Introduction

Since asbestos is on the list of suspect products, a lot of research has been done for asbestos-replacement in friction.

A perfect replacement product does not yet exist. Solutions are to be found in combinations of several products - PROMAXON^® is one of them.

PROMAXON^® has been used as an additive in friction materials for more than one decade. The latest developments show that the material is as suitable for the dry friction application as for wet friction applications.

Porosity, Temperature stability and behavior, unique microporous structure, interactive properties with classical friction materials add value to mixing processes, finished products and performance.

 

Product Description

PROMAXON^® is a synthetic hydrated calcium silicate. By means of a special crystallization process and controlled crystal growth, particles are produced with a more or less spherical morphology. The result is an open inner structure surrounded by an outer shell of close knitted needle-like crystals.

The chemical structure of PROMAXON^® corresponds with the known mineral Xonotlite Ca₆Si₆O₁₇(OH)₂.

PROMAXON^® is a white powder with an open inner structure surrounded by an outer shell of close knitted needle-like crystals

 

Properties

 

Bulk density (g/l)	85 - 130
Average particle size (µm)	35 - 85
Coarse particles (> 254 µm)	< 2 %
Moisture content	< 3 %
Loss on ignition	< 7 %
Specific weight (g/cm³)	± 2.6
Specific surface area (BET m²/g)	> 40
pH-value	9 - 10
Chemical analysis SiO2 CaO Al2O3 MgO Fe2O3	± 50 % ± 43 % ± 0,3 % ± 0,4 % ± 0,3 %
Oil absorption (g/100g)	± 300

Thermal Gravimetric Analysis.

·       perfect stability up to 620°C ; no decomposition within the working temperature of automotive 
    friction materials

·       dehydration between 620 and 750°C – a reversible cooling effect is the result.

·       above 750°C , loss of chemically bound water, but no significant morphological changes will occur
     till 1200°C

 

PROMAXON^® as a mixing aid.

During mixing and depending on the formula and the shear forces applied, some of the PROMAXON^® D-particles will break into individual crystals, acting as short fibers. The unbroken particles will provide porosity and permeability.

Interaction with other ingredients

·       PROMAXON^® provokes better opening of the fibers

·       PROMAXON^® reduces mixing times considerably due to an improved dispersion of all ingredients

·       PROMAXON^® results in an anti-segregation effect as well for mineral wool as for aramid fibers; 
    (and thus improves their efficiency) The same observations are notified with aramid fibers

·       PROMAXON^® neutralizes  electrostatic charges between fibers

·       excellent mechanical bonding of PROMAXON^® crystals to the surface of the reinforcing fibers, 
    hereby increased wetting of fibers by resins and improving thus  fiber-matrix adhesion

 

Preforming and curing

·       addition of 6 and 9% of PROMAXON^® gives a better preform with higher green strength and good 
     edge stability; the result is a fine “cosmetic” product

·       a higher open porosity, bigger pores and improved permeability enables dissipation of the gases 
     during pressing, press curing and heat treatment

·       less cracking at the surface and inside the molded pieces means less quality-rejects and bigger 
     savings

Mechanical Performances

·       a substantial lower density is obtained without negative influence  on the mechanical 
    performances

·       a substantial lower difference between E-modules at low and high temperatures is observed

·       PROMAXON^® used in flexible friction products with rubber matrix reinforces the whole product 
     improving bending strength

 

Physical Performances.

·       porosity measurements have shown a significant increase of the mean pore radius for increasing 
    amounts of PROMAXON^® especially in semi-metallic formulations

·       increase of connected pores improves permeability and  enables easier gas-evacuation from the
     friction and thus increases apparent friction coefficient

·       open pores at the surface of the friction material build space for dust particles and clean the rotor 
    to guarantee stabile performance

 

Frictional Performances

·       Several typical sm and nao -formulations were compounded with addition of 0 to 9 % 
    PROMAXON^® in general PROMAXON^® contributes  significantly to stabilizing the friction level with 
    respect to temperature changes; Krauss test results are available upon request.

·       Besides less fading, better recovery a more comfortable noise-level is recorded.

·       The dehydration process at higher temperature ranges provides an additional cooling effect and 
    is reversible by rehydration at lower temperatures.

 

Health and Safety Aspects

PROMAXON^® has no harmful chemical elements in its composition. Investigations by the P. & M. Curie University in Paris have demonstrated the non-chemical toxicity for this product.

Experiments conducted by Fraunhofer Institute of Toxicology in Hannover (final report of 1993) have shown that PROMAXON^® is a material extremely soluble in a living body.  Introduced in the rat’s lung, more than 99 % of single crystals and about 90 % of the agglomerates of crystals are eliminated already two days after instillation. The remaining particles have an extremely short life time until total elimination.

 

Download Documents

Application Datasheet Friction

MSDS Sheet PROMAXON D

Technical Datasheet PROMAXON D

ISO 9001 2000

ISO 14001 2004