each row is a starting point, confirmed on your own bags and product. Moisture, grade, net weight and anything inside a bag need other instruments.

Agro-processing inspection scenarios: product and line position, what is inspected, typical fault, inspection method and related application
Product / line position	What is inspected	Typical fault caught	Inspection method	Related application
Maize meal bagsafter the filler and bag closer	The grade printed on the bag, such as super or special, and the date code	The wrong grade bag after a changeover; missing or smudged code	Camera over the bag face with diffuse light; OCV on the code	Label & print inspection
White and brown sugar packsafter the packer	Printed date and batch code; top seal	Missing code, open or creased top seal	Camera over the pack with light across the seal	OCR/OCV & code inspection
Cake and bread flour bagsafter dust extraction at the packer	Printed code on the bag face or gusset	Code hidden or smudged by flour dust, missing code	Camera in a purged housing with diffuse light	OCR/OCV & code inspection
Animal feed bagsat the sewing head	Stitch line across the top and the sewn-in label	Missing stitch, missing sewn-in label, unfolded bag top	Side camera just after the sewing head	Fill level, cap & seal
Seed maize bagsat bagging	Cultivar name and lot number on the bag or tag	The wrong cultivar print or tag, missing lot number	Camera over the bag face; OCR/OCV on the lot number	OCR/OCV & code inspection
Rice and dried bean pouchesafter the vertical form-fill-seal machine	End seals and the printed code	Grains trapped in the seal, missing code	Camera at the jaw exit with light across the seal	Fill level, cap & seal
Raisins and dried apricotson the inspection belt before packing	Visible stems, stones and foreign matter on a single layer	Cap stems, stones, twigs	Colour camera over the belt with diffuse light	Surface defect detection
Macadamia and pecan kernelson the belt before retail packing	Visible shell pieces and discoloured kernels	Shell fragments on the surface, dark kernels. Kernel-by-kernel ejection is a job for an optical sorter	Colour camera over a single layer	Surface defect detection
Rooibos tea cartonsafter the cartoner	Flaps closed; printed best-before and batch code	Open flap, missing or wrong code	Camera over the carton end with diffuse light	OCR/OCV & code inspection
Citrus export cartonsin the packhouse, before palletising	Carton label present and readable, with the packhouse and grower codes	Missing, unreadable or wrong carton label	Camera or code reader beside the conveyor	Carton & pallet verification
Egg traysafter the egg packer, before closing	Every cell filled	Empty cell. Cracked shells need a dedicated egg grader	Overhead camera with diffuse light	Presence & counting
Bulk bags (FIBCs)at the bulk bag filler	Label in the document pocket present and readable	Missing label, or the wrong one for the batch	Camera or code reader at the filling frame	Carton & pallet verification

// Environment

Conditions specific to mills, sugar plants and packhouses

These decide whether a station keeps working through a season.

Dust

Flour, sugar and feed dust

Dust dims lenses and lights. Sealed housings and filtered air across the window help.

We askDust sources and the area classification

Humidity

Moisture and condensation

Cold rooms, steam and humid packhouses fog windows. Housing and position allow for this.

We askWhere humidity or cold rooms meet the line

Cleaning

Washdown or dry cleaning

Packhouses are often washed down; mills are usually cleaned dry. Housings and cable glands suit your method.

We askCleaning method and chemicals

Temperature

Hot days and cold mornings

Unconditioned sheds swing between heat and cold. Electronics are rated for the range.

We askConditions in summer and winter

Vibration

Mills, sifters and baggers

Vibration blurs images and loosens focus. Cameras mount on rigid stands with focus locked.

We askWhere the station could be mounted

// Limits

What vision does not do on an agro-processing line

We agree these boundaries before a project starts.

Needs another method

Foreign bodies inside a bag or under the product. These need metal detection or X-ray inspection.
Seal integrity. A seal or stitch can look right and still leak. Leak testing is a separate method.
Net content. Declared quantity needs a checkweigher.
Product quality. Moisture, grade and hidden insect damage need sampling or other instruments.

Works reliably when

Bags arrive flat and consistent. A guide or flattener presents print and seal the same way.
Optics are protected and cleaned. Cleaning is part of the routine.
Recipes follow the product. Each print and pack size has a recipe, selected at changeover.

// Samples & acceptance

What to send for a sample test

We test your own bags and product before proposing a station. The same samples later define acceptance.

Sample preparation guide

Good bags

Sealed bags from normal production, for each pack size and print.

Defect samples

Missing or smudged codes, wrong prints and poor seals, each marked.

Foreign matter

Examples of what must be caught, next to normal product.

Acceptance

False rejects and missed defects at line speed; levels agreed per project.

// FAQ

Agro-processing inspection questions

Can a camera check the print and batch code on maize meal or sugar bags?

Yes, where the code lands on a flat, visible area of the bag. Creased paper, woven sacks and shiny film change how print looks, so we test your own coder on your own bags.

Can vision confirm that a bag or pouch is properly sealed?

It can confirm that the seal or stitch line looks right: present, complete and free of product. It cannot prove the bag is airtight; leak testing is a separate method.

Can machine vision detect foreign material in grain, nuts or dried fruit?

Only on the surface the camera sees, and only when the object differs from the product in colour or shape. Anything inside a bag or under other product needs metal detection or X-ray.

How do cameras cope with flour, sugar and feed dust?

With sealed housings and filtered air across a cleanable window. Dust on a bag can look like a defect, so we test on samples. In a classified combustible-dust zone, that classification decides which equipment may be installed.

Is an optical sorter the same as an inspection station?

No. An optical sorter is a dedicated machine that ejects individual kernels or nuts from a product stream. The stations on this page check packs and visible surfaces on a conveyor and signal a reject.

Can a camera check the labels on citrus or fruit export cartons?

Yes. A camera or code reader beside the conveyor confirms that the carton label is present, readable and carries the expected codes before the carton reaches the pallet. Grading the fruit itself by size, colour and blemish is done by a packhouse grading machine, not by this station.

OCR/OCV & date codes →Fill level, cap & seal →Surface defect detection →Machine vision lighting guide →How we deliver a project →Support & changes →

// Agro-processing

Request an assessment for your line

Tell us the products, bag types, faults and conditions around the line. We will say which checks apply and what a sample test needs.

Request a Vision Assessment