Typical End Products
Teflon® NXT 70 is a fine-cut resin designed for compression molding of blocks and sheets and for use as a base resin for compounds. It can be used for such applications as: seal rings, valve seats, bearing pads, linings, encapsulations, and as a base resin for filled compounds.
Properly processed products (sintered at high temperatures common to the industry) made from Teflon® NXT 70 resin can qualify for use in contact with food in compliance with FDA regulation 21 CFR 177.1550.
Teflon® NXT 70 may be converted by compression molding techniques. For instance, a preform is made at room temperature at the recommended pressure of 14 MPa (2,000 psi) and subsequently free sintered.
Of particular significance for sheet molding is the fact that maximum density after sintering is reached at lower pressures when compared with nonmodified granulars as shown in the chart to the right. This allows the production of larger sheets with existing equipment.
VAPORS CAN BE LIBERATED, WHICH MAY BE HAZARDOUS IF INHALED. Before using Teflon®, read the Material Safety Data Sheet and the detailed information in the "Guide to the Safe Handling of Fluoropolymer Resins, Latest Edition," published by the Fluoropolymers Division of The Society of the Plastics Industry-available from DuPont.
Open and use containers only in well-ventilated areas using local exhaust ventilation (LEV). Vapors and fumes liberated during hot processing, or from smoking tobacco or cigarettes contaminated with Teflon® NXT 70, may cause flu-like symptoms (chills, fever, sore throat) that may not occur until several hours after exposure and that typically pass within about 36 to 48 hours. Vapors and fumes liberated during hot processing should be exhausted completely from the work area; contamination of tobacco with polymers should be avoided. Mixtures with some finely divided metals, such as magnesium or aluminum, can be flammable or explosive under some conditions.
Storage and Handling
Preforming is easiest when the resin is uniformly between 21-27°C (70-80°F). As temperature declines below this range, the resin will be increasingly difficult to mold without cracks and problems with condensed moisture. Higher temperatures inhibit flow and promote lumping. Storage conditions should be set accordingly.
Cleanliness is a critical requirement for successful use of Teflon® NXT 70. The white resin and high sintering temperatures cause even very small foreign particles to become visible in finished moldings. Keep resin drums closed and clean. Good housekeeping and careful handling are essential.