The dual carding system discussed here consists of two feeding zones and two carding zones around a cylinder. Feed the same type of fiber in equal quantities through the two feeding zones. Fix the diameter, r.p.m., settings and metallic wire of the taker-in rollers, workers and doffers in both carding zones under the same conditions. In this case, the ratio of blending, in the slivers, of fibers fed through the two feeding zones are obtainable as follows:
q01/Q₀₁:q02'/Q₀₁=k:k' (1-k)
where Q₀₁: Weight (g/cm) of slivers delivered through doffer (do₁) on which fibers are fed through the two feeding zones fe₁ and fe₂. Q10: Weight (g/cm) of sliver delivered through doffer (do₁) on which fibers are fed through the feeding zone fe₁. q02': Weight (g cm) of sliver delivered through doffer (do₁) on which fibers are fed through the feeding zone fe₂. k: Ratio of transfer from cylinder to doffer (do₁) of the fibers fed through feeding zone fe₁. k': Ratio of transfer from cylinder to doffer (do₁) of the fibers fed through feeding zone fe₂.
The blending ratio obtained experimentally, about 6:4, is explained by a difference in quantity between the fibers fed through the two feeding zones and differences in opening conditions at the point where fibers transfer from the cylinder to the doffer. The author believes that opening by the workers has to be improved to make the blending ratio 5:5 or bring it close to this figure.

View full abstract

The biaxial tensile properties of single tricot warp knitted fabrics with an open lap have been calculated theoretically by developing the analysing method used on the close lap structure. [1-2]. In the new developed method, tensile process is divided into two regions, i.e., bending effective region and stretching effective region. The boarder of thesse two regions is critical stretch ratio. The properties in these regions are analysed separately. The analysed results thus obtained are composed. This analysis takes, as the initial conditions, of calculation fabric structure and yarn properties, that is, tensile and frictional properties.
Both experimental and theoretical researches using some of actual fabrics have been carried out, for the purpose of comparison, with good agreement. The effect caused by fictional properties of yarn can be neglected in the bending effective region.
Differences in this biaxial tensile properties between close and open laps have been investigated by using the theories.

View full abstract

This article deals with the thickness, weight, air permeability, warmth rentention percentage, stiffness, etc. of laminated fabrics. Changes in these properties affect the design of laminated fabrics.
The relations between these properties of a laminated fabric and those of its pre-lamination surface and lining have been theoretically and experimentally analyzed with these experimental results:
(1) The thickness of a laminated fabric is calculable from the sum of the thickness of its surface and lining. The adhesive used has a slight bearing on thickness.
(2) The weight of a laminated fabric is calculable by adding the constant determined by the laminating conditions to the sum of the weights of a surface and a lining.
(3) The air permeability of a laminated fabric, V_B is expressible by: V_B=KV_FV_L/√<V_F²+V_L²> where V_F=the air permeability of a surface, V_L=the air permeability of a lining, K=correcting coefficient.
(4) The warmth retention percentage H_B of a laminated fabric is expressible by: 1/1-H_B=1/1-H_F+1/1-H_L-1 where H_F=the warmth retention percentage of surface, H_L=the warmth retention percentage of lining.
(5) The stiffness of a laminated fabric, GB is expressible by: G_B=G₁(1+t³₂/t³₁)+3G₁(1+t₁/t₂)²/G₁/G₂+t²₁/t²₂ where G=stiffness of fabric, t=thickness of fabric.
Suffix 1 shows which is smaller in Young's modulus, surface or lining.
Suffix 2 shows which is larger in Young's modulus, surface or lining.

View full abstract