Chemical-resistant and lubrication-free: igus high-performance polymers from Treotham for fluid technology

Supplier: Treotham Automation
31 March, 2020

The lubrication-free and maintenance-free igus plain bearing technology is convincing in applications directly in the medium

Treotham is offering igus solutions to meet the special requirements of fluid technology. The range of applications of iglidur plain bearings and drylin linear guides or lead screws is constantly growing. In the moving parts of pumps and drives plain bearings and linear bearings manage without lubricant. The iglidur products have proven particularly successful in pumps, valves, fittings and lifting systems. The drylin thread technology is also used in fittings with rotary knobs and vertical pumping movements. Even aggressive media are no problem for the chemical- resistant materials. Due to these properties, plain bearings and piston rings made of iglidur and dryspin lead screw nuts are frequently used in fluid technology.

In fluid technology drives are moved by the effects of pressure on liquids or gases. This mechanism is mainly used in pumps where the flow of fluids serves to propel movements. The igus motion plastics from Treotham, plain bearings made of high-performance polymers for dynamic applications, start precisely at this point and are continuously optimised for a wide range of applications. In addition to the universally applicable all-rounders, special solutions for food contact, very high or low temperatures, high loads and comprehensive media resistance have been developed. In order to increase the mechanical load-bearing capacity, fibres and fillers are added to the material. There are also embedded solid lubricants that are released as soon as the running partner moves along the sliding surface of the plain bearing. This self-lubricating effect ensures that iglidur plain bearings do not require maintenance: external lubrication is not necessary either during installation or during operation.

Various possible uses in pump systems
Whether in the rotor bearings of wet-running pumps or as knife edge rollers in peristaltic pumps - iglidur plain bearings can be used on a large number of moving parts. It is not only the dry-operating applications that benefit from the classic iglidur advantages such as the self-lubricating effect, the freedom from maintenance and the high wear resistance, but just these properties of the medium benefit the user. Conventional solutions made of metal require complicated sealing, so that the lubricant does not get into the medium to be conveyed. Failure of this seal results in contamination. The use of iglidur plain bearings eliminates this risk.

Easy replacement with iglidur piston rings in fittings and valves
To move the fluids and gases used in fluid technology, the flow through the valves is controlled. For this purpose, a closure section with sealing surface is pressed against an opening in order to close it. Depending on the type of valve, diaphragms or pistons are used as closure sections. Among other things, they can be automatically controlled by actuators. The iglidur clip-on piston rings ensure that the piston moves linearly without any lubrication. For example, the cost-effective igus piston rings from Treotham are used to replace elaborately processed PTFE tapes with just one guide ring, which is simply clipped into place. The possibility to dispense with lubricants is an advantage particularly in medical technology and the beverage industry. Because, here, only special lubricants that meet the requirements of the industry can be used, and the regular cleaning cycles necessitate a regular relubrication of conventional solutions. Using the piston ring product finder, you can select the suitable products online from more than 40 iglidur materials, for example, food-grade piston rings made of iglidur A350 or iglidur A181.

iglidur in pumps: chemical-resistant and wear-resistant
Depending on the operation of the pumps, it is roughly subdivided into displacement pumps and flow pumps. In displacement pumps, the pump cavity, i.e. the cavity in the interior, is reduced by the movement of a body. The medium is displaced from the diminishing space and thus driven forward. For example, iglidur is used in piston or rotary pumps where pistons as well as gears or screws are used for displacement. The iglidur plain bearings meet the special bearing requirements of these bodies. They enable very high precision and are also designed for high speeds and loads. In addition, they are suitable for tumbling loads caused by the pumping motion. In peristaltic pumps, where the medium is forced through the housing with rotating rollers, iglidur knife edge rollers are used, which are maintenance-free and wear-resistant. Whereas the plain bearings usually do not come into contact with the medium in displacement pumps, they do so in flow pumps. A flow is generated by a rotating impeller, which drives the fluid. Depending on the design of the pump, the motor and shaft also run completely in the medium, which lubricates and cools the bearing. In this way higher speeds and a longer service life can be achieved. Such wet-running pumps can be found, for example, in the water cooling of vehicles. Due to their high resistance to media and chemicals, iglidur plastics are suitable for use directly in the medium.

dryspin technology for vibration-free pumping
Vertical pumping movements must be performed as precisely and reliably as possible. Lead screws and matching lead screw nuts enable a smooth running of vertical pumping motions. In addition to the conventional drylin lead screws, the dryspin technology developed by igus is also used. The flank angle of the dryspin lead screws is flatter than that of standard high helix lead screws. As a result, the introduced force is converted more efficiently into a translational movement. The results are a comparatively high degree of efficiency and a longer service life. In addition, due to the radius tooth design, the contact surface between the lead screw nut and the lead screw is reduced. This is why dryspin lead screw nuts are vibration-free and virtually silent. The precise and smooth guidance required in pumps can thus be guaranteed. The drylin thread technology not only stands out for its efficient and long-lasting high helix threads but also for its corrosion-free and dirt-resistant properties. On the igus homepage the suitable systems can be put together quickly and easily via the igus configurator for lead screw units and the thread product finder.

A wide selection of materials for every application
Special requirements for the material arise from the pressure loads in the pumping system and the properties of the used fluids. Frequently, the required emergency running properties result in additional demands, such as extreme pv values, which occur when the pump operates without the medium to be pumped. In individual applications, additional influences such as high temperatures or cleaning agents must also be taken into account. Mineral oils are usually used to generate flow energy for hydraulics application. Here, iglidur materials convince with their comprehensive resistance to media and chemicals. A variety of tests in the in-house 2,750-square-metre laboratory ensures a quick selection of suitable material, tailored to the particular application and the used medium -- the all-rounder iglidur G, the endurance runner iglidur J, or iglidur X as a specialist for high temperatures and chemicals can be selected as standard. The iglidur H1 and iglidur H370, for
example, are excellent for high media resistance, while iglidur A181 and iglidur A500 are usually used in the food industry. The materials mentioned are intended for optimum use in fluid technology, but it is worth taking a look at the entire iglidur range for the selection. The result can thus be optimised depending on the application; for example iglidur UW for high-speed rotation under water. The required iglidur materials can be selected online quickly and easily using the igus product finder and configured to suit the respective application.