Beyond N95: Industrial filters create particle-capturing masks
Japan's Yamashin-Filter utilizes material used in construction machinery
ANNU NISHIOKA, Nikkei staff writerAPRIL 21, 2020 07:30 JST
Yamashin-Filter supplies filter parts for use in construction machinery, including Komatsu’s hydraulic shovels. It has now developed a replaceable insert for face masks and also plans to manufacture its own mask.TOKYO -- Yamashin-Filter, a Japanese manufacturer of filters for construction machinery, has developed a high performance replaceable face mask insert boasting extended particle-blocking performance and plans to ramp up mass production of its own mask next month as demand for protection soars with the spread of the novel coronavirus.
Yamashin has adapted its manufacturing technology for filters in construction machinery to applications in clothing and farming, but now is aiming to expand its consumer-oriented business amid a critical shortage of face masks.
The company is already selling its Nano Filter, which it says can efficiently trap airborne particles, as a replacement insert for face masks. The product takes advantage of technology used in the construction-machinery hydraulic filters it sells to Japan's major construction machinery makers, including Komatsu and Hitachi Construction Machinery. The technology sprays melted resin on to fibers to create a filter mesh with hard-to-penetrate gaps measured at nanometer levels.
Yamashin also plans to use the same technology to manufacture an actual face mask. A mask using the company's filter blocks out 98% of particles measuring 0.3 micrometer, exceeding the percentage figure for N95 masks used by health care workers. The figure drops only to 90% even after 24 hours of use -- exceeding N95 masks by over 10 percentage points -- and makes for longer-lasting performance. Cheaper surgical masks, meanwhile, block just 43% of particles, with the figure dropping to 15% after 24 hours.
Widely available disposable face masks block particles and viruses using static electricity, but performance declines due to the effect of humidity in human breath as well as the passage of time. By contrast, Yamashin's filter uses fibers with a thickness less than one-tenth that of average chemical ones. It is formed in a three-dimensional structure to trap particles and can maintain a high capture ratio for an extended period of time as it does not rely on static, according to the company.
While the diameter of fibers used in typical face masks is about 3 micrometers, those in Yamashin's measure between 0.2 micrometer to 0.8 micrometer. The diameter of one novel coronavirus is 0.1 micrometer, but the mesh formed by the filter has sufficiently fine gaps to block particles bearing the virus, the company said.
About 80% of face masks available in Japan are imports, but Yamashin manufacturers domestically to ensure stable supply to the local market. It has already started production of the replacement insert at its plant in the southwestern Japanese prefecture of Saga. Mass production of its full mask will start in May, with a plan to increase output to 5 million per month by the end of July.
Yamashin plans to make about 360,000 replaceable inserts per month and aims to spend about 50 million yen ($463,000) on production lines and other equipment. The inserts are already on sale at the Yuzawaya chain of craft supply stores operated by Tokyo's Yuzawaya Shoji. Yamashin plans to supply the inserts to face mask makers while selling its own masks through major drugstore chains.
Construction machinery makers represent some 90% of Yamashin's filter sales. Yamashin's revenue suffered after Japanese construction machinery manufacturers lost share to local rivals in a price-cutting competition in the Chinese market, while the company's domestic product shipments remain low. It forecasts revenue to total 12.7 billion yen for the year ended March, down 8%from a year earlier.
For the current year ending March 2021, Yamashin aims to bolster sales of construction machinery filters targeting Chinese construction machinery makers and develop use of its nano filters for purposes other than face masks. The company's filters, for example, are already used in linings for coats manufactured by a men's clothing manufacturer for their insulating quality. Yamashin is also seeking ways to use the filters in home electronics products and automobiles for their sound-absorbing quality.
Yamashin also expects the creation of a mask division will help boost annual sales of its Nano Filter to several billion yen and aims to roll out other consumer-oriented products as well.
