Automatic Film Coating and Drying Machine, 300 and 400 mm Stroke

Automatic Film Coating and Drying Machine - TOB-VCH Series

One heated flat-bed platform, two coating strokes: TOB-VCH-300X250 (300 mm) and TOB-VCH-400X250 (400 mm)

Product Overview and Ideal Applications

The TOB-VCH is a heated flat-bed coater: a doctor blade travels over a vacuum-held substrate at a set speed, lays down a wet film of controlled thickness, and the plate underneath dries that film at up to 130 °C without the film being lifted off and moved. Casting and drying happen on the same surface, so a sample goes from slurry to a dry, handleable film in one pass and one setup.

Two models share that platform. They use the same blade, the same vacuum plate concept, the same PLC and touch screen and the same 0-120 mm/s drive; they differ in coating stroke (300 mm or 400 mm), vacuum plate length (415 mm or 515 mm), heating arrangement, power and footprint. The differences are laid out side by side in the specification section, so you can pick a model without reading two separate pages.

Ideal for:

• Ceramic thin films, where a green layer has to be cast flat and dried without cracking
• Crystal and special nano thin films that need a repeatable wet thickness in the micrometre range
• Battery electrode slurries on copper or aluminium foil, including LFP, where the 0-120 mm/s range is set for that rheology
• Any lab moving from hand casting to a motorised stroke, where operator-to-operator variation is the problem being solved

This is a blade-casting instrument, not a production coater. If your process is defined by a slot-die head rather than a blade, the TOB-JYCM-800 lab slot die coater is the closer match; if you need continuous coating on a moving web instead of one sheet at a time, look at the TOB-SY300J roll to roll coating machine.

TOB-VCH-300X250 set up on a laboratory bench, lid open, with the doctor blade applicator on the coating bed.

Tell us the slurry, the wet thickness you are aiming for and the size of your largest sample, and we will tell you whether the 300 mm or the 400 mm stroke leaves enough margin at the end of the pass.

Complete Specifications

Everything that does not change between the two models is in the first table; everything that does is in the second, in two columns, so a difference can be read off a single row.

1. Shared Specifications

2. How the Two Models Differ

External dimensions are approximate and are confirmed against the final drawing before shipment. Two other members of the family sit outside this page: the shorter-stroke TOB-VCH-300X200 and the production-scale roll-to-roll machines.

Electrical and Mechanical Components

The parts that decide how long the machine stays in calibration are listed below. Three items differ between the two models, and they are shown in both columns rather than averaged.

To meet delivery requirements, the supplier reserves the right to substitute components with equivalent-grade alternatives from other brands based on market availability, without prior notice to the customer.

Why a Heated Vacuum Plate Changes the Film

A wet film is fragile for the first few minutes of its life. Anything that touches it, tilts it or dries it unevenly shows up later as a thickness gradient, a cracked edge or a pinhole, and by then the cause is hard to isolate. The plate addresses three of those failure modes at once.

It holds the substrate flat. Copper and aluminium foil arrive with a curl and a memory of the roll. Taped down at the edges they still bridge in the middle, and the blade then cuts a film that is thinner over the bridge and thicker at the edges. Vacuum pulls the whole sheet onto a machined aluminium face, so the blade sees one plane across its full width.

It dries from the substrate upwards. Heat comes through the plate and the foil into the bottom of the wet layer. The solvent leaves from the free surface while the film is still anchored to the foil underneath, which is the opposite of drying a sample in an oven on a tray, where the film can skin over, blister or lift at the edges as it shrinks.

It removes the handling step. Cast, dry, then release the vacuum and take the sample off as a finished film. Nothing has to be transferred wet, so there is no sag, no ripple and no re-registration of the sample between coating and drying.

The ceiling is 130 °C, held to ±2 °C by a digital controller. That covers water, ethanol, NMP and most low-boiling solvents used in tape casting, but it is a drying temperature, not a sintering or annealing temperature; if your process needs 200 °C or above, this is the wrong instrument regardless of model.

Key Engineering Characteristics

• Large-area uniform heating. The 300X250 heats from the plate over the full working area; the 400X250 heats uniformly from above and below. Both aim at the same thing: no cold band at the ends of the stroke, where a film dries slower and ends up with a different microstructure from the middle.
• Motor-driven blade, stepless speed. The carriage is driven by a stepper motor and the speed is set on the touch screen anywhere in 0-120 mm/s. Hand casting ties film thickness to how fast the operator happens to push, which is why two people produce two different samples from one slurry.
• Vacuum aluminium plate. Foil is placed and released in seconds without tape, and the built-in oil-free pump means no external vacuum line is needed; an external source can be connected instead if the lab already has one.
• Standard film applicator, 0-6 mm gap. The wet thickness is set by the gap rather than by guesswork, and bar coaters or other metering devices can be substituted for manual draw-down when a different shear regime is wanted.
• Small enough for a glovebox. The whole machine is built to sit inside an inert-atmosphere box, which is what makes it usable for lithium metal, sodium and other air-sensitive chemistries where the slurry cannot be exposed to lab air between casting and drying.
• PLC with touch screen. Stroke length, carriage speed, temperature and the vacuum sequence are set as parameters rather than as mechanical stops, so a recipe can be written down, repeated and handed to the next operator.

