There are mainly four types of greenhouse membranes commonly used in China: the first is a polyvinyl chloride (PVC) greenhouse membrane; the second is a polyethylene (PE) greenhouse membrane; the third is an ethylene-vinyl acetate copolymer membrane; The four are light-setting agricultural films.
These kinds of films have the same characteristics in nature and also have different points. Therefore, there are also differences in use effects.
(1) Polyvinyl chloride (PVC) film insulation, light transmission, weather resistance, soft, easy to shape, suitable for greenhouses, greenhouses and small sheds outside the cover material. The disadvantage is that the film has a large specific gravity (1.3 g/cm3). The cover area of ​​a certain weight of the film is reduced by 1/3 as compared with the polyethylene film (PE) and the cost is increased. At low temperatures, the film is hardened and embrittled and easily softened and relaxed at high temperatures. After the auxiliary agent precipitates, the membrane surface will absorb dust, affect the light transmission, and the residual film cannot be burned because of chlorine gas. At present, the main products of PVC film are:
1 The ordinary PVC film is not added with anti-aging additives during the film making process. The use period is only 4-6 months. It can produce one-season crops, waste energy, increase labor and investment, and is gradually being eliminated.
2 PVC anti-aging film in the raw materials added anti-aging additives after the film was calendered. The effective use period is 8-10 months. It has good light transmittance, heat preservation and weather resistance. It is the main material covered in greenhouses and small and medium arch sheds. It is mostly used for spring cultivation after the fall.
3 PVC non-drip anti-aging film (PVC double anti-shedding film) also has anti-aging and drip characteristics, good light transmission and heat preservation, non-drip sustainable for 4-6 months, and safe service life of 12-18 months The application is more extensive, and it is currently the preferred covering material for the energy-efficient solar greenhouse, and it is better to use as a covering material for the greenhouse.
4 PVC weather-resistant dripless dust film In addition to weathering drip performance, the surface of the film is treated, the plasticized parsing yield is less, the vacuum is lighter, the light transmittance is improved, and the winter and spring cultivation of the greenhouse and the greenhouse is more favorable.
(2) Polyethylene (PE) shed film is light in texture (specific gravity: 0.92 g/cm3), soft, easy to mold, good in light transmission, non-toxic, suitable for all kinds of greenhouse film and plastic film, and is the main agricultural film in China. Variety. The disadvantages are: poor weatherability and heat insulation, and difficult to bond. If a greenhouse film is produced, additives such as an anti-aging agent, a drop-free agent, and a heat-insulating agent must be added in order to meet the production requirements. The main products are:
1 Ordinary PE film does not add anti-aging additives such as white film directly produced by the blow molding of raw materials, the current greenhouse and small and medium sheds have a large amount of application, generally in the spring and autumn sheds, the use period is only 4-6 months, only One crop can be grown, energy is wasted, labor is increased, and production is gradually eliminated.
2PE anti-aging film (longevity film) is added to PE resin anti-aging additives, blown into a film. The thickness of the film is 0.08-0.12 mm, and the use period can reach 12-18 months. The crop can be cultivated for 2-3 seasons. It not only extends the use period, reduces the cost, saves energy, but also greatly increases the output and output value. It is The current promotion of agricultural cultivation in the cultivation of key varieties.
3PE non-drip anti-aging film (double anti-agricultural film) also has drip, weather resistance, light transmission and heat preservation, anti-dropping effect can be maintained for 2-4 months, anti-aging life up to 12-18 Month is currently the most comprehensive and widely used agricultural film variety. It can be used not only in greenhouses and large, medium and small sheds, but also in early-spring cultivation of energy-saving solar greenhouses.
4PE insulation film This cover material can prevent infrared radiation to the atmosphere, can increase greenhouse temperature 1-2 °C, in the cold area application effect is better.
5PE multi-functional composite membrane has many functions such as non-dripping, heat preservation, weathering, and longevity. Some of them have the function of blocking ultraviolet rays and reduce the transmission of ultraviolet rays in the booth. Some can inhibit the formation of sclerotinia bacillus and gray mold spores. Use up to 12-18 months.
(3) Ethylene-vinyl acetate copolymer (EVA) EVA resin is a new agricultural film material used in agriculture in recent years. The agricultural film produced by it is superior to PVC in terms of light transmittance, heat preservation, and weather resistance. Or PE agricultural film. EVA agricultural film cover can increase production by about 10% compared with other greenhouse films, and can be used continuously for more than 2 years. It can not be deformed before aging, and can be easily recycled after use. It is not easy to cause soil or environmental pollution.
(4) Light-modulating plastic film Light-emitting film made of rare earth and other functional additives added to PE resin can selectively transmit light. It is a new type of cover material that can fully utilize solar energy, and other Compared with the greenhouse film, the greenhouse has a good effect of warming and heat preservation, and has a strong biochemical effect on crops. It has the functions of early maturity, high yield, and improved nutrient composition for different crops. The rare earth can also absorb ultraviolet rays and extend the service life of the agricultural film. Among them, the special purple film (leaf film) of leafy vegetables is the purple masterbatch added in the film and weather-resistant, heat-insulating, non-dripping masterbatch, blown into a film. The film is slightly bluish-purple, reducing glare, increasing temperature, early growth, high quality and high yield. Suitable for the cultivation of leeks and a variety of green leafy vegetables.