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口罩：材料、生產及檢驗方式
2020年3月29日 星期日
snorkel masks, hazmat suit and respirator/ inhalator, face shields, gowns, chemically modified medical face mask
mask和respirator，中文都翻譯成口罩。
最容易瞭解的方式：台灣最廣泛發放的，乃稱外科用口罩 surgeon mask或 surgical mask。
N95 型口罩，英文稱為 N95 respirator。
N95 型口罩，英文稱為 N95 respirator。
10. 台灣捐了口罩給歐美，博得美名，但這只有象徵意義，因為西班牙已跟中國大陸買了三十億個口罩。全世界口罩荒還是要靠中國大陸來幫忙，這是政治現實。~沈政男 2020.4.2
2020.4.3 讀到瑞士資訊中文網 swissinfo.ch
截至4月2日，瑞士全國確診的新冠病毒感染人數共計18'072人，死亡497人。----
聯邦衛生局的Daniel Koch在4月2日的新聞發布會上說，瑞士感染人數又有所增多，雖然不再是直線上升，但是每天感染的人數依然相當可觀，死亡人數在還在增長。 “現在還沒有達到拐點，”他說，目前做任何預測都為時尚早，更不能放寬政策。
Koch還說，現在聯邦和蘇黎世各購買了一台口罩機。每天能生產6萬支FFP2口罩。瑞士每天需要消耗100萬-200萬支口罩，目前瑞士的口罩儲備量是1400萬-1700萬支。
This document is only intended to help clarify some key similarities between such references, specifically to the following FFR performance standards:---
• N95 (United States NIOSH-42CFR84)
• FFP2 (Europe EN 149-2001)
• KN95 (China GB2626-2006)
• P2 (Australia/New Zealand AS/NZA 1716:2012)
• Korea 1st class (Korea KMOEL - 2017-64)
• DS (Japan JMHLW-Notification 214, 2018)
https://multimedia.3m.com/mws/media/1791500O/comparison-ffp2-kn95-n95-filtering-facepiece-respirator-classes-tb.pdf
Comparison of FFP2, KN95, and N95 Filtering Facepiece ... - 3Mmultimedia.3m.com › mws › media › comparison-f...PDFこのページを訳すComparison of FFP2, KN95, and N95 and Other Filtering Facepiece. Respirator Classes. Description. Filtering facepiece respirators (FFR), which are sometimes called disposable respirators, are subject to various regulatory standards around ...
不織布同業公會今發文表示，N95口罩的發明者鮮為人知，但卻是一位優秀而低調的台灣工程師蔡秉燚（Peter Tsai）博士。
該篇文章表示，N95的「N」表示不防油，而「95」表示至少能過濾掉95%的流感病毒、灰塵、花粉、霧霾、以及煙塵等微小顆粒物。而與醫用外科口罩類似，N95口罩的主體結構是由表層抗濕層、中間過濾吸附層以及內層貼膚層3部分組成，原材料均為高分子材料聚丙烯。
其中表層抗濕層和內層貼膚層，大多都以紡粘不織布和熱風不織布為原料，此類不織布的纖維直徑在15到40μm，透氣性出色，但幾乎沒有過濾能力，它們作為口罩的最外和最內層，主要目的在於定型和保護中間層的熔噴布。
而中間的熔噴布就是口罩製造技術的核心，因此目前在市場上已經被炒到了30多萬元一噸。而熔噴布的過濾原理在於纖維（直徑為1到5μm）細密而錯雜地排列，可以說沒給粉塵、病毒與細菌微沫留任何進入的空檔，發揮著過濾與阻隔的核心作用。
但熔噴布的製造卻需要兩大核心技術支撐。第一，熔噴布需要用穩定又精確的熔噴不織布工藝生產，必須拉出平均直徑小於5μm的超細纖維。 第二，拉出的熔噴布還得經過靜電處理，讓纖維表面帶上大量靜電電荷，借助吸附作用來捕捉細微顆粒物，是過濾防護的關鍵。
而蔡秉燚（Peter Tsai）博士在材料方面涉獵廣泛，同時研究熔噴不織布工藝，及靜電處理，使目前能以成熟技術在高壓、高熱空氣下將聚合物牽伸成超細纖維。而在靜電處理技術方面更是有革命性貢獻，蔡秉燚利用電場使中性的空氣發生電離，產生帶相反電荷的離子和電子，然後通過電場和感應使不織布纖維帶電，便可以吸附各種穿過口罩的微小物體。
而這種方法得到的靜電不織布過濾空氣中顆粒的能力，較無靜電者強了10倍，且不會阻礙空氣流通；這種技術也成了N95口罩的基礎。
該篇文章也說，蔡秉燚做為不織布纖維領域的先鋒，目前擁有12個美國發明專利，超過20個商業產品授權，技術被工業界廣泛使用了30多年；除了用在N95和醫用口罩上，還有HVAC空氣篩檢程式等產品。
而他在田納西大學工作長達35年，去年才剛退休，去年十二月又因新發明再度拿到田大惠利獎，取名為創新者名人獎，是田大有史以來唯一第二次拿該奬的人。
