Polystyrene foam: how to cut it so it doesn’t crumble? How to cut polystyrene foam - maximum results with minimum waste How to cut polystyrene foam

Foam boards are a thick and highly porous material; they consist of more than 95% air; if you are not used to them, they are difficult to cut. How to cut polystyrene foam depends on the type of cut, the availability of tools and the amount of cutting work.

Ordinary polystyrene foam - terminology and material characteristics

IN in a broad sense Foam plastics are a broad class of cellular (foamed) plastics based on polyurethane, polyvinyl chloride, urea, phenol and even formaldehyde. All these materials are united by a minimum density and an internal structure in the form of frequently located and small gas cavities. However, in practice we have to deal with the only type of foam - low-pressure polystyrene foam, abbreviated PSV.

Only it has an affordable price; all other cellular plastics are much more expensive to produce and are rarely used in construction and repair work. The international name for low-pressure polystyrene foam (PSV) is the brand name Styrofoam, patented by the developer BASF back in the 50s of the 20th century. In documentation for imported foam plastic, the abbreviation EPS is often used. For practical purposes, it is important to know that all these terms - styrofoam, EPS andEPS – denotes ordinary polystyrene foam, familiar from childhood.

The structure in the form of small gas pores and the significant dimensions of the slabs determine the main operational advantages of foam plastic:

Excellent thermal insulation on any side of the house. You can perform this procedure from the outside, you can combine external and internal thermal insulation, and the cost of such “double” protection will still be lower than the estimate for a newfangled roll insulation;
Beautiful acoustic protection premises. In fact, sound comfort is already achieved during thermal insulation work - if frost cannot penetrate the foam layer, then loud sounds are even less able to do this;
Environmental safety. Polystyrene foam is absolutely non-toxic, including on exposed cut lines and during long-term use. Some varieties are allowed for contact with food products, which is regulated by European quality standards (!). Moreover, polystyrene foam is safe for repairs; there is not the slightest need to test the walls covered with it;
High resistance to mold, dampness, microorganisms, fungi, algae and other unwanted companions of human life. In order to enhance the durability of such consumer qualities, cutting foam plastic with your own hands must be done accurately and competently;
Easy to install due to its miniature weight. This quality greatly simplifies the transportation and laying of foam plastic, however, when working outdoors, you should pay attention to possible “wind difficulties” - the foam blank can easily be carried away by even a weak breeze.

Of course, before any use of polystyrene foam, it is necessary to consider possible complications. Firstly, this material is destroyed by exposure to most technical liquids - from acetone and gasoline to white spirit and enamel solvents. This destruction is intense even with the vaporous effect of technical liquids on the foam.

Secondly, it is necessary to turn special attention on the expected operating temperature of the surface covered with foam plastic. Already at +50 ˚C - +60 ˚C, some types of foam boards begin to crumble, their internal bubbles combine into large gaps and cavities. Painting surfaces insulated with foam plastic must be thought out in advance, otherwise the thermal comfort of the entire room will suffer from toxic nitro paint.

To renovate kitchens, saunas and brightly sunlit facades, polystyrene foam should be used with great care - high temperatures destroy it.

Areas of application of polystyrene foam...

...are not limited to the construction and repair area. Foam boards and sheets are widely used in the following areas of human activity:

In medicine – cases for equipment, packaging for glass and sharp objects;
In the organization of active leisure - inserts in life jackets, contents of buoys, floats;
Repair of refrigeration and air conditioning equipment;
In shipbuilding, as an unsinkable filler for compartments on small vessels (boats, boats);
For design purposes, construction and modeling.

So the question of how to cut foam plastic is relevant not only for thermal protection of walls. You can use it to make a model of a boat, build protection for the refrigeration circuit in an air conditioner, or make a decorative figurine of a unique design. The light weight and affordability of the material should not be misleading about the simplicity of its mechanical processing - cutting foam plastic has a number of its own secrets and tricks.

How to cut polystyrene foam at home - simple and effective ways

Cutting small foam pieces (for modeling and design) is performed with a well-sharpened knife with a rubber tip on the tip. It is advisable to secure the workpiece in a vice or other auxiliary device. The fact is that it is easy for a steel blade to slip off a small part, and there is a possibility of cutting yourself. All movements when cutting small foam blanks should be directed away from you and to the side.

