A plug wrap paper specification sheet can look like a dense list of numbers, but each line describes something that affects how the paper runs on the machine and how the finished filter performs. This article walks through the main parameters in four groups so buyers know what to check, what to ask for, and how to compare suppliers.
Physical Specifications
The basic physical parameters define the paper as a material and determine whether it fits the filter rod maker.
| Parameter | What It Describes | Why It Matters |
|---|---|---|
| Basis weight | Mass per unit area | Affects stiffness and rod firmness |
| Thickness | Sheet caliper | Influences rod diameter and seam overlap |
| Width and reel size | Slit width, reel diameter, core size | Must match the machine and the target rod circumference |
Width in particular is not flexible: a reel that is slightly off the target can cause wrapping problems regardless of how good the paper is in other respects.
Air Permeability and Porosity
Air permeability is usually the most closely watched figure on the sheet. It describes how readily air passes through the paper and is typically reported in CORESTA units. It influences airflow through the filter and, in turn, draw resistance and filtration behavior.
Read the Tolerance, Not Just the Target
Permeability is normally expressed as a nominal value with an allowed range. Two suppliers may quote the same nominal figure, but the width of the permitted range says more about how tightly each one controls production.
Strength and Processing Properties
Plug wrap paper runs through filter rod makers at high speed, so mechanical properties determine whether it runs smoothly. Tensile strength, measured in both machine and cross directions, indicates how well the web withstands tension without breaking. Elongation shows how much it stretches under load, which affects wrinkling and registration.
Surface condition also matters. The seam is closed with adhesive, so the paper must accept glue consistently. A surface that is too sealed or too uneven can lead to weak seams or visible defects in the finished rod.
Consistency, Testing, and Evaluating a Supplier
A specification is only useful if each delivery matches it. Batch-to-batch variation, especially in permeability, shows up directly as inconsistent draw resistance in the finished product, which is why consistency often matters more than any single figure on the sheet.
When evaluating a supplier, it is reasonable to ask for a batch test report with each shipment, confirmation of the test methods used, retained samples for later comparison, and agreed tolerances written into the purchase specification. These items turn a parameter list into an enforceable standard.
If no standard grade fits the target, a manufacturer with in-house development capability can adjust basis weight, permeability, and surface properties together. Sharing the filter design and machine conditions up front shortens the path to a workable sample.
Reading a plug wrap specification well means looking past the headline numbers to the tolerances, the processing properties, and the supplier's ability to repeat them. Buyers who ask these questions early tend to avoid the most common sourcing problems later.
