The cold dyeing process of rayon fabric includes singeing, stacking, cleaning, tentering, cold pad-batch, finishing and so on.  So we need to grasp the process conditions and processing points and prevent the fabric from breakage and seam mark. If we have select C type cold dyeing produced by Huntsman Corp, which has better effect, but the cost is higher.

The fabric specification and process

1. Fabric specification
9.85 tex×9.85 tex，354pcs/l0 cm×346pcs/lO cm，l60 cm rayon fabric.
19.7 tex×19.7 tex, 394pcs/l0 cm×236pcs/l0 cm，160 cm Rayon fabric.

2. process
Cloth suture inverting→singeing and rolling enzyme→piling(wet cropping roll and seal packing for 4-6h)→boiling and washing→tentering→cold dyeing (dyeing agent)→soft tentering→shrinkproof

3. The preliminary treatment process conditions and controlling point

3.1 Singeing and rolling enzyme
The burner for singeing is one positive and one objective. The padder speed is 100～110 m/min.
Rolling enzyme receipt/(g.L-1)
Amylase                     4
Salt                            5
Penetrant agent        1
Temperature/℃        45～50

3.2 boiling and washing
The machine for boiling is different kinds, such as Loose rope washing machine, compact flat width water washing machine and jig dyeing machine and so on. The choose of different machine depends on the fabric structure. For the general high count sleazy fabric, such as 9．85 tex×9．85 tex,354 pcs/lO cm×346pcs /lO cm,160 cm rayon fabric, it is soft in itself. And it is suitable for boiling in rope washing machine. It is soft in itself, suitable for boiling in rope washing machine. The scratch mark, chicken feet mark in the production process will not affect the dyeing quality. The high count and high-density fabric are hard in itself. The scratch mark, chicken feet mark occurs in the process will affect the dyeing quality.
The sizing for rayon fabric is composed of 80%starch slurry and 20% chemical pulp. Though just enzyme desizing, it will reach the levelling effect for the cold dyeing process. If printing is need, especially sensitive color, we need to add a process of alkali desizing or hydrogen peroxide desizing in the process of washing and steaming.

3.3 tentering and drying
The dyeing process of Rayon fabric after stretching and drying are done by flat width cold dyeing machine, so it is very important. The swelling and swelling of the fiber occurred after wetting, with little change in length and more in diameter. As a result, the yarn diameter increases suddenly when the fabric is dipped and dyed. Because the cold dyeing is a tight type device, the fabric is subjected to greater tension and the warp diameter increases until the fabric is wrinkled.
If the width of the warp is uniform before dyeing, the gap between the warp yarns is the same, and when the fabric is dyed, swelling and swelling occur after wetting, and there is a certain space between the warp yarns, so that wrinkles can be prevented.

Practice has proved that the dry cloth must be stretched before dyeing, and the width of the stretching door is equal to or slightly larger than that of the wet cloth door.