久久精品黄,亚洲自拍一区在线观看,97久久精品人人爽人人爽蜜臀,美女双腿大开被绑在床扒衣服,国产久99,国产一区二区三区免费播放,亚洲二区在线视频,久久精品久久久久久久

Fireproof and Disaster-resistant Door Technology


Published Time:

2025-09-25

  Material & Gauge Selection
Door leaf and frame components are fabricated from hot-dipped galvanized steel sheet to EN 10346 or ASTM A653, typically 1.2 mm – 1.5 mm thick for integrity and 0.8 mm – 1.0 mm for stiffeners. Zinc coating ≥ Z275 g/m2 guarantees corrosion resistance after bending without micro-cracking. 

   C N C Press-Brake Setup
? Machine: 6-axis C N C press brake (±0.1° repeatability, 320 kN – 500 kN).
? Tooling: 28 mm gooseneck punch paired with 60° die opening; tip radius 0.8 t to avoid stress concentrators that could compromise fire resistance.
? Back-gauge: Servo-driven fingers with ±0.05 mm positioning to maintain cumulative tolerance ≤ 0.3 mm on leaf perimeter—critical for intumescent seal compression.
   Bend Sequence & Spring-Back Compensation
? Air-bending at 85° to counter 3–5° spring-back (typical for 1.5 mm Z275 steel).
? Sequence: outer frame → hinge reinforcement channels → lock pocket. Each bend is under-cut 0.2 mm on flange length to guarantee positive fit-up before MIG welding, minimizing weld distortion that could jeopardize fire seal alignment.
   Compliance Checks
? Dimensional: diagonal difference ≤ 1 mm (EN 1634-1).
? Micro-cracking: 10× magnified visual inspection on outer radius; zinc layer intact, no substrate exposure.
? Angle: sampled 1 per 50 parts; SPC chart maintained for CE/UL traceability.
  Post-Bend Treatment
Edges are vibratory-deburred to remove shear burrs < 0.1 mm, preventing hot-spot corrosion and ensuring uniform intumescent seal adhesion. Parts are then alkaline cleaned and zinc-phosphate pretreated prior to epoxy-powder coating (min. 60 μm) for 240 min fire rating compatibility.
Outcome
The above protocol yields leaf and frame components that maintain < 1 mm gap under 500 °C deflection tests, satisfying EN 1634-1 (120 min) & UL 10C (90 min) requirements while enabling clean intumescent seal closure.

主站蜘蛛池模板: 日韩一级片免费视频| 国产91高清| 黄色91在线观看| 91一区在线观看| 精品国产一区二区三| 91黄在线看| 午夜诱惑影院| 日韩无遮挡免费视频| 国产一二三区免费| 国产伦精品一区二区三区免费优势| 91麻豆国产自产在线观看hd | 欧美精品久| 黄色91在线观看| 国产精品自产拍在线观看桃花| 狠狠插影院| 亚洲三区二区一区| 97久久超碰国产精品| 国产免费一区二区三区四区五区| 美女张开腿黄网站免费| 国产精品99在线播放| 亚洲精品日日夜夜| 欧美日本一二三区| 久久激情网站| 精品一区欧美| 片毛片免费看| 精品久久9999| 7799国产精品久久99| 国产精品v欧美精品v日韩| 国产农村乱色xxxx| 欧美精品xxxxx| 中文字幕一区二区三区四| 欧美一区二区三区免费电影| 久久久久久久久亚洲精品| 一级久久精品| 日韩精品中文字幕一区二区| 鲁丝一区二区三区免费观看| 欧美日韩卡一卡二| 91久久精品在线| 国产精品一区二区毛茸茸| 欧美一级免费在线视频| 色噜噜狠狠狠狠色综合久| 中文字幕在线一区二区三区 | 国产精品二区一区| 伊人av中文av狼人av | 强行挺进女警紧窄湿润| 国产vsv精品一区二区62| 欧美日韩高清一区二区| 亚洲欧美日韩精品suv| 少妇太爽了在线观看免费| 国产精品久久久久免费a∨大胸| 素人av在线| av午夜剧场| 国产在线视频二区| 国产精品欧美一区乱破 | 国产精品日本一区二区不卡视频| 91精品一区在线观看| 国产男女乱淫真高清视频免费| 午夜一二区| 亚洲精品日韩激情欧美| 久久99精| 精品在线观看一区二区| 国产999在线观看| 久99久精品| 中文字幕一区二区三区乱码视频 | 福利电影一区二区三区| 日韩偷拍精品| 扒丝袜网www午夜一区二区三区| 国产精品九九九九九九九| 最新国产一区二区| 欧美一级日韩一级| 99欧美精品| 制服丝袜二区| 秋霞av电影网| 99久久精品一区二区| 午夜影院你懂的| 欧美一区二粉嫩精品国产一线天| 7777久久久国产精品| 亚洲精品日韩激情欧美| 99re久久精品国产| 日韩av在线免费电影| 欧美日韩国产欧美| 国产无遮挡又黄又爽免费网站|