For particularly precise cutting of foam elements, you can use a soldering iron with a special knife attachment. With light movements of the heated blade, the material is given the desired shape of any kind. Be alert to the danger of hot plastic droplets coming into contact with your hands or other parts of the body. If it is necessary to cut sheet foam with precise adjustment of parts for continuous installation, the following methods are used:

For sheets up to 40 mm thick - an ordinary shoe knife with a wide blade and a blunt point. Before work, the blade is sharpened, and in general the sharpener needs to be kept at hand - after every 1.5-2 meters the knife will have to be sharpened again. The work will be accompanied by a characteristic “squeal” of the foam being cut, so it won’t hurt to stock up earplugs or headphones. Knife processing is good when adjusting the sheet to a specific installation size, for example, when installing final strips of thermal insulation;
A wood hacksaw, but with fine teeth, is suitable for thick sheets< 80 мм. Чем меньше величина зубцов, тем точнее и ровнее будет срез. При резке с помощью ножовки прикладывается гораздо меньшее усилие, чем при использовании самого острого ножа, да и вероятность травматизма куда меньше. Способ актуален при необходимости длинных, прямолинейных разрезов однотипного характера;
Processing with hot wire is the best and most productive method for cutting foam. Unfortunately, it requires a stationary location of the cutting tool, but in terms of cutting speed and accuracy it has no equal.

We will need a long knitting needle, nichrome wire, a 12-24 Volt step-down transformer, an adjustable rheostat and electrical wires sufficient section. Electrical components are assembled in serial circuit, the knitting needle is fixed on the layout, and a nichrome thread is stretched between its ends. When a small current is applied, nichrome heats up and easily cuts foam of any thickness.

Additional benefit nichrome cutting consists in the fact that with it the “bubbles” of the foam structure are sealed again. Thus, the thermal insulation qualities of the cut blanks are not inferior to factory sheets; when processed with a hacksaw or knife, such a property is unattainable.

Thermal insulation structures are assembled from modern polystyrene foam, decorative elements are cut out and produced large number other things.

Its scope of application is very wide. And not least because this material is easy to process, quick to install and can be cut with your own hands.

However, you also need to be able to cut foam plastic with your own hands. After all, to get a really high-quality cut and final detail, you need to try hard. Note that it is not dangerous.

1 Cutting foam

So, polystyrene foam, like any other material, needs to be processed before use. Initially, it is supplied in ordinary slabs with a certain thickness. However, the shape of the slabs is not always sufficient to use them wherever necessary.

Often the slab has to be cut into pieces, trimmed, and cleaned. Sometimes it becomes necessary to cut off a decorative part at the edge of the slab or make a certain angle.

There are actually a lot of options. But one question remains. How to cut foam? It would seem, why else invent some additional units, buy a special cutter for foam plastic if you can not only cut it, you can even break it with your own hands. And this is literally true.

Here we need to turn to the features of polystyrene foam itself and. The foam itself consists of small polystyrene balls.

The initial raw material in it is a polymer that is mixed with foam fillers and air. The result is a fairly pliable and very light structure that can be easily cut or broken by hand.

But breaking foam plastic is not best solution. Your break line will never be accurate. The polystyrene foam balls will distort it, making the final structure unsuitable for precision work.

However, we still note that it is very easy to break or cut foam. That is, cutting foam plastic at home is quite possible. Another question is how to do this accurately and with minimal destruction of the material. This is where a foam cutter or any homemade device will come in handy.

2 Cutting tools

The foam cutting tool may have different designs. It depends on the design and type of cutting how exactly the foam cutter will cope with its tasks.

The cutters are:

Mechanical on ;
Thermal.

A mechanical cutter is used to be able to carry out relatively small work in cramped conditions. You can cut the body of polystyrene foam with a mechanical device. But the quality of the cut that ends up may not be what we would like.

The thermal cutter for foam plastic is already professional equipment. It is used by builders, designers and other similar professionals.

The thermal cutter quickly makes holes or cuts lines in any type of polystyrene foam. Starting from regular and ending with extruded high-density foam.

The thermal apparatus basically uses a hot filament or wire.

Based on the type of assembly, the machine for cutting polystyrene foam can be divided into:

Branded designs;
Homemade samples.

In the first case, we are dealing with units that were created at the factory. They were specially designed and conceived to give a person maximum productivity and convenience while working.

Branded models include both specialized foam knives and large thermal cutters or other professional equipment.

For example, the same laser cutting foam plastic is possible only through the use of low-power factory lasers, which are controlled by a computer. They are expensive, bulky and quite complex, but as a result of working with them you will get almost perfect cutting.

2.1 Mechanical cutting

Mechanical cutting is performed with tools that are based on the force of mechanical action or friction.

These include:

Knives;
Bulgarians;
Jigsaws;
Saws.

Most often, such equipment is used at home. When you don’t have the opportunity to buy a thermal cutter, and don’t have the desire. Let's not forget that a high-quality thermal cutter can be quite expensive.

And it’s not always worth buying it, especially if you just need to cut a couple with your own hands polystyrene foam boards for thermal insulation.

The easiest way to cut foam is to take a regular knife, especially if the foam is cut into. A utility knife with a medium-hard blade is ideal. With its help, you can cut a slab up to 6-8 cm thick without any problems. Moreover, the slab will be cut with high quality, especially if you already have at least basic experience.

