Foamed PVC: technical characteristics. Foamed polyvinyl chloride (PVC): treatment methods

Polyvinyl chloride (PVC) is a polymer material that is widely used in various areas of advertising products, in the process of repair and construction work, in the design of interiors of premises.

History of success

The rich 30-year history of PVC material in the field of thermoplastic plastics is striking in its uniqueness. Due to its excellent properties and characteristics, foamed PVC has a huge variety of applications in all areas of everyday life of modern man. The raw materials for the production of polyvinyl chloride are such types of raw materials as coal, oil and gas. In the process of polymerization of the intermediate product of vinyl chloride, a final PVC material is formed, consisting of molecules of carbon dioxide, hydrogen and chlorine.

Numerous developments in the sphere of production, improvement of formulations and methods of processing showed that due to its unique molecular structure, the substance occupies a special place among other types of thermoplastics.

Foamed PVC has a lot of positive qualities: durability of operation, resistance to temperature changes, mechanical influences, a variety of processing methods and excellent chemical resistance. Excellent impact resistance and the ability to use outside the room is achieved through the use of various additives. Foamed PVC sheet is the most common type of PVC products.

The first in Russia manufacture of PVC plastic was introduced by the company "United Extrusion" under the brand UNEXT. The use of modern high-tech equipment makes it possible to produce products that meet all international standards. Thanks to the use of better raw materials and a unique recipe, PVC foamed UNEXT is no different from its European counterparts.

Types of sheet plastic

Since the appearance of sheet material on the market, PVC foamed plastic has quickly become a universally used product. A variety of types of sheet polyvinylchloride with special properties makes it possible to use the material for the implementation of ideas in various fields.

There are several types of the most common sheet plastics from solid PVC:

• Inert foamed PVC sheet - is manufactured using the latest technology. As a result, the internal structure is uniform and porous, and the outer surface on both sides is smooth and glossy;
• Freely foamed PVC sheet - light plastic made of solid polyvinyl chloride, characterized by a silky surface and a fine porous structure;
• Compact sheet - has good impact resistance and high stability;
• Compact transparent PVC sheet - transparent plastic, which has excellent light conductivity and shock resistance;
• Wavy transparent sheet - created specifically for roofing, characterized by difficulty in igniting;
• Composite PVC sheet - the inner part consists of free-foam plastic, and the outer layer is a two-sided aluminum coating.

The variety of types and high technical reliability of PVC sheets make the plastic universal for various applications: interior decoration of buildings, construction of advertising and information stands, the creation of interior shops and trading platforms, engineering, etc.

Foamed PVC: general characteristics

1. The material does not absorb water and moisture from the air, due to which it does not swell and, as a consequence, does not deform during the entire service life. Even when in the water for a long time, the appearance of the plastic and its performance characteristics do not change.
2. One of the main advantages of sheet PVC is its fire safety - plastic belongs to the group of flammable materials that do not support combustion in the air.
3. Foamed PVC has excellent light fastness.
4. The material is used to create elements of complex shape with the help of thermo-, pneumo- and vacuum-forming methods.
5. Plastic is resistant to the most common chemical agents: household detergents and disinfectants, solutions of acids and alkalis.
6. PVC refers to environmentally friendly materials that do not contain heavy metals and do not adversely affect human health and the environment.
7. The material is easily subjected to machine and manual processing with the help of ordinary tools: it is easily cut, drilled, sawed, bent, glued, fastened with nails, screws and rivets.
8. The surface of the plastic is ideal for coating self-adhesive and laminating film, as well as for printing screen printing, silkscreen paints and varnishes.

Ways of processing

PVC foamed sheet is easily exposed to any kind of processing and gluing. Due to its mechanical features, plastic does not require the use of complex and expensive equipment. PVC sheets can be processed by conventional tools, which are used for working with wood or metal.

Sawing up of PVC plastic

Foamed PVC sheet can be hand-sawed with a disk and band saw, as well as a jigsaw. The material can be sawed with a hand saw, designed for woodworking. Saws for metal can be clogged due to the proximity of the denticles. Optimum parameters for sawing:

• Speed up to 300 m / min;
• Feed rate 30 m / min.

Experts recommend the following indicators of the angles of the teeth: α = 5 - 10 ° - anterior angle, b = 10 - 20 ° - posterior, with a step of teeth from 5 to 10 mm.

Drilling

Foamed PVC is drilled with conventional drills designed for working with metal. The most optimal effect is achieved at a speed of 50 to 300 rpm and feed from 3.5 to 6 m / min. It is recommended to use angles with the following values:

• Φ = 100 - 110 ° - angle at the top;
• Β = 30 ° - angle of ascent;
• Α = 0-5 0 is the front angle.

