Wednesday, 9 September 2009

Warp Knitting | Spacer Fabrics

Manufacturing Methods and Applications

During recent years,spacer fabrics have become a new generation among textile fabrics.From the technology point of view,they are not quit new,they practically have existed since 15 years,however they have gained commercial importance since a few years only.
Conventional textile fabric do not meet the brilliant features of spacer fabrics or only as a compounded fabric combination.Therefore spacer fabrics were in short time successful in getting market share as substitutes for laminates,in sports and safety wear,as basic construction for composites.for filter and in the medical field.

Spacer fabric are warp knitted double face construction of which both fabric faces are interconnected by the spacer yarn.
Both fabric face can be equal or different,of dense structure,plain or patterned with small design or with a napped surface on one side.

Both faces or only can be of open structure,even with different mesh size on each side.By the choice of stitch construction,spacer fabric can be almost stable but also of controlled stretch used elastic yarn.

For connection of both fabric generally mono filament yarn is used.The thickness of the spacer yarn depends amongst other criteria on distance between the fabric space and whether the space is knitted with one guide bar or with two guide bars each one knitting in opposition to each others.

Spacer fabric are knitted on warp knitting raschel machines with two needle bars.Depending of the product and its requirement,a minimum of four guide bars normally,however five to seven guide bars are in use.The distance between the needle bars is adjustable in certain ranges and is different for the various machines types for knitting spacer fabrics.

Possibilities face structures on spacer fabrics

Type A
Dense and plain,one or both faces can be combined with type B or C.

Type B
Dense and with overall motifs,one or both faces can be combined with type A and C.


Type C
Small open structure,one or both faces can be combined with type A or B.

Type D
Dense structure with additional dimension for napping on one side,rear side dense or semi dense grid structure.
Type E
Honey comb open structure on both faces.
Type F
Rhomboid open structure on both face

Spacer fabrics and their way of manufacture

Spacer fabrics produced on double needle bar raschel machines.The distance between the needle bars respectively the trick plate is adjustable in certain ranges depend on the type of the machine which is used for the manufacture of spacer fabric.
For the construction type A -F two guide bars for each face are normally used,i.e. including the bar for the space,a total six guide bars are used.
For certain applications one or both faces can be knitted with one guide bar only.The spacer up to 3 mm thick could be knitted with one guide bar for the space,preference however should be given to two bars half set,both knitting in opposition to each other.
For many applications it might be possible to knit the spacer construction half set,whenever the required  shore reading and resilience do allow that.By this method the content of expensive mono filament yarn can be reduced by approx 50%.

For spacer fabric with a patterned decorative face up to three guide bars are needed,in this case two guide bars are available for the opposite face and two for the space.

Application for automotive textile

Seat covering;
spacer fabric with two dense fabric faces,height : 3mm - 8 mm,substitute for foam lamination with decorative fabric.
Produce on warp knitting raschel machine type : RD 6 N with gauge 22E - 28E.

The current car seat offered in global marketplace consist of three layers : top layer which is often plush and made of polyester ;the middle layer made of polyurethane foam;and the bottom layer a polyamide warp knitting 
Interior lining;
e.g. doors,columns,back seat covering,dash board,sun-shield,roof liner and similar areas
Spacer fabrics with two dense fabric faces or one side with patterns or structure with one fabric side with napped surface.Height : 3mm -6mm.
Produce on warp knitting raschel machine type : RD 6 N with gauge 22E-28E and RD 7 DPLM with 22E.

Finder splash guard for trucks and buses;
Very open structure on one side and dense on opposite side,height : 10mm-12mm,produce on warp knitting raschel machine type RD 6 DPLM/30 with gauge 16E.

Seat heating within spacer fabric;
Both side are dense structure heating wire is laid-in in the spacer area.

Bolstering material as part of the seat construction;
Both side are semi open structure totally made from mono filament yarn,height : 12mm-16mm,produce on warp knitting raschel machine type : RD 6 DPLM/30 with gauge 16E.


Anonymous said...

Dear Author !
The helpful information