But grinders and jigsaws, if they can be used, should be used very carefully. Here you need to understand that a strong rotational moment has too serious an effect on the weak structure of polystyrene foam. If you do not guess correctly with the torque and the choice of disk, you can ruin the stove with your own hands.

The recommendations here can only be general. It is advisable to buy special equipment for cutting foam plastic. If you don’t have anything like that on hand, then at least try to find the thinnest disc for an angle grinder or a jigsaw blade. The thinner it is, the better.

In general, you need to be careful with saws. It is better not to use a regular saw for foam plastic. Unless you don't need cutting precision at all. But in this case it is easier to simply break it.

If you buy a special saw, then the conversation is different. But in any case, you need to be very careful, since the saw, due to the uneven force, has a greater chance of seriously damaging the material.

2.2 Thermal cutting

For thermal cutting, a thermal cutter is always used. Thermal cutter is a special unit for cutting polystyrene foam, it costs almost the same as.

It consists of only a few parts. The main part is the working transformer, which supplies voltage. The transformer may have batteries, or it may be powered directly from the network. It all depends on the specific model.

There are two arcs or mounts extending from the mini-transformer. These arcs are essentially the body of the working element. A special thread is tied to each end of the arc. Nichrome is most often used. The thread is stretched between the ends of the arc so as to form a tightly taut wire.

When the transformer is turned on, it supplies electricity to the arcs, which, in turn, heat up the filament itself.

The hot thread cuts through foam without any problems in any position and any size. After all, the polymer is extremely unstable, and it interacts very poorly with high temperatures.

The big advantage of a thermal cutter is that it gives you the opportunity to work with filigree precision. More precisely, cutting can only be done with lasers. And even then, if we exclude the human factor.

Nichrome heated to a serious temperature cuts foam like a knife cuts hot butter. Moreover, it doesn’t even really touch the stove, meaning you don’t have to apply any physical pressure. Why is this convenient? Yes, because putting in physical effort is always fraught with the possibility of making a mistake.

If all the work is done by a heated wire, which melts the foam rather than cutting it, then the chance of making a mistake becomes minimal.

2.3 Homemade thermal cutter

Clever radio technicians have probably already thought that the design of a thermal cutter is very simple, which means that it can be assembled with your own hands. Indeed, you can assemble a thermal cutter without any problems.

Your main task will be to select a transformer small sizes for cutting and similar products. Well, this is actually not such a problem. You can take a transformer from a TV or convert it from a working sample.

Next you need to assemble an analogue of the arcs. The simplest such mechanism is to attach two long screws to a wooden plank. The tree will not allow them to conduct electricity among themselves, so the only conductor will remain a nichrome stretched thread.

The thread is pulled between the heads of the screws. Then all that remains is to connect the transformer to the screws, then turn on the electricity and adjust the voltage.

It is advisable not to overdo it with voltage and clearly understand that there is a certain correlation between the thickness of the nichrome thread and the operating voltage at the output.

Too high a voltage will heat the thread red-hot, and in this position it will simply burn out the polystyrene foam without even touching it. As a result, you will not be able to cut smoothly.

2.4 An example of creating a homemade thermal cutter for polystyrene foam (video)

In construction, work is often carried out related to the insulation of structures, where polystyrene foam is used as the most inexpensive material. Accordingly, the density of such insulation is low, which, when cutting it, leads to the formation of a lot of debris, which is quite difficult to collect, since pieces of foam plastic tend to become electrified and stick to everything that comes their way. To facilitate the process of cutting insulating material, there are many methods and devices that help cut foam without crumbs.

Cut out foam parts with straight cuts

What and how to cut foam plastic

In order to cut a specific shape of insulation, any device for cutting foam plastic can be used:

hacksaw for wood or metal;
soldering iron;
an angle grinder called a “grinder”;
thin metal wire like a string;
thermal cutter;
foam cutting machine;
jigsaw with heated file.

If you choose a hacksaw for wood, then its teeth should be as small as possible. All tools that are not heated to a certain temperature do not guarantee that the foam will not crumble. Such tools are used for small volumes of work, but when it is necessary to insulate all the enclosing structures of a house, it is better to use a foam cutting machine, the action of which is based on heating the cutting element.

How to properly cut polystyrene foam with a knife so that it does not crumble

When slabs are used in the process of insulating walls, ceilings, and roofs with your own hands polymer material, thermal cutters are not always justified. Structures, as a rule, have strictly geometric shapes, and it is quite possible to cut the material with a simple knife, the main thing is that the blade is thin and its length exceeds the thickness of the insulation sheet. A good tool for such work is a stationery knife if you have to cut thin polystyrene foam.

To cut foam with a knife, you need to choose a long blade

The fact is that the blade of such a tool is very thin and when cutting a sheet of great thickness, a perfectly even cut is unlikely to be achieved; wrinkles may form on the cut, which will not allow the individual parts of the insulation to fit tightly together. And this will lead to the formation of cold bridges.

