a) The wheel: The main component of a caster that touches the ground and is being rolled to move the whole application. There are certain variations of a wheel according to each different application.
Polyamide (PA – Nylon) wheel: It is mainly used in static applications wherever floor conditions are suitable.
It should not be used on wooden or plastic floors since it is a high risk of damaging the floor. It should not also used on uneven floors or floors with ceramic tiles due to noise and possible vibrations on the trolley and the environment, however it should be highly recommended on carpets since the low friction in between wheel and carpet improves considerably the maneuverability. It is resistant to most of the common chemical substances (however it has always to be checked) and its working temperatures are proposed in between -15oC/+80oC. Default color is white but other colours could also be available on request.
Polypropylene (PP) wheel: it has more or less similar characteristics to Polyamide however it is softer as material and should be recommended in light duty static applications.
Thermoplastic elastomer rubber: It is the most common wheel in the institutional casters market as it offers noiseless floor protective and low rolling resistance operation, appropriate for hard floors and floors with obstacles as well, as the elasticity of the rubber can easily absorb shocking vibrations. Made from the highest quality elastomeric original Santoprene in hardness of 86 shA, however it could be also available in softer versions such as 55shA, 72shA etc. The center of the wheel is made from grey pure Polypropylene (Copolymer 6). Its working temperatures are proposed in between -15oC/+80oC. Default color is grey but other colours could also be available on request.
Electric conductive grey rubber: It is used in applications where static electricity causes malfunction to the carried device or product; Made from electric conductive material it is practically grounding the trolley. RODA SA can offer both options; Conductive that offers a resistance R<10ΚΩ or Antistatic that offers a resistance 100KΩ<R<10MΩ. Default color of the tread is grey and of the rim is black.
b) The yoke: is the part of the caster connecting the wheel to the trolley that also offers the directional ability of the movement.
It can be fixed or swivel, with or without brake in various types of fittings.
It can be produced in standard or stainless steel for demanding applications in corrosive environments such as food industry and health care applications.
In decorative applications, it can be nickel or bronze plated or colored in various epoxy colors.
c) Axle bearing: According to each different application there are several types of axle material in the wheels, such as:
Plain bearing: is the most common and economic solution in institutional applications. It is recommended in light trolleys with relatively small travel distances. It is maintenance FREE and can be used also in corrosive environment by using stainless axle tube.
Double conus bearings: It is recommended in cases where the trolley or the device should move frequently and in considerably long distances. It offers low rolling resistance and also affects positively to the maneuverability of the trolley. For demanding applications in corrosive environments such as food industry, health care applications, cleaning machinery, can be optionally offered in stainless steel version.
Single precision bearing: It is far the best solution in demanding applications with heavier loads and continuous use in long distances, such as super market trolleys – airport trolleys – catering trolleys e.t.c. It offers the lowest possible rolling resistance, smooth and silent rolling, long life and it is maintenance FREE. In corrosive environments it is also available in stainless steel version.