Polyester Elastomer PELPRENE™│TOYOBO Elastomers│ENPLA Department │TOYOBO


Discover PELPRENE™

  • PELPRENE™ is the commercial name for TOYOBO MC's thermoplastic polyester elastomers.
    PELPRENE™ is an engineering elastomer combining the features of rubbers and engineering plastics.

  *Values and properties listed here are typical values, not guaranteed values.

Topics List


Polyester Elastomer PELPRENE™

  • A comprehensive range of performance across four composition types
  • A wide range of hardness
  • Excellent oil and chemical resistance
  • Excellent bending fatigue resistance
  • Excellent low temperature properties
  • Compatible with injection, extrusion, and blow molding and more, offering a wide range of possibilites for applications


The chemical structure of PELPRENE™

  • PELPRENE™ P-Type

These general purpose grades have the best balance of properties like flexibility, cold resistance, and moldability

  • PELPRENE™ S-Type

This type offers middle and high hardness grades with heat aging resistance and weather resistance.


This type has excellent oil and chemical resistance and exceptional dimensional stability against heat.

  • PELPRENE™ C-Type

This type has excellent resistance to heat aging, water, and oil.

The hardness of the polymer changes depending on the ratio of hard segments to soft segments.


Main Grades

Type Category Grade Feature
P-Type Injection P-30B Low Hardness
P-40B Low Hardness
P-40H Low Hardness
P-55B Medium Hardness
P-70B Medium Hardness
P-90B Medium Hardness
P-150B High Hardness
P-280B High Hardness
E-450B High Hardness
Adhesion P-75M Injection, Low Hardness
P-150M Injection, Medium Hardness
Extrusion P-90BD Medium Hardness
Blow Molding P-47D-HW Fatigue Resistant
S-Type Heat Aging Resistant S-2001 Injection, Medium Hardness
S-3001 Injection, High Hardness
S-6001 Injection, High Hardness
S-6002FR2 High Hardness, Flame Retardant
(V-0 equivalent/1.6mm thickness)
EN-Type Chemical Resistant EN-1000 Medium Hardness, Good Dimensional Stability
EN-2000 High Hardness, Good Dimensional Stability
EN-3000 High Hardness, Good Dimensional Stability
EN-5000 High Hardness, Good Dimensional Stability
C-Type Super Heat Aging Resistant C-2003 Medium Hardness, Injection, Hydrolysis Resistant
C-2005 Medium Hardness, Blow molding, Hydrolysis Resistant

Comparison of PELPRENE™ with rubber, plastic, and metal

Temperature ranges of various elastomers

Elastic modulus of PELPRENE™ types P, S, EN, and C

Thermal Durability of PELPRENE™

The figure shows thermal durability of general purpose PELPRENE™ grades. Thermal durability for each grade is defined as the time for which the elongation drops to one half of its initial value in a high temperature aging test.

  • Test piece

    JIS #3 dumbbell

    Thickness 2mm


  • Applications:CVJ Boots

    Advantages:Resistance to flexural fatigue
    and suitibility for blow molding

  • Applications:Accelerator pedal

    Advantages:Resistance to flexural fatigue
    and good appearance

  • Applications:Cable Jackets

    Advantages:Thermal Resistance
    and flexibility

  • Applications:Noiseless gears

    Advantages:Noise Reduction
    and Good Moldability

  • Applications:Moisture permeable film

    Advantages:Moisture Permeability
    and Flexibility

  • Applications:Hot curler

    Advantages:Thermal Resistance
    and Flexibility

  • Applications:Curl dryer

    Advantages:Thermal Resistance
    and Flexibility

  • Applications:Fuel gas cap tether

    and Chemical resistance

  • Applications:Mascara Brush

    and Fluidity

  • Applications:Gear shift parts

    Advantages:Thin-wall molding
    and Abrasion resistance

PELPRENE™ can be used for injection, extrusion, and blow molding using conventional equipment. It's also compatible with compression molding, melt casting, and rotational molding. Additionally, PELPRENE™ can be post-processed by painting, printing, vacuum metallizing, and cathode spattering, along with hot-melt adhesion of molded articles. Its pellets being applies packed in a moisture-proof bag after drying, PELPRENE™ can be processed as received. However, unused or dampened pellets should be dried again for 4 or more hours at 100-120°C before use.