In addition to the knife you will need:

A rigid measuring ruler or a ruler of ideal shape.
Roulette.
Simple pencil, marker.

They cut polystyrene on a solid base so that the sheet does not “play” in your hands. Marks are made on the surface of the polystyrene plate the right size, after which they lay down a rigid ruler or rail, and make sharp knife incision If the length of the knife blade is not enough, you can make cuts on two opposite sides of the sheet, the main thing is not to lose the size. Then the sheet is simply broken along the cut. With proper skill, the work will proceed quickly, without unnecessary noise and waste of electricity. Of course, there will be debris, but not as much as from a hacksaw. The main thing is that the tool is very sharp and of the required length.

Before cutting the material, the tool must be heated and the blade must be sharpened periodically.

The foam is cut stationery knife and thermal - comparison of the cut line

How to cut polystyrene foam without using heat tools

The principle of cutting sheets of foam plastic using a hacksaw, regardless of whether it is for metal or wood, is no different from cutting with a knife, the main thing is that the teeth are small and the blade is of sufficient length.

In this case, the cut will be smoother and a lot of small debris will not form. The saw movements must be made smoothly, without jerking. But even with this cutting method there will be a lot of expanded polystyrene crumbs.

You can cut foam sheets using an electric jigsaw or an angle grinder (grinder). However, with this method, a huge amount of garbage is guaranteed.

Grinder for cutting foam plastic

The high speed of rotation of the grinder disk and fairly large teeth will provoke severe destruction of the structure of the material at the cutting site. When using a jigsaw, it is also impossible to obtain a perfectly flat surface on the cut due to vibration of the file, which also leads to the formation of small polymer debris.

The least amount of foam crumbs is formed when cutting it, if used homemade device for cutting foam plastic. The simplest type of such a device is an ordinary thin wire (string), with handles attached to the ends for greater convenience. The wire diameter should be chosen as small as possible, no more than 0.5 mm. One person cannot cope here; an assistant will be needed. The wire is installed along the intended mark on the foam and made uniform movements on both sides. As a result of the friction of the metal wire against the polystyrene foam, it heats up and the material begins to melt at the cut site.

Cutting foam plastic with a string – the method is the most effective in terms of the formation of a minimum amount of debris, but the time spent on such work is much longer than when cutting with other tools.

Thermal apparatus and devices

Cutting penoplex on a thermal machine

The use of insulation does not always involve cutting it to the correct geometric dimensions. Sometimes you have to cut out semicircles, holes and other shapes with intricate contours. And here a knife or hacksaw will no longer help. But a machine for cutting foam plastic, which you can easily build yourself, can cope with such work.

Figured products made of foam plastic and penoplex

The operating principle of such devices is that electrical voltage is applied to the cutting element, as a result of which it is heated to a certain temperature, which can be adjusted special device. And given the fusibility of the material, cutting polystyrene foam with a heated string or wire is easy and quick. And at the same time, difficult-to-remove small debris is not formed.

How to build your own thermal cutter for foam plastic

If you choose the best way to cut insulation without creating small debris, then, of course, professional equipment will come first. But for home use purchasing such a device can be an expensive “pleasure”, so many craftsmen make a machine for cutting foam plastic with their own hands.

Schematic drawing of a thermal cutter for horizontal cutting of foam plastic

Required materials and tools

To assemble a thermal cutting device you will need:

Tungsten (nichrome) wire Ø 0.2 mm.
Materials for making the frame are bars, metal profiles of any section. Springs for fastening tungsten filament.
Rheostat or step-down transformer.
Insulators.
Terminals.

Tungsten wire can be purchased at a specialty store or obtained from household appliances- from any heater, including oil. Cut the desired piece of the spiral and straighten it so that it is even.

The heater's spiral is made of tungsten wire

The frame of the device must be assembled on a solid and durable base. This could be a table, workbench, or some other surface. You will need to attach the vertical metal elements to the base at such a distance that a sheet of polystyrene foam can freely pass between them. Next, springs are attached to the vertical posts, insulators are attached to the springs, and tungsten wire is attached to them.

Springs are needed in order to maintain the wire in a horizontal position, since when heated, it tends to change its dimensions upward, which threatens it to sag if there are no springs. Instead of springs, you can use weights, the task of which will be the same as that of springs.

When you rarely use such a cutter, a battery can serve as a power source, which is undoubtedly safer compared to electrical network, where the voltage is more than 220 V, while the battery produces no more than 10 -12, and this is quite enough to heat the wire. If there is a rheostat, the voltage supplied to the tungsten filament can be adjusted depending on the thickness of the sheet and the speed of its movement along the table.

This device will allow you to cut foam into horizontal plates, the thickness of which will depend on the distance between the wire and the table. If it is necessary to cut the material vertically, the wire must also be installed vertically.

