Knitted Geogrid: Which Raschel Platform Makes Your Width and Aperture
Knitted geogrid is reinforcement mesh produced on a raschel warp knitting machine from high-tenacity yarns such as HDPE and polyester, or from slit film. Two different platforms in our range make it: a double needle bar raschel for net, and a raschel net machine running latch needles. They overlap in what they can produce, but not in width range, not in gauge range, and not in whether they can take film instead of yarn, and that is what decides which one you buy.
Get that choice wrong and you do not lose a feature; you lose either the width or the aperture your customer specified.
What fixes the grid before the machine is chosen
Three things on the drawing decide the platform: the aperture, which the gauge sets; the roll width; and whether you feed yarn from a creel or extrude and slit film. Grids that are built with inserted weft yarns and selected by grid type are covered on the grids warp knitting machine page; this page is about the net-raschel platforms and which of the two reaches your specification.
The two platforms, side by side
| Double Needle Bar Raschel for Net | Raschel Net Machine, latch needle | |
|---|---|---|
| Working widths | 130″, 180″, 210″, 256″ | 181″, 205″, 268″, 283″, 335″, 413″, 503″ |
| Gauges | E2, E3, E6, E9, E12, E18 | E3, E6, E8, E10, E12, E18 |
| Needle arrangement | Double needle bar | Latch needles, mounted in blocks or inserted individually |
| Bar set | Not published for this platform | Single needle bar, knockover comb bar, slider bar, stitch comb bar; 2 to 8 bars |
| Warp beams | 4, 6, 8 or 9 positions, 32-inch beams | 2 to 8, free-standing, 812 mm (32″) flanges |
| Yarn let-off | One drive per beam | Electronic, geared motor |
| Pattern drive | GrandStar® COMMAND SYSTEM | N-drive with 2 to 8 pattern discs and a tempi change gear |
| Film handling | Not published for this platform | FTL system cuts and stretches film in step with knitting |
| Take-up | Motor with four rollers | Friction drive on a servomotor, under motion control |
Width decides first, gauge second, film decides the rest
Width settles most decisions before anything else does. Above 256 inches the double needle bar platform is out, and the latch needle machine at 268, 283, 335, 413 and 503 inches is the only one on the list that reaches.
Gauge settles the other end. E2 exists only on the double needle bar platform; the latch needle machine starts at E3. If the grid specification calls for the coarsest aperture in the range, that single line picks the platform for you.
If you extrude and slit film rather than feeding yarn from a creel, the FTL system on the latch needle platform cuts and stretches the film in step with the knitting process. Nothing equivalent is published for the double needle bar machine.
Yarn feed and fault detection
Both platforms run HDPE, polyester and the other high-tenacity yarns used in construction fabrics. On the latch needle machine the yarn feeding section runs three or four feeding positions, each carrying three rollers, and works together with a creel.
Fault detection is where the money is saved rather than earned. A Laserstop system watches the process and halts the machine when something goes wrong, and the electronic pattern drive keeps the repeat honest at speed. On a grid that is going under a road, a fault that runs for a hundred metres before anyone notices is not a scrap problem, it is a liability problem.
What the machine needs from your building
On the geo textile configuration of this platform the published operating envelope is 25 °C ± 6 °C and 65% ± 10% relative humidity, on a three-phase 380 V ± 10% supply with a 25 kVA load. Working widths there run from 181″ to 275″, with compound needles and up to eight guide bars supporting GB1 to GB4 stitch formation, electronically controlled let-off at up to four warp beam positions, a motion-control take-up and a floor-standing batching unit.
Check the supply and the room against those figures before the crate ships, not after. Voltage and humidity are cheap to fix in a drawing and expensive to fix around an installed machine.
If the grid spec is fixed, buy for width; if it is not, buy for range
If you produce one grid specification at volume, then buy the narrowest machine that covers the width and the exact gauge the specification calls for, and put the money you save into beam positions so you stop less often. If you serve varied civil work where aperture and width change job to job, then buy the wider latch needle platform and the larger bar count; 2 to 8 bars and 2 to 8 pattern discs is what lets one machine cover several specifications without a rebuild.
Neither rule holds if the grid is written into an engineering drawing you do not control. There, aperture and gauge are given to you, and the only decision genuinely left open is width.
Related machines on this site
- Double needle bar raschel machine: the platform in the left-hand column above.
- Raschel warp knitting machine: where the net machines sit in the wider raschel range.
- Fishing net warp knitting machine: the same net principle for a different end use.
- Multi axial warp knitting machine: for reinforcement laid at set fibre angles rather than as a grid.
Send the grid specification, with aperture, width, yarn and whether you feed yarn or film, and the platform choice usually resolves itself in one reply. Start from our contact page; commercial terms and the wider group range are handled at grandstarcn.com.
Frequently Asked Questions
What working widths can a knitted geogrid machine be built in?
It depends on the platform. The double needle bar raschel for net is built at 130, 180, 210 and 256 inches. The latch needle raschel net machine goes considerably wider: 181, 205, 268, 283, 335, 413 and 503 inches.
Which gauges set the aperture?
The double needle bar platform covers E2, E3, E6, E9, E12 and E18. The latch needle machine covers E3, E6, E8, E10, E12 and E18. If your specification needs E2, only the double needle bar platform reaches it.
Can the grid be made from film instead of yarn?
Yes, on the latch needle platform. Its FTL system cuts and stretches film in step with the knitting process. No equivalent is published for the double needle bar machine, so a film-fed programme points to the latch needle route.
What yarns are used for knitted geogrid?
HDPE and polyester are the usual choices, along with other high-tenacity yarns used in construction fabrics. The latch needle platform feeds through three or four feeding positions of three rollers each, working with a creel.
What power supply and room conditions does the machine need?
On the geo textile configuration the published envelope is 25 degrees C plus or minus 6, 65% relative humidity plus or minus 10, a three-phase 380 V supply plus or minus 10%, and a 25 kVA load. Confirm your supply against those figures before shipping.
Hey, I’m Vincent!
Solving complex challenges with precision and creativity in the warp knitting industry. Passionate about advancing textile engineering and turning innovative ideas into reality. Shaping the future of warp knitting.
