Good day brain artisans! Our team once needed a vacuum forming table to create a variety of homemade, but there was no large-sized table on sale. Without thinking twice we made it with your own hands!

Step 1: Desk Box

A vacuum table is essentially a hollow box with many small holes through which air is pumped out of the workspace. We chose MDF to create this box, but any durable sheet material will do. So, we create a table box from MDF and drill small holes in the front panel, either on a machine, or we can use a regular one brain drill.

We attach the legs to the box and install partitions with large holes, about 7.5cm. These partitions will keep the table flat and will not allow it to sag.

Step 2: Heat Source

Initially we planned to use nichrome wire as a heater, but it is quite expensive and difficult to obtain. Therefore, we settled on GU10 halogen lamps, which provide little light, but provide enough heat.

We drill holes in the metal sheet for ceramic lamp sockets and install these sockets. Next, for ease of installation of the circuit, in order to reduce the amount of soldering, we create from printed circuit boards conductive tracks, install them, and then solder the tracks into a circuit. For this panel with MDF lamps we make a box with a removable brain cap for maintenance, and accordingly we place the light panel in this box.

Step 3: Management

The heat source option we have chosen allows us to heat not only the entire table, but also, if necessary, only some of its sections when molding small crafts. Of course, connecting the lamps becomes more complicated.

The table control unit consists of several elements:

The front panel contains an alphanumeric LCD display, LED indication of each heating row, a table switch key, and a button emergency stop table operation, and table operation mode switches.
ATmega644 microcontroller board, which works with firmware written in C. A temperature sensor in the table, a pressure sensor, an LCD display, mode switches from the front panel, as well as a relay for controlling the power of the heaters (lines of light bulbs) are connected to this board.
Controller board alternating current, which synchronizes the signal from the microcontroller, the triac and the AC line.
A relay board, which consists of 6 electromechanical relays controlled by a microcontroller. One of the relays turns on the fan, and the rest turn on the heater lines.
Neutral relay board, which consists of 7 relays controlled by a microcontroller and connecting the heater lines to the neutral wire, as well as a temperature sensor in the table space.
A triac consisting of two opto-isolated thyristor solid-state relays, rated at 20A, 240V, which regulates the fan and heating of the table space.

Step 4: Installing Supports

On our table box crafts, and by the way it is 600x900mm in size, we mount the supports for the heater panel and install the panel itself with the lamps. We also make a frame for the plastic and insert it into the supports on bearings; we seal the junction of the table box and the frame with insulating porous tape.

Step 5: Vacuum Fan

To the bottom side of the box brain table We attach a vacuum source, simply a fan. For our vacuum fan, we made an additional plate from MDF and with its help, as well as with the help of neoprene gaskets, we installed it.

Step 6: Final Assembly and Testing

On final stage We connect all the elements, check that everything is installed correctly and proceed to testing. We insert a sheet of plastic for molding into the frame, turn on the table and mold!

Here's how our table works:

Successful homemade and I hope our guide will help you with this!

Making a vacuum table is the most critical stage in constructing a thermal vacuum press with your own hands. At the design stage, it is necessary to determine the dimensions of the table, select the material for its manufacture, and think over ways to fix and seal detachable elements to maintain internal negative pressure (vacuum). The vacuum table is made with the same basic set of tools as.

Further in the text, we will call a vacuum bath a part of a vacuum table - a steel container, inside of which the workpieces to be coated are located, and from which air is pumped out. By working dimensions (dimensions) of a vacuum bath we mean it useful volume, measured by internal dimensions. We will agree to call the vacuum table the entire structure as a whole, consisting of a vacuum bath, an upper (movable) pressure frame, clamps and other smaller elements.

External and working dimensions of the vacuum bath.

Let's consider general principles choosing the size of the vacuum bath, we will designate specific numbers for our press.

