Concave-Shaped Office Chair

The pre-shift chair is a typical representative of concave-shaped office chairs, with its design features and functions meeting the needs of office scenarios. The specific analysis is as follows:

The pre-shift chair is a配套用具 (supporting tool; here, it can be translated as 'supporting piece of furniture') in the classification of office chairs, and its core design includes a concave-shaped thickened seat cushion. This structure forms an ergonomic support surface with a depressed middle and raised sides: the depressed part fits the curve of the buttocks, dispersing pressure; the thickened areas on the sides can support the outer thighs, reducing numbness caused by prolonged sitting. Meanwhile, the inclination angle of the seat cushion (usually 5°-10° forward tilt) can guide the lumbar spine to maintain a natural forward convex posture, alleviating lower back fatigue caused by improper sitting postures, especially suitable for office scenarios that require maintaining an upright sitting posture for long periods.

In terms of frames and materials, the pre-shift chair offers two frame options: solid wood and steel. The solid wood frame uses natural wood (such as oak and walnut) as the base material, which is processed through drying, sanding, and other techniques, featuring environmental friendliness, durability, and a warm touch. However, it has a relatively high cost and requires regular maintenance to prevent moisture. The steel frame is made of cold-rolled steel plates or aluminum alloys, formed through welding and spraying processes, possessing high strength and resistance to deformation, suitable for high-frequency use environments, and is relatively lightweight for easy movement.

In terms of upholstery, the pre-shift chair is covered with leather or PU leather. The genuine leather upholstery mainly uses natural top-grain leather, which has excellent breathability and a soft touch but is relatively expensive and should avoid direct sunlight. PU leather (polyurethane synthetic leather) is made by simulating the texture of genuine leather, with lower cost, strong wear resistance, and easy cleaning, suitable for use in public office areas. Some high-end models are also equipped with a mechanical swivel function, which enables 360-degree automatic return through built-in springs or damping devices, preventing the chair from deviating from its original position after being rotated by external force and improving convenience of use.

It should be noted that the safety performance of the pre-shift chair must comply with industry standards (such as QB/T 2280-2016), including gas rod compression tests and five-star foot load-bearing standards. When purchasing, focus on checking whether the gas rod has passed certifications such as SGS and BIFMA to ensure there is no risk of explosion; also observe the material of the five-star foot (nylon or steel) and the type of chair wheels (hard or soft wheels) to match different floor environments.