Tension controller with taper for rewinding (reducing winding tension as the roll diameter grows)
The taper function of a rewind tension controller · lowering tension as the roll grows so warm or extensible material does not telescope the roll or crush the core, measured or calculated roll diameter, how a taper percentage is applied, and linear, hyperbolic, hybrid and parabolic taper profiles
A rewind tension controller holds the web tension set for winding. On a centre-wound roll, keeping that tension constant all the way to full diameter builds up pressure in the inner wraps, so controllers offer a taper function that reduces tension as the roll grows. How the taper is defined, where the diameter comes from and which profile shape is used decide whether the roll comes off sound.
Tension controllers with taper (diameter-dependent tension reduction) for rewinding web, film, foil, paper and similar materials. Web tension control as a closed-loop system is covered on the Web tension control: follow the force and the feedback page; coil winding wire tensioners on the Wire tensioner for coil winding page; wire pay-off dancers on the Wire pay-off tensioning system for spring coilers, wire benders and nail machines: dancer arm, turntable drive and brake page; electrode calender tension on the Web tension control system (front and back tension around the nip of a battery electrode calender) page.
CNFX editorial research · Sources checked October 13, 2026 · 3 sources
Why tension is tapered, and how a taper percentage works
Jonathan Wilcox of Montalvo (2015) writes that when centre winding film or other extensible material, "If you maintain a constant tension on the web, as the diameter of the roll increases, the wraps become tighter"; warm film from a dryer stretches more, and as it cools it shrinks and "either telescopes the roll or crushes the core". [1]
Montalvo's controllers vary rewind tension inversely with roll diameter using a taper percentage: when the diameter doubles, tension drops by half the taper percentage of the initial tension, then by a further quarter at the next doubling and a further eighth at the next. Its example: 80 lb initial tension with 40% taper gives 64 lb at twice the starting diameter. [1]
Editorial calculation from that rule: at four times the starting diameter the drop is 20% + 10% = 30% (56 lb), and at eight times 35% (52 lb). Montalvo prefers measured diameter, from an ultrasonic sensor or two pulse tachometers, at better than 1%, against about 5% for the controller's internal diameter calculation, and says the amount of taper is "mainly a trial and error operation". [1]
Give the controller supplier the material, core and maximum roll diameters, starting tension and whether a lay-on roll is used, and ask how its taper percentage is defined and whether diameter is measured or calculated.
02
Linear, hyperbolic, hybrid and parabolic taper profiles
C. W. Lee, J. W. Lee, K. H. Shin and S. O. Kwon (Konkuk University and Sung An Machinery, KSPE spring conference 2007, in Korean) describe linear taper, which lowers tension in a straight line, and hyperbolic taper, which lowers it along a curve, as the two usual methods. On OPP film 0.02 mm thick and 1,010 mm wide, they found telescoping concentrated in the early part of winding and smaller with linear taper, while hyperbolic taper gave a more stable radial stress inside the roll; their hybrid profile was proposed to combine the two. [2]
Changwoo Lee (Changwon National University, J. KSPE 2014) writes that internal stresses in centre-wound rolls can cause buckling, spoking and cinching, and proposes a parabolic taper profile. He reports that with smaller maximum winding ratios the hyperbolic profile has difficulty converging to the set taper value, whereas the parabolic profile converges even then. [3]
Ask whether the controller offers only a fixed taper law or selectable profiles, and plan trial rolls on your material to set the taper amount.
03
Rewind taper tension controller details
Paste it into your enquiry below or into an email to a maker, then replace every bracket.
3 companies list this product among what they make. Company figures are quoted from each
company's own website; every card states where the relationship came from.
Precision Converting Co.,Limited
Manufacturing site to be confirmed for the order
Lists an automatic tension controller on its own website; ask whether taper and diameter measurement are included.
Explore company information and manufacturing capabilities, then discuss the scope of your project with a relevant supplier.
Share this page
Compiled and source-reviewed by the CNFX editorial team.
Each manufacturer above links to the page on that company's own website where the product is listed, with the date we checked it. How we source and review
· Page last updated 13 October 2026
Buyer questions
Why reduce tension as the roll grows?
Montalvo explains that constant tension tightens the wraps and, with extensible film, can telescope the roll or crush the core. [1]
What does a 40% taper do?
In Montalvo's controllers, 80 lb falls to 64 lb when the diameter doubles. [1]
Which taper profile limits telescoping?
Lee et al. found telescoping smaller with linear taper early in winding; hyperbolic gave more stable radial stress. [2]
How accurate is calculated diameter?
About 5% for Montalvo's internal calculation against better than 1% with external sensors. [1]
Sources and what still needs a direct check
Sources checked 2026-10-13. Montalvo publishes its taper tension note (2015); the Korean Society for Precision Engineering published the 2007 conference paper by C. W. Lee et al. and the 2014 journal paper by Changwoo Lee (both in Korean, read through KoreaScience).
