Multiflex® G 60 A 11 BT 13893 Thermoplastic Elastomer

• Excellent compression set
• Colorable
• Natural color
• Standards approvals: CSTB
• Compatibility: PP/PE

Multiflex® brand Automotive GT Range is based on styrenics thermoplastic elastomer, designed for high compression set applications. Compatibility with polyolefins enables bi-material parts (continuous process or cold insert).
Please find below some indications to follow to transform the product. This does not replace molder experience, every mold having its own specificity, but this is useful for initial parameter choice.

Background

Multiflex® Automotive GT Range can be transformed between 190°C to 230°C. In this temperature range, materials are stable, above, thermal degradation occurs, resulting in yellowing and significant odor emanation.

Pre-drying

Multiflex® Automotive GT Range is not humidity sensitive, Pre-drying is not needed. In case of "incident", predrying at 80 - 90°C during 1 to 2 hours is sufficient.

Machinery cleaning

High flow thermoplastic must be used, PEHD, PELD or PP.

Coloring

Multiflex® Automotive GT Range is easily colorable by using color masterbatch based on PP, PE or ethylene copolymers (EVA).

Recycling

Multiflex® Automotive GT Range is 100% recyclable without properties loss. We recommend a maximum level of 10% of recycling material in virgin material.

Injection

On a general point of view, viscosity of SEBS based material is principally dependent of applied shear, so Multiflex® Automotive GT Range must be injected with high injection speed. Due to their high fluidity, easy mold feeding for single or multiple cavities geometries are possible.

Processing parameters

Screw: Geometry: standard injection machine, L/D > 20, compression rate 2:1 to 3:1 (if higher, risk of thermal degradation). A screw speed between 100 to 150 rpm, ensures thorough melting of the material without excessive temperature generation. Start with 120 rpm.

Back pressure

Must be between 7 and 15 bars. This will ensure a uniform melt without severe shear heating.

Temperatures (°C)

See Figure 1.

Feed Zone: 160 +/- 10
Zone 1: 190 +/- 10
Zone 2: 200 +/- 10
Nozzle: 210 +/- 10

Figure 1: Injection molding processing temperatures

Injection speed

Injection speed and fill time are highly dependent on part geometry, complexity and gate design. Faster speeds typically result in easier mold filling, while lower speeds result in better surface appearance. Start with an injection speed around 70% of maximum speed.

Holding pressure

Start with a pressure equivalent to 30% of maximum injection pressure. Excessive holding pressure can result in distortion in the area of the gate due to elastomeric characteristics of the material.

Holding time

Three seconds can be used to start to ensure sufficient time for gate freeze off. Holding time can be slowly reduced until changes in part appearance or weight occur.

Mold

Use conventional mold design (venting, finish, draft) with temperatures from 10 to 60°C. In the range of 40°C typically gives good results.

Hot Runners

Apply a temperature of 190°C +/- 10.

Extrusion

Multiflex® Automotive GT Range can be processed on all extrusion machines for PVC, polyolefin. A screw, with a compression ratio of 3 is recommended.

Temperatures (°C)

See Figure 2.

Feed Zone: 160 +/- 10
Zone 1: 180 +/- 10
Zone 2: 190 +/- 10
Die: 200 +/- 10

Figure 2: Extrusion processing temperatures

This product is neither tested nor represented as suitable for medical or pharmaceutical uses.

This product is available in a variety of container sizes.

Containers should be kept tightly closed and kept in cold storage at all times to extend shelf life. Shelf life is indicated by the Use Before date found on the product label.