Plastic pipe inkjet inspection
See how curved pipe marks change character visibility and the tracking of a faulty length.
Line solution
Test this on your samplesPipe print inspection and cable marking checks
// Short answer
Pipe print inspection is a camera check at the printer exit of a pipe or cable extrusion line that reads the printed marking, compares it with the text the line should be printing, and checks that the metre count runs in sequence. addaScan builds it on HIKROBOT cameras timed by an encoder, from one camera to three around the product, with an alarm or marker output. An indicative installed budget for a typical application is R 110 000 – R 650 000 excluding VAT.
// At a glance
The station in three lines
- Faults caught
- Missing, smeared or incomplete marking; wrong marking text for the job; metre count out of sequence
- Configuration
- HIKROBOT vision sensor with OCR (low) or three cameras around the product with deep-learning OCR (high), encoder-timed
- Line link
- Alarm, fault code and marker output to the line PLC; expected text from the PLC, MES or operator screen
// Fit & limits
What this station will not do, and what it needs
What it will not do
- Product dimensions: the station reads what is printed; diameter, wall thickness and conductor size stay with the line gauges and tests.
- Print durability: rub and weather resistance of the marking are not tested.
- Standard compliance: it checks the string you specify; whether that string meets the SANS marking clause is your quality department’s decision.
- Rotating print, one camera: with one camera, print that turns out of view is reported missing, not read.
What makes it work
- Samples: printed lengths of each product colour and print method, including faulty print.
- An encoder: on the haul-off, for image timing and the metre check.
- The expected text: per job, from the PLC, MES or the operator screen.
- A steady product: pipe or cable running straight through the camera position, without whipping.
// On South African lines
Pipe and cable marking in South Africa, and how it goes wrong
Plastic pressure pipe in South Africa is made and sold against product standards. SAPPMA, the plastic pipe makers’ association, whose members include the majority of leading Southern African players, lists product certification to SANS ISO 4427-2 for HDPE pipe and SANS 966-1 for uPVC pipe (SAPPMA). According to a SAPPMA webinar, SATAS issued its first permit to a plastic pipe manufacturer in 2016, for product made to SANS 4427-2, and SANS 966-1 certification followed (SAPPMA webinar, 2025). For electric cables, the compulsory specification requires cables for fixed installations from 300/500 V to 1 900/3 300 V to comply with SANS 1507 (VC 8075, 2003 text); the text was amended in 2017.
These pipe marking standards, and the cable standard, set what the printed marking must contain. The SANS texts are paid documents, so this page does not restate their marking clauses: your quality department works from the current text and gives the station the string it must expect. The rule sets the outcome, a correct and legible marking; a camera is one way to check it along the whole length instead of at the end of a coil or a stack.
On the line, the marking comes from a pipe printing machine or a cable printing machine after the cooling bath, by inkjet, hot foil or embossing. It fails quietly: a blocked nozzle, ink running on a damp surface, a print head knocked out of line, last job’s text left in the printer after a size change. PVC pipe printing on a grey or white wall and print on a black HDPE pipe or cable sheath behave very differently under light, which is why lighting is settled on samples. A wrong length is hard to find again once it is cut, bundled or wound.
What the extrusion crew reports, and what pipe print inspection checks
| What the line reports | What a station checks | Where it stops |
|---|---|---|
| “The printer ran dry and nobody noticed for a whole coil” | Marking present at each print repeat, timed by the encoder: a missing print in its expected window raises the alarm. | If print rotates to a side the camera cannot see, one camera reports it missing; three cameras around the product prevent that. |
| “The marking is there but smudged and unreadable” | Every character read by OCR (deep-learning OCR in the high case) and compared with the expected text; unreadable characters fail. | Rub and weather resistance of the print are not tested. |
| “Wrong size printed after a changeover” | Marking text compared with the job’s expected string from the PLC or the operator screen, field by field as you define them. | The station checks the text, not the product: diameter and wall thickness stay with the line gauges. |
| “Metre marks jump or repeat on the drum” | Metre count read at each print and checked to rise in step with the encoder distance. | The check is only as complete as the reads: a missed read is reported as a gap, never filled in. |
| “Black on black, we can hardly see the print ourselves” | Lighting angle and exposure chosen on samples; embossed or low-contrast print gets low-angle light. | If the print cannot be made visible on samples, the check is not offered for that product. |
// The complete solution
Pipe print inspection station: hardware, software and installation
The cameras sit after the printer, where the product runs straight and steady. An encoder on the haul-off times each image to the print repeat and gives the distance for the metre check. One camera covers print that always lands on the same side; three cameras around the product cover print that rotates. Faults raise an alarm and, if a marker is fitted, flag the length for cutting out.
[Schematic]Plan view, not to scale
Swipe sideways to see the whole drawing →
[1]: Encoder on the haul-off times images to the print repeat and measures distance.
[2]: One camera above, or three cameras around the product in the high case.
[3]: A bar light per camera, at a low angle for embossed print.
[4]: Alarm to the crew and an optional marker on the faulty length.
