As the new coronavirus outbreaks around the world, we are paying attention to the progress of the epidemic, and hope everything goes well for both of us will back to normal.
We have read some articles recently, everyone is sharing how to fight the virus. For example, US CDC says you can make masks at home. In fact, in the now time of the US, especially in New York, this does make sense. Although using old T-shirts or similar materials, you can really make a cotton mask. But as we mentioned in our last post, the cotton mask has limited protection against corona viruses due to their material and physical characteristics. You can read our last post ‘Do Surgical Face Mask Works for New Coronavirus?’
Teaching video for masks DIY from CDC
So how to make a qualified mask? Especially KN95 or N95 masks, I think most people are interested in knowing how masks are produced, let’s take a look.
First of all, we are only talked about mass production by machines, the general process is, Raw material loading – Nosepiece assembly/embossing – Letters printing – Earloop welding – Lable Attached – Cutting and waste recycling – Finished. We will talk about these processes one by one.
Tips, All medical masks must be produced in a dust-free workshop. Generally, the number of fine dust particles in the workshop> = 0.5μm is used to judge whether the workshop is qualified or not. The US standard data is that the number of particles is less than 100,000.
1. Raw Material Loading
N95 / KN95 masks are generally composed of 3-6 layers of fabric (see the image above for details). As you can see, this mask machine can load up to 6 rollers at the same time. So you just place the amount of fabric roller that you want. For example, if you want to produce 4 layers mask, just place 4 roller fabric, so easy.
The structure of this part is mainly driven by the motors, which drive the roller shaft to pull the fabric flat. The core part is the tensioning module. Considering that most readers are not professionals, we will briefly explain the principle here. This part is to control the screws of the discharge area and the feed area by the driving motor. The roller will be up and down for gravity when the screw works, thus controlled the discharge and feed works over and over again.
Of course, the actual situation is more complicated such as the sensors and counterweights participation. We are no longer explain details here. In a word, this part is that the mechanical drives the physical transmission, so that the discharging and feeding are carried out in an orderly manner to ensure production.
2. Nosepiece Assembly / Embossing
In general speaking, N95 / KN95 masks are different from disposable surgical/medical masks, because the latter one can implant the nosepiece in folding progress ( KN95 / N95 mask insert nosepiece in flat status ). That’s why KN95 / N95 mask must have the outermost layer input separately, and wrap the nosepiece from this layer of fabric.
The mechanical principle of the nosepiece assembly is relatively complicated. The general structure is included the nose bridge wire tray, feed box, cutter, guide/drive mechanism, and loading mechanism. The workflow is that the motor drives the nose bridge line to move from the material tray. The nose bridge line passes through the guiding/driving mechanism and enters the feed box through the fixed material channel. Push the piece into the fabric, and repeated it.
Regarding the embossed structure, first of all, the drive power is shared with the previous nose bridge assembly parts, because this can perform these two steps simultaneously to form coherence. As far as this part of the structure is concerned, it is relatively simple. It passes the mold cylinder ( the shape of KN95 / N95 has been marked on the cylinder in advance ) and then presses the fabric surface that has been fused with mechanical pressure to complete this process( Actually, there is an ultrasonic welding system under the mold cylinder and it works at the same time, which can achieve rapid welding while embossing ). Of course, it is necessary to fuse 3-6 layers of fabric and keep it flat is not easy. The most advanced and stable technology in the industry is ultrasonic welding now so that the cloth comes out smooth and almost without burrs. After this step is completed, a blank flat mask with a pattern you can get it.
3. Letters Printing & Earloop Welding
The two work stations also have a closed relationship, there are front and the back, so we discussed together.
Actually, these so-called letters printed are included the model No, warning information, and standards conformity that everyone sees on the surface of the N95 / KN95 face mask. The industry solutions included: pad printing machine and laser engraving machine, both of which have Pros and Cons. In general, laser engraving is more stable and more efficient. Dozens of characters can be almost visually completed within 1s and can not be removed. As a professional laser equipment manufacturer, our laser cutting machine & engraving machine are leading in the industry, you can refer to our products for details.
Welding mold of the ear loop, this part more relies on mechanical mechanism cooperates. The main structure is the ear straps feeding device, ear cutting mechanism, and welding device. The specific processing steps are, the ear strap is output from the feeding mechanism, then the hook of the ear strap welding mechanism pulls an equal length of ear strap, then the ear strap cutting mechanism cuts the head, and finally, the ear strap welding mechanism welds the ear strap on the mask body for complete this procedure. The difficulty is to pull the same length of ear straps every time and no stuck. For the welding part, the ultrasonic welding technology is recommended in the industry, because the welding strength of this welding area with small stress area is very important. If the welding is not good, it looks likely that the ear straps will be broken during the daily wearing, resulting in the scrapping of the mask even it is new.
4. Lable Attached
On surgical disposable masks and even N95 / KN95 masks, most of them do not have labels, but considering the different brands sold in different regions ( such as 3M KN95 masks sold in China, it contains a small green paper label ), so we still briefly explain this part.
The mechanical structure of this part is relatively simple, mainly including label stock tray, roller, and backing paper traction mechanism. The material tray is to install the whole roll of labels with backing paper. When they pass the roller through mechanical force, the label of the spring on the roller peels the label and sticks it to the surface of the mask. Finally, the remaining backing paper is pulled by the backing paper traction mechanism and completes automatic recovery.
5. Cutting & Waste Recycling
This is the last station. Overall, it includes a mask folding mechanism, roller mechanism, cutting mechanism, ear strap turning mechanism, and mask output mechanism.
Let’s start with folding, considering the KN95 / N95 is foldable masks, and the masks produced in the previous process are still unfolded, so we need to fold the mask from the center line and then enter the roller station. This station will flatten the folded mask, which also includes the nosepiece. Then going to the cutting mechanism, which can cut the folded mask quickly by cutting the embossing mold and ultrasonic heating, and then through the ear strap turning mechanism, the role of this station is to turn the ear strap vertically, easy to next station such as packaging. Finally, after the mask output station, you can get the finished mask at this time.
If you want to achieve 100% automation, you can also install robots or conveyor belts in this station, and getting the produced mask directly into the packaging box.
The above is just a brief introduction to the working principle of the KN95 / N95 automatic mask machine. The actual situation is still missed tons of details for it can not be clearly explained through the text-only. We have some customers considering the mask machine is very simple, but in their factory, they got many failures or errors in production progress. We strongly recommend buying machinery and equipment from professional machinery and equipment manufacturing suppliers to avoid losing money. Otherwise, the shutdown machine will totally waste your time and opportunity.
That’s it. You can contact us by post comments, email or phone if you have any questions or you have interested in our products, our sales and customer service team will serve you 24 hours.