It really does depend on the quality of your filament and how much moisture has been absorbed, but having a dry box can be helpful but not needed. Moisture can be dried out of filament quite easily.

Reduced waste: Because the filament will extrude from the nozzle in good condition, your 3D prints will always come out when they are good (assuming other factors are kept constant). ABS (Acrylonitrile Butadiene Styrene): ABS is a thermoplastic polymer that is widely used in 3D printing. It is moderately hygroscopic and can absorb moisture from the surrounding environment. The presence of moisture in the filament can cause warping and deformation during printing, leading to poor dimensional accuracy. Drying the filament before printing can improve the dimensional accuracy of the printed object. Another user has pointed out that they would prefer a manual on/off button on the Dry Box since the current way of doing that demands a few too many presses from you. Other features that come in handy are automatic timers and presets for different filament drying. One other thing I think the Sunlu comes up short in is the angle of the print opening for drying while printing. The port is just in a weird position. Its just not good for brittle filaments because the awkward angle. This is pretty easy to eyeball if you are looking for it. As referenced below, the red shows the approximate odd angle for full rolls (which isn’t too bad for low rolls). I got around this problem by using a piece of PTFE tube in the port (which appears to be exactly the right size for that, so they likely intended this, but didn’t tell the buyers). This tube allows the filament to bend at a more friendly radius. And not all materials are the same - for example BL PAHT-CF seems less suspectible to moisture than Polymaker CoPA. I also have several brands of PETG, some don’t care about moisture at all, others (Devil Design, Extrudr) hate moisture and will foam if left out of the drybox just overnight. PLA is mostly resistant, except when it has some sort of fill, like fibers or CF (though again - BL PLA-CF seems to be pretty resistant). Verbatim PETG claims “hygroscopic”, which is absolutely not true but drybox with some dessicant bags works fine.At the same price, is a single spool filament dryer or a multi spool filament dryer is more suitable for you in your usage scenarios?（We are talking about ‘unit price’ here, one spool slot is recorded as 1 unit price.） To use a desiccant, you have to get yourself an airtight container or bag that can comfortably store your 3D printer filament. The size of the container entirely depends on you. For one, not only does this Dry Box store and dry your filament spool whenever needed but because of two built-in holes that allow seamless extrusion, you can 3D print with your drying filament too. You can also use it to store and dry your food, apart from 3D printing filament. People have admired its ease of use, easy cleaning, and top-notch effectiveness. The hygroscopicity of 3D printing filaments can be affected by various factors, including the chemical structure of the material, temperature, humidity, and storage conditions. The chemical structure of materials used in filaments can impact their hygroscopicity, with materials containing polar functional groups being more hygroscopic. Temperature can affect the ability of materials to absorb moisture from the air, while higher humidity levels result in a greater concentration of water vapor in the air and can increase the amount of moisture absorbed by the filament. Proper storage conditions, such as storing filaments in a sealed container with a desiccant or in a dry environment, can reduce the amount of moisture absorbed by the filament.

Nylon: Nylon is a synthetic thermoplastic material that is known for its strength and durability. It is highly hygroscopic and can absorb moisture from the surrounding environment. The presence of moisture in the filament can cause issues such as warping, deformation, and reduced mechanical properties. Drying the filament before printing can improve the mechanical properties of the printed object.Filament dryers are like storage boxes for your filament with temperature and atmosphere controls to create the best environment to increase the longevity of your filaments. You might not want it for you’re looking for a standalone filament dryer. Where this product really shines is making an already dried filament stay dry for an extensive period of time. The SUNLU Dry Box aims to maintain a constant temperature and prevents excessive heating that could potentially damage the filament.

PLA (Polylactic Acid): PLA is a biodegradable thermoplastic polymer that is derived from renewable resources such as corn starch or sugarcane. It is less hygroscopic than ABS and is less prone to absorbing moisture. However, the presence of moisture in the filament can still cause issues such as poor adhesion between layers and clogging of the printer nozzle. More expensive than other options. But, it’s the best filament drying box around – you get what you pay for. While others have praised how it’s very effective for drying Nylon and PETG, and some also spoke of the great customer service, many complained about the absence of a humidity sensor.

While standard Sunlu Dry Box is a great budget option for drying a single spool of filament, enthusiasts using multiple materials will want to invest in the S4 when it’s released. Rather than use an oven for this Nylon which can be troublesome and not temperature-accurate, he put the spool of Nylon in the filament dryer for 12 hours at 70°C (the maximum temperature) using the useful timer feature, and it completely dried the filament like it was a new spool. Secondly, if you compare it to the Polymaker PolyBox or even the SUNLU Filament Dryer, the Aibecy eBOX has much lesser functionality and is an underachiever for its price point.