In extreme low-temperature environments, what caster materials are suitable to use?

Recommended caster materials for extreme low-temperature environments

Extreme low-temperature environments (generally below -40°C, such as outdoor locations in extremely cold regions, deep cold storage facilities, and cryogenic laboratories) place extremely high demands on caster materials' low-temperature toughness, brittle crack resistance, and rolling stability. Materials with outstanding low-temperature resistance should be prioritized. The following four categories are recommended:

1. Low-temperature modified nylon (-40°C to -60°C)

Low-temperature modified nylon is an upgraded version of ordinary nylon. By adding toughening agents (such as POE and EPDM elastomers) or using specialized nylon grades (such as PA12 and PA612), its low-temperature performance is significantly improved. It is a cost-effective choice for extreme low-temperature environments:

Performance Advantages: It maintains good toughness even at -60°C, with an impact strength of 8-12 kJ/m² (compared to 1.5 kJ/m² for ordinary nylon at -40°C), eliminating the risk of brittle cracking. It also retains the wear resistance and high load-bearing properties of nylon (single wheel load capacity). (100-300kg), suitable for low-temperature warehouse cargo carts and cold storage equipment transfer vehicles.

Suitable applications: Food cold storage with temperatures between -40°C and -60°C, pharmaceutical deep-freeze storage areas, and cleaning equipment outdoors in northern winter (below -45°C).

Note: Requires use with low-temperature-resistant bearings (such as SUJ2 bearings) and low-temperature grease (synthetic hydrocarbon-based grease) to prevent bearing freezing and seizure.

2. Polyurethane (PU) - Low-Temperature Resistant (-50°C to -70°C)
Low-temperature-resistant polyurethane, through molecular structure adjustments (such as the use of polyether soft segments), resists hardening and brittleness at low temperatures. It offers both elasticity and wear resistance, making it suitable for extreme low-temperature environments requiring shock absorption.
Performance Advantages: Excellent low-temperature toughness. Shore hardness changes by no more than 10 degrees at -70°C, while maintaining good elasticity, providing cushioning against floor bumps (such as the bumpy surfaces found in low-temperature workshops). The surface friction coefficient is moderate, ensuring a non-slip surface. It is also resistant to grease and mild chemicals, making it suitable for low-temperature, oily environments (such as low-temperature machinery maintenance carts).
Suitable Applications: Low-temperature laboratories (for transporting precision instruments) operating between -50°C and -70°C, polar research equipment (for outdoor portable carts), and low-temperature food processing workshops (for lightly oiled floors).
Precautions: Avoid prolonged contact with strong solvents (such as acetone) to prevent material swelling. The load capacity is slightly lower than that of nylon, with a recommended single-wheel load of 50-200kg.

3. All-Metal Material (Stainless Steel/Cast Iron, Below -80°C)
All-metal casters (both the wheel body and the wheel frame are metal) offer the highest low-temperature resistance, eliminating the risk of brittle cracking. They are suitable for applications involving extreme low temperatures, heavy loads, and high wear resistance.
Performance Advantages: Stainless steel (such as 304 and 316) and cast iron maintain rigidity below -80°C without loss of toughness, resulting in extremely high load capacity (a single wheel can carry 500-2000kg). The wheel body surface can be hardened, offering superior wear resistance compared to plastic, making them suitable for heavy equipment operating at low temperatures (such as cold storage racks and supports for cryogenic pressure vessels).
Suitable Applications: Ultra-low-temperature cold storage below -80°C (such as liquid nitrogen storage equipment), heavy-duty outdoor projects in northern regions (such as construction material transfer below -50°C), and areas surrounding low-temperature industrial furnaces (requiring resistance to alternating high and low temperatures).
Precautions: Poor elasticity and shock absorption make them unsuitable for carrying precision instruments or fragile items. Bearings require regular application of low-temperature grease to prevent metal parts from seizing at low temperatures.

4. Polytetrafluoroethylene (PTFE, -200°C to 260°C)
Polytetrafluoroethylene (commonly known as "Teflon") has one of the widest temperature resistance ranges. Its performance remains stable even at extremely low temperatures, making it suitable for ultra-low temperature and highly corrosive environments.
Performance Advantages: It offers low-temperature resistance down to -200°C, without any embrittlement or deformation at ultra-low temperatures. It is also resistant to strong acids and alkalis (such as concentrated hydrochloric acid and sodium hydroxide) and strong solvents, making it suitable for environments with both low temperatures and corrosive environments (such as reagent transport vehicles in low-temperature chemical plants). Its smooth surface offers an extremely low coefficient of friction and low rolling resistance.
Suitable Applications: Ultra-low temperature laboratories operating between -80°C and -200°C (for transporting highly corrosive reagents), supporting cryogenic chemical storage tanks, and supporting ultra-low temperature equipment in the aerospace industry.
Precautions: Its mechanical strength is relatively low, with a weak load-bearing capacity (recommended single wheel load ≤ 50kg). Its cost is relatively high, making it recommended only for use in ultra-low temperature and highly corrosive environments.