A test plan for evaluating a bio-based sheet sample

A sample arrives, and the temptation is to bend it, pull it and decide. A better evaluation starts before the parcel is opened. This note gives a staged test plan for an R&D team handling a bio-based sheet sample, such as the one Kora has listed. It is deliberately about method. Kora has not published test data for its sheet, and nothing here predicts a result.

Stage 0. Write the requirement before the test

Take the product the material is meant for and list what it must do. Express each need as a measurable property with a pass level. For example:

• the sheet must survive a stated number of flex cycles without cracking;
• it must keep its surface after a stated abrasion exposure;
• it must not absorb more than a stated amount of water;
• it must reach a stated tensile load at the thickness used.

The levels come from your product, your customer or your current material. If you do not have them, take a sample of the material you currently use and test it by the same methods, so that you have a benchmark.

Stage 1. Check what arrived

Record the sample before any test:

• identification and batch information from the supplier;
• thickness at several points, and size;
• weight per area;
• visible condition: colour variation, surface defects, edges;
• how it was packed and how long it was in transit.

This costs little and protects you from drawing conclusions from a damaged or atypical piece.

Stage 2. Screening tests

Run quick, cheap tests to see whether the material deserves the full programme.

1. Flex by hand and with a simple rig. Look for cracking and surface change.
2. Water exposure. Weigh before and after a stated soak and drying cycle, and note any change in feel or shape.
3. Rub test. A basic rub with a standard cloth, dry and damp.
4. Process trial. Cut, stitch, bond and print a small piece the way you would in production.

Write down conditions, since screening results are only comparable if conditions are the same each time.

Stage 3. Standard method tests

For the properties that matter, use recognised methods and, where you can, an accredited laboratory. Standard methods exist for tensile strength, flex endurance, abrasion resistance and water absorption of sheet materials used in leather goods. Pick the ones that your customers or your market already accept, and state the method number in the report. Test several pieces from the sample, and note which direction you cut them.

Stage 4. Application test

Make a small number of finished items or a part of one and test them as the user will: carried, folded, wiped and worn. A material can pass every laboratory test and still fail in the actual product, because the assembly, the stitching and the adhesive all take part.

Stage 5. Decide, and say why

Give the result in three states:

• go: the material meets the pass levels, and you proceed to a larger trial;
• go with conditions: it meets most levels, and the missing ones are specified;
• no go: it does not, and the failure is described.

Each state should come with the data, so that a colleague can follow the decision later.

Stage 6. Share the result with the supplier

Supplier and buyer both benefit from a shared result. Kora is open to R&D partners who test samples against their own requirements, develop an application and help define a first test plan. Tell the supplier what failed and what passed. Agree beforehand who may use the data and whether it stays confidential.

What to expect from Kora today

Kora has not published a test result, a composition or a product status for the sheet, so a test plan from you is likely to be the first systematic data. That is a reason to be precise: record the method, the conditions and the sample identification for every test.

Start with a note

If you want to begin testing a bio-based sheet sample, write to us through the sample interest page or the contact page with your application, the properties you must measure and the tests you can run. We reply within two business days.