Methods and apparatuses for making elastomeric laminates with elastic strands provided with a spin finish
The present disclosure relates to methods for making elastomeric laminates that may be used as components of absorbent articles. The elastomeric laminates may include a first substrate, a second substrate, and an elastic material located between the first and second substrates. During assembly of an elastomeric laminate, a beam is rotated to unwind the elastic strands from the beam, wherein the strands may include a spin finish. First bonds are applied to bond discrete lengths of the stretched elastic strands with and between the first substrate and the second substrate, wherein the discrete first bonds are arranged intermittently along the machine direction. In addition, second bonds are applied between consecutive first bonds to bond the first and second substrates directly to each other, wherein the second bonds extend in the machine direction and may be separated from each other in a cross direction by at least one elastic strand.
1. A method for making an elastomeric laminate, the method comprising steps of:
providing elastic strands wound onto beams, wherein the elastic strands comprise a spin finish, and wherein a first elastic strand is supplied on a first beam at a first tension and a second elastic strand is supplied on a second beam at a second tension, wherein the first tension is not equal to the second tension;
rotating the beams to unwind the elastic strands from the beams;
advancing the elastic strands from the rotating beams;
stretching the elastic strands, wherein the first elastic strand is stretched to a first elongation and the second elastic strand is stretched to a second elongation, wherein the first elongation is greater than the second elongation;
bonding discrete lengths of the stretched elastic strands with and between a first substrate and a second substrate with discrete first bonds arranged intermittently along a machine direction; and
applying second bonds extending in the machine direction between consecutive first bonds to bond the first and second substrates directly to each other, wherein the second bonds are separated from each other in a cross direction by at least one elastic strand.
2. The method of claim 1 , wherein the first bonds comprise discrete regions of adhesive.
3. The method of claim 2 , wherein the discrete regions comprise at least 10 gsm of adhesive.
4. The method of claim 2 , further comprising a step of applying the adhesive to the first substrate.
5. The method of claim 1 , wherein the second bonds comprise adhesive.
6. The method of claim 5 , further comprising a step of applying the adhesive to the first substrate.
7. The method of claim 1 , wherein the step of applying second bonds further comprises applying mechanical bonds to the combined first substrate, second substrate, and elastic strands.
8. The method of claim 7 , wherein the mechanical bonds comprise ultrasonic bonds.
9. The method of claim 7 , wherein the mechanical bonds comprise heat or pressure bonds.
10. The method of claim 1 , wherein the step of stretching the elastic strands further comprises changing first cross sectional areas of the elastic strands in an unstretched state to second cross sectional areas of the elastic strands in a stretched state, wherein the second cross sectional areas are less than the first cross sectional areas; and further comprising the step of immobilizing portions of the elastic strands between at least two second bonds by releasing tension from the stretched elastic strands to increase cross sectional areas of the elastic strands from the second cross sectional areas to third cross sectional areas.
11. The method of claim 1 , wherein the elastic strands comprise a decitex of less than 400.