Standard injection molding temperatures

Example of applicable grades P-30B~P-40H P-55B~P-90B P-150B~P-280B
C1 160~180℃ 190~210℃ 200~230℃ 220~240℃ 230~250℃
C2 180~200℃ 200~230℃ 220~240℃ 230~250℃ 250~270℃
C3 180~200℃ 200~230℃ 220~240℃ 230~250℃ 250~270℃
NZ 180~200℃ 200~230℃ 220~240℃ 230~250℃ 250~270℃
Mold temperature 20~40℃ 20~60℃ 20~60℃ 20~60℃ 20~60℃
  • Standard extrusion molding temperatures
Example Grades P-90BD
Rear 180~200℃
Middle 200~220℃
Front 200~220℃
Die temperature 200~220℃
  • Standard blow molding temperatures
Example Grades P-47D-HW
Rear 200~220℃
Middle 220~230℃
Front 220~240℃
Mold Temperature 20~40℃

Mold Shrinkage

Reuse of PELPRENE™

Sprues and runners of PELPRENE™ can be recycled via remolding. To ensure molded parts of consistant quality, thoroughly dry and pulverize material to be recycled, then blend with virgin pellets up to around 30% recycled content. Note that the ratio of recycled material that can be used varies with molding conditions. Contact us for details.

PELPRENE™ Dry and Conditioned Data

Injection Molding Troubleshooting

Trouble Cause Countermeasure
Sink marks Condition 1. High resin temperature
2. High/low mold temperature
3. Low holding pressure
4. Insufficient holding pressure time
5. Insufficient cooling time
6. No cushion
1. Reduce the cylinder temperature
2. Set the mold temperature accordingly
3. Increase the holding pressure
4. Increase the holding pressure time
5. Increase the cooling time
6. Make cushion 5-10mm
Design 1. Small runner/ gate
2. Unsuitable gate location
1. Enlarge the runner/gate size
2. Relocate the gate to a thicker area
Machine 1. Back-flow during injection

1. Inspect or exchange the backflow valve

Warpage, Deformation Condition

1. Unsuitable injection conditions
2. Insufficient holding pressure time
3. Insufficient Cooling time

4. Temperature difference between cavity and core

1. Increase the injection pressure/speed
2. Increase the holding pressure
3. Increase the cooling time

4. Control the temperature of cavity and core separately

Mold 1. Unsuitable ejector pin placement
2. Insufficient ejector pin size

1. Balance ejector pin placement
2. Enlarge ejector pin size
3. Increase the draft angle


1. Unsuitable gate location
2. Extreme change in part thickness
3. Not enough gates for the part size

1. Change gate location
2. Even out the part thickness
3. Increase the number of gates
Flash Condition 1. High resin temperature
2. High injection speed
3. High holding pressure
4. Low mold clamping force
5. Filling resin Volume is too high
1. Reduce the resin temperature
2. Reduce the injection speed
3. Reduce the holding pressure
4. Increase the mold clamping force
5. Set the cushion about 5mm
Mold 1. Mold surface doesn't mate properly 1. Modify the mold
Burn marks Condition

1. High resin temperature
2. Air entrapment
3. High injection speed
4. Filling resin volume is too high

1. Reduce the resin temperature
2. Reduce the screw rotation
3. Reduce the injection speed
4. Decrease the residence time
Mold 1. Inadequate venting 1. Increase gas ventilation

1. Unsuitable gate location
2. Small gate size

1. Change the gate location to make the welding line on the PL

2. Enlarge the gate size

Welding line Condition 1. Low resin temperature
2. Low mold temperature
3. Low injection speed
1. Increase the cylinder temperature
2. Increase the mold temperature
3. Increase the injection speed
Mold 1. Inadequate holding pressure

1. Increase gas venting and/or change gate location to move the weld line onto the parting line.

Poor surface appearance Condition 1. Low resin temperature
2. Low mold temperature
3. Low injection speed
4. Inadequate holding pressure
5. Insufficient amount of resin for fill
1. Increase the cylinder temperature
2. Increase the mold temperature
3. Increase the injection speed
4. Increase the holding pressure/time
5. Make cushion 5-10mm
Mold 1. Inadequate holding pressure
2. Unclean mold
1. Increase the holding pressure/time
2. Clean the mold


  • Molding operation
  • When purged resin contains a large quantity of gas or steam, the resin may have been insufficiently dried. We recommend re-drying the resin.
  • Resin held in the cylinder for an extended period of time may lose viscosity or experience other impacts on quality. Please resume molding only after thoroughly replacing the resin that has been held too long in the cyliner with new resin.
  • When switching from PELPRENE™ to another polymer, replace the PELPRENE™ with polyethylene or polypropylene to purge. Local and general ventilation are recommended.
  • Keep hands and face away from the nozzle during molding to prevent burn injury.
  • Please ensure proper ventilation, as a small amount of gas and fine dust may be produced during molding.
  • Protective equipment
  • Wear appropriate protective equipment such as protective clothing, safety glasses, and gloves to protect eyes and skin from the molten resin.
  • Emergency response
  • Should molten resin adhere to the skin, cool the area immediately with cold water or an ice pack and then seek medical attention. Do not attempt to peel the resin off of the skin.
  • Other
  • Do not let molten resin touch electric wires or hoses.
  • Molten resin reaches high temperatures and can catch fire if it forms large clumps when purging. Break up large clumps and allow to cool before disposal.
  • Spilled pellets can be a slipping hazard, so be sure to clean them off the floor immediately.