Related Information

Before learning how to measure TPE (thermoplastic elastomer) moisture with the VM-E01 halogen moisture analyzer and its operating procedures, you may also want to know the following:

Common questions about TPE and plastics

WKT-A9 Karl Fischer Trace Moisture Analyzer Coulometric

Reference Value Determination

In this test, the VicoMeter WKT-A9 Karl Fischer moisture analyzer was used to determine the reference moisture value of TPE (thermoplastic elastomer). Paired with the WKT-V2 Karl Fischer oven, the sample is transferred into the oven chamber and the released moisture is carried by dry nitrogen into the electrolytic cell for measurement.

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.

Procedure for measuring TPE (thermoplastic elastomer) samples with a halogen moisture analyzer

Place the VM-E01 rapid halogen moisture analyzer in a suitable location, switch it on and warm up for 30 min, level it (bubble centered), and perform weighing and temperature calibration. You can then start the TPE (thermoplastic elastomer) moisture measurement procedure (installation, operating environment, warm-up and calibration are covered inPreparation 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 135°C standby, press tare to zero.

Add Sample

2. Using a spatula, quickly and evenly spread about 30 g of TPE (thermoplastic elastomer) sample on the sample pan and wait for the reading to stabilize.

One-Touch Start

3. Once the reading is stable, press the start key. After a few minutes, the TPE (thermoplastic elastomer) moisture result is displayed on the screen.

Test Data

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

VM-E01 Settings Reference

• Heating mode: Standard

• Heating Temperature: 135°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 description: TPE, beige, high-modulus grade, with non-fading stabilizer.

• Typical maximum permissible moisture content [%]: 0.08

• Hygroscopicity (23°C/50% rH) [%]: 0.2

Moisture measurement chart of TPE (thermoplastic elastomer) samples before and after drying

Chart Notes

Moisture measurement data of TPE (thermoplastic elastomer) samples 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

Thermoplastic elastomers TPE/TPR, also known as artificial or synthetic rubber, combine the excellent properties of conventional cross-linked vulcanized rubber—high elasticity, aging resistance and oil resistance—with the easy, versatile processing of ordinary plastics. They can be processed by injection molding, extrusion and blow molding, and sprues and offcuts can be 100% directly recycled after grinding. This simplifies processing and lowers costs, making TPE/TPR the latest material to replace traditional rubber. Eco-friendly, non-toxic, comfortable to the touch and refined in appearance, it enables more creative products—a more human-centered, high-grade new synthetic material and a globally standardized eco-friendly material.

Thermoplastic elastomer, abbreviated TPE or TPR (thermoplastic rubber), is a class of elastomers that is rubber-elastic at room temperature and plastically moldable at high temperature. Structurally, it consists of resin segments and rubber segments with different chemical bonds: the resin segments form physical cross-linking points via interchain forces, while the rubber segments are highly elastic chains that provide elasticity. The physical cross-linking of the plastic segments changes reversibly with temperature, giving TPEs their thermoplastic processability. TPEs thus combine the physical-mechanical properties of vulcanized rubber with the processability of thermoplastics—a new polymer material between rubber and resin, often called the third generation of rubber.

Since Bayer first produced thermoplastic polyurethane (TPU) in 1958, TPEs have developed rapidly. Especially after styrenic TPEs appeared in 1963, the preparation theory was progressively refined and applications continued to expand.

Thermoplastic elastomers are a new polymer material between rubber and resin; they can partially replace rubber and also modify plastics. With the dual properties of rubber and plastic, TPEs are widely used in the rubber industry for everyday goods such as rubber shoes and coated fabrics, and for industrial products such as hoses, belts, strips, sheets, molded parts and adhesives. They can also replace rubber in large quantities for modifying general-purpose thermoplastics such as PVC, PE, PP and PS, and even engineering plastics such as PU, PA and CA, opening a new landscape for the plastics industry.