The longer the vacuum bath, the more workpieces can be placed in it, or the workpiece can be lined bigger size. On the other hand, the longer the bath, the more film has to be consumed in one working cycle, the larger the dimensions of the machine, which entails a greater consumption of room space. Need to find optimal size. As experience has shown, the optimal working length of a vacuum bath intended for the manufacture of standard furniture facades and decorative door trims, we can consider the value to be from 2.4 to 2.6 m. We will make a vacuum bath 2500 mm long, the working length of which will be 2500 - 40 x 2 = 2420 mm (40 mm is the width of the short wall profile pipe).

The width of the bath is directly related to the width of the PVC film used. Depending on the film manufacturer, there may be different meanings width, the most common is 1.4 m, which is what we will focus on. Let's choose the width of the bathtub to be 1400 mm, the working width will be 1400 - 40 x 2 = 1320 mm. When facing tall workpieces, for example, for curved (radius) facades, the width of the bathtub must be reduced (made smaller than the width of the film), but to work with such workpieces a press of a different design is needed, so these issues will not be considered.

The working height of the bathtub should be calculated based on the requirement that there is a small free space between the upper surface of the facades and the covering film. In other words, the film stretched over the workpieces should not touch them before air is pumped out. The calculation is as follows. First, the vacuum (breathable) table top that will be placed first on the vacuum table will be made of MDF boards 10 mm thick. Secondly, the linings for the facade blanks will be small pieces of MDF board 16 mm thick (this is the simplest, most common and best option linings). Thirdly, the thickness of the veneered blanks will range from 8-10 mm (door linings) to 16-32 mm (facades and other furniture elements). Fourthly, sealing rubber will add about 2 mm to the bath depth. Eventually, maximum height the total “pie” inside the bathtub will be equal to: 10 + 16 + 32 = 58 mm. To make a vacuum bath, we will use a profile pipe with a cross-section of 60x40 mm, placing it on the short side. At the same time, the height of the free space will be no less than: 60 + 2 - 58 = 4 mm, which is quite enough.

Making a vacuum table.

Vacuum bath.

The bottom of the vacuum bath will be a sheet of steel 2 mm thick. To minimize sheet deflections under the influence of negative internal pressure, and giving the table surface an even shape (close to an ideal plane), it is necessary to make a rigid frame. To make the frame we will use the same profile pipe 60x40x2. The pre-cut pipe, in accordance with the design, is laid on the slipway, rigidly fixed with clamps, and all connections are welded. After making the stiffening frame, a steel sheet is welded on top of it. This is the most critical stage welding work, it requires a continuous weld to be hermetically sealed (double penetration is recommended).

To avoid warping of the sheet under the influence of prolonged high temperatures, you can use the following alternative method welding the sheet to the stiffening frame. Before installation steel sheet on the stiffening frame, along its perimeter, it is necessary to apply a sealing compound that can withstand high temperatures(for example, silicone high-temperature sealant), and welding is carried out not with a continuous seam, but with small regular fixing tacks with a pitch of about 50 mm. This method is designed to ensure that short-term, local welding effects will not damage (burn out) the entire sealant, but only a small part of it in the immediate vicinity of the tacks, while most of the sealant, after curing, will perform its direct function.

Vacuum table dimensions.

Detailing of the stiffening frame and the procedure for assembling the vacuum bath: the stiffening frame is welded, a steel sheet is welded to it, a stationary (lower) frame with a part of the hinge joint for attaching the lifting (upper) frame is hermetically welded around the perimeter of the steel sheet.

Photo of the vacuum table from below.
The stiffening frame is made partly from an angle profile.

Lifting (pressing,top)frame.

Frame material - profile pipe 60x40x2 mm. The dimensions of the pressure frame must be exactly the same as those of the vacuum bath. If it was not possible to find a sufficiently even (not bent, not twisted) profile, then it is necessary to pre-select in pairs several of the smoothest rods from which the parts of the vacuum table will be made tightly adjacent to each other.
The clamp frame will rise thanks to adjustable hinge joints. The adjustment of the hinges is carried out after gluing the seal - strips of sheet rubber of medium hardness, about 2 mm thick.