而台灣民眾雖不見得認識蔡秉燚博士，卻可能已經看過他所寫的文章。日前台灣網路上有不少民眾轉傳一篇關於口罩使用及消毒的建議的Q&A，也是蔡博士所撰寫的。該篇文章說明口罩是否可加熱消毒、可用次氯酸水消毒或水洗。
該篇文章表示高品質的口罩在70度Ｃ30分鐘殺病毒的條件下，電荷消失微乎其微，可以加熱30分鐘處理數次。次氯酸鈉（漂白水，非次氯酸）如無界面活性劑、不會在口罩表面散開，就不會使口罩的靜電消失。是否可水洗清潔，則要視口罩本身材質而定，一般而言靜電不會消失，但也不能一蓋而論，僅限使用合格材料口罩。
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陳志傑說，台灣的醫護人員用的是一般的醫療口罩或是N95口罩，但口罩的密合度不佳，也會影響防護作用，醫護人員是防疫的重中之重，雖然職安署預計今年開始購入更強的呼吸防護器具作為醫療使用，但其實有點緩不濟急，除了密合度測試，也要做教育訓練，「應該早就要做，下一次就可以用了。」，同時也建議在第一線的醫療系統中加入氣膠技術專業，或是呼吸防護專業者。
韓國忠清日報於1月30日報導，韓國的口罩生產業因口罩用的「濾膜」原材料不足面臨一週內停止運作的危機。由於現時受到「武漢肺炎」肆虐的影響，韓國本地對於口罩的需求愈來愈大，甚至一度出現短缺。中國內地亦為確保內地境內的口罩供應，禁止中國製口罩原材料「濾膜」的輸出，導致韓國的口罩廠無可避免受到影響。
前線醫護批醫管局提供較低防護力口罩 未達世衛建議標準
2020/1/29 — 16:26
武漢肺炎疫情不斷蔓延，由於病徵不明顯及部份病人隱瞞近期外遊紀錄等，增加前線醫護人員受感染機會，而世衛早前已建議醫護接觸一般病人時，應使用防水及過濾細菌能力較高的ASTM F2100-11第二及第三級別口罩，惟有醫生及前線醫護人員向《立場新聞》表示，現時除隔離病房以外，大部分醫管局醫護人員只獲提供屬低防護的第一級別口罩，令不少醫護擔憂口罩防護力不足，隨時受到感染。
根據美國材料和試驗協會（American Society for Testing and Materials, ASTM）F2100-11標準，口罩可根據其防護力分為三級，分別為低防護的第一級別、中等防護的第二級別及高防護的第三級別，當中第一級別的口罩細菌過濾率須大於或等於95%，第二及第三級別口罩的細菌過濾率須大於或等於98%，第三級別口罩阻擋液體的能力則較高。
世界衛生組織於今年1月11日公佈，有關接觸新型冠狀病毒時的防護裝備規格的建議，醫護人員在接觸一般病人時，應使用符合ASTM2100-11標準的第二或第三級別的口罩，惟有前線醫護向《立場新聞》透露，現時醫管局為醫院及門診醫護人員提供的外科口罩，大部份只屬於低防護的第一級別，有醫護已向管理層反映問題及擔憂，但暫未獲回應。
內科病房醫護及病理實驗室職員只獲第一級別口罩
該名現於醫管局任職的醫生表示，現時不少患者到醫院求診時不會主動透露自己近期曾到訪內地，直到見醫生時才透露外遊紀錄，加上武漢肺炎的病徵不明顯，大幅增加前線醫護人員被感染的機會，不少醫護及其家人都十分擔心，該醫生擔心如疫情爆發，醫管局是否可提供足夠的第二及第三級別口罩予前線醫護，並認為醫管局應加快提供應變措施，「唔好過晒時機先做野」。
另外，有前線物理治療師亦向《立場新聞》表示，大部份普通科門診的前線醫護均只獲提供第一級別的口罩，但現時已有數宗疑已被感染的「隱形病人」先向普通科門診求診，其後才被確診，令防護裝備不足的前線醫護人員更為擔心。
該名物理治療師又透露，除普通科門診外，東區醫院有一個內科病房的醫護只獲提供第一級別外科口罩；有九龍西聯網病理實驗室工作的職員，亦只獲提供第一級別外科口罩，令一眾前線醫護人員人心惶惶，擔心防護裝備不足下隨時被感染。
《立場新聞》已就事件致函醫管局查詢，醫管局指回覆指將會安排香港大學李嘉誠醫學院微生物學系講座教授袁國勇，以及醫院管理局總感染控制主任賴偉文醫生於今日下午5時會見傳媒，講解公立醫院的感染控制措施，包括外科口罩的標準及應用。
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Dust Mask and Filter Cartridge Ratings
Respiratory Filters come in a variety of ratings that relate to how the respirator performs (how much it filters) and what environment type it is designed to be used in. When choosing a respirator it's important to understand that as the letter rating and number rating increase, breathing fatigue will increase. While you certainly don't want to choose a rating that is too low, you don't necessarily always want to pick a P100 filter for every application - particularly if you're just looking for a simple dust mask to do home improvement work. Typically, an end user will find an N95 respirator cooler, and easier to breath through than a P99 or P95 dust mask.
