How to choose polycarbonate for greenhouses, with maximum efficiency
crop yields in many regions of our country can be obtained only by using technology protected agriculture.Polycarbonate is the best material for greenhouses and polytunnels.Facilities of this type are often erected owned gardens and farms on their own without the involvement of specialists.In such circumstances, the question arises how to choose polycarbonate for greenhouses best in terms of price and quality.The range of panels in the market is great, and not all of them suitable for the construction of such facilities.
- What type of polycarbonate is best suited for greenhouses?
- device and main characteristics of polycarbonate
- optimum thickness of polycarbonate for the different types of greenhouses
- protective properties of polycarbonate UV
- sheet size is most suitable for the greenhouse
- Color polycarbonate sheets for greenhouses
- selection procedure polycarbonate store
- VideoHow to choose a quali
What type of polycarbonate is best suited for greenhouses?
to make an informed decision on the matter is necessary to understand the characteristics and technical characteristics of this material.Industry produces two kinds of polycarbonate: monolithic and cellular, the latter is just used for the construction of greenhouses.Such panels on the parameters best meet all the requirements that apply to roofing materials for such structures.
Before the appearance on the market of cellular polycarbonate for this purpose used silicate glass and plastic film.
use of polycarbonate has several advantages over the above materials:
Depending on the type of panel, its mass is at least an order of magnitude lower than that of the glass sheet of the same size.
Polycarbonate does not disintegrate under the stress on individual pieces such as glass, and is not prone to tear as the plastic film.
high resistance of the material to climatic influences: large temperature variations, rain and snow.
4. Low thermal conductivity.
Low thermal conductivity and hence excellent insulation properties, which significantly reduces the cost of heating greenhouses.
5. Light transmission and UV protection.
excellent light transmission panels in some species more than 86% and protection against hard ultraviolet.
6. The high ductility of the material.
ductility material: During installation it can be bent to a certain diameter and stored in this position for a long time.
Polycarbonate different durability, with proper selection and installation of the panels lifetime of 10 years or more without significantly changing the properties.
important factor for choosing polycarbonate as the material for greenhouses is the financial side of things.It is considerably cheaper than glass and high durability in view of its advantageous application using a polyethylene film.In addition to the direct effect on the choice of polycarbonate as the material for greenhouses exist side.
The use of these panels allows you to use load-bearing frame with a smaller margin of safety, which will save a lot of money in the construction of such facilities.Polycarbonate due to their unique specifications are becoming more common in the construction of greenhouses.
device and main characteristics of polycarbonate
unique properties of polycarbonate is determined by two main factors: a cellular structure and chemical composition of the material.Polycarbonates of this type is a multilayer panel with transverse partitions, providing its sufficient strength and rigidity.A honeycomb in cross section of the sheet may be rectangular and triangular shaped in various combinations.
total number of layers in the material can be from two to four, depending on the thickness and type.
main technical characteristics of the most common varieties of polycarbonate are shown in Table:
|sheet thickness, mm||4||6||8||10||16||20||25|
|length and width of the panel, mm||6000 (12000) × 2100|
|The proportion of material kg / m2||0,8||1,3||1,5||17||2,7||3,0||3,5|
|thermal conductivity of the sheet m 2 × ° C / W||0,24||0,27||0,28||029||0,42||0,56||0,68|
|minimum bending radius of the sheet, m||0,7||1,05||1,5||1,75||2,8||3,5||4,4|
|Change propertiesartificial aging material, cond.years||10||20||30|
analysis of the data in the table allows you to draw some conclusions that facilitate the process of selecting material for greenhouses.
most important characteristics for multi-wall polycarbonate used in the construction of greenhouses, are as follows:
- light transmission;
- thermal resistance to heat;
- specific gravity;
- mechanical strength;
A simple comparison of the parameters for the different types of panels allows to uniquely identify the direct dependence of these characteristics on the thickness of the sheet.Based on the results of this study, it can be concluded that the performance of this material will be directly affected by this parameter.
optimum thickness for different types of polycarbonate greenhouses
determining factor in what to choose for polycarbonate greenhouse is the thickness of the panel, which is directly dependent on its performance.One of the most important indicators for the roofing material is a greenhouse light transmission.Panels whose thickness is more than 10 mm, absorb and scatter from a quarter to half of the luminous flux.This situation will adversely affect the illumination of greenhouses and become the reason for the decline in yields.
second most important factor for greenhouses thermal resistance to heat transfer of the material, which increases with the thickness of the polycarbonate.This reduces the costs for heating greenhouses and accordingly production costs.But, as mentioned above, the increase in thickness will have a negative influence on the light transmittance.Another characteristic of the panel into account when determining its optimal thickness is mechanical strength.
often in order to save the greenhouses used in the manufacture of 4-mm polycarbonate.This is quite possible, if the panel does qualitative and their thickness corresponds to the nominal parameter.Some manufacturers in order to reduce the cost of this parameter may be reduced to 3.5 - 3.8 mm.In the eyes it is imperceptible, but during the operation possible premature failure of the material under the wind load or due to accumulation of snow mass.From the use of the polycarbonate should be abandoned.