Welded washers are needed to increase the friction area. The hinge pin is a D12 steel rod with threaded ends.

To hold the clamping frame in a raised state, gas lifts can be used. For safety reasons, it is recommended to install four gas lifts (two per side) and ensure that any three of them can support the frame. If the opening angle of the frame (45°) turns out to be insufficient, the frame will cause significant inconvenience in operation; it can be raised as high as possible at an angle of slightly more than 90°, using the thermal module parked behind as a support (gas lifts are not used).

Clamps.

To securely and tightly hold the film during vacuum pressing, it is necessary to firmly and evenly press the upper frame to the perimeter of the vacuum bath, achieving an overall fit rubber seal. For these purposes, you can use various ready-made clamps, or make them yourself.
For the manufacture of homemade clamps working on the eccentric principle, you will need the following rolled steel: half a meter of DN50 pipe (external diameter about 60 mm), two meters of rod with a diameter of 10 mm, and approximately the same amount of profile pipe with a cross-section of 20x20x2 mm.

Firstly, the DN50 pipe is cut into 8 equal 60 mm sections. Each pipe section is finished with a semicircular central cutout having a width of 10-11 mm and an arc length equal to 3/4 of the length of the outer circumference of the pipe. We get 8 pieces of eccentric rotary cylinders, to which we need to weld a handle 220 mm long from square profile 20x20 mm.

Secondly, the steel rod is cut into 16 pieces: 8 pieces 190 mm long (for studs) and 8 pieces 55 mm long (for kingpins). An M12 nut (or M10 with a drilled thread) must be welded to one end of the stud so that it can rotate freely on the pivot, and an M10x50 thread must be cut at the other end.

Thirdly, to complete the manufacture of the clamp, we weld the ends of the pin (with a nut with a welded pin pre-attached to it) to inner surface eccentric rotary cylinders.

To install clamps on the vacuum table of the press, at eight points of the table, according to the project, drill through holes with a diameter of 10 mm. After which, the upper holes are enlarged, giving them an oblong shape. The clamps are adjusted by installing combination nuts in Right place threads of the stud, followed by fixation with locknuts. This operation is performed on last stage manufacturing a vacuum table, after gluing the rubber seal.

Elements and dimensions of the hinge clamp.

The hooks for the clamps are made from 50x50x3 angle steel.

If it was not possible to achieve a flat table surface.

If during the welding process the sheet has undergone significant deformations that go beyond the permissible values, then there is no need to pick up a grinder and cut off the welds and redo everything again. Provide perfect flat plane vacuum table is possible additional measures, namely through the use of epoxy leveling compounds, which are used in the manufacture of poured floors. To do this, the vacuum table is set strictly according to the level, the required volume of the filling mass is determined (for example, by test filling with water), the bottom of the vacuum bath is cleaned of rust, and it is primed. Fill with the prepared epoxy mixture according to the manufacturer's instructions. For reasons of economy, the mixture can be diluted with some cheap filler, for example, quartz sand. To speed up the curing of the mixture after pouring, the table can be controlled from above with heat from the thermal module. This operation It makes sense to perform filler leveling after the vacuum press is fully ready, test samples of products have been manufactured, and a decision has been made about the need to improve the geometry work surface.

Estimate for material for a vacuum table.

