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3層外科口罩Surgical Mask 3 Ply


Engineered Fabric 工程用布

(English version at rear part / 简体参阅后半部)

醫工布-由3層PP聚丙烯紡黏不織布製成,過濾進入口鼻空氣。商品名外科口罩,是當下市場上最搶手的物資,而歲月靜好時它們曾被遺忘於一隅。

小小提示:外科口罩的外層–有色層或褶皺向下;有鼻夾為上方。

此類工程紡織品的生產是專門應對一次性使用,以便有效消除交叉感染。

業界廣泛採用PP作為該產品的材料,這不僅是因為其成本較低,還因為:

---無毒:符合FDA食品級原料;

---抗菌:不發霉;

---棄置後(相對)容易降解,因此減輕了對我們周遭環境的負擔 ;

目前業界慣常採用不織布工藝生產此類產業用布,該因不織布生產流程短,高度集約具有很高的生產能力。

不織布是紡織品製造工業的術語,表示既不是梭織也非針織物。不織布由原材製成長絲/纖維,之後鋪成網狀結構,然後通過機械,熱學或化學等手段固成片狀材料。他們直接由原料製成布匹,而跳過慣常的紡紗,以及緊接的梭織或針織工序。

紡織工業有著眾多方式的不織布工藝,僅舉一些:水刺,針刺,熱封,紡黏/熔噴,閃紡...

外科口罩用布普遍採用PP紡黏工藝,因是最直接成布的方法。當PP聚合物被擠出並拉伸以形成連續的長絲,然後鋪排成網狀,利用自黏形成布。但此種工藝僅適合生產輕薄面料。

三層外科口罩,配置為SMS:

外層(S層) - 為標稱20g / sq.M的紡黏PP不織布,經疏水處理,具有防液體和飛濺物;

中層(M層) - 為標稱20g / sq.M的熔噴PP不織布,駐極(關鍵詞!)加工,作為過濾細菌的屏障。

內層(S層) - 標稱20g / sq.M的紡黏PP不織布,經親水處理,吸濕;

其中M層-PP熔噴工藝與紡黏機理基本相同但加添步驟以實現細度為2 µm的超細旦PP纖維(而S層的PP長絲纖度約為20 µm)。因此,熔噴PP纖維天生就是非常好的過濾材料,過濾能力約為35%。但這仍然遠遠未能達到醫用口罩的要求。如果我們僅增加M層過濾網的厚度,將最終導致口罩無法呼吸而不適合佩戴。因此,除卻利用布朗氏擴散,攔截,慣性碰撞,重力沉降此類機械過濾手段外,工業界還需要引入一種新的過濾機理以便應用於外科口罩。因此,駐極空氣濾材應運而生。駐極處理作簡單說明,就是在PP纖維上添加靜電,利用帶電荷纖維的庫侖力去捕獲PM2.5微粒,甚至新的冠狀病毒飛沫(氣溶膠),因此大大提高空氣過濾效率的同時降低空氣阻力。此外,據研究駐極纖維的靜電場會可損壞細菌細胞膜,起殺菌作用。

目前,駐極方法包括靜電紡絲,電暈放電,摩擦電,熱極化和低能電子束轟擊。工業上現較多採用電暈放電方法,因為它可以集成到PP熔噴生產中。

緊接到了口罩生產廠,SMS這3層不織布經裁剪,利用超聲波設備將3層面料,耳繩和鼻扣焊縫,這是一項原為勞動密集型加工工序,現在可以經全自動生產線實現。

普通口罩無需滅菌,但醫用口罩需經過環氧乙烷(EO)滅菌。 EO是一種低溫,廣譜殺菌劑,現為醫療產品的主導滅菌手段。將外科口罩放置在400mg / L的EO環境中。滅菌處理後,EO仍會殘留在面罩表面,因其是致癌物,所以,外科口罩應放置7天甚至更長作解析期,直到殘留的EO釋放後以滿足相關的安全標準為止。 (中國國家標準:GB18279.1-2015 <10μg/ g)。但EO滅菌處理後通常會在3年內失效。

括言之,到目前為止,PP不織布是製造一次性口罩最具成本效益的方法。整個行業具備從材料到布料和口罩成品的足夠生產能力,通常可以應對市場。但是,市場於短期內井噴式的需求無法解決。 EO滅菌處理後的靜置期,以及EO滅菌失效期限,均不利於立即供貨以及作長期戰略存儲。

有關重用此類用即棄產品:

---可惜家居無法實施EO滅菌處理,而醫用酒精會中和M層駐極濾網的電荷,影響過濾率;

---滾水和蒸汽會破壞PP,因此外科口罩盒會標明警告,僅在60°C以下儲存和使用

---紫外線和陽光會降解PP材料,因為這種高分子合成材料專門針對一次性醫用等功能,在製造過程中並未進行抗紫外線等耐候處理

Medtech- make of 3 ply (layer) PP (Polypropylene) spun bond non-woven fabric, filter air entering the mouth and nose. Commonly known as surgical mask, now the hottest item in the market which are almost negligible during those lazy days.

