{"id":6497,"date":"2026-11-04T11:46:04","date_gmt":"2026-11-04T03:46:04","guid":{"rendered":"https:\/\/www.bacintl.com\/?p=6497"},"modified":"2026-11-04T08:16:29","modified_gmt":"2026-11-04T00:16:29","slug":"operating-specifications-precautions-for-horizontal-flow-clean-bench-to-maintain-cleanliness-compliance","status":"publish","type":"post","link":"https:\/\/www.bacintl.com\/ar\/operating-specifications-precautions-for-horizontal-flow-clean-bench-to-maintain-cleanliness-compliance\/","title":{"rendered":"Operating Specifications & Precautions for Horizontal Flow Clean Bench to Maintain Cleanliness Compliance"},"content":{"rendered":"

\"\"<\/p>\n

1. Pre-start Inspection<\/h3>\n

Inspect the equipment thoroughly before each use to avoid operation under fault conditions. Check the power supply circuit and control panel, confirm the emergency stop button is reset. Read the differential pressure gauges of pre-filter and HEPA filter and compare with historical records. If the differential pressure exceeds the final resistance significantly, the filter is clogged and the equipment must not be started. Clear debris, leftover samples and packaging materials inside the chamber, as obstacles will disrupt laminar flow and create vortex accumulation. Ensure the front shield and air inlet\/outlet are not blocked; do not stack cartons, tools or consumables near return air and supply air openings. Verify UV lamp, lighting and fan functions. If disinfection has just finished, allow sufficient ventilation time for ozone and disinfectant vapors to dissipate before operation. For new units or equipment shut down for a long time, run pre-purge in advance.<\/p>\n

2. Standard Pre-purge Procedure (Easily Neglected On-site)<\/h3>\n

Particles will settle inside the chamber during standby, so pre-purging is mandatory for unidirectional laminar benches. Under normal conditions, pre-purge for 15\u201330 minutes<\/strong> before starting work. Extend pre-purge to over 30 minutes if the bench has been shut down for more than 24 hours, freshly wiped and disinfected, after filter replacement or maintenance. Startup sequence: Power on \u2192 Turn on fan, confirm wind speed stabilizes within the normal range (0.35\u20130.50 m\/s for horizontal flow bench) \u2192 Turn on work lighting. UV disinfection can only run when the chamber is unoccupied and the shield is closed. UV lamp is strictly forbidden during operation<\/strong> to prevent skin and eye injury. Watch for abnormal fan noise, vibration and odor during pre-purge, confirm differential pressure, wind speed stay stable without alarms.<\/p>\n

\"\"<\/p>\n

3. Operating Requirements<\/h3>\n
    \n
  1. Personnel Attire<\/strong>: Wear cleanroom suit, clean cap, gloves and mask before approaching the work zone. Ordinary cotton gloves and wool caps are prohibited. Remove watches and jewelry where possible. Disinfect hands with 75% ethanol. Avoid large, fast arm movements that disturb laminar flow and generate turbulence.<\/li>\n
  2. Material Placement<\/strong>: Clean all tools and materials outside the bench before transferring them inside. Place items along both sides of the work surface. Never stack goods in front of the rear HEPA air outlet<\/strong>, which will block airflow and cause turbulence. Leave gaps between items for air passage. Heavily contaminated unclean materials cannot be brought into the clean zone.<\/li>\n
  3. Operation Sequence<\/strong>: Put clean components on the upstream side (close to the HEPA filter), and semi-finished \/ processed products on the downstream side. Contaminants travel forward along horizontal airflow. Reversing the upstream-downstream layout will easily lead to cross-contamination.<\/li>\n
  4. Front Shield Control<\/strong>: Do not open the operation window wider than the specified height. An oversized opening will entrain dirty ambient air and break unidirectional laminar flow, resulting in failed cleanliness. Avoid frequent movement of items outside the opening to reduce air disturbance.<\/li>\n
  5. Prohibited Operations<\/strong>: Do not perform grinding, crushing or other processes generating massive dust and splashes inside the bench. Avoid large-volume volatile strong acid or alkali solvents without exhaust adsorption, which are hazardous to operators and accelerate filter fouling.<\/li>\n<\/ol>\n

    4. Shutdown Procedure<\/h3>\n

    After work, remove all materials and waste out of the bench. Wipe the worktop, inner wall and shield with lint-free cloth and suitable disinfectant, wiping from rear to front following airflow direction<\/strong>. Do not wipe backward, which will carry downstream contaminants to the upstream HEPA side. Keep the fan running for another 10\u201315 minutes after wiping to blow out suspended particles, then turn off fan and lighting. If UV sterilization is needed, close the shield and start UV timing. Cut off the UV power after disinfection. For long-term storage, disconnect the main power and cover the bench for dust protection.<\/p>\n