In determining the optimum thickness of polycarbonate taken into account the following factors:
- Features carcass structure (the radius of curvature of the arcs and the distance between them, as well as between the transverse profiles).
- Climatic zone of the region where the greenhouse is being built.
- Have the heating system and the period of use of facilities for its intended purpose.
As practice shows, for greenhouses used polycarbonate thickness 4, 6 and 8 mm.In some instances, the 10 - mm panel for sufficiently large permanent agricultural facilities.Thicker sheets reduce light transmission and greatly increase the load on the frame, which makes their use impractical.
protective properties of polycarbonate UV Polycarbonate
itself exposed to the destructive effects of ultraviolet rays, which, if prolonged exposure to destroy the polymer.To protect against such photochemical processes on one or both surfaces of a polycarbonate coextrusion layer applied light stabilizing agent.
thickness of the coating is from 0.0035 to 0.006 mm, and this is enough to protect the sheet from destruction.The protective layer is applied in the production process and the resulting material is its partial diffusion in the substrate.The interpenetration of light stabilizer and polycarbonate excludes them delamination, which increases the service life of the material.
1. Polycarbonate provides reliable protection of plants against the most dangerous for their hard ultraviolet.Radiation of this part of the spectrum is absorbed and scattered panels.
Ultraviolet rays backsheet photo stabilizing agent, and that is enough for reliable crop protection from the harmful radiation.
2. Information about the presence of the stabilizing layer of light is reflected in the documentation and on the packaging film.Determine at a glance the presence of the protective coating is impossible and should not believe unscrupulous suppliers, approving the introduction of such additives in the production of the melt granulate panel.
Thus, trying to sell low-quality material suitable only for internal works.
sheet size is most suitable for the greenhouse
industry produces two main types of panels dimensions, which depend on the thickness of the sheets.Sheet size polycarbonate sheets is wide, 2100 mm long and 6000 mm and 12000, with a tolerance from the nominal value in the transverse direction of not more than 3 mm in the longitudinal not more than 10 mm.This should be considered when choosing a roofing material for a greenhouse.
the purpose of rational and fullest use of the material without scraps and residues in the production of scaffolds greenhouses should take into account such factors:
1. The length of the arc power structure recommended is 3, 4, 6 and 12 m, thus avoiding cross jointsbetween the individual sheets.
2. The distance between the bearing elements is selected in such a way that the joints were in the profiles.This significantly increases the strength of the roof of the greenhouse.
3. When making the choice of ready-made arches or taken into account the minimum allowable radius of curvature, which depends on the thickness of the sheet.
4. With the construction of greenhouses with sloping roofs and vertical walls should calculate their size so that a sheet of 6 or 12 m shared without residues.
Taking into account all of the above recommendations will build a strong and durable greenhouse that is in service will not require repairs and any additional costs.
Please note that the installation of cellular polycarbonate frame greenhouses carried out in such a way that the cell went along the slope.At the ends of the greenhouse sheet is attached so that the cells were vertically.This will ensure the removal of condensate from the cells and prolong the life of the material.
Color polycarbonate sheets for greenhouses
Companies producing polycarbonate panels offer a wide range of different colors.Choice of color sheet polycarbonate greenhouses for the device is determined primarily by the appointment of the facility.It made cultivation of plants that need sunlight specific spectrum and intensity.
for greenhouses and polytunnels used transparent polycarbonate with maximum light transmission.For a panel thickness of 4 mm and 6, the figure is 85%.The use of colored sheets impractical because it will negatively affect the development of plants and, ultimately, on the crop.
selection procedure polycarbonate
shop before heading to the store to buy this material, you should decide what is needed for polycarbonate greenhouses.
customer must know exactly the following characteristics he needed panels:
sheet thickness .Normally used for the construction of greenhouses polycarbonate with a thickness of 4 mm to 10 mm, and its value is determined by the project.In choosing the material can be made of this parameter measured using calipers.Significant deviations from the declared value in the smaller side, as a rule, evidence of poor quality sheet.
the presence of light-stabilizing coating .Particular attention should be paid to the presence in the acquiree polycarbonate protective coating against UV radiation.Check out this document and can only find this information in the certificate of conformity.In addition, the protective film indicate which side of the sheet should be facing the sun.
color material .For the installation of greenhouses must be used exclusively transparent polycarbonate.
required number of panels of different sizes .Ask the seller you need the presence of the size of the material.
purchase quality polycarbonate allow to build robust greenhouse, suitable for seasonal or year-round use.Keep in mind that cheaper materials are usually made of recycled or low-quality raw materials and in violation of the technology.Little-known manufacturers often offer products of dubious quality.Experts recommend buying polycarbonate those brands that have proven themselves on the positive side.
Video: How to choose a high-quality polycarbonate
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