Respirator Rating Letter Class
- N - Not oil resistant
- R - Resistant to oil
- P - Oil Proof
Respirator Rating Number Class
- 95 - Removes 95% of all particles that are at least 0.3 microns in diameter
- 99 - Removes 99% of particles that are at least 0.3 microns in diameter
- 100 - Removes 99.97% of all particles that are 0.3 microns in diameter or larger. HE or HEPA quality filter.
Respirator Ratings & Considerations
Quite simply, a respirator with a rating of P100, has been tested to be proof against oil, and tested to filter 99.97% of all particles 0.3 microns in diameter or larger. To the right you can see various examples of the size (in microns) of various substances for comparison.
N95 Masks
Most commonly used for Flu or Influenza prevention, these masks are effective according to the CDC in helping to prevent the spread of Flu, swine flu and avian flu transmission from person to person. N95 masks are designed to fit over the nose and mouth of the wearer, and properly fitted can provide excellent protection. Our most popular N95 mask is the 3M 8210 Dust Mask.
P95 Masks
Most commonly used for working in environments exposed to oil-based particles, P95 respirators are approved by NIOSH for 95% filtration efficiency against oil-based and non-pil-based particulates. I deally suited in the petrochemical and pharmaceutical sectors. Our most popular P95 mask is the 3M 8271 Dust Mask.
Filters & Cartridges
Used in conjunction with full face respirators or half face respirators, filters and cartridges are used where a more secure fit is desired for the user. Unlike disposable masks which only filter out air-based particulates, cartridges are capable of filtering out non-particulate hazards ranging from organic vaporsr to chlorine and tear gas. Cartridges and filters are sold in pairs typically, and are attached to the masks and discarded when they are worn out. You can explore our full selection of filters & cartridges here. Full masks are typically used in environments where contaminates will irritate mucus membranes and a users eyes.
Are N95 Masks Really Effective against the flu?
A little online research will reveal that the flu virus is .17 microns in size. Clearly smaller than even N100 masks can filter out. However, it is critical to understand that the flu virus does not float in the air by itself. The flu virus is transported from patient to patient on droplets of excretions from sneezing and coughing. These particles are typically 5 microns or larger. When a sick patient wears a respirator, the respirator can be very effective at preventing infectious material from leaving the patients body, and when worn by healthy individuals, it prevents inhalation of said material. More importantly, wearing a mask is a excellent way of preventing the user from rubbing or touching their mouth or nose, which is a very high risk factor. At the end of the day will an N95 mask guarantee to protect you from the Flu? No. But it can substantially reduce your risk or receiving or transmitting the disease.
When do Dust Masks/Filters wear out?
In general, dust masks and filters should be discarded after each "encounter" or "procedure". The risk of contamination can also be heightened by removing and applying the mask multiple times. In general, once removed, the Dust Mask should be disposed of. Additionally, proper hand hygiene should be observed when touching a potentially contaminated mask. Further concern should be given to cross-contamination when wearing masks into different rooms or areas. Regardless of usage, masks should be discarded when used beyond 8 hours, and careful review and testing should be performed in regards to hazardous chemicals/particles.
Example Particle Sizes
| Particle | Particle Size (microns) |
|---|---|
| Anthrax | 1 - 5 |
| Asbestos | 0.7 - 90 |
| Atmospheric Dust | 0.001 - 40 |
| Bacteria | 0.3 - 60 |
| Beach Sand | 100 - 10000 |
| Bone Dust | 3 - 300 |
| Bromine | 0.1 - 0.7 |
| Carbon Dioxide | 0.00065 |
| Copier Toner | 0.5 - 15 |
| Corn Starch | 0.1 - 0.8 |
| Fiberglass Insulation | 1 - 1000 |
| Lead | 0.1 - 0.7 |
| Metallurgical Dust | 0.1 - 1000 |
| Mold Spores | 10 - 30 |
| Oil Smoke | 0.03 - 1 |
| One inch | 25400 |
| Oxygen | 0.0005 |
| Pesticides & Herbicides | 0.001 |
| Radioactive Fallout | 0.1 - 10 |
| Red Blood Cells | 5 - 10 |
| Saw Dust | 30 - 600 |
| Smoke from Natural Materials | 0.01 - 0.1 |
| Smoke from Synthetic Materials | 1 - 50 |
| Spores | 3 - 40 |
| Sugars | 0.0008 - 0.005 |
| Tobacco Smoke | 0.01 - 4 |
| Typical Atmospheric Dust | 0.001 to 30 |
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