Monolithic polycarbonate can only be molded at temperatures above the "glass transition temperature" of 150°C. If this condition is not observed, internal stresses arise in the molded product, which lead to a deterioration in impact strength and an increase in sensitivity to chemical attack. Unlike other sheet materials, internal stresses in a monolith are not visible to the naked eye. Of course, you can deal with them by annealing the product, but this procedure is labor- and energy-intensive and does not pay for itself.

Sheet polycarboate must be dried before thermoforming. Drying of ordinary sheets should be carried out at a temperature of 120 ° C, for mirror and reflective sheets at a temperature of 110-115 ° C. The duration of the process depends on the thickness of the sheet and the amount of moisture6 that the sheet has absorbed during storage. To determine the time, we recommend doing the following. From a sheet of an experimental batch, cut 2 - 3 small samples. - Place them in an oven heated to 110° - 120°C. Every 2 - 3 hours, remove the next sample from the oven and heat it up to a molding temperature of 170 ° - 180 °C. Watch for bubbles on the sample. If no bubbles form after 10 minutes, the material is dry. If bubbles appear, this will indicate that additional drying is required.

Thermoforming with a protective outer coating is only possible when the material does not require pre-drying and when there are no high demands on the optical properties of the product. In other cases, it is recommended to remove the plastic film.

Vacuum forming.

It is carried out on any modern machine for vacuum forming. It is advisable to use automatic machines for this purpose, which capture the sheet from all sides and hold it throughout the entire process. This is especially important when working with sheets 1 - 2 mm thick, which can shrink up to 5%, and therefore must be firmly fixed.

Pressure molding.

This process is similar to vacuum forming. It allows easy molding of domed surfaces and lids. This method can also be used without pre-drying, since it requires little relative stretching and the shape of the product is very simple (spherical or almost spherical).

free molding

Can be done without pre-drying, but requires careful temperature control to avoid localized overheating. In this case, ovens with controlled air circulation should be used. In the production process, it is necessary to monitor the shrinkage of the material, since in this method the sheet is not fixed to the frame.

Bending along the heating line

Can be carried out without pre-drying, but precise temperature control is required. Initially, overheating will be detected at the ends of the bend line, where the sheets heat up faster. Particular care must be taken to ensure that bending is not carried out in areas whose temperature is below 150 ° C. Otherwise, internal stresses occur, due to which the sheet loses its impact strength.

To check the quality of the bend, you can conduct an experiment and, putting it on a flat surface with the bend up, strike with a hammer. Failure of the sample will indicate that the bending temperature is too low.

monolithic polycarbonate with a thickness of more than 3 mm can be qualitatively bent only on equipment that allows double-sided bending. For sheets up to 6 mm thick, bending is possible without removing the protective film. With a thickness of more than 6 mm, the time and temperature of heating require the removal of the protective film at least from the place of the bend.

A person who decides to independently engage in repairs of a capital nature, or the construction of small structures in his summer cottage (located outside the city or in an urban area) will definitely face the need to solve several problems. For example, which building material to choose, which tool to use, or how to bend polycarbonate (if the choice fell on it).

Benefits of polycarbonate

Polycarbonate is used by man in various areas of his life. For example, it is used in the construction of greenhouses and gazebos in summer cottages, balconies, roofs, canopies, areas intended for adults and kids to relax. Such popularity of the polymer is due to the presence of a large number of undoubted advantages. These include the following properties:

1. Long service life exceeding ten years.
2. The material does not lose its qualities during use in a wide temperature range, the limits of which are forty degrees of frost and heat of one hundred and twenty degrees.
3. Ease of processing. Thermoplastic can be cut, drilled, using a simple, handy tool.
4. High soundproofing properties make it possible to use thermoplastic in the construction of soundproof screens along motorways passing through residential areas or for office partitions, allowing each employee to create a quiet, comfortable, separate workplace.
5. The high degree of flexibility of the thermoplastic panels allows the material to be bent at different angles, creating various complex and simple shapes.
6. material transparency. Polycarbonate is able to pass through itself about ninety percent of the light of the sun.
7. Ease. Thermoplastic panels are much lighter than other similar materials, particularly glass. This makes it easier to work with material at high heights.
8. Strength. The material is able to withstand heavy loads emanating from the severity of precipitation, which can accumulate on the surface of the plates.
9. The material can be bent in a heated and cold state, which positively distinguishes the polymer from other materials with similar properties. Curved sheets do not crack even when bent into oval shapes, but with a slight degree of bending. This is made possible by the excellent fluidity of the thermoplastic.
10. The structure of polycarbonate is such that when cutting the sheets, their edges, in the places of the cut, are not sharp, which significantly reduces the possibility of a person getting hurt while working with the material.