    5. Daily Maintenance & Validation Management<\/h3>\n
      \n
    1. \u0627\u0644\u0641\u0644\u062a\u0631 \u0627\u0644\u0645\u0633\u0628\u0642<\/strong>: Inspect weekly, clean or replace according to differential pressure, generally replaced every 1\u20133 months. As the first barrier, clogged pre-filter reduces air volume, breaks laminar uniformity.<\/li>\n
    2. \u0641\u0644\u062a\u0631 HEPA<\/strong>: The core filtration component, do not disassemble by yourself. Record differential pressure regularly. Replace the HEPA when reaching final resistance, wind speed drops sharply or particle test fails. After replacement, PAO leak test and wind speed uniformity test must be performed to confirm no leakage and normal flow pattern before putting back into service. The HEPA of horizontal flow bench is installed at the rear close to the operator zone; leakage will quickly spread contaminants to products.<\/li>\n
    3. Cleaning Notes<\/strong>: Use lint-free cloth only. Steel wool and rough rags are forbidden to avoid scratching the surface and filter guard. Select low-residue disinfectants compatible with stainless steel. Do not spray liquid disinfectant directly onto the HEPA filter surface, which will damage filter media and cause moisture failure.<\/li>\n
    4. Periodic Validation<\/strong>: Conduct suspended particle test and wind speed uniformity test per the validation plan, keep complete records. Particle monitoring at least every six months is recommended for GMP and laboratory quality traceability.<\/li>\n<\/ol>\n

      \"\"<\/p>\n

      6. Critical Risk Reminders (Distinguish from Vertical Flow Bench<\/a> & Biosafety Cabinet)<\/h3>\n
        \n
      1. Horizontal flow airflow blows directly toward operators. It only protects samples and products, and cannot protect personnel<\/strong>. Operations involving pathogenic microbes, infectious aerosols and toxic biological samples are prohibited on horizontal flow benches. A Class II biosafety cabinet must be adopted to avoid operator exposure.<\/li>\n
      2. Environment Layout: Place the bench away from doors, air-conditioning outlets and high-traffic walkways. External cross airflow is the top cause of particle overrun. Reserve sufficient space around the unit for maintenance.<\/li>\n
      3. ESD Risk: For electronics and optical workshops, choose ESD horizontal flow models. For standard benches handling static-sensitive components, equip grounding and anti-static wrist straps to prevent ESD damage.<\/li>\n
      4. No Unauthorized Modification: Do not adjust fan speed, modify air duct or remove shields arbitrarily. Improper changes will destroy the designed airflow and create turbulent dead zones.<\/li>\n<\/ol>\n

        7. Common Causes of Cleanliness Failure<\/h3>\n

        Most particle non-compliance issues are not caused by broken filters, but improper operation: insufficient pre-purge time, blocked air outlet, oversized opening, placement in draughty aisles, violent movements disturbing airflow, reversed upstream\/downstream layout, and overdue pre-filter replacement. Standardize operation and regular inspection & validation to maintain stable Class 100 cleanliness and prevent batch product contamination.<\/p>","protected":false},"excerpt":{"rendered":"

        A horizontal flow clean bench is a local unidirectional laminar purification device. It delivers clean airflow horizontally to form an ISO Class 5 (Class 100) clean working zone. Unlike vertical flow clean benches where air flows downwards, the horizontal flow bench discharges clean air from the rear HEPA filter and blows forward in parallel. It features a short airflow path, uniform wind speed and low resistance, and is suitable for applications such as electronics assembly, optical component inspection, wafer testing and sample packaging where product protection is the priority. Nevertheless, the horizontal airflow blows directly toward the operator, and aerosols may drift toward the human body, so its application scope has clear limitations. To keep cleanliness stable and prevent particle overrun and product contamination, operators must strictly follow startup procedures, operation specifications, maintenance schedules and safety requirements.<\/p>","protected":false},"author":3,"featured_media":6498,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[92],"tags":[],"class_list":["post-6497","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-industry-technology"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.bacintl.com\/ar\/wp-json\/wp\/v2\/posts\/6497","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.bacintl.com\/ar\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.bacintl.com\/ar\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.bacintl.com\/ar\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/www.bacintl.com\/ar\/wp-json\/wp\/v2\/comments?post=6497"}],"version-history":[{"count":2,"href":"https:\/\/www.bacintl.com\/ar\/wp-json\/wp\/v2\/posts\/6497\/revisions"}],"predecessor-version":[{"id":6502,"href":"https:\/\/www.bacintl.com\/ar\/wp-json\/wp\/v2\/posts\/6497\/revisions\/6502"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.bacintl.com\/ar\/wp-json\/wp\/v2\/media\/6498"}],"wp:attachment":[{"href":"https:\/\/www.bacintl.com\/ar\/wp-json\/wp\/v2\/media?parent=6497"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.bacintl.com\/ar\/wp-json\/wp\/v2\/categories?post=6497"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.bacintl.com\/ar\/wp-json\/wp\/v2\/tags?post=6497"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}