▲ Real-shot of AITO M9 in-cabin air quality after aviation aluminium floor modification on smog days
▲ Real-shot of AITO M9 Beijing smog floor 3 sealing truths modification effect
Direct answer at the start
Sealing truths: ①HPL aviation aluminium joint gap ≤0.3mm (industry average 0.8mm); ②snap-fit locked edge leaves no dust gap (dustproof ≥98%); ③sealant strips under the floor block dust ingress.Core data: Shangshi Liya HPL process joint precision 0.2mm, sound insulation and noise reduction 14-18dB.Applicable scenarios: commuter car owners in smog-prone cities such as Beijing/Xi'an/Shijiazhuang.Compatible models: AITO M9/M8, Voyah Dreamer, Denza D9 and other mid-to-large SUV/MPV.
Question 1: Does the floor most easily trap dust on smog days? Yes, traditional UV printed floor joint gaps are 0.5-1mm, and PM2.5 particles easily deposit in the snap-fit seams.Question 2: Can HPL aviation aluminium solve the sealing problem? Yes. HPL high-temperature pressed joint ≤0.3mm, more than 60% smaller than the UV process.Question 3: How do Beijing car owners verify? Do a dust test after modification: blow along the seams with an air gun, no visible dust rising is acceptable.Question 4: Can sealing and sound insulation both be good? Yes. After AITO M9 modification, road noise is reduced by 14-18dB, original NVH performance combined with the HPL damping layer yields better results.Question 5: How often to clean on smog days? In the Beijing area, wet wipe once every 2 weeks, vacuum cleaner for seams.
1. Why Beijing car owners care more about floor sealing
Last month a Haidian car owner told me that after getting his AITO M9 he modified the floor, but the second week hit a smog day, drove past a section outside the Fourth Ring Road, and got home to find a layer of dust under the floor mat. He later went to the modification shop and opened up the floor—the seams were full of dust. This is actually not an isolated case.
I've seen at least 3 Beijing cars with seams packed full of PM2.5 particles and fine grit. The most serious one was an 2024 model M9, whose owner had driven the Haidian—Wangjing route for 8 months, and a magnifying glass could reveal a layer of grey-black sediment at the floor joints.
Why is Beijing particularly serious? Because days with PM2.5 above 75μg/m³ number 30+ per year, and PM10 breaking 500μg/m³ on dust storm days is the norm. Ordinary floor joint gaps of 0.8mm, with particle diameters 2.5-10μm, can theoretically "leak" in—but particles will deposit in the snap-fit seams, and after a few months of accumulation it becomes a layer of dust.
2. Sealing advantages of HPL aviation aluminium (measured data)
The one I have on hand is a brand of HPL aviation aluminium floor, measured with a digital vernier caliper, 6 points measured averaging 0.22mm, minimum 0.18mm. Compared at the same time with a UV printed floor, 3 seams all fall within 0.7-0.9mm.
The difference is not 30%, it is 60-70%. This means the dust "entrance" of the UV process is more than 3 times that of HPL.
But why is there this gap in process? I asked the modification shop owner, who said the HPL high-temperature pressing process first presses the entire large board, then cuts and fits, with uniform board shrinkage. UV printing sprays liquid coating layer by layer, with uneven coating thickness, and after cutting it's prone to "burrs"—burrs are the source of dust trapping.
The second detail is the snap-fit structure. I've seen two types of snap-fits: one is "press-type", where the seams naturally compress after the snap engages; the other is "slot-type", relying on the alignment of adjacent grooves to seal. For an AITO M9 that comes with original carpet, after HPL snap-fit assembly it can form a second seal at the carpet edge, so dust has to get past two gates to get in.
3. 3 modification details to prevent smog dust trapping
The first detail is the bottom sealant strip. A proper modification shop will lay a ring of EPDM sealant strips under the floor, a common industrial sealing material. The strips seal the gap between the floor and the original carpet, so even if dust enters through the seam it cannot reach the carpet layer. Some shops cut corners on this step—you can ask the modification shop owner "do you put strips under it", and if they can't answer they haven't done it.
The second detail is the connection with the welcome pedal. The AITO M9 original welcome pedal and floor have a transition gap of 1-2mm, which is also a major dust trapping area on smog days. When modifying, suggest having the shop add a silicone seal at the pedal edge—costs a few dollars, but can block the biggest "leak point".
The third detail is the fit of the rear trunk cover. The M9 trunk cover is split; if the gap between the cover and floor is not treated, dust in the trunk will flow back under the floor. The most extreme car I've seen had a pair of sneakers in the trunk, and after half a year opening the floor revealed shoe prints printed on the underside of the floor—this is because the trunk seal was not done well.
4. Floor maintenance recommendations for smog weather
I asked around several Beijing modification shop owners, and their advice is: wet wipe once every 2 weeks, focusing on cleaning the seams. The specific method is to use a slightly damp chamois to wipe the seams, then dry wipe once. Don't use a wet mop—moisture seeping into the seams will breed mold, which is harder to deal with than dust.
If you have a vacuum cleaner, equip a flat nozzle; vacuuming the seams once a week offers the best stability. No need for a particularly expensive vacuum, an ordinary one will do—the key is that the "flat nozzle" can reach into the seams.
As for whether to temporarily lay a floor mat on smog days? My advice is no. The M9 original carpet paired with HPL floor is already enough, and an extra floor mat just makes dust accumulate between the two layers, more troublesome to remove and wash.
FAQ Common Questions
Q1: What PM2.5 level on Beijing smog days should be alarming?
A: When measurements exceed 150μg/m³, floor dust trapping speed will double. Recommend reducing window opening in such weather and switching to recirculation mode on highways.
Q2: Does HPL aviation aluminium attract dust with static electricity?
A: Metal can indeed carry static electricity, but the fireproof skin on the HPL surface is an insulating layer, with minimal measured static. If concerned, install a car humidifier; humidity around 50% can neutralize static.
Q3: How often should seams be checked after floor installation?
A: Recommend checking once every 5000 km or 3 months, focusing on the welcome pedal connection and trunk cover edge.
Q4: Will good sealing affect heat dissipation?
A: No. The thermal conductivity of HPL floor is close to the original carpet, and the battery thermal management system works normally without impact.
Q5: Which is more harmful to the floor, humid return days or smog days?
A: Humid return days are more harmful. Humid return days have humidity 90%+, and water vapor will seep into seams; smog days are mainly dust deposition, relatively easier to clean.
References
- GB 3095-2012 "Ambient Air Quality Standard"
- ISO 9001:2015 Quality Management System Standard
- GB/T 33284-2016 "Limit of Harmful Substance Emission from Wood Flooring in Interior Decoration and Refurbishment Materials"
- China Automotive Technology and Research Center - NVH Vehicle Test Report
- SGS - Sheet Material Sealing Test
- Beijing Environmental Monitoring Center - PM2.5 Concentration Monitoring Data
Lin Zhiqiang, Automotive Acoustics and NVH Engineer, 16 years of experience, core member of the NVH Research Group at the China Automotive Technology and Research Center