About the polymer material Rimamid
Rimamid is a high-strength polymer that is designed to replace bronze, brass, fluoroplastic, textolite, caprolon, sintered powders, ZAMAK, cast iron, stainless and other types of steel.
Different grades of Rimamid are classified by chemical composition and physical properties. To solve every specific task, it is recommended to select a certain grade of Rimamid, of which there are currently more than 70.
Laboratories of StartPlast SPA are continuously developing new types of Rimamid in accordance with the needs of our customers.
Compared to traditional materials Rimamid has many advantages, which are discussed below.
Rimamid parts have the following advantages over their metal counterparts:
- not subjected to chipping out, as have no adhesion either with metals or other polymers;
- perfectly dampen impact loads, which protects the locking elements (pins, keys, splines) from damage;
- adapt well to the shape of the mating part, which contributes to a more uniform distribution of loads on the contact surfaces;
- Rimamid parts are highly resistant to short-term high load and fully restore their original shape after its removal.
Rimamid parts have the following advantages over their metal counterparts:
Due to its chemical formula and stable molecular bonds Rimamid has unique strength characteristics, which allows to use it as a substitute for metal parts in high-loaded assemblies.
Rimamid parts have the following advantages over their metal counterparts:
Rimamid has the property of surface saturation - lubricating material (oil) penetrates its surface to the depth of 2 mm. In case of oil starvation, the temperature in the assembly unit increases, which leads to the release of oil from Rimamid part surface. Thus, using Rimamid can reduce after-effects of oil leakage.
Low friction ratio has a positive effect on the service life duration of the assembly unit. For example, the use of Rimamid for friction bearings allows not only to reduce the cost of replacing the bearings, but also significantly extends the service life of the counterpart.
Another positive effect is a significant temperature reduction in the friction zone. For example, on KAMAZ MASTER sports truck in the assembly unit with a bronze bushing when in motion the temperature could reach 500ºC. When crossing water barriers the assembly unit could be instantly cooled down, where such temperature difference would cause cracking with further breakdown of the entire unit. Replacing the bronze bushing with the Rimamid bushing made it possible to lower the operating temperature of the unit from 500°C to 70°C and eliminate the problem of the part damage upon shock cooling due to contact with water.
Positive effects of friction ratio reduction:
- reduced wear of parts;
- decrease in temperature;
- increased efficiency;
- resistance to oil starvation.
Low friction ratio and good antifriction properties of our material allow to extend the service life of the unit by more than 3 times, to increase efficiency and reduce the risks of the unit failure during oil starvation.
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In addition to the obvious benefits of weight reduction, we will review several additional ones:
- In a working mechanism to make a part move a certain force is to be applied to overcome the force of inertia and the heavier the part is, the greater force is required. Thus, weight decrease of parts in the mechanism reduces energy consumption and increases efficiency.
- Rotary parts after balancing always have residual unbalance, which inevitably leads to vibration. Mass reduction of the rotary part leads to decrease of unbalanced inertial forces and of vibration level of the mechanism, which prolongs the service life of the mechanism and enhances comfort of staff and customers.
- Mass reduction of parts leads to decrease in shock loads at the moment of taking up backlash in conjugation when starting, stopping or switching the mechanism.
Specific gravity of Rimamid is 1.18 g/cm3, for comparison, it is 6.5 times less than specific gravity of steel or 7.5 times less than specific weight of bronze. Low specific weight of products from Rimamid facilitates transportation and installation.
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Despite this, there are conditions in which Rimamid is not effective without prior treatment. For example, it is not resistant to sulfuric acid, but after special treatment, Rimamid worked for more than 24 hours in a 40% solution of sulfuric acid without losing its physical properties. For comparison, specialized steel parts were replaced every 3 hours under the same conditions. As can be seen from the example above, the use of parts from Rimamid, even in very aggressive environments, is possible and more efficient, than use of traditional materials.
Our specialists always exercise an individual approach to each task, and will help to select the Rimamid grade meeting operating conditions best of all.
Rimamid has high chemical resistance to various environments: water, synthetic and mineral oils (including with various additives), diesel fuel and gasoline, coolants, alcohols, weak acids solutions (except for some organic acids) and alkalies.
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Rimamid parts adapt well to the shape of counter parts and compensate for geometric errors of manufacture and assembly, and consequently no grinding is required.
During grinding metal parts are subject to great wear, that leads to the appearance of abrasive particles, which getting into the oil, spreads through the mechanism and negatively affects all its parts.
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Parts are made of them by means of machining on milling, turning, gear-cutting and other machines. Processing conditions of workpieces directly affect the cost of finished parts.
The most important factor affecting the cost is the time spent on processing one part. The faster the part is made, the fewer labour hours will be included in its cost price. Rimamid machining is, on average, 5 times faster than that of metals due to increasing cutting speed and tool feed. Consequently, it allows to manufacture 5 times more parts from Rimamid than from metal or bronze during the same time period.
