How a Double Raschel Machine Works and What It Can Knit
A double raschel machine is a warp knitting machine with a front and a back row of needles: each row knits its own base fabric, and yarns carried between the two rows tie those faces together. That is why one machine can deliver a spacer mesh, a plush blanket or a tubular fabric, depending on how the bars are threaded and how far apart the two needle rows are set.
Search for this machine type today and you mostly land on patent PDFs and sales pages. This guide is written for the mill owner or technical manager who has to decide whether a double needle bar raschel belongs on the floor, and which configuration to ask for.
How a double raschel machine forms fabric
On a single-bar raschel, every guide bar laps around one row of needles and you get one fabric face. On a double needle bar machine there are two rows. Patent literature describes it plainly: a front base fabric is knitted by the front needle row and a back base fabric by the back needle row.
The guide bars decide what happens between those faces:
- Outer bars lap on one needle row only and build the front or the back face.
- Middle bars lap on both rows in turn, so their yarn crosses the gap and locks the two faces at a fixed distance.
Leave the connecting yarn in place and you have a three-dimensional spacer structure. Cut it down the middle after knitting and you get two pile fabrics, which is the route used for blankets and plush. Join the two faces only at the edges and the result is a tube.
The knitting elements, using our own machine as the example
Abstract descriptions only go so far, so here is the element set listed on the spec sheet of our GS-RD7/2-12 EL double raschel for spacer textiles:
- Two needle bars with latch needle units
- Two knock-over comb bars
- Two movable stitch comb bars
- A central trick plate between the two knitting zones
- Seven ground guide bars, each with its own electronic drive
The number that matters most on this list is the knock-over comb bar distance. On the GS-RD7/2-12 EL it adjusts from 2 to 12 mm, and that setting is what fixes the gap the connecting yarn has to bridge. A buyer who asks only about working width and gauge, and forgets to ask about this range, often finds out later that the machine cannot reach the fabric thickness the customer wants.
Two more items from the same page deserve attention when you compare quotations. The yarn let-off is electronically controlled, and the take-up is driven by a geared motor through four rollers. On a double-face fabric the two faces and the connecting yarn consume warp at different rates, so let-off control per bar is not a luxury item on this machine class.
What a double raschel machine can knit
Manufacturer listings and our own application notes point to the same families of end products:
| End product | How the two faces are used | What to check on the machine |
|---|---|---|
| Spacer and 3D air-mesh fabric for shoe uppers, mattress textiles, automobile seats | Both faces kept, connecting yarn left in place | Comb bar distance range, number of ground bars |
| Blankets, plush and other pile fabrics | Connecting yarn cut to give two pile fabrics | Distance range for the pile height you sell |
| Tubular fabrics and garments without side seams (sportswear, yoga wear, hosiery) | Faces joined at the edges only | Jacquard version of the machine |
| Netting and mesh for sports, agricultural and filtration use | Open structures on one or both faces | Gauge and working width |
Our product page also lists technical textiles for industrial, automotive and construction use, home textiles such as curtains, and elastic fabrics for sportswear, medical bandages and lingerie. If you need the patterned variants, the RDPJ series guide covers double needle bar jacquard machines in more detail.
How to choose a double raschel by end product
Start from the fabric, not from the catalogue.
If you knit spacer fabric, then fix the finished thickness first and confirm it sits inside the comb bar distance range of the machine. Next count the bars you need: two faces plus connecting yarn already use several, and every extra structure on a face needs another one. The seven-bar GS-RD7/2-12 EL exists because fewer bars limit what each face can do.
If you knit wide goods, then match the working width to your finishing line. Our spec sheet lists 3505 mm (138″), 5334 mm (210″) and 7112 mm (280″), in gauges E18, E22 and E24.
If your patterns need long underlaps, then ask about the guide bar drive. The standard EN-drive on this model runs seven electronic guide bar drives; the optional EL-drive handles shog distances up to 150 mm.
This advice does not apply if your product is a flat single-face fabric such as tricot lining or a plain net. A double needle bar machine adds elements, setting work and threading time you will not use; a single-bar raschel or tricot machine is the right tool there. Our overview of raschel knitting machine types shows where each one fits.
Questions to put to any supplier
- What is the adjustable distance between the knock-over comb bars, and is the change made mechanically or from the operator panel?
- How many ground guide bars, and can each be driven electronically?
- Is warp let-off controlled electronically on every bar?
- Which working widths and gauges are actually built, not just listed?
- Where is the nearest service team? Ours work locally in Turkey, India, Vietnam, Indonesia and the USA.
For the commercial side of the range, the group site grandstarcn.com carries the full machine line. If you already have a fabric sample and want to know which bar count and distance range it needs, send the sample details through our contact page and an engineer will map it to a configuration.
Frequently Asked Questions
What is a double raschel machine?
It is a warp knitting machine with a front and a back row of needles. Each row knits its own base fabric, and yarns carried by the middle guide bars cross between the two rows to connect them.
What is the difference between single and double needle bar raschel?
A single-bar model makes one fabric face. A double-bar model makes two faces at once and can tie them together, which gives spacer structures, cut pile and tubular goods that one row of needles cannot produce.
What fabrics can a double needle bar machine make?
Typical products are spacer and 3D air-mesh for shoe uppers, mattresses and car seats, blankets and plush, tubular sportswear and hosiery on jacquard versions, and netting or mesh for sports, agricultural and filtration use.
How thick can spacer fabric be on a double raschel?
Thickness follows the gap between the two knock-over comb bars. On our GS-RD7/2-12 EL that gap adjusts from 2 to 12 mm; other models are built for other ranges, so always confirm it against your target fabric.
Which gauge and width should I ask for?
Decide from the end product and your finishing line. Our seven-bar spacer model is offered in E18, E22 and E24, with working widths of 3505 mm, 5334 mm and 7112 mm.
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.