Milling

For the processing of PVC plastic, standard universal vertical and horizontal milling machines can be used. To prevent damage to the surface of the material, when fixing, use plastic or wooden gaskets. Optimal mode of operation:

• Cutting speed not more than 900 m / min;
• Material delivery 0,3 - 0,6 m / min;
• Front angle α = 5 - 20 °;
• The rear angle γ = 10-25 °.

Sheet Edge Processing

PVC foamed sheet requires final processing of the edges. For this purpose, you can use a plane, sandpaper or other equipment used to cut the edges of wood or plastic. If the material experiences constant dynamic loads, unevenness may attach to the appearance of faults or cracks. A sheet of PVC, having a thickness of not more than 3 mm, can be cut with a conventional knife.

Stamping PVC plastic

The effectiveness of stamping depends on several factors:

• Sheet thickness - sheets up to 3 mm thick are easily punched. If you use special equipment and apply the right methods, you can stamp simple shapes from PVC with a thickness of 4 to 6 mm. Note that the edges of the sheet are slightly rounded;
• Sheet temperature - with a slight heating of the material, the punching quality is improved;
• Equipment for stamping - suitable equipment for stamping cardboard and other foamed materials;
• Angle blade - an indispensable condition for quality stamping is the location of the blades at an angle of 30 °.

Hot bending

For this purpose, any standard equipment for bending thermoplastic is used. A neat bending depends on a uniform temperature distribution and preliminary determination of the zone of constant heating. The most optimal level of temperature is from 115 to 130 ° C. If the temperature is above this maximum, there is a high probability of cracking and splitting of the cellular structure of PVC. Most often this happens when bending thicker sheets. In case of insufficient heating, the material will be subjected to a strong voltage and, possibly, will return to its original state.

When bending foam materials, one-sided heating is successful only up to a certain point, so the bending radius can be visually unsatisfactory. In this case, a V-notch is applied to the inside of the sheet. A prerequisite is the fixation of the resulting product to complete cooling of the material.

Bonding of PVC sheets

PVC foam foil can be glued to different types of adhesive. If you need to glue the sheets together, you can use a solvent glue for cold welding or reactive (second) glue. When gluing non-porous and non-absorbent materials, the following types of glue are suitable:

• Solvent contact - applied to both surfaces in a ratio of 150 g per 1 m ² ;
• Two-component polyurethane - only one surface is covered.

Bonding of PVC with porous and absorbent materials takes place using an aqueous dispersion glue or a two-component polyurethane adhesive.

Experts recommend testing for each specific case, taking into account factors that may affect the effectiveness of bonding: resistance to weathering and chemicals, elasticity of the adhesive seam.

Foamed PVC welding

PVC sheets can be combined with hot air. In the welding process, certain criteria must be met: the preparation of the welding seam and the use of the correct temperature. The main thing that should be paid attention is providing uniform heating, while avoiding local overheating. For the treatment of foamed PVC, a standard welding rod can be used, which should be preheated to a level of 70 - 80 ° C.

Basic parameters of work:

• The edges of the seams of PVC sheets must be beveled by 60 °;
• Optimal welding temperature 280 - 290 ° С;
• During operation it is necessary to use a high-speed welding nozzle (3.5 m / min).

Thermoforming

Foamed PVC can be pulled or bent after heating to a certain temperature. However, due to the fact that the material is a two-phase system, half the volume of which is occupied by the air inside, it is necessary to observe some limitations. For the processing of sheets, a two-sided heating is recommended. Form the material after it becomes elastic. Before thermal exposure, remove the protective film from the PVC sheets.

Printing and varnishing

Due to its structure, the surface of foamed PVC is ideal for screen printing and varnishing. For these purposes, special vinyl-acrylic dyes are suitable. Before applying the seal and varnish, the sheet surface is degreased by wiping with alcohol.

Field of application of expanded PVC

Due to its high sound, heat insulation and moisture resistance, the PVC profile has been used for many years in window and door production, serving as balconies and loggias. Transparent and wavy sheets of polyvinyl chloride are used in the field of roofing and glass substitutes.

PVC profile differs from other materials by its reliability, durability, unpretentiousness in operation.

Continuous improvement of processing methods and manufacturing techniques allows manufacturers to discover new possibilities for using PVC products. Mat made of foam PVC is used as an anti-slip coating for the floor in the bathroom. It has a soft texture and does not absorb moisture.

Perfectly suited for use in external conditions, sheet foamed PVC. The price of this material is significantly lower than other types of thermoplastic. It is suitable for advertising or as a display. Sheet plastic is characterized by good resistance to weather conditions and exposure to ultraviolet rays.

Foamed PVC, whose price has competitive advantages, is widely used in advertising, construction and industry. It is an easy and durable material with which you can realize any design and color solutions.

Manufacturers of building materials offer a wide range of PVC products. All of it is distinguished by a variety of colors, thickness of sheets, properties. The price of one sheet of 2x3 m in size varies from 1500 rubles to 4,500,000 (depending on the manufacturer and other characteristics).