Expander roll specialist
Osaka Senshoku Machinery Co., Ltd.
With over 70 years of specialized technology and experience, we eliminate wrinkles and shrinkage in films, paper, metal foils, and nonwoven fabrics.
Osaka Senshoku Machinery Co., Ltd.
Practical skills for real-world situations!
Optimal installation methods and adjustment points for expander rolls
In manufacturing lines for films, paper, nonwoven fabrics, and other materials, the "correct installation method" of expander rolls is crucial for reliably preventing wrinkles and creases. We will introduce the optimal installation procedures and key points to maximize wrinkle removal effectiveness, based on various on-site standards from both domestic and international sources.
Maximize the effect!
The golden ratio of installation distance (path line)
Setting the distance (path line) between the expander roll and the roll before and after the roll is the most important factor directly related to the widening effect.
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The exit distance (distance A to the next roll) should be short. The distance from the sheet that has passed through the expander roll to the next roll it touches should be as short as possible.
As a guideline, an optimal distance is considered to be approximately 2.5 times the diameter of the expander roll.
If this distance is too long, the sheet that has been widened may shrink or wrinkle again before it reaches the next roll.
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The entry distance (distance B from the previous roll) is long, and the distance from the previous roll to the expander roll is longer than the exit distance.
The optimal length is approximately two to three times (or more) the exit distance.
If the distance is too close, it can hinder the width-extending effect of the expander roll.
Conversely, if the sheet is too long, it can cause the sheet to slip, leading to accelerated wear of the rubber on the roll surface, so caution is necessary.
Contact angle (winding angle) and how to thread the web
Because the curvature of the roll is used to smooth out wrinkles, there are strict theories regarding the entry angle and method of passing the sheet (web).
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Entry from the concave side: The sheet should always enter the roll from the concave side.
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Equalizing entry and exit angles: As a basic setting to prevent wrinkles, the entry and exit angles are made identical.
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Adjusting the contact angle (wound angle) to suit the material: The optimal contact angle (wound angle) varies depending on the material and its thickness.
For example, paper and cardboard require a temperature of 15-30 degrees Celsius, typical films (PP and PA) of 8-20 microns require 45-60 degrees Celsius, and ultra-thin films of 1-6 microns require 60-90 degrees Celsius. Fine-tuning is necessary depending on the material.
Thorough horizontal and parallel alignment
The precision of the alignment (positioning) when attaching it to the machine frame also affects the success of wrinkle removal.
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Maintaining right angles and horizontal alignment: Position the roll so that it intersects the sheet (web) horizontally and at a right angle.
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Parallelism and Centerline Alignment: Parallelism to the front and rear rolls, as well as precise alignment of the centerlines, are essential requirements.
Quotation and technical consultation
We will propose the optimal roll to meet your specific needs. Please feel free to contact us for specification consultations or quotation requests.
Strengths of our expander roll and support system
Osaka Dyeing Machinery's expander rolls can be used in either left-hand or right-hand rotation direction. The rubberized surface has strong resistance to dyes, pigments, acids, alkalis, and other chemicals.
Furthermore, it boasts excellent heat resistance and abrasion resistance, ensuring stable performance over long periods even in harsh field environments.
Why not test its effectiveness on an actual production line?
We will propose the optimal roll to meet your specific needs. Please feel free to contact us for specification consultations or quotation requests.