Hardware
| Component | HIKROBOT example | Role in this station |
|---|---|---|
| Camera (low) | HIKROBOT SC3000-series mono vision sensor (MV-SC3050M) with OCR and logic tools in the sensor | Reads the marking from one side at the printer exit |
| Cameras (high) | 3 × HIKROBOT CS-series 6 MP mono GigE cameras (MV-CS060-10GM) with 25 mm 10 MP lenses, on a ring mount around the product | Read the marking wherever it lands around the circumference |
| Processing (high) | HIKROBOT VC3000 vision controller (MV-VC3302P) running HIKROBOT VisionMaster with deep-learning OCR | Reads the three views, compares with the job and checks the metre sequence |
| Lighting | HIKROBOT bar lights (MV-LLDS-H-600), one per camera | Even light along the print; the angle is chosen for inkjet, foil or embossed marking |
| Housings (high) | Not HIKROBOT: IP67 camera housings | Protect the cameras from cooling-water spray and steam near the bath |
| Encoder | Local supply: incremental encoder on the haul-off or a measuring wheel | Times each image to the print repeat and gives the distance for the metre check |
| Alarm and marker output | Local supply: alarm beacon and output to the line PLC; the marker device itself is yours or quoted separately | Tells the crew at once and flags the length for the saw or the winder |
Software and vision tools
| Tool or software | What it does here |
|---|---|
| SCMVS OCR and logic tools (low) | Reads the marking in the vision sensor and checks it against the expected text. |
| HIKROBOT VisionMaster deep-learning OCR (high) | Reads curved, low-contrast and slightly distorted characters on a round product. |
| VisionMaster OCV | Verifies the printed string against the job template, character by character. |
| Metre sequence logic | Checks each metre reading against the previous one and the encoder distance; a jump, repeat or gap raises the alarm. |
| Job recipe | Expected marking text per product and batch, from the PLC or MES, or chosen on the screen at changeover. |
Installation and integration
01
Mounting and enclosure
Cameras on a ring or bracket after the printer, where the product is dry and runs steady; IP67 housings where spray or steam from the cooling bath reaches.
02
Lighting and shrouding
Bar lights along the print direction, a shroud against daylight from the factory doors, and a separate exposure per product colour.
03
Encoder and tracking
Encoder on the haul-off, so image timing follows the line speed through start-up and speed changes, and every fault is logged with its metre position.
04
PLC link
Alarm and fault code to the line PLC; expected text from the PLC or MES. The vision sensor lists PROFINET and EtherNet/IP; the VC3000 controller has opto-isolated digital I/O.
05
Alarm, marker and confirmation
A continuous product cannot be pushed off: a fault raises an alarm that must be acknowledged and, if fitted, fires the marker. If the station is not ready, the alarm stays on, so the line never runs unchecked without the crew knowing.
06
Recipes and operator screen
Recipe per product chosen at changeover; the screen shows the last string read next to the expected one, so a wrong job in the printer is seen at once.
// Indicative cost in South Africa
What this station costs, excluding VAT
Indicative budget for a typical application of this kind. Every project involves custom requirements (your products, line speed, layout, PLC and acceptance criteria), so the final price differs from case to case. A firm price follows the sample test.
- Low
- R 110 000
- one camera, alarm only
- High
- R 650 000
- three cameras, deep learning, sequence check
- Basis
- Typical application of this kind, indicative
- South African rand, excluding VAT
- Prices as at 2 October 2026
- Travel (Gauteng): outside Gauteng quoted separately
// Included and excluded
The low figure is one vision sensor with OCR at the printer exit, timed by an encoder, raising an alarm when the marking is missing or wrong; it suits print that always lands on the same side. The high figure puts three cameras around the product with deep-learning OCR on a VisionMaster controller and adds the metre-sequence check and a marker output. The marker device itself, changes to your line, utilities and VAT are excluded.
Hardware is priced from public list prices converted at the ECB reference rate, plus freight, clearance and margin; engineering at R 900 – R 1 300 per hour. How these ranges are built →
Swipe the table sideways to see the high figure and the basis →
| Cost block | Low | High | Basis |
|---|---|---|---|
| Vision hardware (landed, with margin) | R 48 700 | R 146 300 | Low: one mono vision sensor with OCR and a bar light. High: three 6 MP cameras with lenses and bar lights, VC3000 controller, three IP67 housings |
| Software licence | R 0 | R 120 000 | Low: vision sensor software carries no licence fee. High: HIKROBOT VisionMaster with the deep-learning tier |
| Local materials and reject | R 15 000 | R 60 000 | Low: encoder, mount, cabling; alarm output only. High: encoder, ring mount around the product, panel; alarm and marker output |
| Engineering (recipes, PLC link) | R 32 400 | R 182 000 | 36 h at R 900 to 140 h at R 1 300 |
| Installation, FAT, SAT, training, documents | R 14 400 | R 72 800 | 16 h to 56 h |
| Project management | R 7 200 | R 31 200 | 8 h to 24 h |
| Travel (Gauteng) | R 2 000 | R 6 000 | Outside Gauteng quoted separately |
| Total (rounded) | R 110 000 | R 650 000 | Low: one camera, alarm only. High: three cameras, deep learning, sequence check |
// Related technology
Which technologies this scenario uses, and why
The technologies behind this station, how much each matters here, and where each is explained in depth.