1 - Tungsten wire
2 - Cargo
3 - Frame
4 - Base of the device

The vertical foam cutter is suitable for cutting shaped elements from extruded and regular foam. When using such a device, the cut is smooth and without crumbs. This device works on the principle of a jigsaw. In order to make a shaped part, it is better to use penoplex, a material obtained by extrusion from polymer feedstock - styrene, while polystyrene foam is not pressed styrene.

Cutting foam plastic with a modernized soldering iron

You can quickly make a thermal cutter using a soldering iron. To do this, install a blade on the end of the tool if you need to cut foam plastic vertically or horizontally, or a crown from an electric drill when you need to make a hole or recess in the material. Instead of a crown, it is allowed to use a homemade one round piece which is made from galvanized iron.

The main point of the article

How to cut polystyrene foam - with a mechanical tool - a knife, a file, an electric one - an angular one grinder, jigsaw, or using devices with a heated cutting element, everyone chooses at their own discretion. Thermal devices eliminate the formation of debris, but are expensive. For home use, there is an opportunity to save money and make your own thermal foam cutting machine.

Foam plastic is widely used today as sound and heat insulation building material, which has to be processed during the work process. In order for the sheets of material to correspond to the dimensions of the surface that is being insulated, they have to be cut. Cutting polystyrene foam can be done in several ways, one of which you can use in your work. The cutting process requires a certain approach for the reason that foam plastic can crumble and break if cut incorrectly.

Tools and materials

To work you will need:

foam;
ruler;
pencil.

Return to contents

Methods for cutting foam plastic

Expanded polystyrene can be cut using a wallpaper knife. This tool will not only cost less, but will also be silent in operation, and cutting will be carried out in short terms. The advantage of this method is the minimal amount of waste.

Before you start cutting, you need to check how sharp the knife is. This characteristic of the tool will allow you to perform work faster and with better quality.

Foam with a greater thickness is more difficult to cut, and you should not use a knife for cutting if the thickness of the material exceeds 5 cm, as it will be ineffective.

A jigsaw will also not allow you to get an even cut line; in addition, there will be a lot of debris.

Before you start cutting, you should purchase a long saw: it will allow you to cut sheets whose thickness does not exceed 10 cm.

It is preferable to cut polystyrene foam hand saw designed for woodworking. If you intend to use a regular knife for the process, you will need to sharpen it before starting. Then the blade should be heated, only after that you can start cutting. In this case, cutting the material will be accompanied by melting of the edge. The cutting line will be smooth, the material will not crumble, and debris will be generated in minimal quantities.

You can cut polystyrene foam with your own hands and in an unusual way, which involves the use of hot nichrome wire. However, before you begin, you will have to do a little work on creating the tool. It can be made from wire, spring and transformer. The table must be installed at an angle of 60°. A wire has to be pulled across it; on one side, its end must be strengthened as rigidly as possible, and on the other, the end must be strengthened through a spring. To the ends of the wire you need to connect the wires of the transformer, which should be powered from the mains. After this, it is necessary to apply current and lay a sheet of heat insulator on the surface on top of the wire. Since the table is inclined, the thermal insulation sheet will move by sliding, succumbing to the influence of its weight.

To cut, you need to wait until the wire is almost red hot, but you should not let it get too hot. If this is allowed, the cut will become too wide. As the nichrome wire heats up, it will become longer. This indicates the need to use a strong spring in the design. This will allow you to adjust the length.

Cutting can be done with a grinder equipped with a metal disc. The thinnest disc should be used. This method cannot be called the most comfortable. In addition, the tool creates a lot of noise and a lot of debris will be generated.

Foam plastic lends itself well to processing with a soldering iron. The use of this tool will allow you to complete the work in the shortest possible time. The end of the soldering iron must be flattened with a hammer. After this, you need to put a special part on it, made of a blade and a steel cap taken from fountain pen. The blade needs to be installed at the end. Then the soldering iron should be heated and you can start cutting the blades.

In addition to the fact that even sheets can be made from foam plastic, they can be subjected to figure cutting, giving the workpieces a variety of shapes.

If you create shaped elements from foam plastic, the material can be used not only as insulation, but also as decor for any room.

Polystyrene foam is not afraid of staining, which is why its surface can be coated with paint after cutting. Each of the above cutting methods has its own advantages, but you should prefer the one that will be less difficult for you.

Cut out foam parts with straight cuts

What and how to cut foam plastic

In order to cut a specific shape of insulation, any device for cutting foam plastic can be used:

hacksaw for wood or metal;
soldering iron;
an angle grinder called a “grinder”;
thin metal wire like a string;
thermal cutter;
foam cutting machine;
jigsaw with heated file.

