Product Information
Oct 2019
Ultradur® B 4520
Polybutylene Terephthalate (PBT)

Product Description
Ultradur B 4520 is a medium viscosity, rapidly freezing injection molding grade.

Typical applications include chassis and housings for home appliances, office and sewing machines, and coil formers.

PHYSICAL ASTM Test Method Property Value
Specific Gravity D-792 1.30
Mold Shrinkage (1/8" bar, in/in) 0.015
Moisture, % D-570  
    (50% RH) 0.25
    (Saturation) 0.5
MECHANICAL ASTM Test Method Property Value
Tensile Strength, Yield, MPa (psi) D-638  
    23C (73F) 60 (8,700)
Elongation, Yield, % D-638  
    23C (73F) 3.7
Flexural Modulus, MPa (psi) D-790  
    23C (73F) 2,300 (334,000)
IMPACT ASTM Test Method Property Value
Notched Izod Impact, J/M (ft-lbs/in) D-256  
    -40C (-40F) 37 (0.7)
    23C (73F) 43 (0.8)
THERMAL ASTM Test Method Property Value
Melting Point, C(F) D-3418 223 (433)
Heat Deflection @ 264 psi (1.8 MPa) C(F) D-648 60 (140)
Heat Deflection @ 66 psi (.45 MPa) C(F) D-648 163 (325)
UL RATINGS UL Test Method Property Value
Flammability Rating, 0.75mm UL94 HB
Relative Temperature Index, 0.75mm UL746B  
    Mechanical w/o Impact, C 140
    Mechanical w/ Impact, C 130
    Electrical, C 130
Flammability Rating, 1.5mm UL94 HB
Relative Temperature Index, 1.5mm UL746B  
    Mechanical w/o Impact, C 140
    Mechanical w/ Impact, C 130
    Electrical, C 130
Flammability Rating, 2.8mm UL94 HB
Relative Temperature Index, 2.8mm UL746B  
    Mechanical w/o Impact, C 140
    Mechanical w/ Impact, C 130
    Electrical, C 130
ELECTRICAL ASTM Test Method Property Value
Volume Resistivity (Ohm-m) D-257 >1E13
Surface Resistivity (Ohm) D-257 1E13

Processing Guidelines
Material Handling
Max. Water content: 0.04%
To ensure optimum part performance, this product must be dried prior to molding and maintained at a moisture level of less than 0.04%. Dehumidifying or desiccant dryers operating at 100-120C (212-248F) at 4 hours drying time is recommended. Further information concerning safe handling procedures can be obtained from the Safety Data Sheet. Alternatively, please contact your BASF representative.

Typical Profile
Melt Temperature 250-270C (482-518F)
Mold Temperature 40-80C (104-176F)
Injection and Packing Pressure 35-125 bar (500-1500 psi)

Mold Temperatures
This product can be processed over mold temperatures of 40-80C (104-176F), although 80C (176 deg F) will result the best surface.

Injection pressure controls the filling of the part and should be applied for 90% of ram travel. Packing pressure affects the final part and can be used effectively in controlling sink marks and shrinkage. It should be applied and maintained until the gate area is completely frozen off.

Back pressure can be utilized to provide uniform melt consistency and reduce trapped air and gas. A maximum of 10 bar (145 psi) is recommended due to the risk of excessive shear.

Fill Rate
Fast fill rates are recommended to ensure uniform melt delivery to the cavity and prevent premature freezing. Surface appearance is directly affected by injection rate.

Although all statements and information in this publication are believed to be accurate and reliable, they are presented gratis and for guidance only, and risks and liability for results obtained by use of the products or application of the suggestions described are assumed by the user. NO WARRANTIES OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, ARE MADE REGARDING PRODUCTS DESCRIBED OR DESIGNS, DATA OR INFORMATION SET FORTH. Statements or suggestions concerning possible use of the products are made without representation or warranty that any such use is free of patent infringement and are not recommendations to infringe any patent. The user should not assume that toxicity data and safety measures are indicated or that other measures may not be required.

  BASF Corporation
Engineering Plastics
1609 Biddle Avenue
Wyandotte, MI 48192
General Information: 800-BC-RESIN
Technical Assistance: 800-527-TECH (734-324-5150)
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