Reminder: outer layer of surgical mask – colored layer or layer with pleat (fold) down; Up side with nasal clip.

Such engineered textile is effective made for the purpose of disposable in order to eliminate the cross infections.

The industry widely adopts PP as the material for this product not only because its lower cost, and also due to:

---non-toxic: compliance to FDA food grade raw material;

--- Antibacterial: does not mold;

---(comparatively) easily degraded after disposal, hence cause less burden to our environment;

And such fabric is widely manufactured by non-woven which is a shorter and integrated processing with very high production capacity.

Here Non-woven fabric is a term of textile manufacturing industry to denote fabrics which are neither woven nor knitted. They are manufactured from raw material into filament/ fiber and lay into web structure and then bond together by means of mechanical, thermal or chemical to form a fabric. Where they skip the spinning and then weaving or knitting for fabric formation.

They are various of types non-woven, just name some: Needle punch, Spunlace, Heat-sealed, Spunbond/Meltblown, Flashspun.

Surgical mask fabrics are widely adopted PP spun bond processing which is rather a direct way to make fabric. As polymer is extruded and stretched to form continuous filaments, and then laid into a web, which are self-bond into non-woven fabric. But limit to light weight fabrics.

3 ply surgical mask with configuration of SMS:

Outer layer (S layer) - Spun Bond PP non-woven of nominal weight 20g/sq.M with hydrophobic treatment, fluid repellent;

Middle Layer (M Layer) - Meltblown PP non-woven of nominal weight 20g/sq.M with

Electret (key word!) treatment, as the filter to barrier to germ;

Inner Layer (S layer) - Spun Bond PP non-woven of nominal weight 20g/sq.M with

Hydrophilic treatment, moisture absorption;

Where M layer - Meltblown PP with the similar processing of Spun Bond theory and further add addition step in order to achieve super fine PP fibre of fineness 2 µm (S layer with PP

Filament of nominal fineness 20 µm). Hence Meltblown PP filament born to be a very good

filtration material and capable with filterability about 35%. But this is still far to reach the requirements of medical masks. If we merely increase the thickness of M-Layer will endup the mask with irrespirable to wearer. So besides the mechanical filtration means of diffusion, interception, inertial collision, gravity settlement, the industry need to introduce a new mechanism of filtration to apply to surgical mask. Hence eletret air filter material came into being. Electret treatment, make simple, means adding electrostatic charge to the PP fibres, and the coulomb force of the charged fibre can capture the PM2.5 and even novel coronavirus droplets (aerosols), so the filtration efficiency increases and the air resistance decreases. In addition, will kill the bacteria as electrostatic field can damage bacterial cell membrane.

The current electret methods include electrostatic spinning, corona discharge, triboelectric, thermal polarization, and low energy electron beam bombardment.

The industry widely adopts the corona discharge method as it can be integrated in the PP meltblown process.

SMS layers, ear loop and nasal clip are then welding up by ultrasonic devices, which is rather a labor-intensive processing and now can be managed by fully automatic production line.

Household mask not need to sterilize, but the surgical mask should undergo the Ethylene oxide (EO) sterilization. EO is a low temperature broad-spectrum sterilant dominant the sterilization of healthcare products. And surgical masks are placed in the environment of 400mg/L ethylene oxide. After treatment, ethylene oxide will still remain on the surface of the mask, which is carcinogens. Therefore, surgical mask should undergo the resolution period of 7 days or even longer until the residual ethylene oxide must be released to meet the safety standard. (China National standard:GB18279.1-2015 <10μg/g). But EO sterilization normally will expired within 3 years’ time.

Conclusively, PP non-woven fabric so far is the most cost-effective mean to manufacture the disposal surgical mask. The whole industry with production capacity enough from material to fabric and mask production normally can deal with the market. But the rocket high demand from the society within short period cannot be tackled. The standstill period right after manufacturing and expiry of EO sterilization are drawbacks for immediately supply as well as the strategic long-term storage.

Concerning the re-use of such disposable item,

---Sadly, the we cannot do the EO sterilisation at home, alcohol will neutralise the charges of M layer filter and lead to downscale the filterability;

---boiling water and steam will destruct PP, so surgical mask will indicate warming that only store and use below 60°C

---UV light and sunshine, will degrade the PP material, as this synthetic material do not apply

weathering proof treatment during manufacturing as aim at disposable medical function.

