ASTM D3368 Standard Specification for FEP Sheet and Film

Get Certified ASTM D3368 Testing for FEP Sheet and Film 

Controlled physical, mechanical, dimensional, and electrical properties are required to ensure reliable performance in FEP sheets and films. ASTM D3368 specifies requirements for these properties and allows manufacturers to determine if their FEP products meet the material type and grade. The standard may be used in laboratories to assist with quality control, product certification, material selection, production verification, and supplier evaluation. The specification also allows for the use of recycled or reprocessed FEP provided that the final product meets the performance and toxicological requirements. 

• Covers FEP sheet and film below 3.175 mm and unfilled and unpigmented FEP resin.
• Allows qualifying recycled, reprocessed, and reworked FEP and classifies four FEP material types.
• Covers general-purpose and cementable films, films for demanding thermal and chemical service, and mold-release films.
• Specifies tensile strength and elongation requirements and evaluates dimensional change on heating.

What are the uses of ASTM D3368 testing? 

ASTM D3368 testing helps manufacturers verify the quality and performance of FEP sheets and films before use or shipment. Laboratories can use the specification to compare material properties with the requirements for the selected type and thickness. Applications include-

• Evaluates FEP sheet and film quality, verifies tensile strength and elongation, and checks dimensional stability during heating.
• Evaluates the cementability of applicable Type II film, determines dielectric strength and density.
• Verifies thickness and thickness tolerance and supports production quality control.
• Supports material certification and product qualification and helps manufacturers compare FEP products for specific applications.

Which Materials Can Be Tested Under ASTM D3368? 

ASTM D3368 applies to FEP-fluorocarbon resin sheet and film that contains no filler or plasticizer. The material may be recycled, reprocessed, or reworked FEP if the finished product meets the physical, mechanical, performance, and toxicological requirements of the specification.

Why is ASTM D3368 important? 

ASTM D3368 sets uniform specifications for FEP sheet and film, enabling manufacturers and laboratories to assess material quality based on criteria. The specification relates to material type, material thickness, mechanical performance, dimensional stability, cementability, dielectric strength, and density. This method ensures that manufacturers can produce consistently, and the purchasers can find materials to satisfy the requirements for the chosen FEP type.

ASTM D3368 Testing Process and Data Collection 

Technicians first determine the FEP type, grade, nominal thickness, and applicable requirements. Then, technicians take representative samples and cut out portions that have visible flaws. They measure thickness and prepare specimens for the required mechanical, dimensional, electrical, and physical tests. Analysts condition specimens when required and perform testing at the specified laboratory conditions. They document tensile strength, elongation, dimensional change, cementability, dielectric strength, density, and thickness (where applicable). Finally, laboratories compare the measured values with the requirements for the specified material type and thickness.

Common Challenges and Troubleshooting 

Accurate ASTM D3368 results rely on representative sampling, preparation, accurate thickness measurement, and test equipment. Common challenges include selecting the wrong FEP type or grade, measuring thickness inaccurately, cutting specimens from defective areas, using incorrect specimen geometry, inadequate conditioning, improper tensile-test setup, and inconsistent heating conditions. Before testing, technicians should confirm the material code, specimen thickness, equipment condition, and applicable test procedure.