How to properly cut polystyrene foam with a knife so that it does not crumble

When slabs of polymer material are used in the process of insulating walls, ceilings, and roofs with your own hands, thermal cutters are not always justified. Structures, as a rule, have strictly geometric shapes, and it is quite possible to cut the material with a simple knife, the main thing is that the blade is thin and its length exceeds the thickness of the insulation sheet. A good tool for such work is a stationery knife if you have to cut thin polystyrene foam.

To cut foam with a knife, you need to choose a long blade

In addition to the knife you will need:

A rigid measuring ruler or a ruler of ideal shape.
Roulette.
Simple pencil, marker.

They cut polystyrene on a solid base so that the sheet does not “play” in your hands. Marks of the required size are made on the surface of the polystyrene plate, after which a rigid ruler or strip is laid and a cut is made with a sharp knife. If the length of the knife blade is not enough, you can make cuts on two opposite sides of the sheet, the main thing is not to lose the size. Then the sheet is simply broken along the cut. With proper skill, the work will proceed quickly, without unnecessary noise and waste of electricity. Of course, there will be debris, but not as much as from a hacksaw. The main thing is that the tool is very sharp and of the required length.

Before cutting the material, the tool must be heated and the blade must be sharpened periodically.

Foam plastic is cut with a stationery knife and a thermal knife - comparison of the cut line

How to cut polystyrene foam without using heat tools

In this case, the cut will be smoother and a lot of small debris will not form. The saw movements must be made smoothly, without jerking. But even with this cutting method there will be a lot of expanded polystyrene crumbs.

You can cut foam sheets using an electric jigsaw or an angle grinder (grinder). However, with this method, a huge amount of garbage is guaranteed.

Grinder for cutting foam plastic

The least amount of foam crumbs is formed when cutting it if you use a homemade device for cutting foam. The simplest type of such a device is an ordinary thin wire (string), with handles attached to the ends for greater convenience. The wire diameter should be chosen as small as possible, no more than 0.5 mm. One person cannot cope here; an assistant will be needed. The wire is installed along the intended mark on the foam and uniform movements are made on both sides. As a result of the friction of the metal wire against the polystyrene foam, it heats up and the material begins to melt at the cut site.

Cutting foam plastic with a string – the method is the most effective in terms of the formation of a minimum amount of debris, but the time spent on such work is much longer than when cutting with other tools.

Thermal apparatus and devices

Cutting penoplex on a thermal machine

Figured products made of foam plastic and penoplex

The operating principle of such devices is that electrical voltage is applied to the cutting element, as a result of which it is heated to a certain temperature, which can be regulated by a special device. And given the fusibility of the material, cutting polystyrene foam with a heated string or wire is easy and quick. And at the same time, difficult-to-remove small debris is not formed.

How to build your own thermal cutter for foam plastic

If you choose the best way to cut insulation without creating small debris, then, of course, professional equipment will come first. But for home use, purchasing such a device can be an expensive “pleasure,” which is why many craftsmen make a machine for cutting foam plastic with their own hands.

Schematic drawing of a thermal cutter for horizontal cutting of foam plastic

Required materials and tools

To assemble a thermal cutting device you will need:

Tungsten (nichrome) wire Ø 0.2 mm.
Materials for making the frame are bars, metal profiles of any section. Springs for fastening tungsten filament.
Rheostat or step-down transformer.
Insulators.
Terminals.

Tungsten wire can be bought at a specialty store or obtained from household appliances - from any heater, or oil heater. Cut the desired piece of the spiral and straighten it so that it is even.

The heater's spiral is made of tungsten wire

When such a cutter is rarely used, the power source can be a battery, which is undoubtedly safer compared to the electrical network, where the voltage is more than 220 V, while the battery produces no more than 10 -12, and this is quite enough to heat the wire . If there is a rheostat, the voltage supplied to the tungsten filament can be adjusted depending on the thickness of the sheet and the speed of its movement along the table.

This device will allow you to cut foam into horizontal plates, the thickness of which will depend on the distance between the wire and the table. If it is necessary to cut the material vertically, the wire must also be installed vertically.

1 - Tungsten wire

4 - Base of the device

Cutting foam plastic with a modernized soldering iron

The main point of the article

How to cut foam plastic - with a mechanical tool - a knife, a file, an electric one - an angle grinder, a jigsaw, or using devices with a heated cutting element, everyone chooses at their own discretion. Thermal devices eliminate the formation of debris, but are expensive. For home use, there is an opportunity to save money and make your own thermal foam cutting machine.

How to cut polystyrene foam so as not to crumble

Polystyrene foam or expanded polystyrene refers to a universal material that is used for insulation and sound insulation in building structures. The basis of its structure is formed by foamed plastic. This explains why foam plastic quite often crumbles when cutting.

When processing the material, you need to decide what to use to cut it so that the cut line is smooth and there are as few crumbs as possible.

Foam cutting is carried out using mechanical and thermal types of tools. Beginners, especially with small cutting volumes, are recommended to use a mechanical tool.

