Features
Thermoplastic polyester resin VYLOPET™
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Mechanical properties are not compromised by water absorption
Minimal dimensional changes with ambient temperature
Can be used in high heat applications
Easy to achieve an excellent surface appearance
High flow properties enable thin-wall molding
Excellent electrical properties
Recyclable

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Spec・Quality
Chemical Structure

Structural formula of
PET

Structural formula of
PBT

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Spec・Quality
VYLOPET™ Main Grades
TypeProperty

The physical properties can be found in the Product search on the top page of VYLOPETTM.

GradeFeature

GF Reinforced

EMC-330K

GF30%, High Cycle

Flame Retardant

EMC-133T

GF30%, Flame Retardant (V-0 Equivalent Rating/1.6mm/IEC60695-11-10), Hydrolysis Resistant

GF Reinforced

EMC-430X-8

GF30%, Good Appearance

GF Reinforced

EMC-445

GF40%, Good Appearance

High Stiffness

EMC-450

GF55%, High Stiffness, Good appearance

High Stiffness

EMC-060A

GF60%, High Stiffness, Good appearance

Low Warpage

EMC-405AX-14A

MD20%, Low Warpage、High Flow

Flame Retardant

EMC-617Y(GF+MD)35%, Flame Retardant (V-0 Equivalent Rating/3.2mm/IEC60695-11-10)

Unreinforced

EMC-701EXT

Unreinforced, High Cycle, Low to No Outgassing

GF Reinforced

EMC-HF715

GF15%, Easy Welding

GF Reinforced

EMC-736P

GF30%, Easy Welding

GF Reinforced

EMC-730L

GF30%, Hydrolysis Resistant

PET

PBT/PETPBT

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Spec・Quality
Comparison to Other Resins
Polyester

Polyamide

Item

PC

PP

Excellent

Fair

Poor

Excellent

Excellent

Average

Average

Average

Average

Average

Average

Poor

Poor

Poor

Average

AverageExcellent

Average

Fatigue endurance

GoodGood

Average

Average

Poor

AverageOrganic solvent resistanceExcellent

Excellent

Excellent

Excellent

Poor

Excellent

Mild acid resistanceExcellent

Excellent

Average

Average

Excellent

Excellent

Weak alkali resistance

Average

Average

Average

Average

Average

ExcellentElectrical properties

Excellent

Excellent

Poor

Poor

Excellent

Excellent

Dimensional Accuracy

Average

Average

Poor

Poor

Excellent

Average

PET

PBT

PA6

PA66

Heat resistanceExcellent

Average

Average

Flammability

Average

Average

Rigidity

Excellent

Impact resistance

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Spec・Quality

Dry/Conditioned Flexural Modulus for Various Materials

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Heat Deflection Temperature of Various Materials

VYLOPET™ Processing Conditions
Molding Conditions
Pre-Drying
A small amount of moisture could be the cause for not only bubble release, leak from the cylinder nozzle, and bad surface
appearance but also deterioration of properties due to hydrolysis of the thermoplastic polyester material. The pre-drying
process is important for molding stability and to ensure good quality. Additionally, material exposed to the air for more than
30minutes must be dried.
Pre-drying Conditions
Resin temperature

Drying time

130℃

4〜6h

140℃

3〜5h

VYLOPET™ must be dried before molding.
VYLOPET™ should be processed with a moisture content of less than0.025% (Ideally less than 0.020%).
VYLOPET™ can be dried with either a shelf-type dryer or a hopper
type dryer, but a dehumidification dryer is strongly recommended.
Recommended drying conditions vary slightly depending on the dryer
type and amount of resin to be dried, so please check the pellet
temperature. For parts that are particularly susceptible to gassing
issues, we recommend reducing the moisture content as much aspossible with a longer drying time.

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VYLOPET™ Processing Conditions
Molding Condition
Typical Temperature
Typical cylinder temperature settings (except under the hopper) are shown in the table. For flame resistant grades, it isimportant to set the cylinder temperature as low as possible.

PET

PBT/PETPBTExample Grade

EMC-330

EMC-430X-8

EMC-730

C1245〜265℃

240〜260℃

220〜250℃

C2

265〜285℃

260〜280℃

240〜270℃

C3

265〜285℃

260〜280℃

240〜270℃

NZ

265〜285℃

260〜280℃

240〜270℃

Mold Temperature

120〜140℃

50〜100℃※

50〜90℃*Ideal range for appearance parts : 80-120℃

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VYLOPET™ Processing Conditions
Residence TimeLong residence time in the cylinder leads to material degradation, deterioration of mechanical properties, changes in flow
properties, and discoloration. Residue left in the cylinder should be removed by several shots of purge when the machine isstopped for longer than for 10 minutes.

Mold Temperature
The mold temperature should be set based on consideration of the dimensions of the part, warpage, surface appearance,and cycle time. For PET types, it is generally recommended to set the temperature to 120℃(-135℃) higher.
Molding at 40-70°C is also possible for PET materials, but the second-order shrinkage becomes large.
The general molding temperature of PBT/PET materials is 50-70°C for a typical molded part, though a mold temperature of80-100°C is recommended for molded parts requiring a good surface appearance.