Necessary steps for bending polycarbonate

To use a polymer material to create structures of complex configuration, you will need to have knowledge that can become the answer to the question: "How can I bend cellular or monolithic polycarbonate?". Information about the properties of the thermoplastic and advice on working with the material can act as the required knowledge. Resin Bending Recommendations:

1. Preparing the tool that will be used to bend the polymer. Such a tool is a vise that is installed and fixed on a table or workbench used in the work of locksmiths.
2. From the documents that are attached to the purchased material, you should find out what is the minimum radius for bending the panels. For example, plates 4 mm thick can be bent with a radius of more than 60 centimeters.
3. If the plates are honeycomb thermoplastic, then they are allowed to bend only along the length of the cells. Otherwise, the material may receive mechanical damage.
4. The sheets should be fixed in a vice, after which they can be safely bent even with “bare” hands.

If you yourself are engaged in construction or major repairs, there are always many problematic issues. For example, you have chosen polycarbonate as a building material, which needs to be curved. Today we will tell you how to bend polycarbonate at an angle or 90 degrees with your own hands.

Advantages

Due to its excellent qualities, this material is becoming increasingly popular. It is used in various areas of life. Carbonate sheets are used in the construction of recreation areas, roofs for small buildings, canopies over balconies. Its service life is more than 10 years. Polycarbonate is a transparent, lightweight and durable plastic material. At the dacha, greenhouses and gazebos are built from it, as shown in the photo.

• Due to its structure, the material is very durable, so it has found application in various areas of construction;
• Ease. Plastic sheets are several times lighter than ordinary glass. This makes it possible to work even at height;
• The material is transparent. Monolithic polycarbonate, transmits almost 90% of daylight. But the second type of this product is cellular, it transmits light much worse;
• The sheets are flexible. They can be bent at any angle, while creating different shapes;
• Does not require complex processing. The product can be cut and processed with improvised tools;
• It can withstand temperature conditions - 40 degrees to + 120 degrees. This is another advantage of this material: it can be used in the internal parts of the building, where there is a high temperature;
• Keeps noise out.

To date, there are two types of polycarbonate - it is monolithic and cellular. They are becoming very popular in modern construction. To understand how sheets can be bent, for example, at a right angle, we first look at how one type differs from another.

Monolithic

Cast material can be easily processed: sawed and drilled, while using improvised tools for wood and metal, as shown in the photo.

The plastic product is strong enough. So the carbonate, which is 12mm thick, is bulletproof. The smallest sheet thickness is 2 mm. Accordingly, such sheets are cheaper.

Cellular

It is a lightweight plastic material. The product is made of 2-3 sheets connected with special jumpers, as shown in the photo. Special voids are formed between the plates. 1 sq.m. The sheet weighs about 800 grams.

Both types of this material are more similar to roofing iron in terms of properties. Polycarbonate has enough strength that when bent at an angle, it can resist change.
Polycarbonate differs from other plastic and plastic materials in that it can be bent even when cold. While other materials for bending at an angle of 90 degrees, you need to heat. For work with carbonate, it is imperative to take into account the cold bending radius, which is permissible according to the standards. You can check this information with the seller.

In order to bend the sheet, you need to place it in a vise, after which you can bend it at an angle with your hands, as shown in the photo. Thanks to its excellent qualities, the product bends without problems, and you can give it the desired shape. The good strength of the carbonate, even under pressure, does not destroy the material. It does not break and does not crack, remains smooth and just as strong.

It is worth considering that the plastic has good fluidity. Even at temperatures up to +120 degrees, the indicator remains almost the same as at room temperature. This means that in order to bend carbonate, you should not heat it, because it will bend anyway.

If you are working with a honeycomb product, be aware that it can only be bent along the honeycomb cells, as shown in the photo. However, these types of materials cannot be bent to the same angle as metal sheets. In this case, even heating the product will not help to reduce the bending radius. Therefore, it makes no sense to heat carbonate in order to create an angle of 90 degrees.

Polycarbonate sheets, which have fairly good construction qualities, are often used in the manufacture of greenhouses, canopies, etc.

Summing up

In order to bend polycarbonate, you just need to take a sheet and do it with your hands, without resorting to heating the material. Just be sure to check what is the minimum bending radius of the material you are buying. In addition, it must be taken into account that the simplicity and ease of work depends on the thickness of the sheets.

The two most interesting qualities of polycarbonate are its transparency and flexibility. The first property makes it possible to use the material together with silicate glass - the polymer is stronger, cheaper to manufacture and inferior to glass in transparency by only 10–15%. Designers willingly use the second quality, creating light-transmitting structures of various configurations.

Areas of use

• Furniture - transparent plastic instead of glass not only reduces the cost of ultra-modern techno-style furniture, but also gives it extremely unusual contours. Chairs and tables, armchairs and shelves of a round curved shape, original outlines easily turn an ordinary interior into a unique one.

