Method comparison of steel lined fluoro-plastics
| No. |
Forming type |
Lined materials |
Advantages |
Limitations |
Sample products |
| 1 |
smooth sheet |
PTFE turning plate |
1 low price;
2, the simplest process, short cycle;
3, cam make elliptical shape of product by by pressure or vacuum. |
1, the life of PTFE turning board generally is not long;
2, there are secondary formed products, can affect the quality
3, hard to use in complex equipment
4, isn't resistant to negative pressure and high pressure;
5, isn't resistant to alternating temperature. |
tower, end plate, disc end plate |
| 2 |
winding |
Turning PTFE Turning membrane + turning plate |
1, 1 low price;
2, for some complex shape parts , they can be lined or fully covered;
3, lining can be strengthened with steel, solve the problem. of resistance to negative pressure |
1, there are secondary formed problem too;
2, high demanding on the processing environment and process control
3, hard to find the potential defects between films ;
4, because of strengthened with steel, its quality is unreliable for big difference between these two materials on linear expansion;
5, not for parts with flat surface;
6, hard to use in large parts (DN2000 & above) |
tower, straight tube, reaction kettle (bottom and cylinder separation) and grille, etc. |
| 3 |
Equal pressure forming |
PTFE molding powder |
1,low price;
2, can be used in complex shape, suitable for lining pipe tee, etc.;
3,one-time forming, no welding seam;
4, Thickness of lining is about 4-12mm, so can withstand a certain temperature, and negative pressure |
1, In the processing of small quantity, the making time and cost of mold are higher
2, for large parts, it has less life for chinese lining has low density and bad anti-permeability |
tower, end plate, reaction kettle (bottom and cylinder separation), pipes and pipe fittings, etc. |
| 4 |
trombone |
PTFE, PFA, FEP |
1 low price;
2, processing is simple, suitable for lining of straight pipe;
3, tight lining , can withstand the negative pressure operation in certain temperature, |
1, its quality is determined by the quality of PTFE trombone, while the quality of most PTFE trombone in China isn't so good
2, not for large parts, only for straight tube (DN2000 or less). |
Straight tube |
| 5 |
hot mold press |
Mold press granules of PFA, FEP, ETFE (not include PTFE, TFM) |
1, one-time-forming in fused state, small internal stress, no welding seam;
2, lining thicker, up to 3-8mm, can withstand a certain temperature, the negative pressure operation; Thickness of lining is about 3-8mm, so can withstand the negative pressure operation in certain temperature
3, suitable for complex parts in mass production , high precision, good surface quality;
4, can be used for industries that require a super pure. |
1, In the processing of small quantity, the making time and cost of mold are higher
2, not for large parts, only for DN500 or less
3, high demanding on the processing of workpiece . |
Pipe fittings, valves, small type tower, end plate |
| 6 |
spraying |
ETFE exclusive material |
1, is resistant to vacuum in 150°C or less;
2, can be used in complex shape;
3,wall thickness of liner is thin, about 0.21-1.2mm, less bad effects on equipment size |
1, thin wall, worse anti-permeability effect than other methods
2, high demanding on the pre-processing of workpiece
3, Operational temperature <150 ° C. |
tower, reaction kettle, end plate, filters, mixers, etc. |
| 7 |
rotation |
ETFE plastic |
1, one-time-forming in fused state, small internal stress, no welding seam;
2, can be used in complex shape of large parts;
3, is resistant to vacuum in 150°C or less;
4, the cylinder body wall can be attached to the components with the height of 50mm or less;
5, no mold, fixture only. |
1, high demanding on the treatment of workpiece surface
2, corrosion resistance of ETFE is less than PTFE, PFA, FEP |
tower, storage tank, reaction kettle, etc. |
| 8 |
laminated sheet |
PFA, PVDF, TFM, FEP and composite panels |
1, advanced technology, long life;
2, can be used in large parts;
3, is resistant to limit vacuum high pressure within allowable temperature
4, good weldability, easy to maintenance;
5, in the same working conditions, its Operational temperature is higher than rotating form;
6, can be applied to industries that require a super pure. |
1, need make new mold for products with complex structure;
2, higher prices. |
tower, storage tank, reaction kettle, paddle-type mixer, etc. |
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