Low Back Telescopic Grandstand Structure Design Description

　　Design specifications of movable grandstand

　　1、Structure specification of grandstand bracket: step width 700mm, step height 300mm.

　　2. Seat name and specification: low-back seat, seat width 420 mm, seat depth 420 mm, seat height 180 mm, seat installation distribution center distance 460 mm-520 mm.

　　3, bleacher seat material introduction: 1, the design, selection and installation of the seat with the stadium design, beautiful and comfortable, safe, durable, easy to install maintenance and management . The seat surface adopts hollow blow molding manufacturing process, selecting high-density polyethylene materials (HDPE) one-time processing and molding, with the seat surface edges and corners smooth, molecular weight concentration, high bonding strength at the confluence joints, high rigidity and toughness, good mechanical properties and high temperature, anti-aging, impact resistance, high and low temperatures, oil resistance is better.

　　2, the comprehensive performance of the seat should be in line with the standards and industry standards.

　　3, mechanical properties: chair static load 2000N, 20 times, chair back static load 800N, 20 times, seat balance load 2000N; seat durability: chair surface load 960N, 200,000 times, chair back load 350N, 200,000 times, chair impact height 360mm, 20 times, chair back impact height 630mm, 20 times; seat parts without fracture or crack phenomenon, loading parts without obvious deformation, seat structure without 360mm, 20 times, chair back impact height 630mm, 20 times; seat parts without fracture or open phenomenon, no obvious deformation. There is no obvious deformation in the seat parts and no loosening of the seat structure.

　　4, aging resistance aging test ≥ 3500h, impact strength retention rate should not be less than 60%, the appearance of color change rating is not less than 3 levels;

　　5, high and low temperature performance: According to the technical conditions of the enterprise, in the high temperature +80 ℃, low temperature -60 ℃ 72h, no local changes, cracks, spots, bubbles and obvious deformation and other appearance changes.

　　6、Flame retardant performance: seat density ≤ 50 %, flame retardant level 1.

　　7, the color of the seat group: provide international standard plastic color (PANTONE) by the owner, the design institute to determine.

　　4, bleacher expansion mode: manual, electric contraction.