Name	Length, mm	Quantity, pcs.	Purpose
Profile 60x40	2500	6	Rigidity frame. Bath. Lifting frame.
Profile 60x40	1380	4	Rigidity frame.
Profile 60x40	1320	4	Bath. Lifting frame.
Profile 60x40	1001	6	Rigidity frame (diagonals).
Profile 60x40	753	3	Rigidity frame.
Profile 60x40	250	4	Hinge.
Profile 60x40	180	2	Hinge.
Profile 60x40	150	2	Clamp support.
Profile 60x40	140	2	Hinge.
Corner 50x50x3	50	8	Lifting frame (clamp hook).
Profile 20x20	220	8	Clamp
Pipe DN50	60	8	Clamp
Rod D10	190	8	Clamp
Rod D10	55	8	Clamp
Rod D12	150	2	Hinge.
Nut M10 combi		8	Clamp
Nut M10		12	Clamp Table mount.
Nut M12		16	Clamp Hinge.
Washer d12		12	Hinge.
Bolt M10x60		4	Table mount.
Sheet 2500x1500x2		1	Table (bottom of the bath).
Gas elevator		2	Lifting frame.

Upon completion of the main volume of work, the vacuum table is installed on the frame (on specially provided supports) and fixed in the corners with four bolts, as shown in the figure, after which proceed to small jobs: installation and adjustment of clamps, adjustment of the lifting frame hinge, gluing the seal.

The metal structure is beginning to take on the shape of a future thermal vacuum press, but it still lacks many elements: a vacuum system, a thermal module, an electrical control unit, which will be discussed in the following articles.

Vacuum tables for CNC machines – a vacuum surface designed for fastening workpieces and sheets ready for milling and curved cutting. Its dimensions may vary, depending on the dimensions of the existing machine, and the working surface is evenly divided into sectors.

Sections milling machine equipped with grooves for uniform distribution of vacuum over the entire area of the table and holes that act as suction cups to ensure immobility of the material.

Types of vacuum tables for CNC

Modern industrial stores offer to buy a vacuum table for a CNC router, made according to special technology and allows you to work with various materials: wood, metal, thanks to the reliable attachment of the workpiece to the working surface. Also, the device allows you to easily change tools, which speeds up the work process and improves the quality of the finished product.

Today you can buy the following vacuum table for CNC:

Lattice.
Turning.
Splined.
With inserts made of porous materials.

Grid vacuum table

The lattice vacuum table for a CNC milling machine is popular among enterprises of various sizes, because such equipment creates closed loop workpiece. During the processing of the material, it is laid on the working surface and a vacuum is applied, as a result of which the sheet is suctioned to milling table over the entire fastening area.

If you have a second grid table and if you need to increase the working area, you can connect the vacuum boards to each other. Also, the device allows you to work with round workpieces.

Rotary vacuum table for CNC

According to the principle of operation, a rotary machine does not differ from a lattice machine, however, it is capable of turning, which simplifies the work process. Connecting the vacuum hose to in this case It is permissible both in the central part of the table and in the end part of the board. As a result, it is possible to make longitudinal, vertical and transverse movements on the surface being processed.

Additionally, Rotary table allows you to create the required angle of inclination to process a round or spiral-shaped object in various planes, to perform milling, rounding or transitions.

Slotted Vacuum Table

The slotted vacuum table is designed to work with products that have many holes and small details. Such a device has a high coefficient of friction, which results in an increased vacuum force and reduces the risk of the object being processed moving from its intended location.

During the work process, a frame (flat) with holes under the work object is laid out on the table surface. Next, the resulting frame becomes an auxiliary fastening material.

Modern manufacturers offer to buy a splined vacuum table for CNC at a favorable price, so many enterprises use it as a main or auxiliary board.

Tables with porous inserts

Vacuum tables with a porous insert allow you to work with an object without the use of foil and other thin materials, as well as without reconfiguring the table for another type of work. The porous blocks of the device can be made of aluminum, bronze or steel material, as well as from compressed porous raw materials.

This board is designed to work with any shape of object, but the fastening force will depend on the area of the material being processed, the table and the final quality of the work performed.

How to make a vacuum table for CNC with your own hands

Despite store offers, some people prefer to make such a device themselves. However, given the complexity of the procedure, the master will need to stock up on patience and materials.

