High-density PTFE -

Lower friction than low-density PTFE - proven

PTFE is a “family“ of polymers, about 1200 strong. Most of them have molecular chains which are branched. In bulk, these have a much lower specific weight than the high-density versions, and suit themselves well to producing the relatively thick coatings found, for example, in cooking pots. But they are far from suitable for the much finer coating, about 1 - 1.5 microns, which is needed in engineering. By comparison, “heavy“ PTFE consists of much longer, unbranched molecular chains, which make it possible to achieve a much more dense coating on surfaces. Just as a truck loaded with Christmas trees will carry much less weight than one carrying straight tree-trunks.

Scientists Tabor and Williams proved in 1961 in the world-famous Cavendish Laboratory in Cambridge, that there is at least 30% less friction between PTFE surfaces where the molecular chains are running parallel to each other than if they are running at 90°. This optimum situation can only be achieved in an engine with heavy PTFE, where the motion “combs“ the molecular chains into the direction of motion. The light variety can only splatter the surface, not fully coat it (one reason why a producer using light PTFE was fined $10 million in the USA for making this and other unfounded claims).

Heavy PTFE cannot be produced by the simple method used to produce light PTFE powder (grinding from solid). It has to be produced directly in the basic solution, which demands a much more complicated and more expensive production method. But this then gives a full coating, and the full benefits of the treatment are there within 100 km. The lesser effect of light PTFE takes up to 3000 km to develop, because of the greater difficulty in „bedding-down“ the untidy particles on the metal.

One problem met with both types of PTFE in preparing a coating product, is that the particles tend strongly to settle out and form a putty-like mud at the bottom of the bottle (even light PTFE is heavier than oil), which does not disperse easily (if at all) when shaken. To prevent this clotting, a special chemistry is required. While there are several light PTFE products on offer, so far only QMI has solved this problem to be able to deliver the superior performance of heavy PTFE.

It is recognised that PTFE has the lowest co-efficient of friction of all solid substances in the world. And the friction between parts coated with heavy PTFE is lower than with light PTFE (as well as giving a complete coating, impossible with the light varieties). Whatever lubricant is used, there will be a drag between the oil film and the metal surface, which QMI will reduce better than any other product. So it is no surprise that the QMI product produces much better results that any light PTFE product.

Read the independent test reports, compare them with the unsubstantiated claims of light PTFE producers, and you will understand why serious motor sport people swear by QMI.

Quite simply:

...you can’t drive with less friction !

Ersparnisrechner



Gearbox | 50,000 miles | Sequence III E | High-density PTFE | Test results | What is an honest test?

Press Release | How to use QMI | QMI in industry | QMI in trucks