Blog Archives

Part 1: Seven Common Web Spreading Systems

Is your spreader functioning properly?

Spreaders are found on most converting machines. Their most common role is to flatten a web prior to a critical process such as coating, embossing, laminating, printing, slitting, winding and so on. Sometimes spreaders are needed to reduce wrinkling so that a web might merely cross a roller without creases and foldovers. Spreaders are also used to separate slit webs prior to winding and to permanently widen some nonwoven products.
[caption id="attachment_2647" align="alignright" width="200"]Web Spreading Spreader Streamlines Figure 1 -...
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Part 2: Concave Web Spreading Rollers

The Concave Web Spreading Roller is the Simplest and Least Expensive

[caption id="attachment_2648" align="alignright" width="200"]Web Spreading Concave Spreader Roller Figure 2 - Concave Spreader Roller[/caption] The simplest and least expensive spreader is the Concave Web Spreading Roller (sometimes called a Bowtie Web Spreading Roller). As seen in Figure 2, this spreader is a conventional spreading roller whose diameter at the ends is slightly greater than at the center. In its ideal configuration, the diameter profile of the roller is cut as an arc of a circle. However,...
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Part 3: Bowed Web Spreading Rollers

Traction is Vital for the Bowed Web Spreading Roller

[caption id="attachment_2649" align="alignright" width="200"]Web Spreading Bowed Roller Figure 3 - Bowed Roller[/caption] Bowed Web Spreading Rollers, as seen in Figure 3, have a curved stationary axle upon which a rotating sleeve(s) are mounted over numerous bearing sets. The axle may have either a fixed or variable bow. The sleeve is typically a one-piece flexible tube of a soft synthetic composite, or may consist of numerous narrow metal shells. The amount of bow is very important because too little will reduce...
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Part 4: Bent Pipe and D-Bar Web Spreading Rollers

Simple Construction Makes Bent Pipe Spreading Roller Popular

[caption id="attachment_2651" align="alignright" width="200"]Web Spreading D-Bar Spreader Figure 5 - D-Bar Spreader[/caption] The popularity of the Bent Pipe Web Spreading Roller lies with its simple construction. Unfortunately, this simplicity often leads to crude manufacturing practices and dubious spreading qualities. A D-bar spreader takes its name from the characteristic 'D' cross-section of the bar as seen in Figure 5. The only functional difference between a D-bar and bent pipe spreader is that the D-bar's shape can be adjusted by intermediate...
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Part 5: Dual Spreader Rollers

Dual Spreader Rollers used on Narrow Slit Webs

[caption id="attachment_2652" align="alignright" width="200"]Dual Bowed Spreader Roller Figure 6 - Dual Bowed Spreader Roller[/caption] There are several types of Dual Spreader Rollers that are occasionally used for the spreading of narrow slit webs. The Dual Bowed Spreader Roller, as seen in Figure 6, consists of two bowed rollers pointing perpendicular to the ingoing and outgoing web runs. The amount of spread may be adjusted by pivoting the spreaders or by changing bow magnitudes. [caption id="attachment_2653" align="alignright" width="200"] Read more

Part 6: Expander Web Spreading Rollers

Expander Web Spreading Rollers Operate Successfully in Traction

[caption id="attachment_2654" align="alignright" width="200"]Expander Web Spreading Rollers Figure 8 - Expander Web Spreading Rollers[/caption] Expander Web Spreading Rollers, as seen in Figure 8, have shells that stretch outward from the centerline as the web transits from the ingoing to outgoing tangents. In one version, cam operated half-width slats slide at their junction in the middle. Another version has numerous elastomeric bands connecting across the width to adjustable cams on each end. Finally, another variant has a very flexible cover...
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Part 7: Edge Pull Web Spreading Rollers

Edge Pull Web Spreading Roller are the most powerful spreaders, and are sometimes capable of increasing web width by hundreds of percent.

Edge Pull Web Spreading Rollers are the most powerful spreaders, and are sometimes capable of increasing web width by hundreds of percent. Obviously, strains this large are limited to very stretchy materials such as films, nonwovens and textiles. Indeed, the intent may be to draw the web permanently wider. [caption id="attachment_2655" align="alignright" width="200"]Edge Pull Web Spreading Roller Figure 9 - Edge Pull Web Spreading Roller[/caption] Edge...
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Part 8: Benefits of Web Flattening without Web Spreading Rollers

Web Flattening

As we've seen, Web Flattening with Web Spreading Rollers is an active process which temporarily forces a web to be wider than it would like to be. However, Web Spreading Rollers are expensive and are not always required if Web Flattening would suffice. Web flattening is a passive process which allows the web to be as wide as it would prefer to be. [caption id="attachment_2656" align="alignright" width="200"]Web Spreading A Wrinkle Crossing A Roller Figure 10 - A Wrinkle Crossing A Roller[/caption] Web Flattening works on the...
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