• Dishes are the same unbreakable transparent utensils that both look attractive and do not deform: the strength of the polymer is 250 times greater than the strength of glass.
• Internal and external structures - partitions, noise barriers, doors, entrance groups, facade cladding - a transparent bending material is indispensable.
• Small architectural objects - greenhouses, greenhouses and, of course, gazebos. It is the latter that are most often made by hand. In the photo - a round gazebo.
• Light transmission structures - glazing of stadiums, circuses, large buildings, frame canopies, hangars, skylights and so on. Today, the vast majority of arched structures are sheathed with polycarbonate, since it is much easier to give it the desired bend.

Material molding

Forming is the process of giving a material a certain curvilinear shape. As a rule, this requires heat treatment of the sheet, a matrix for shaping, and so on. However, in the case of polycarbonate, other methods are also possible, which are quite affordable at home.

Heat treatment

The ability to bend, maintain bending and not deform at the same time is provided with a sufficient yield index. With increasing temperature, the fluidity increases to some extent, that is, the sheets can be given not only a bend, but also a complex shape. Both monolithic and cellular polycarbonate are processed.

1. For a polymer, the optimal heating temperature is considered to be 150–190 C. To carry out molding at home, it will be necessary to equip a furnace with lower and upper heating elements.
2. The sheets are pre-dried - placed in an oven at a temperature of 115 C.
3. Drying takes about 2.5 hours. The material is considered ready if, after drying and heating the sample to 200 C, bubbles do not appear on it.
4. For molding, polycarbonate is heated to 180-220 C, and then placed on matrices - a mold template.
5. Sheets are heated on both sides.

Depending on the features of the last stage of molding, three types are distinguished.

• Vacuum - sheets fixed on the frame are heated, then placed in a mold, from where air is removed. Vacuum molding is rarely used at home, as it requires additional equipment, and is designed to obtain a thin complex relief - dishes, masks, toys.
• Forming by pressure - in this case, the drying process can be ignored, and the material can be immediately heated to 200 C. Then the sheet is placed in a mold and, under its own weight, takes the desired form. In this way, simple spherical elements are made with their own hands.
• Mechanical force - the material is pressed down by the negative part of the matrix.

Line bending

This method is most often used at home. Monolithic or honeycomb sheets for arched structures - a visor, greenhouses, do not need a complex shape, only a smooth bend or bend at an angle, if we are talking about a polygonal arch.

The technology is simple: the required area is heated with a building hair dryer and bent at the desired angle. The possible value of the angle is indicated in the product passport, since it differs for materials with different thicknesses. In the photo - a working moment.

cold forming

Requires only physical effort. Polycarbonate does not warm up and does not dry out, but is processed under normal conditions. In production, metal rollers are used for this.

With your own hands, the sheet is fixed in a vice and manually given the required shape.

• You need to bend without warming up slowly, it is advisable to use a template. Deforming the material is quite simple, but unlike other options, on monolithic polycarbonate, the onset of deformation is not visually determined, but manifests itself during further operation.

• The maximum angle is calculated based on the thickness of the sheet: the value is multiplied by 150.
• However, if during thermal forming the material solidifies, taking shape, then during cold forming, the residual stress causes the sheet to try to return to its previous position. In order for the material to hold the required angle, it must be bent by a value greater by 25%.

In the video, the molding of the product is considered in more detail.

Bending, cutting, gluing monolithic polycarbonate

Bending along the heating line can be carried out without pre-drying, but this also requires precise temperature control. Initially, overheating will be detected at the ends of the bend line, where the sheets heat up faster.

Particular care must be taken to ensure that bending is not carried out in areas whose temperature is below 155 ° C. Otherwise, internal stresses will occur, due to which the sheet will lose a significant proportion of its impact strength.

It is highly recommended to experiment with small bent samples of the material and test their impact strength by striking with a heavy hammer on the bend line of the sample laid on the floor or work bench with the bend line up. Sample failure would mean that the bending temperature was set too low.

When bending sheets with a thickness of more than 3 mm, satisfactory results can only be obtained on equipment that allows double-sided bending along the line. Bending along the heating line can be performed while maintaining a protective polyethylene film on the product only for sheets with a thickness of less than 6 mm

In the case of sheets with a thickness of 6 mm or more, the heating time and the temperature on the surface of the sheet will be too high, which will cause local melting of the polyethylene. Prior to molding, the polyethylene can be stripped along the heating line, thereby preventing it from melting, and leaving the polyethylene coating on most of the rest of the sheet surface, making it easier to handle after molding.

Cutting monolithic polycarbonate:

Sheets are easily cut with wood saws. High speed steel cutting equipment should be avoided as high friction causes the polycarbonate to melt. You can use guillotine cutting, but this method is not recommended for thicknesses above 5 - 6 mm, since the cut edge is rough and deformed.

It is possible to use laser cutting with the help of industrial infrared laser systems. The cut edge usually looks burnt and due to the high local temperature, internal stresses can develop. After laser cutting, it is recommended to anneal the products at 130 °C for 1 - 2 hours. Good results can be obtained using hydromechanical cutting on an adjusted machine.