Related Information

Before measuring PA6 samples with the VM-E01, you may also want to know:

Common Questions About PA6 and Plastics

WKT-A9 Karl Fischer Trace Moisture Analyzer Coulometric

Reference Value Determination

The PA6 reference moisture value was determined with the VicoMeter WKT-A9 Karl Fischer moisture analyzer and WKT-V2 Karl Fischer oven; released moisture is carried by dry nitrogen into the electrolytic cell.

Recommended Settings for Plastics Industry Samples

If you have no reference method for plastics samples on the VM-E01, VicoMeter recommends these settings from experimental experience:

• Heating mode: Standard

• Shutoff mode: Automatic (1 mg/140 s)

• Sample size: 30 g

• Resolution: High (0.1 mg/0.0001 g)

• Warm-up: standby, 100°C; at standby temperature, preheat the empty pan for 1 minute, then tare.

Selecting the Drying Temperature

Figure 1: Same Sample Heated at Different Temperatures

(Click image to enlarge)

Choose a drying temperature matching the Karl Fischer reference value. Melting or marked color change means the temperature is too high. Some samples inevitably discolor when heated (polyamide unavoidably turns brown).

Figure 1 compares samples after two heating runs. Left: correct temperature — no melting or discoloration. Right: the sample browned, so the temperature was too high.

Plastic Sample Handling

Measure samples promptly. Otherwise, fill the container completely (use a smaller one if needed) and seal it to minimize air and prevent moisture uptake during storage.

Operating Steps for PA6 (Nylon 6, Polyamide 6) Samples

Place the VM-E01 in a suitable spot, warm up 30 min, level it (bubble centered), and perform weighing and temperature calibration. Then measure PA6 samples (installation, environment, warm-up, calibration: seePreparation Before Formal Measurement with a Halogen Moisture Analyzeras discussed in that article; click the link to learn more.).

Tare Sample Pan

1. Place the empty pan on the center holder, preheat 1 min at 130°C standby, press tare to zero.

Add Sample

2. Quickly spread about 30 g of PA6 sample evenly on the pan; wait for a stable reading.

One-Touch Start

3. Press start; the PA6 moisture result appears within minutes.

Test Data

VM-E01 Halogen Moisture Analyzer（0.1mg/0.0001g）

VM-E01 Settings Reference

• Heating mode: Standard

• Heating Temperature: 130°C

• Shutoff mode: Automatic (1 mg/140 s)

• Sample size: 30 g

• Resolution: High (0.1 mg/0.0001 g)

• Warm-up: standby, 100°C; at standby temperature, preheat the empty pan for 1 minute, then tare.

Sample Information

• Sample 1 Description: PA6, beige, medium viscosity.

• Sample 2 Description: PA6, gray, good flowability, easy processing, good sliding friction.

• Beige Sample 1 Typical Maximum Allowable Moisture Content [%]: 0.2

• Gray Sample 1 Typical Maximum Allowable Moisture Content [%]: 0.15

• Beige Sample 1 Hygroscopicity (23°C/50% rH) [%]: 2.3

• Gray Sample 2 Hygroscopicity (23°C/50% rH) [%]: 3

Sample 1: Moisture Chart for Beige PA6 Before and After Drying

Sample 2: Moisture Chart for Gray PA6 Before and After Drying

Chart Notes

Sample 1: Moisture Data for Beige PA6 Before and After Drying

Sample 1: Moisture Data for Gray PA6 Before and After Drying

Sample-Specific Test Notes

Maximum allowable moisture for pellet processing must always follow supplier specifications. Values here are typical only and may not suit your material or process.

These drying parameters were obtained on common plastics and do not cover all grades or colors; optimizing them may be needed for best results on a specific material.

Dr. Wei's Classroom

Nylon 6 (PA6, polyamide 6) is a high-molecular-weight compound similar to nylon 66, but with a lower melting point and wide processing window. Its impact and solvent resistance exceed nylon 66, but it is more hygroscopic — a key design factor. Modifiers improve its mechanical properties: glass fiber is most common; synthetic rubbers (EPDM, SBR) add impact resistance. Unfilled PA6 shrinks 1%–1.5%; glass fiber reduces it to 0.3% (slightly more transverse to flow). Shrinkage depends on crystallinity, moisture uptake, part design, wall thickness, and process parameters. Drying before molding: PA6 absorbs moisture readily — keep moisture-proof packaging sealed; if moisture > 0.2%, dry 16 h in hot air above 80°C; if air-exposed over 8 h, vacuum dry at 105°C for 8+ h.