To make a vacuum table for CNC with your own hands, you will need drawings, tools and an understanding of the principle of operation of the device. Usually MDF is used for this and metal sheets(for making a table box), in which holes are drilled with a drill and the legs are attached to the resulting box. Then, non-chrome wire or halogen lamps are placed there, used as a heater.

You will also need to place in the device:

Fan.
Neutral relay.
AC Controller.
6 electromechanical relay boards.
Symmetrical thyristors from 20A and 240V.
Front panel with liquid crystal display.
Temperature sensor, mode switch, pressure indicator, etc.

Despite the complexity of manufacturing the structure, some craftsmen still carry out its installation. However, buying a vacuum table is much more reliable, because it uses original spare parts and technologies that increase service life.

Vacuum clamp for workpieces: pumps or blowers?

Currently, in various industries of processing metal, wood or plastic products, to hold the workpiece on the work table instead mechanical devices, the so-called “vacuum clamp” is used. With this holding method, a force is used that presses on the workpiece, pressing it against the table, from which air is pumped out and a vacuum is created. This force pressing the workpiece appears immediately after the air begins to be pumped out of the table and disappears when air enters there again.

The clamping force can be assessed in familiar quantities and calculated what it can be. Since it is a consequence of the vacuum created in the table on which the workpiece is located, or rather the difference in air pressure inside and outside the table, its maximum value is equal to the product of one atmosphere times the area of the workpiece being pressed. Since it is impossible to pump out air deeper than one atmosphere, then “ operating pressure“to create this force cannot be more than 10 tons per 1 square meter.

What devices allow this method to be implemented?

The most correct, reliable and effective is to use vacuum dry rotary vane pumps. These pumps, although they do not create the theoretically possible maximum vacuum, guaranteeing the coveted 10 tons per square meter, are capable of pumping out 88% of the air and creating a pressure drop of up to 8.8 tons per square meter. At the same time, unlike, for example, oil ones, which have a better residual pressure indicator, they are more convenient to use and are better suited to work at intermediate pressure values (below atmospheric, but above the maximum residual pressure). In addition, like all vacuum pumps, they are not afraid of operation with completely blocked suction and discharge pipes.

The second most correct and popular applications (which, by the way, are constantly growing and are already comparable to the popularity of pumps) are Vortex blowers. If you connect a vortex blower with a suction pipe to a vacuum table, then it, working as a pump, is also capable of creating a vacuum, but the vacuum depth is 2-3 times worse than when pumping with a rotary vane vacuum pump. That is, a blower (with the exception of special high-pressure series) is, in principle, not capable of creating a vacuum deeper than 0.4-0.5 atmospheres. In addition, it cannot work for a long time with blocked pipes, as it will overheat and fail. This is where their weak points end and one can understand why in many cases they are preferred to rotary vane pumps.

There are many types of processing materials on vacuum tables, when, in principle, a large clamping force is not required or when, due to the large area of the workpiece, even a small pressure can create a force sufficient for clamping. This applies, first of all, to the processing of panels made of plastic and wood. The second important argument in favor of blowers is the size of the table and the impossibility of creating an absolutely sealed pumped volume - there is almost always a reverse movement of air into the system. Therefore, the pumping speed comes first - it is this that compensates for leakage. Pumps with a capacity of more than 150 cubic meters per hour are always more expensive than blowers with the same pumping speed and are heavier. And when customers see in the characteristics of a blower the maximum performance (one and a half to two times higher than the actual operating point), the blower, as an alternative to a vacuum pump, seems even more attractive.

Let's summarize. When should you choose a pump and when should you choose a blower?

If the table dimensions do not exceed 3-4 meters in length, the parts are small, complex shape, the vacuum table is made with high quality (with a good fit of the parts and without possible leakage), it is required to obtain a pressure drop of at least 5 tons per square meter, then the best solution will oil-free rotary vane pump.

