MILASTOMER™

Thermoplastic Vulcanizate (TPV)

Usage detail

A low density, heat and chemical resistant, olefin-based TPV offering rubber elasticity at higher service temperature, in automotive and appliance parts, building materials, and sporting goods.

Usage
Characteristic
  • Introduction
  • Characteristics
  • Applications

MILASTOMER™ is a Thermoplastic Vulcanizate (TPV) elastomer, derived from olefin-based rubber and polyolefin resin. MILASTOMER™ TPVs offer the sustainability benefits of a polyolefin with the durability and flexibility of a vulcanized rubber. Produced with the olefin polymerization and synthetic rubber technology of Mitsui Chemicals, MILASTOMER™ does not require compounding or vulcanization. It is a thermoplastic resin that can be extruded, or molded into flexible parts. MILASTOMER™ is available in standard black, or in natural grades that can be easily colored.

MILASTOMER™ key performance benefits:

  • Light Weight – density less than 900 kg/m3
  • Heat Resistance – Higher softening temperature than other elastomers
  • Rubber Elasticity – Deformation recovery superior to vulcanized rubber in long-term compression set
  • Weatherability – MILASTOMER™ B (black) grades may be used outdoors over the long-term
  • Secondary Processing – Outstanding vacuum forming, thermal adhesiveness, and coating performance

There are many grades of MILASTOMER™ available, ranging from flexible grades comparable to vulcanized rubber to semi hard grades comparable to low density polyethylene. Grades of MILASTOMER™ are available with unique characteristics, to suit specific applications.

Dashboard Skin
Axle Boots
Door Trim and Weather Seals

Processing

Milastomer™, thermoplastic Vulcanizate (TPV), contains no hygroscopic filler, so there is no need to dry prior to processing. The material can be processed using injection or extrusion molding.

Injection Molding

Milastomer™ has good fluidity and low crystallinity, enabling the development of products with nice aesthetics because it is difficult for sink marks to form at ribs and parts with uneven thickness, and welds tend not be conspicuous. Spruces, runners, burrs, and scraps can be reused. The thermal stability of Milastomer™ is good and corrosive gases tend not to be produced even by thermal decomposition. General purpose molding machines are suitable for processing.

Machine: General purpose injection molding machine
Mold and shrinkage factor: Low hardness grades have fluidity inferior to high hardness grades necessitating the design of spruces, runners and gates to be shorter and larger. The mold shrinkage factor varies, depending on the processing conditions and product form, from 10/1000 to 16/1000.
Processing conditions: Standard processing conditions are shown below, however adjustments may be necessary dependent on product shape.
  Product wall thickness Cooling time
1 Cylinder temperature C1/C2/C3/N=200/220/220/220 (°C)
2 mm
3 mm
20 sec
30 sec
2 Die temperature 30-50 °C 4 mm 40 sec
3 Injection Speed Set comparatively slow 5 mm 50 sec
4 Cooling time Varies depending on product shape and die temperature. Product wall thickness and standard cooling times are given in the table at right.

Extrusion Molding

Milastomer™ has comparatively high melt viscosity, low temperature dependence of viscosity and relatively small die swell, facilitating extrusion molding of an odd shape with complex profile. Odd shapes with complex profiles are difficult to mold with conventional polyolefin resin.

Machine: A general purpose machine for polyolefin can be used. Ideal specifications are an L/D ratio of 24 or more, and a metering type screw with a compression ratio of 3-4. To obtain a good appearance, the resin must be adequately and uniformly plasticized by, for example, using a screen pack (80-120 mesh).
Dies:
Plate dies are used for odd shaped extrusion, and a land length of about 10mm is appropriate. Land length must be adjusting by engraving from the backside at thin-walled parts where it is difficult to achieve the desired shape.
Sizing Equipment (Calibrator):
Sizing equipment may have to be used, depending on the product shape and required dimensional precision.

Other

If you are considering other types of molding such as blow molding, calendar molding, thermal fusion bonding, vacuum molding, and foaming, please contact  Mitsui Chemicals America.

Density

Milastomer™ is the lightest general purpose elastomer material with a density of at most 900 kg/m3. By using Milastomer™ instead of ordinary vulcanized rubber, product weight can be reduced by about 30%.

Comparsion of Density

Heat Resistance

Milastomer™ is ideal for use in high temperature applications with a heat resistance superior to other elastomers.

Comparsion of Softening Temperature

Rubber Elasticity

Milastomer™ has outstanding rubber elasticity at high temperatures, with deformation recovery superior to vulcanized rubber in long-term compressing set testing.

Chemical Resistance

Excellent resistance to water, acids, alkalis, alcohols, acetone and vegetable oils. However, care must be taken because it is susceptible to attack by aromatic organic solvents, gasoline, and mineral oil etc.

Weatherability/Ozone Resistance

The B (Black) Grade of Milastomer™ has outstanding weatherabilty and is suitable for outdoor use. Both the B and N (Natural) grades have superior ozone resistance.

Electrical

Similar to polyethylene and polypropylene, Milastomer™ has outstanding electrical insulation performance.

The thermoplastic elastomer provides a wide range of performance, aesthetic and functional characteristics and is ideal for a variety of diverse applications including automotive, building material, and consumer goods.

Automotive Applications: Exterior Parts

The TPV material can be used in numerous automotive exterior parts ranging from weather seals, mud guards, and glass run channel.

Automotive Applications: Interior Parts

Milastomer™ is used in automotive interior parts ranging from interior skins, instrument panel and door trim.

Other Applications

Milastomer™ is used in building materials, sporting goods, appliance parts and daily consumer necessities.

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Contact Us

MITSUI CHEMICALS AMERICA, INC.
TEL+1 914-253-0777
FAX+1 914-253-0790