Through-roll profile unwind control system and method
View Patent ↗A method of unwinding material in a process system for producing a product includes the steps of loading a roll of material in an unwind system, programming a controller with an unwind equation, the controller in communication with the unwind system, computing a material feed rate based on a predetermined product circumference and an average stretch-to-stop roll profile, and putting a diameter of the roll of material and the material feed rate in the unwind equation of the controller, and unwinding a varying amount of material from the roll of material at a varying unwind speed, the controller being responsive to the unwind equation to vary the unwind speed for forming a plurality of products, each product defining a respective circumference substantially equal to the predetermined product circumference.
1. A method of unwinding material in a process system for producing a product, the method comprising the steps of:
loading a roll of elastomeric material in an unwind system, the roll of elastomeric material defining a diameter;
programming a controller with an unwind equation, the controller in communication with the unwind system;
computing a material feed rate based on a predetermined product circumference and an average stretch-to-stop roll profile;
inputting the diameter of the roll of elastomeric material and the material feed rate in the unwind equation of the controller; and
unwinding a varying amount of material from the roll of elastomeric material at a varying unwind speed, the controller being responsive to the unwind equation to vary the unwind speed for forming a plurality of products, each product defining a respective circumference substantially equal to the predetermined product circumference.
2. The method of unwinding as in claim 1 , wherein the controller is selected from the group consisting of a computer, a programmable logic controller and combinations thereof.
3. The method of unwinding as in claim 1 , wherein the material feed rate is defined as the predetermined product circumference/([(the average roll stretch-to-stop profile/100%)+1]×2).
4. The method of unwinding as in claim 1 , wherein the respective circumferences are one of a waist opening circumference, a hip circumference or a leg opening circumference.
5. The method of unwinding as in claim 1 , wherein the respective circumference is within a predetermined margin of error of the predetermined product circumference.
6. The method of unwinding as in claim 5 , wherein the predetermined margin of error is from about 0.05% to about 5%.
7. The method of unwinding as in claim 1 , further comprising the step of sampling a plurality of roll diameters of a plurality of elastomeric rolls to determine the average stretch-to-stop roll profile.
8. The method of unwinding as in claim 1 , further comprising the step of sampling a plurality of roll diameters of a plurality of elastomeric rolls from batch to batch, deckle to deckle, or lane to lane within a deckle to determine the average stretch-to-stop roll profile.
9. The method of unwinding as in claim 1 , further comprising the step of loading the controller with a statistical analysis program, the statistical analysis program being configured to implement the unwind equation.
10. The method of unwinding as in claim 1 , further comprising the step of sensing the diameter of the roll of material with a roll diameter sensor, wherein the sensor is selected from the group consisting of a laser, an electro-optic sensor, an acoustic sensor, an electromagnetic sensor or combinations thereof.
11. A method of unwinding material in a process system for producing a product, the method comprising the steps of:
determining an average stretch-to-stop roll profile;
loading a roll of elastomeric material in an unwind system;
sensing a diameter of the roll of elastomeric material;
programming a controller with an unwind equation, the controller in communication with the unwind system;
computing a material feed rate based on a predetermined product circumference and the average stretch-to-stop roll profile;
inputting the diameter of the roll of elastomeric material and the material feed rate in the unwind equation of the controller; and
unwinding a varying amount of elastomeric material from the roll of elastomeric material at a varying unwind speed, the controller being responsive to the unwind equation to vary the unwind speed for forming a plurality of products having substantially similar circumferences.
12. The method of unwinding as in claim 11 , wherein the controller is selected from the group consisting of a computer, a programmable logic controller and combinations thereof.
13. The method of unwinding as in claim 11 , wherein the material feed rate is defined as the predetermined product circumference/([(the average roll stretch-to-stop profile/100%)+1]×2).
14. The method of unwinding as in claim 11 , wherein the circumferences are one of a waist opening circumference, a hip circumference or a leg opening circumference.
15. The method of unwinding as in claim 11 , wherein the circumferences are within a predetermined margin of error of the predetermined product circumference.
16. The method of unwinding as in claim 15 , wherein the predetermined margin of error is from about 0.05% to about 5%.
17. The method of unwinding as in claim 11 , further comprising the step of sampling a plurality of roll diameters of a plurality of rolls to determine the average stretch-to-stop roll profile.
18. The method of unwinding as in claim 11 , further comprising the step of programming the controller with a statistical analysis program, the statistical analysis program being configured to implement the unwind equation in the controller.
19. The method of unwinding as in claim 11 , further comprising the step of sensing the diameter of the roll of material with a roll diameter sensor, wherein the sensor is selected from the group consisting of a laser, an electro-optic sensor, an acoustic sensor, an electromagnetic sensor or combinations thereof.
20. A process system for unwinding material to produce a product, the process system comprising:
an open-loop unwind system for unwinding a roll of elastomeric material;
a sensor for sensing a diameter of the roll of elastomeric material disposed in the open-loop unwind system; and
a controller in communication with the open-loop unwind system and the sensor, the controller being configured for programming with an unwind equation for compensating through-roll variability, the unwind equation being populated with the diameter of the roll of elastomeric material and a material feed rate as a function of a predetermined product circumference and an average stretch-to-stop roll profile, the unwind equation of the controller being configured to vary an unwind speed of the open-loop unwind system such that a varying amount of material from the roll of material is unwound for forming a plurality of products, each product defining a respective circumference substantially equal to the predetermined product circumference.
21. The process system as in claim 20 , wherein the controller is one of a computer or a programmable logic controller, and further comprising a statistical analysis program being configured to implement the unwind equation in the controller.
22. The process system as in claim 20 , wherein the material feed rate is defined as the predetermined product circumference/([(the average roll stretch-to-stop profile/100%)+1]×2).
23. The process system as in claim 20 , wherein the respective circumference is one of a waist opening circumference, a hip circumference or a leg opening circumference.
24. The process system as in claim 20 , wherein the respective circumference is within a predetermined margin of error of the predetermined product circumference.
25. The process system as in claim 20 , wherein the sensor is selected from the group consisting of a laser, an electro-optic sensor, an acoustic sensor, an electromagnetic sensor or combinations thereof.