When the tables have linear dimensions of more than 5 meters, the workpieces being processed are also large and have small specific gravity, the tangential load (shearing the workpiece) is small and is compensated by a clamping force of about 10 tons for the entire part, which has an area of several square meters, the rigidity of the table does not guarantee the preservation of its shape during the vacuum process, the tightness of the system is low, and cost comes to the fore, then preference is given to blowers.

If you tell us the specific clamping force, we can tell you and offer you a specific pump or blower model.

Machines and devices using vacuum clamping are used in almost all industries. We offer solutions for each of them: small-sized vortex blowers for holding sheets of paper or plastic in cutting plotters to specialized units capable of withstanding repeated ingress of cutting fluid into a vacuum system.
The performance of the vacuum pump used for vacuum clamping determines the speed of pumping out the system to the required pressure and, mainly, the ability to compensate for air leaks through leaks or cuts formed during material processing.
The pressure difference created by the vacuum pump determines the clamping force of the workpiece. Pumps with a large pressure drop are recommended for use in cases where it is necessary to achieve maximum clamping force at small area contact between the workpiece and the vacuum gripping device.

MSH blowers for vacuum tables of CNC machines

This type of equipment makes it possible to provide high performance at a relatively small pressure drop. Devices of this type are used for pressing workpieces with large area contact to vacuum tables of CNC machines, for example, they can be used to clamp plastics, vinyl film, plywood, etc. sheet materials. An important advantage vortex blowers with high productivity is that when cutting through the material with a tool, as a rule, the possibility of continuing processing is preserved, because air leakage through the slot is compensated by increased productivity. Vortex blowers are extremely unpretentious in operation, have no wearing parts, and can be supplied with frequency converters, additional filters, mufflers and reversing machines.

Elmo Rietschle oil-free rotary vane vacuum pumps for vacuum clamping systems

Machines of this type are most widely used in vacuum clamping systems. Not only do they create a pressure differential sufficient to clamp most types of workpieces and sheet materials, but they can also have quite high productivity. Rotary vane oil-free vacuum pumps operate without the use of lubricants in the working chamber. These pumps are easy to operate and maintain. As standard, pumps in this series already have built-in air filters and mufflers.

Water-ring vacuum units ROBUSCHI (Italy) with closed water circulation for vacuum clamping

Used as an alternative to dry rotary vane pumps. These installations can provide almost any performance required for vacuum clamping. They require virtually no Maintenance, resistant to dust, lubricating and cooling liquid, can work for a long time with atmospheric pressure on suction. At a cost lower than rotary vane for most sizes vacuum pumps, they do not require costs for consumables and pay for themselves very quickly.

Vacuum gauges and vacuum relays

In our company you will always find a wide range of vacuum gauges and vacuum relays necessary to monitor the operation and control of vacuum clamping systems. Our product range includes: mechanical and digital vacuum gauges, mechanical and electronic vacuum relays, as well as other accessories: filters for vacuum systems, check and shut-off valves, vacuum receivers, safety valves, fittings, vacuum hoses.

Working with MSH Techno Moscow (MSH Techno), you can be sure that the wide range of supplied equipment will allow you to choose exactly what is truly best suited for your tasks. If you have any questions about the equipment presented on our website, we will be happy to answer them!

Nowadays, you can see products everywhere that are made using vacuum forming technology. This approach allows you to quickly produce plastic dishes, packaging, mannequins, paving slabs and much more. To do vacuum forming at home, you will need a special machine. Such devices are expensive, and they are too bulky. This article will look at an example of creating simple machine vacuum forming, which uses only a vacuum cleaner and an oven.

Of course, the power of such a machine will be small, so it will not be possible to produce bulky objects or simply make a large number of products in a short time. But for the sake of interest and small household needs, such a machine is quite enough. In addition, with the help of such a machine you can perfectly make cases for various models, be it ships, planes or cars. You can also make elements for various homemade products. This device is a kind of original analogue of a “3D printer”.

