国产高潮一区二区三区久久久久久,国产精品一级毛片久久久网曝门,黄色免费成人A片视频,特级西人体人体444www,91亚洲熟女乱综合一区二区

上海獅邁科技有限公司

在線咨詢
微信

微信掃一掃

長按二維碼關注微信加好友

? 免費咨詢熱線:400-077-8606

Effectiveness of Helmet and Face Shield For Waterjetting Protection

發(fā)布時間:2017-07-26 14:26

Katakura and Guo* presented a research study in this subject, aiming to provide data necessary for establishing industrial safety standards.

A waterjet with a diameter of 0.2 mm and up to 200 MPa pressure was used in this study. Commonly used industrial safety helmets were cut in halves and then impacted with the jet at different angles, different stand-off distances, and different pressures. The helmet is made from fiber-reinforced plastics (FRP). Its thickness varies between 1.4 mm and 2.8 mm. The face shield was simulated with 2 mm thick acrylic resin plates. The time from the jet exiting the nozzle till penetration was recorded with a hand-operated stop watch. Jetting was stopped after 30 seconds if no penetration occurred.

The results are summarized as follows:

  • No penetration occurred on the helmet within 30 seconds of impact if the jet is 200 mm away, shotting at the front of the helmet, and the pressure is below 40 MPa.
  • Penetration occurred 100% on the helmet within 30 seconds of impact if the jet is only 100 mm away, shotting at the front of the helmet, and the pressure is above 100 MPa.
  • When the pressure reached 200 MPa, the helmet was penetrated at the weakest spot within 30 seconds when the jet was at 350 mm or within 10 seconds when the jet was at 320 mm.  The helmet was not penetrated within 30 seconds when the jet was 410 mm or further away.
  • The chance of penetration is higher if the jet hits the side (instead of front) of the helmet.
  • The jet aiming at an angle (instead of perpendicular to the target surface) has a lower chance of penetration.
  • The simulated face shield (2 mm thick acrylic resin plate) was not penetrated within 30 seconds under 200 MPa if the jet was 0.5 meter or further away. The plot to the right shows the safe distance at different pressures


Their conclusion was that the commercially available helmets and face shields are useful protective devices if the jet is kept at a suitable distance away.

* Katakura, H. and Guo, C. (2006) Research on personal protective devices for water jetting operation --- performance of head and face protectors, Proceedings of the 8th Pacific Rim International Conference on Water Jet Technology, Oct. 10-12, Qingdao, China, Paper 42.

掃一掃在手機上閱讀本文章

精品国产乱码久久久久久蜜柚 | 免费观看自慰喷水www久久久 | 亚洲精品久久久无码白峰美 | A√国产精品一级特成人午夜影院 | 红桃视频无码视频欧美 | 国产电在线观看一区二区三 | 少妇黃色A片三級三級三級 精品秘 无码一区二区久久 | 三级片无码在线观看 | AV无码播放一级毛片免费野外内设 | 欧人又大又粗XXXXⅩXX | 亚洲第一啪啪啪Av | 三级毛片啪啪视频 | 免费毛片A片试看20分钟 | 国产精品毛片VA一区二区三区 | 又粗又硬又爽18级A片 | 国产伦精品一区二区三区免.费 | 日本熟女中出一区二区三区在线 | 日韩人妻中文字幕 | 极品少妇人妻aV无码久久伦理电影 | 91在线免费视频 | 91精品久久久久久综合五月天 | 亚洲国产一区二区三区在线播放 | 国产精品美女久久一国产成人 | 国产性猛交普通话对白 | 偷拍农村妇女BBBBBB视频 | 亚洲成人午夜电影 | 国产69精品久久久久久久久久久久 | 久久久久裸体模特视频 | 久久综合精品一区二区三区 | 国产 中文字幕 公司 | 中國老女人50-60岁一級片 | 91丨牛牛丨国产人妻 | 亚洲欧美日韩线观看视频 | 中文字幕免费看线人 | 淫香淫色一区二区三区四区 | 欧美精品久久久久久久久爆乳 | 欧美日韩高清无码 | 熟女人妻第10页 | 综合天堂AV久久久久久久 | 亚洲国产成人AⅤ毛片大全密桃 | 国产丝袜在线播放竹菊 |