Operating Recommendations, Maintenance and Safety

1. Before and during a coating run

1. Wipe the plate and the blade with alcohol and a soft cloth. A single dried slurry flake under the blade shows up as a longitudinal stripe in the film.
2. Lay the foil or substrate on the vacuum plate, switch the vacuum on, and check that the sheet is flat to all four edges before going further.
3. Set the wet gap on the applicator, anywhere in the 0-6 mm range, and lock it.
4. Enter the stroke length and the carriage speed on the touch screen. Both are stepless, so the number you write in the lab book is the number the machine runs.
5. Set the plate temperature and wait until it holds at setpoint within ±2 °C. Casting onto a plate that is still climbing produces a film that dries at a changing rate along its length.
6. Cast, then leave the film on the plate to dry before releasing the vacuum and lifting the sample. Releasing early is the most common way to get a curled or cracked film.

The same machine with the lid closed, the position it is left in while a film dries on the plate.

The plate stays at temperature after the carriage stops. Move samples with tweezers or a blade, not fingers.

2. Maintenance and safety

• Cleaning. Wipe regularly with a soft cloth dampened with alcohol, and keep the plate and the blade free of dried slurry.
• Lubrication. Oil the moving parts so the carriage keeps running smoothly; a dry guide rail shows up first as a speed ripple.
• Long idle periods. Clean the moving surfaces, then spray them with anti-rust oil before the machine is stored.
• Fasteners. Check screws, nuts and pins on a schedule. A loosened fastener on a coating machine is both a quality risk and a safety risk.
• Hands out of the travel zone. Never put hands or any part of the body into the moving area or the working zone while the machine is running, and allow only one person to operate the machine at a time, so that nobody is caught by a start they did not expect.
• No unauthorised dismantling. External technicians and personnel who have not been designated by the factory must not take the equipment apart.

Engineering FAQ

Q1: Why stop at 130 °C, and what can this machine not dry?

Because 130 °C is a drying temperature, not a heat-treatment temperature. It removes water, ethanol, NMP and the other low-boiling solvents used in tape casting quickly enough that the film sets while the particles are still where the blade put them. What it will not do is anneal a ceramic, sinter a cathode, or drive off a high-boiling additive that only leaves above 200 °C. If your recipe needs those temperatures, the limitation is the plate, not the model, and a tube furnace or a high-temperature coater is the right instrument.

Q2: Why vacuum-hold the foil instead of taping it down?

Tape only touches the edges, so the middle of a curled foil still bridges, and the blade rides over that bridge cutting a thinner film than the gap says. Vacuum acts on the whole area at once and pulls the sheet onto a machined plane. It also leaves no adhesive on the foil, which matters if the coated sheet goes straight into a cell assembly step where residue would contaminate the stack.

Q3: Doctor blade or bar coater - which one, and why?

The blade is the standard tool on this platform: one gap, one speed, a film of constant thickness over the full stroke, which is what you want when the variable being studied is the slurry rather than the coating method. A bar coater applies a different shear history and is better for very thin films or for reproducing a literature recipe that specifies a wire bar. Both can be used here; the blade ships as standard and the bar is a manual draw-down option.

Q4: Why does the 400X250 need 3 kW where the 300X250 needs 1.5 kW?

Consistent with the two differences listed in the specification table: the plate is longer (515 mm against 415 mm), and the 400X250 heats from above and below while the 300X250 heats from the plate. A longer heated area plus a second heating surface is roughly double the heat to supply, which is the order of the difference between 1.5 kW and 3 kW. It is also why the 400X250 needs its own supply check before installation rather than sharing a bench circuit.

Q5: Why put a coating machine inside a glovebox?

Because for lithium metal, sodium and several sulfide systems the slurry cannot see lab air between casting and drying. Moisture and oxygen react at the fresh film surface, and the damage is done before the sample ever reaches a cell. Casting and drying inside the box keeps the whole sequence in one atmosphere, which is also why the machine is built compact: an instrument that will not pass through the antechamber is an instrument that cannot be used this way at all.

Q6: Which model do I need, 300X250 or 400X250?

Start from the sample, not the specification. The stroke has to be longer than your longest sample plus a lead-in and a lead-out at each end, otherwise the blade is still accelerating or already decelerating over part of the film. Then check the vacuum plate length against that same sample, because a 415 mm plate cannot usefully hold a 400 mm sheet with margin at both ends. Finally check the footprint and the supply: 560 x 530 mm on 1.5 kW, or 660 x 550 mm on 3 kW. If even the 300 mm stroke leaves too much unused plate for the samples you actually run, the shorter 300X200 in the same family is the smaller and cheaper answer.

Send us the slurry, the wet thickness, the solvent and the size of the largest sample you need to coat, and we will tell you which of the two strokes fits, and whether the standard 100 mm applicator is enough or you need the 150 mm or 250 mm version.

tob.amy@tobmachine.com | +86 181 2071 5609

Reviewed by: Science Wang, Six Sigma Black Belt, Battery Lines | Last updated: 2026-10-21