Suspended PTFE

(Suspended PTFE for Molding )

Suspended PTFE for molding has two types : Suspended Fine Grain ( PTFE 7C ) and Suspended middle grain ( PTFE 7A ) .

PTFE granular molding powders are ideal for molding many different products and stock shapes , such as rods, tubes and sheets . products fabricated from PTFE stock shapes are unaffected by nearly all chemicals and feature superior electrical properties . These products , some of which are rated for continuous service at 260 C ( 500 F ) , also provide exceptional low-temperature toughness , plus unique adhesion and flame resistance .

Processing : PTFE granular molding powders are processed by preparing a pre-form , sintering the pre-form , and then fabricating functioning machined parts form the sintered stock shape . Filled compounds are easily produced from this PTFE granular powder by mixing 5% to 60% , by weight , of inorganic fillers that selectively enhance properties .

Pre-forming: Adequate pre-form pressure are required to maximize end-use performance. Typical pressure range from 3,000 to 4,500 psi with dwell times varying with pre-form size . Stock shapes pre-formed at lower pressures exhibit inferior physical properties ( Specific density , tensile strength , elongation , flex life ) , electrical properties , and permeation and chemical resistance .

Sintering : Adequate sintering requires a programmable oven . The temperature is slowly raised from room temperature to 363 to 382 C ( 685 to 720 F 0 . Hold times at these temperatures vary with part geometry and dimensions . The oven temperature is then slowly lowered to room temperature . Stock shapes that are not properly sintered exhibit inferior physical properties (( Specific density , tensile strength , elongation , flex life ) , electrical properties , and permeation and chemical resistance

	Items	Unit	PTFE  7C1		PTFE  7C2
			Grade 1	Grade 2	Grade 1	Grade 2
1	Smooth & Clean		White sheet surface , even quality , no foreign matter .		Even Sheet quality . Total residue &Spots: 6 Max Reside ( 0.5-2 mm ): 2 Max Spot ( 2-3 mm )    : 1 Max
2	Tensile strength	MPa	29.0 Min	27.4 Min	29.0 Min	27.4 Min
3	Extension at break	%	300 Min	280 Min	300 Min	280 Min
4	Bulk density	g/L	300 – 450
5	Residue on sive ( 65 um )	% um	15% Max
6	Moisture	%	0.04% Mx
7	Melting point	°C	327+/- 5 °C
8	Standard relative density		2.13 – 2.19
9	Thermal instability index		2 Max
10	Electrical strength	MV/m	100 Min	80 Min

	Items	Unit	PTFE  7A1		PTFE  7A2
			Grade 1	Grade 2	Grade 1	Grade 2
1	Smooth & Clean		Clean & White surface , even quality , no foreign matters . Diameter =57 mm , no color difference for rod cross section		Clean & white surface , even quality , no metal residue , .   Residue (1mm Max) : 2 Max
2	Tensile strength	MPa	27.0 Min		25.5
3	Extension at break	%	250
4	Volume density	g/L	500 +/- 100
5	Average Particle size	um	180 +/- 80
6	Moisture	%	0.04 Max
7	Melting point	°C	327+/- 5 °C
8	Standard relative density		2.13 – 2.18
9	Thermal instability index		20 Max
10	Electrical strength	Mv/m	60 Min

Suspended Middle Grain , PTFE 7A , is widely used in field of skived film and sheet , gaskets, bridge or pipeline bearing pads , shaft bearings , electrical insulators , piston rings, expansion bellows , diaphragms, and chemical linings .