Mechanical cutting . The most common available tools include a knife, jigsaw, saw and grinder.

Ordinary knife . When choosing a knife, the main attention is paid to its blade. If it is sharp, the cutting process proceeds faster and less waste is generated. The knife must be preheated before cutting.

The disadvantage of this method is that the use of a knife is possible with a foam thickness of 1-5 cm.

Shoe knife . As a rule, this knife is initially quite sharp. Therefore, its blade passes through the cellular structure of the foam with relative ease.

Disadvantages in use:

Ability to cut only thin sheets;

The knife blade quickly becomes dull;

The need to have a sharpening stone.

Stationery knife . The stationery version of the knife is best used for soft material. This knife has thin and flexible blades, so it is not used for processing thick slabs.

Advantages:

Little trash;

Availability of purchase;

Low cost.

The stationery knife has a set replaceable blades. Dull blades break off, which leads to a lot of wastage.

Jigsaw . Trimming with a jigsaw is used when cutting foam up to 10 cm in thickness. This method does not require much effort.

Flaws:

The cut is never perfectly straight;

A sufficient amount of crumbs is formed;

Cannot be used when there is no power supply

Hand saw for wood . If the thickness of the foam reaches 40 mm, then it is better to cut it with a hacksaw. The method is quite simple and fast, without much physical effort.

A saw with fine teeth is better suited. This tool is only used to obtain straight cuts.

"Bulgarian" . The advantages of the grinder are that it seems to cut the foam itself if you use the thinnest circles.

However, it is not recommended to cut thick material with a grinder. You won't get a high-quality result, but there will be a lot of garbage.

In addition, this option is not very good due to the squealing noise that occurs when the foam interacts with the circle of the machine. Plus, the noise of the instrument’s engine is added to it. Therefore, if you are cutting a large number of foam boards, you should wear headphones from the very beginning of the work. Add to this list the electricity consumption that you will need to pay.

Nichrome wire cutter . Practice working with foam plastic shows that a high-quality cut is formed when using a tool with a heated wire. The edges are even, smooth, and there are practically no crumbs. The advantages of the method include high cutting speed and productivity in volumes similar to industrial ones.

The active use of the method is hampered by the difficulty of purchasing it due to its absence in stores. If there is an urgent need for a machine, there is only one way out - to make a cutter yourself. This is a separate question, which is covered by many good articles on the Internet containing step by step instructions and illustrations.

Easy way to cut

Cutting can be done with thin steel wire. It should be secured to wooden handles. They are placed at different ends of the surface intended for cutting. The cut is reminiscent of the process of sawing firewood. You will need an assistant to hold one of the handles. Friction causes the string to heat up, so the cut line is even and smooth.

Follow safety rules, taking into account that when heated, substances harmful to the body are formed and released. Work should be done in a well-ventilated area or outdoors.

Bottom line

From the review we can conclude general conclusion, that the process of cutting foam is quite simple and fast. The processing method is selected depending on the selected tool, the volume of work, and the shape (straightforward, tortuous or volumetric) in which the result should be obtained.

How and with what to cut polystyrene foam at home

The widespread availability of massive full-size foam boards automatically led to a boom in the use of a relatively durable, soft and at the same time easy-to-process material at home. In fact, it has become possible to manufacture a huge number of all kinds of useful things from a thick foam plastic sheet; you just need to choose a way, how and with what to cut the foam plastic, in order to prevent deformation, breakage or crumbling of the material.

Why is it difficult to cut foam?

The widespread use of foam plastic material has been largely hampered porous structure, resembling a compressed layer of tiny polystyrene cells filled with a gas-forming agent.

If you have ever cut foam sheets, you have probably noticed this feature:

The denser and heavier the material, the easier it is to cut it with sharpened tools. The thinner the cutting edge, the easier and faster it is to cut even the hardest urea foam;
Lightweight grades of foam are easiest to cut with power tools. The higher the cutting edge speed, the cleaner the cutting surface. In industrial conditions, thin foam plastic boards are cut with a thin water jet, with virtually no waste;
When you try to cut a slab with a sharp blade in several movements, a situation arises where each new cut almost doubles the amount of foam sawdust and dust.

Advice! Craftsmen prefer to cut thin foam plastic slabs using the shoemaker's method. To do this, use a sharpened wide blade with great effort to make a cut with the knife towards you, without changing the angle of inclination and depth of the cut.

Most modelers and craftsmen who work professionally with foam plastic will argue that cutting foam plastic boards is not at all difficult, especially since the density and strength of the material is relatively low. And they will be right. Cutting polystyrene foam at home is not difficult; you just need to accurately select the mode and equipment for cutting foam plastic.