The second component influencing the product prime cost is the cost of the processing tooling. Rimamid has a homogeneous structure and does not contain abrasive inclusions, therefore, there is practically no tool wear and its maintenance and replacement cost is distributed among a greater number of parts.
Parts are made of them by means of machining on milling, turning, gear-cutting and other machines. Processing conditions of workpieces directly affect the cost of finished parts.
Rimamid is supplied in rods, plates and other shapes for further machining. Rimamid castings can be made bespoke, including manufacture of large-sized parts.
Parts are made of them by means of machining on milling, turning, gear-cutting and other machines. Processing conditions of workpieces directly affect the cost of finished parts.
Parts from Rimamid are well adapted to the shape of counter parts, as a result of which the alignment of contact pressures happens, which reduces local wear and increases the service life of the whole mechanism.
All cumulative properties of Rimamid allow details from it to be in operation longer even in high-loaded units. That not only affects the cost of equipment ownership, but also significantly reduces its downtime.
Low specific weight, high strength and reduced friction ratio result in the fact, that Rimamid parts serve several times longer, than parts made from caprolon, bronze or even steel. The ability to to dampen impact loads enables to preserve the performance of the assembly unit even in heavy duty conditions. Due to the low friction ratio, parts made of Rimamid wear out less than similar metal parts, and counter parts do not wear out either.
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In final calculations, in addition to the part price, it is also necessary to consider the cost of ownership, which includes the cost of its installation on the assembly unit, the frequency of maintenance, the cost of lubricants, the frequency of replacement and the impact on the mating parts. Keeping in mind such Rimamid benefits, as low weight, low friction ratio, absence of abrasive inclusions, high damping ability and others the cost of ownership of Rimamid parts will be significantly lower than the cost of ownership of parts made from traditional materials.
On codition that, quality standards are maintained, any customer is concerned about the cost of the finished product, not about the cost of the material from which it is made. Since Rimamid is 5-7 times lighter than metals, 5-7 times more parts from the same weight can be made. Alongside with this, almost always the main share in the cost of the finished product is not the material, but the cost of manufacture.
Hide Read moreRIMAMID polymer material belongs to the class of polyamides and is made in the form of blanks (plate, rod, and other geometrical shapes) of various sizes for further mechanical processing on turning, milling and other processing machines.
The main advantage of this material is low friction ratio against steel, which provides an increase in the service life of parts in the friction unit by 3-4 times. When using RIMAMID material with the addition (or the application of coatings) of antifriction components (oil, molybdenum sulfide, graphite, etc.), friction ratio decreases and there is need to add the lubricant to the friction unit.
RIMAMID material is 6.8 times lighter than steel, 6.5-8 times lighter than bronze, almost 2 times lighter than fluoroplastic. Thus, the cost of RIMAMID blank is 9-10 times lower, than the cost of the similar bronze or fluoroplastic blank. Besides, lightness of the material reduces the time required for installation and replacement.
High wear resistance of the material (1.5 times more than that of textolite, 10 times more than that of bronze) and low friction ratio reduces noise level in sliding units, and also makes it possible to use such parts in dusty installation areas. In addition, this material is shock-resistant, which allows to maintain the efficiency of the unit at a critical moment.
| Property name |
|
Test procedure | |
| Melting point, °C | not set | not set | GOST 21553 |
| Density, kg/m3 | not set | not set | GOST 15139 |
| Tensile stress at break, MPa | not set | not set | GOST 11262 |
| Relative elongation at break, % | not set | not set | GOST 11262 |
| Modulus of elongation, MPa | not set | not set | GOST 9550 |
| Charpy no notch impact energy, kJ/m2 (20°C) | not set | not set | GOST 4647 |
| Water absorption in 24 hours, % max, % |
not set | not set | GOST 4650 |
| Heat conductivity coefficient at room temperature, W/m⋅K | not set | not set | GOST 23630.2 |
| Average linear thermal expansion coefficient per 1°С in temperature range: from -50°С to 0°С from 0°С to 50°С |
not set | not set | GOST 15173 |
| Shore D hardness | not set | not set | GOST 24621 |
| Surface electrical resistivity, Ohm | not set | not set | GOST 6433.2 |
| Specific volume electrical resistivity, Ohm⋅m | not set | not set | GOST 6433.2 |
| Loss angle at 106 Hz frequency | not set | not set | GOST 22372 |
| Dielectric constant at 106Hz | not set | not set | GOST 22372 |
| Electric strength, kV/mm | not set | not set | GOST 6433.3 |
| Dry friction coefficient against steel | not set | not set | GOST 11629 |
| Lubricated friction coefficient against steel | not set | not set | GOST 11629 |
| Percentage of extractable substances, % | not set | not set | GOST 17824 |