医工布-由3层纺粘聚丙烯(PP)不织布制成,过滤进入口鼻空气。商品名外科口罩,是当下市场上最抢手的物资,而岁月静好时它们曾被遗忘于一隅。

小小提示:外科口罩的外层–有色层或褶皱向下;有鼻夹为上方。

此类工程纺织品的生产是专门应对一次性使用,以便有效消除交叉感染。

业界广泛采用聚丙烯作为该产品的材料,这不仅是因为其成本较低,还因为:

---无毒:符合美国食品药品管理局食品级原料;

---抗菌:不发霉;

---弃置後(相对)容易降解,因此减轻了对我们周遭环境的负担 ;

目前业界惯常采用不织布工艺生产此类产业用布,该因不织布生产流程短,高度集约具有很高的生产能力。

不织布是纺织品制造工业的术语,表示既不是梭织也非针织物。不织布由原材制成长丝/纤维,之後铺成网状结构,然後通过机械,热学或化学等手段固成片状材料。他们直接由原料制成布匹,而跳过惯常的纺纱,以及紧接的梭织或针织工序。

纺织工业有着众多方式的不织布工艺,仅举一些:水刺,针刺,热封,纺粘/熔喷,闪纺...

外科口罩用布普遍采用聚丙烯纺黏工艺,因是最直接成布的方法。当聚丙烯聚合物被挤出并拉伸以形成连续的长丝,然後铺排成网状,其被自黏成无纺布。但此种工艺仅能生产轻薄面料。

三层外科口罩,配置为SMS:

外层 (S层) - 为标称20克 / 平米的纺粘聚丙烯不织布,经疏水处理,具有防液体和飞溅物;

中层 (M层) - 为标称20克 /平米的熔喷聚丙烯不织布,驻极 (关键词!)加工,作为过滤细菌的屏障。

内层 (S层) - 标称20平米 / 平米的纺粘聚丙烯不织布,经亲水处理,吸湿;

其中M层-聚丙烯熔喷工艺与纺粘机理基本相同但加添步骤以实现细度为2 微米的超细旦聚丙烯纤维(而S层的聚丙烯长丝纤度约为20 微米)。因此,熔喷聚丙烯纤维天生就是非常好的过滤材料,过滤能力约为35%。但这仍然远远未能达到医用口罩的要求。如果我们仅增加M层过滤网的厚度,将最终导致口罩无法呼吸而不适合佩戴。因此,除却利用布朗氏扩散,拦截,惯性碰撞,重力沉降此类机械过滤手段外,工业界还需要引入一种新的过滤机理以便应用於外科口罩。因此,驻极空气滤材应运而生。驻极处理作简单说明,就是在聚丙烯纤维上添加静电,利用带电荷纤维的库仑力去捕获PM2.5微粒,甚至捕获新的冠状病毒飞沫(气溶胶),因此大大提高空气过滤效率的同时降低空气阻力。此外,据研究驻极纤维的静电场可损坏细菌细胞膜,起杀菌作用。

目前,驻极方法包括静电纺丝,电晕放电,摩擦电,热极化和低能电子束轰击。工业上现多采用电晕放电方法,因为它可以集成到聚丙烯熔喷生产中。

紧接到了口罩生产厂,SMS这3层不织布经裁剪,利用超声波设备将3层面料,耳绳和鼻扣焊缝,这是一项原为劳动密集型加工工序,现在可以经全自动生产线实现。

普通口罩无需灭菌,但手术口罩需经过环氧乙烷(EO)灭菌。 环氧乙烷是一种低温,广谱杀菌剂,现为医疗产品的主导灭菌手段。将外科口罩放置在400毫克 / 升环氧乙烷的环境中。灭菌处理後,环氧乙烷仍会残留在面罩表面,因其是致癌物,所以,外科口罩应放置7天甚至更长的解析期,直到残留的环氧乙烷释放後以满足相关的安全标准为止。 (国标:GB18279.1-2015 应少于10微克/克)。但环氧乙烷灭菌处理後通常会在3年内失效。

括言之,到目前为止,聚丙烯不织布是制造一次性口罩最经济有效的方法。整个行业具备从材料到布料和口罩成品的足够生产能力,通常可以应对市场。但是,社会於短期内井喷式的需求无法解决。 环氧乙烷灭菌处理后的静置期,以及环氧乙烷灭菌失效期限,均不利於立即供货以及作长期战略存储。

有关重用此用即弃产品:

---可惜家居无法实施环氧乙烷灭菌处理,医用酒精会中和M层驻极滤网的电荷,影响过滤率;

---沸腾的水和蒸汽会破坏聚丙烯,因此外科口罩盒会标明警告,仅在60°C以下储存和使用

---紫外线和阳光会降解聚丙烯材料,因为这种合成材料专门针对一次医用等性功能,在制造过程中并未进行抗紫外线等耐候处理