Materials and tools for homemade work:
- vacuum cleaner (the more powerful, the better);
- oven (needed to heat the plastic);
- wooden blocks;
- drill;
- self-tapping screws;
- screwdriver or screwdriver;
- plywood or chipboard (thickness 16 mm);
- silicone (as a sealant);
- Fiberboard for the working surface (plywood is also suitable);
- aluminum tape;
- wood, plaster (or other materials to create a form).

Machine manufacturing process:

Step one. Vacuum machine dimensions
The main element of a vacuum machine can be considered a frame on which the plastic is heated, as well as a vacuum chamber. The dimensions of the frame should be such that it fits in the oven. You also need to take into account the size of the plastic sheets from which future products will be created. The frame is made of wooden blocks.

Step two. Making a vacuum chamber
The vacuum chamber is needed to “suction” the plastic, which, in turn, will envelop the mold underneath it. To make a vacuum chamber you will need a 16 mm thick chipboard sheet or plywood. Technically, a vacuum frame is a box; its dimensions must correspond to the dimensions of the frame that will rest on it.

First, a frame is made from timber, and then plywood is screwed to its bottom. Since the chamber must be sealed, all seams must be coated with sealant during assembly.

The vacuum chamber also has a working surface, that is, the place where the products are formed. It is a sheet with evenly drilled holes. Fiberboard works well for these purposes, but plywood can also be used. It is important to understand that the working surface should not sag, so a spacer is installed in the center.

Step three. Connecting the vacuum cleaner
To conveniently connect the vacuum cleaner to the vacuum chamber, the author used a vacuum cleaner attachment. It needs to be screwed to vacuum chamber, having previously made a hole in it to pump out air. The nozzle is attached using self-tapping screws; it must first also be lubricated with silicone or other sealant.
If there are doubts about the tightness of the structure, it can be covered with aluminum tape or other adhesive tape on top.

Step four. DIY molds. Product creation process
To create a form you can use various materials, for example, gypsum, wood and others. If the forms do not have to be perfectly smooth, then polyurethane is ideal for these purposes, since it can be easily processed with a stationery knife.

If there are concave places on the form, then you need to drill holes here so that the plastic can be “sucked” into these recesses. A drill with a diameter of 0.1 - 0.5 mm is suitable.

Once the mold is made, you can proceed directly to the molding process. The work will be carried out in the kitchen, as access to the oven is required.
First you need to connect the vacuum cleaner to the vacuum chamber and place the mold in the center of the working surface. At the bottom of the mold you need to place spacers 1 mm thick; coins will do. This is done so that the plastic fits the shape at the bottom better.

Then you need to cut a sheet of plastic around the perimeter of the frame; PVC, PET and other types are suitable. Due to the fact that the vacuum cleaner does not create a very high vacuum, it will not be possible to use thick plastics. The thickness of the plastic for this homemade product should be in the range from 0.1 to 0.4 mm.
The sheet of plastic must be nailed with staples, maintaining a distance of at least 2 cm between them. There is no need to spare the staples, since heated plastic can easily break out of its fastenings.

Now you can place the plastic in an oven heated to 190 degrees (for each type of plastic there is optimal temperature softening). After some time, the plastic will heat up and begin to sag in the frame. Now it needs to be removed and installed on a vacuum machine. Subsequently, the vacuum cleaner turns on and the plastic begins to envelop the mold. When working, you need to use gloves, as the frame will be quite hot.

The vacuum cleaner needs to run for about 20 seconds, then the frame can be removed to remove the product. If in some places the plastic does not adhere well to the mold, you can use construction hairdryer.

That's all, now the product can be processed at your discretion and painted in required colors. According to the author, such a homemade product can work without problems with a type of plastic such as polyethylene terephthalate, which is what bottles are made from. Well, what to do depends on the personal needs and fantasies of each homemaker.