Injection Speed
An easy way to get a good surface appearance with VYLOPET™ is to set a high injection speed. However, a high injection
speed may lead to warpage or burn marks on the surface of the part. Appropriate judgment will be necessary when balancing
these concerns to achieve a good surface appearance.
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VYLOPET™ Processing Conditions
Mold Design
Mold Material
The typical mold materials for PET are wear-resistant steel alloys.
SKD11 (D2) is the most popular alloy for GF-reinforced material, but SKD-61 and stainless steels like SUS420 or SUS440 are used as well. The
hardness of all should optimally be higher than R55 or R60 with HRC after hardening and tempering. SUS310 or SUS440 that have good
corrosion resistance are effective for improving mold durability.

Mold Temperature Control
It is normal to use cartridge heaters, hot water, or hot oil to control the mold temperature.
The mold temperature is strongly affects cycle time, surface appearance and quality, therefore it is very important to check the mold temperature
distribution, and cooling of the cavity's core.
To maintain a uniform temperature distribution, it is effective to use a heat insulating plate between the mold and the platen.

Runner and Sprue
Fully round or trapezoidal runners are preferred, semi-circular or rectangular runners should be avoided.
Cold slug catchers should be placed at the end of each runner and sprue.

Draft Angle
Though it depends on the mold surface, polish level and mold shrinkage of the material, normally the draft angle should be 0.4-1 degrees.

VentingVYLOPET™ molds must be vented in order to allow for the air present in the mold to escape when the molten material fills runners and cavities.
Inadequate venting can lead to incomplete parts, burn marks, flash, poor surface appearance, or weak welding lines. In addition, well-vented tools
will allow for a faster cycle time.
The depth should be at least 0.02-0.05mm, width should be secured as wide as possible. The depth should be 3mm around 0.75mm far fromcavities, and lead the vent to the edge of the mold.
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VYLOPET™ Processing Conditions
Injection Molding Troubleshooting
TroubleSink marks
Condition

DesignMachine
Warpage,
Deformation

Condition

Mold

DesignFlashCondition

Mold
Burn marks
Condition
Mold
DesignWelding line
Condition
Mold
Poor surface
appearance
Condition

Mold

Cause
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. Small runner/ gate
2. Unsuitable gate location
1. Back-flow during injection
1. Unsuitable injection conditions
2. Insufficient holding pressure time
3. Insufficient Cooling time
4. Temperature difference between cavity and core

1. Unsuitable gate location
2. Extreme change in part thickness
3. Not enough gates for the part size
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. Mold surface doesn't mate properly
1. High resin temperature
2. Air entrapment
3. High injection speed
4. Filling resin volume is too high
1. Inadequate venting
1. Unsuitable gate location
2. Small gate size
1. Low resin temperature
2. Low mold temperature
3. Low injection speed

Countermeasure
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
1. Enlarge the runner/gate size
2. Relocate the gate to a thicker area
1. Inspect or exchange the backflow valve
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
1. Balance ejector pin placement
2. Enlarge ejector pin size
3. Increase the draft angle
1. Change gate location
2. Even out the part thickness
3. Increase the number of gates
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
1. Modify the mold
1. Reduce the resin temperature
2. Reduce the screw rotation
3. Reduce the injection speed
4. Decrease the residence time
1. Increase gas ventilation
1. Change the gate location to make the welding line on the PL
2. Enlarge the gate size
1. Increase the cylinder temperature
2. Increase the mold temperature
3. Increase the injection speed

1. Inadequate holding pressure

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

1. Low resin temperature
2. Low mold temperature
3. Low injection speed
4. Inadequate holding pressure
5. Insufficient amount of resin for fill
1. Inadequate holding pressure
2. Unclean mold

1. Increase the cylinder temperature
2. Increase the mold temperature
3. Increase the injection speed
4. Increase the holding pressure/time5. Make cushion 5-10mm
1. Increase the holding pressure/time
2. Clean the mold

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

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ProcessingSafety
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 cylinder with new resin.
• When switching from VYLOPET™ to another polymer, replace the VYLOPET™ 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.

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NotesDisclaimer••
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All of the property data is based on natural color or general black. Data may vary depending on color.
All information in this technical data sheet is based on the experiences of TOYOBO MC Corporation.
These information may vary depending on mold condition and application.
There may also be laws and regulations depending on intended use. Please be careful of this things when using thisproduct.
If this material is to be used for medical, military, or food contact applications, or if it is to be used in a product where adefect in the product is likely to result in death, bodily harm, or substantial property damage, please contact us separately
beforehand.
Export of our materials and products using our materials must comply with the Foreign Exchange and Foreign Trade Law
and other relevant laws and regulations.
Chemical substances used in this material may be regulated by laws and regulations related to chemical substances ineach country, and separate applications may be required or import/export may not be allowed. If you are an importer orexporter of this material, please inquire about compliance with regulations in the relevant country.
The information of this document is based on materials, methods and data available at the time of document preparation.
Please note that the information is subject to revision without prior notice based on subsequent findings.

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