Compare tensile results only after checking the test direction, method, specimen dimensions, conditioning and reported quantity. MD and CD describe different directions in the material. A larger breaking-force number does not, by itself, prove that one facer is better for converting, bonding or finished-board performance.
The buyer’s question is straightforward: are these two data-sheet values genuinely comparable, and what do they tell us about the intended facer application?
This guide provides a report-reading framework. It does not set a minimum tensile value for GRECHO materials or prescribe a test method for every coated, woven or reinforced construction.
Read the direction before the number
EDANA defines machine direction as the length direction in which the fabric is produced. Cross direction is perpendicular to it within the plane of the fabric. These are commonly abbreviated MD and CD. [1]
Keep those labels attached to both the sample and the result. A detached square specimen may no longer make its original running direction obvious. Ask for a direction mark rather than assigning MD to whichever cut edge happens to be longer.
Never average MD and CD into one unlabelled “strength” figure. The two results answer different directional questions. Nor should the labels be treated as a rule that MD must always be stronger; they identify orientation, not a guaranteed ranking.
Establish what was actually measured
A report may use the heading “tensile strength” while displaying a breaking force in newtons for a specified strip. Another may show force per unit width, elongation at break, or a result from a different specimen arrangement.
ISO 9073-3:2023 addresses strip testing of nonwovens for breaking force and elongation in conditioned or wet states. ISO 9073-18:2023 addresses a grab method. Naming both methods does not make their results interchangeable. [2][3]
Before comparing values, fill in the following fields from the reports rather than from assumptions.
| Report field | What to record | Why it belongs in the comparison |
|---|---|---|
| Material tested | Actual facer reference, coating and reinforcement, where relevant | The base web and finished facer are not automatically the same specimen |
| Direction | MD or CD, with sample orientation | Avoids comparing different directions |
| Method | Standard, edition and stated procedure | Separates strip, grab and other test arrangements |
| Specimen and setup | Width, gauge length and test speed as reported | Makes differences in the test setup visible |
| Conditioning | Conditioned/dry or wet state and reported treatment | Prevents an unlabelled comparison of different states |
| Quantity | Breaking force, force per width, or elongation, with unit | Prevents a number from being detached from its meaning |
| Summary basis | Individual result, mean, minimum or declared specification | Avoids comparing a typical average with a guaranteed limit |
If a field is missing, mark it “not reported”. Do not fill it with a familiar value from a different test procedure.
Unit conversion is not method conversion
Converting newtons to another force unit changes the expression of a result. It does not reconstruct the experiment.
Illustrative comparison—not GRECHO product data: Report A states 120 N for an MD specimen 50 mm wide. Report B states 80 N for an MD specimen 25 mm wide. Dividing the force by width gives 2.4 N/mm and 3.2 N/mm respectively. That arithmetic does not establish that B is the better facer: the reports still need compatible procedures, conditioning and specimen construction, and width-normalisation is not proof that results scale linearly across different test arrangements.
The same discipline applies to elongation. A percentage needs its reported method and measurement basis. Do not treat it as the amount of stretch that a production line can safely impose.
Separate a material result from a production decision
A tensile report can be useful in material review without being a complete runnability test. For the proposed board trial, ask which decision it supports: comparison of identified lots, review of a handling concern, or checking a supplier-declared characteristic.
It does not directly establish facer-to-core adhesion, resistance to a local cut or puncture, or finished-panel performance. Those questions require evidence suited to the relevant mechanism and specimen.
For a reinforced construction, first confirm what was tested. Was the specimen the reinforcement alone, the coated facer alone, or the complete composite? Commercial options belong in the reinforced composite facer route; tensile data should support that review rather than replace it with a single-number ranking.
Make the next request specific
Instead of asking for “a stronger facer”, state the application, the observed concern and the comparison that is needed. A useful request might read:
“Please confirm whether the attached MD and CD figures refer to the supplied composite or its base web. Provide the method, specimen width, conditioning, result type and any declared acceptance limit that applies to this reference.”
That request asks for traceable information without inventing a specification. Where data cannot be aligned, propose a side-by-side review using an agreed method and identified materials. The testing party should confirm that the method is suitable for the actual construction.
The technical-document request guide explains how to distinguish a data sheet from a supporting test report.
Frequently asked questions
Is the highest MD result always the best choice?
No. First compare like-for-like reports, then relate the results to the application. A high directional breaking force does not answer every handling, bonding or board-performance question.
Can a grab result replace a strip result?
Not automatically. They are different test arrangements. Request the method and procedure and avoid a direct ranking unless the comparison has a justified technical basis. [2][3]
Should wet and conditioned results be combined?
Keep them separately labelled. They describe different specimen states and should not be merged into an unqualified material value.
Request a scoped data review
GRECHO supports selected facer evaluation and technical documentation coordination. Identify the board application and the reported values you need to compare.
Request technical data review from GRECHO.
References
[1] EDANA — Nonwovens glossary: machine and cross direction.
[2] ISO 9073-3:2023 — Strip tensile testing, public method scope.
[3] ISO 9073-18:2023 — Grab tensile testing, public method scope.
The standard references identify test scope. This article does not reproduce the complete procedures or establish that every facer construction falls within their applicability.