| Technology | Role | Why it matters in this scenario | Read more |
|---|---|---|---|
| OCR/OCV of printed codes | Core | The marking must be read and checked character by character against the job’s expected text. | OCR/OCV inspection |
| Area scan cameras with a vision controller | Core | Three cameras on a VC3000 cover print that rotates around a round product. | Camera and lens selection |
| Deep learning (classification, segmentation, DL OCR) | Supporting | Curved, low-contrast print on black or grey compounds is where deep-learning OCR helps. | Rule-based vs deep learning |
| Vision sensor (HIKROBOT SC1000–SC3000) | Supporting | One vision sensor with OCR is enough when the print always lands on the same side. | Choosing a smart camera |
| Lighting technique | Supporting | Inkjet on a glossy wall, hot foil and embossing each need a different light angle. | Machine vision lighting |
| Code content matched to PLC, MES or WMS data | Supporting | The text and the metre count are compared with the job and the encoder distance, not only read. | Carton and pallet verification |
// Acceptance
How the station is proven before handover
Every station is accepted on your products, against numbers agreed in writing before the build. How we deliver →
01
Sample test
Printed lengths of your pipe or cable in each colour and print method, with good, faint, smeared and missing print; the result states which print is reliably read with one camera and which needs three.
02
FAT with challenge samples
Before delivery, marked samples (missing print, wrong text, smeared characters, metre count out of sequence) must each raise the alarm, and good print must pass.
03
SAT on the line
On your extrusion line at production speed, faults are produced on purpose (for example a wrong job text in the printer), and false alarms and missed faults are counted over an agreed run.
// FAQ
Questions about pipe print inspection
What does pipe print inspection check on an extrusion line?
Pipe print inspection checks that the marking is there, readable and right. A camera after the printer reads every print by OCR, compares the text with what the job should print, and checks that the metre count rises in step with the line’s encoder. A missing, smeared or wrong marking raises an alarm, and a marker can flag the length for cutting out. It does not measure the pipe itself or test how durable the print is.
Can it check cable marking and metre marks on a cable line?
Yes. On a cable line the camera reads the cable marking on the sheath and the metre count, and checks that each metre reading follows the last in step with the encoder distance; jumps, repeats and gaps raise the alarm. Small cables and embossed or black-on-black marking need the right lighting and are confirmed on samples. Conductor size and insulation are not checked; those stay with the cable tests.
Does the station know what the SANS standard requires on the pipe?
No. The pipe marking standards, such as SANS 966-1 for uPVC and SANS ISO 4427-2 for HDPE, and SANS 1507 for cables, set what the marking must contain; your quality department turns that into the expected string for each product. The station checks every print against that string. It does not interpret the standard, and this page does not restate its clauses.
How much does pipe print inspection cost in South Africa?
An indicative installed budget is R 110 000 – R 650 000 excluding VAT, at 2 October 2026 prices. The low figure is one vision sensor with OCR at the printer exit, timed by an encoder, with an alarm output. The high figure is three cameras around the product with deep-learning OCR on a controller, the metre-sequence check and a marker output. Both include hardware, software, engineering, installation, FAT and SAT in Gauteng; a firm price follows a sample test. This is a typical application: every project involves custom requirements, so the final price depends on your products, line and acceptance criteria.
Do we need one camera or three?
One camera is enough when the print always lands on the same side of the product, because the printer and the product do not turn relative to each other. If the pipe or cable twists so the print moves around the circumference, three cameras around it keep the print in view whatever its position. The sample test and a look at your line decide which you need, before anything is quoted firm.
Can the station reject a bad length of pipe or cable?
Not by pushing it off, because the product is continuous. It raises an alarm and, if you fit a marker, marks the faulty length so it is cut out at the saw or found on the drum; every fault is logged with its metre position. The high budget includes the marker output; the marker device itself is supplied by you or quoted separately.
Sources
- SAPPMA homepage: product certification to SANS ISO 4427-2 (HDPE) and SANS 966-1 (uPVC); members include the majority of leading Southern African players (association page, SANS content title and scope only, checked 2026-10-02)
- SAPPMA Webinar V, 10 July 2025: first SATAS permit to a plastic pipe manufacturer in 2016 (SANS 4427-2), then SANS 966-1 (association presentation, checked 2026-10-02)
- Compulsory specification for the safety of electric cables (VC 8075, Government Gazette 24734, 2003): fixed-installation cables to comply with SANS 1507 (gazette, 2003 text amended 2017, checked 2026-10-02)
- HIKROBOT VisionMaster: deep-learning OCR for complex-background, low-contrast and deformed characters (vendor page, checked 2026-10-02)
- HIKROBOT Smart Product Catalog 2025Q4: VisionMaster defect tools including OCV (p.62) (vendor catalogue, checked 2026-10-02)
Related:
More line solutions in building materials and metals:
// Next step
Send us printed lengths, good and bad
Describe the line, the products and the fault. We test on your good and faulty samples and reply with a feasibility note and a budget.