Spreading Quality Specifications

Spreading quality must be measured with respect to the following factors

(1)   Ply alignment: length and width       

(2)   (2) Ply tension: stretch, slack edge

(3)   Grain alignment: bowing

(4)    (4) splicing: waste and precision;

(5)   (5) damage placement: economy of placement;

(6)   (6) surface direction; and

(7)    (7) static electricity.

Type Of Spreads

There are two types of spreads with respect to alignment:

 Straight Edge

 A straight-edge spread has all the ply edges on one side of the spread superposed perfectly in a vertical line. The ply edge alignment on the other side of the spread may not be superposed in a vertical to the table. This will depend on the variations in cloth width among the bolts of fabrics used in the spread. If there is no width variation, both sides will form vertical lines to the table surface in a straightedge spread. If the fabric width varies from bolt to bolt, or within each bolt, only one side of a straight-edge spread will have vertical superposing. The greater the width variation, the greater the unevenness in the nonstraight edge. This is also true for both sides of a straight-edge spread, which has poor side edge alignment on the supposed straight-edge side.

Centered Edge

A centered spread is one in which the plies are spread with their longitudinal centers superposed in a vertical line. In a perfect quality spread of this type both side edges of every ply are equidistant from the lengthwise center of the spread. Width alignment refers to the superposing precision at the sides of the spread. The greater the variation in width or length alignment, the greater the waste in precision cutting since the ends and sides must be trimmed to the narrowest and shortest plies. Precise cutting of a spread of superposed plies demands that each cut side of a components block be a vertical line to the table surface.

Ply Tension: Stretch, Slack, Edge

Practically all spreads should be made without tension or slack. A tight spread is one in which the plies have been stretched during the spreading process. Such a spread will contract its length after spreading. It will contract during the time the spread lies waiting to be cut and during the chopping processing on the spreading table. The greater the tension in spreading, the greater the contraction from the market component to the cut component. A tight spread can be detected during spreading by inspecting the ends or checking the spread’s tensile freedom. If the ply (or plies) are stretched, the ply ends will tend to shrink toward the middle of the spread. Tensile freedom is checked by inserting one or more fingers under the straight length-wise side and raising the plies approximately one inch. If the lift is resisted or if the lift makes the ends contract, the spread is tight. The larger the spread, the greater the lift should go before resistance or contraction is encountered. Although this method is subjective, it can be made objective by lifting the edge with the L end of a push-pull gauge. The force necessary to life the edge should not be greater than the completed weight of cloth in the lifted area.

Slacked Lay

A slack spread possesses excess length within the stipulated ends of the spread. Billows and ridges on the surface of the spread are indications of slackness. Cut components slack spreads will tend to be oversized. The over sizing is wasted fabric. The amount of slackness in slack plies can be determined by testing for tensile freedom. In slack spreads, the tensile freedom test lift on the edge will lift the plies higher than 1” without decreasing the spread length of the lifted plies. The excess cloth in the spread is equal to

2(  (

when the lift force can be released to zero by fixing the lift triangle out of the spread. Excess length in slack spreads can also be measured by pushing and flattening all the billows and ridges toward and beyond one end of the spread.

Tight-Edge Spread

A tight-edge spread is one in which one edge of the cloth has a higher filling or course counter than the opposite edge. This is due to faulty finishing in the fabric, whereas tight or slack spreads are due to faulty spreading method. Either one side of the fabric was unduly stretched in the finishing, or it’s opposite side sharank. In a tight-edge spread, the tight-edge side tends to rise in a straight line and the loose edge takes on billows and ridges in order to fit into the tight length. The ends of the tight-edge side tend to contract toward each other. The best way to get flat spreads with tight-edge fabrics is either to notch or remove the tight edge before or during spreading. In woven cloths the tight edge is condensed selvages; therefore the tight selvage of the fabric is notched at appropriate intervals across the selvage of the fabric is notched at appropriate intervals across the salvages width. Optimum spacing can be determined by computing the difference in count between both selvages. If the selvage is too tight for notches, the selvage must be cut off or ripped off. In circular knitted fabrics the tight-edge tension can be released by slitting the tight-edge fold as well as notching it or cutting it off.