Number of options practical application and the use of polystyrene foam for those who know how to work with their own hands has long exceeded one hundred. Dozens of foam materials are made from various models, injection molds, toys, stucco moldings, decorative elements, insulation, details speaker systems and even refrigerators. The main problem accompanying any attempts to process the material mechanically, is the selection of the mode, how and with what to cut the foam so that it does not crumble, as a result, cutting is always accompanied by the formation of a large amount of waste.

If the tip cutting tool is not sharpened enough or moves at low speed, when trying to cut the smallest gas-filled balls, the cutting edge does not cut them, but slides along the polystyrene foam, crushes them and tears them out of the compressed mass of foam plastic. It is possible to cut a foam sheet in this way, but a huge amount of waste is generated.

Technology on how to properly cut a sheet of foam plastic

For home use, we can offer several proven methods:

Using a sharpened shoemaker's or construction knife;
A hacksaw for metal with an improved hacksaw blade;
A powerful soldering iron with a razor blade attached to the tip;
A thermal cutter or a hot nichrome spiral;
A jigsaw or grinder.

Important! Whenever attempting to cut a foam sheet using hot blades, wires or high-speed tools, it is necessary to work under a hood or outdoors, since melting the foam releases a large amount of volatile toxic substances.

If you need to cut foam plastic using a jigsaw or grinder, you should definitely use a respirator and safety glasses. When cutting, foam dust becomes highly electrified and sticks with incredible force to the skin of the hands, face, and gets into the eyes and lungs.

Scheme of cutting foam plastic mechanically

The easiest way is to cut a thin slab, up to 50 mm, using a regular knife, even a table knife. For this foam board Place it on the edge of the work table and make an incision. The cutting edge of the knife should be as close as possible to the supporting plane. Before cutting, the blade must be sharpened and trimmed on a polishing wheel.

The part of the sheet to be cut must be supported so that the material does not break off under load. To cut with maximum quality, the knife is moved with little effort in one direction - “away from you”; the reverse stroke of the blade is performed “idle”. If you have to cut a sheet laid out on a table top with a shoe knife, then the direction of application of the force changes to the opposite - “towards you”.

It is strictly not recommended to cut thin-sheet foam material while hanging or in a vertical position.

It is much easier to cut foam with a hacksaw. For dense grades, the hacksaw blade does not need to be changed; for highly porous foam sheets side surfaces The blades are ground on a grindstone to remove tooth set. With a hacksaw you can cut in almost any position without restrictions.

The most productive tool for cutting sheets is an angle machine or grinder. Depending on the diameter of the cutting wheel, a grinder can cut foam up to 50 mm thick on the fly. In this case, the quality of the cut will be much higher than when using a knife or saw. The disadvantage of this method is the large amount of dust and chips. If you reduce the cutting speed of foam plastic to a minimum, the material will begin to burn and melt, which is not always allowed by the cutting conditions.

Simply cut the foam sheet using a jigsaw. In terms of productivity and cutting quality, a jigsaw is inferior to an angle grinder, but it has an invaluable advantage - it can be used to make shaped cuts that are difficult to obtain using other mechanical cutting methods.

Thermal methods for cutting foam plastic

The second most common method of cutting foam is a thermal cutter. Essentially, it is a nichrome thread laid on a frame in the form of a frame. When passing electric current By nichrome wire the metal surface heats up and melts the foam. There are several design options for the cutter. The simplest one looks like a nichrome string stretched on ceramic insulators installed at the ends of a wooden or metal frame.

With this tool you can cut not only foam sheets, but also wooden slats, plastic pipes, any material with a melting or decomposition temperature of up to 270 o C.

If you need to cut slabs with a long cutting length, then it will be more convenient to use a machine in the form of a vertically stretched thread on a PCB stand.

To control the heating of the nichrome string, an LATR or rheostat is used. Too much high temperature surfaces can lead to melting and even ignition of the foam. A remarkable property of this cutting method is complete absence dust and shavings, in addition, the cut surface turns out to be melted, as if covered with alkyd varnish.

If in the process of processing foam you need to cut off only small fragments of the foam block, for example, when making a sculpture or model, it is best to use a nozzle for a powerful electric soldering iron.

Special mention should be made of the most interesting way cutting foam plastic with a laser. This may seem like science fiction; laser cutting of foam plastic is possible even at home, photo. A conventional LED laser with a power of 2-5 W allows you to cut a sheet of foam along a completely arbitrary trajectory.

While such a tool is capable of cutting paper and foam plastic within 10-15 minutes, it will be very difficult to achieve large volumes of cutting with it.

Conclusion

You can cut foam plastic with a laser beam only if the white surface of the foam is treated with a black or dark absorbing layer, for example, a regular acrylic paint. It would be more rational to install a laser on the machine or homemade CNC carriage from a router. In this case, you can not only cut, but also form 3D models from thick foam blocks. To obtain the exact dimensions of the model, the laser must operate in pulsed mode.

Discuss the article on the forum

How to remove mold in the bathroom