These kinds of films have the same characteristics in nature and also have different points. Therefore, there are also differences in use effects.
(1) Polyvinyl chloride (PVC) film insulation, light transmission, weather resistance, soft, easy to shape, suitable for greenhouses, greenhouses and small sheds outside the cover material. The disadvantage is that the film has a large specific gravity (1.3 g/cm3). The cover area of ​​a certain weight of the film is reduced by 1/3 as compared with the polyethylene film (PE) and the cost is increased. At low temperatures, the film is hardened and embrittled and easily softened and relaxed at high temperatures. After the auxiliary agent precipitates, the membrane surface will absorb dust, affect the light transmission, and the residual film cannot be burned because of chlorine gas. At present, the main products of PVC film are:
1 The ordinary PVC film is not added with anti-aging additives during the film making process. The use period is only 4-6 months. It can produce one-season crops, waste energy, increase labor and investment, and is gradually being eliminated.
2 PVC anti-aging film in the raw materials added anti-aging additives after the film was calendered. The effective use period is 8-10 months. It has good light transmittance, heat preservation and weather resistance. It is the main material covered in greenhouses and small and medium arch sheds. It is mostly used for spring cultivation after the fall.
3 PVC non-drip anti-aging film (PVC double anti-shedding film) also has anti-aging and drip characteristics, good light transmission and heat preservation, non-drip sustainable for 4-6 months, and safe service life of 12-18 months The application is more extensive, and it is currently the preferred covering material for the energy-efficient solar greenhouse, and it is better to use as a covering material for the greenhouse.
4 PVC weather-resistant dripless dust film In addition to weathering drip performance, the surface of the film is treated, the plasticized parsing yield is less, the vacuum is lighter, the light transmittance is improved, and the winter and spring cultivation of the greenhouse and the greenhouse is more favorable.
(2) Polyethylene (PE) shed film is light in texture (specific gravity: 0.92 g/cm3), soft, easy to mold, good in light transmission, non-toxic, suitable for all kinds of greenhouse film and plastic film, and is the main agricultural film in China. Variety. The disadvantages are: poor weatherability and heat insulation, and difficult to bond. If a greenhouse film is produced, additives such as an anti-aging agent, a drop-free agent, and a heat-insulating agent must be added in order to meet the production requirements. The main products are:
1 Ordinary PE film does not add anti-aging additives such as white film directly produced by the blow molding of raw materials, the current greenhouse and small and medium sheds have a large amount of application, generally in the spring and autumn sheds, the use period is only 4-6 months, only One crop can be grown, energy is wasted, labor is increased, and production is gradually eliminated.
2PE anti-aging film (longevity film) is added to PE resin anti-aging additives, blown into a film. The thickness of the film is 0.08-0.12 mm, and the use period can reach 12-18 months. The crop can be cultivated for 2-3 seasons. It not only extends the use period, reduces the cost, saves energy, but also greatly increases the output and output value. It is The current promotion of agricultural cultivation in the cultivation of key varieties.
3PE non-drip anti-aging film (double anti-agricultural film) also has drip, weather resistance, light transmission and heat preservation, anti-dropping effect can be maintained for 2-4 months, anti-aging life up to 12-18 Month is currently the most comprehensive and widely used agricultural film variety. It can be used not only in greenhouses and large, medium and small sheds, but also in early-spring cultivation of energy-saving solar greenhouses.
4PE insulation film This cover material can prevent infrared radiation to the atmosphere, can increase greenhouse temperature 1-2 °C, in the cold area application effect is better.
5PE multi-functional composite membrane has many functions such as non-dripping, heat preservation, weathering, and longevity. Some of them have the function of blocking ultraviolet rays and reduce the transmission of ultraviolet rays in the booth. Some can inhibit the formation of sclerotinia bacillus and gray mold spores. Use up to 12-18 months.
(3) Ethylene-vinyl acetate copolymer (EVA) EVA resin is a new agricultural film material used in agriculture in recent years. The agricultural film produced by it is superior to PVC in terms of light transmittance, heat preservation, and weather resistance. Or PE agricultural film. EVA agricultural film cover can increase production by about 10% compared with other greenhouse films, and can be used continuously for more than 2 years. It can not be deformed before aging, and can be easily recycled after use. It is not easy to cause soil or environmental pollution.
(4) Light-modulating plastic film Light-emitting film made of rare earth and other functional additives added to PE resin can selectively transmit light. It is a new type of cover material that can fully utilize solar energy, and other Compared with the greenhouse film, the greenhouse has a good effect of warming and heat preservation, and has a strong biochemical effect on crops. It has the functions of early maturity, high yield, and improved nutrient composition for different crops. The rare earth can also absorb ultraviolet rays and extend the service life of the agricultural film. Among them, the special purple film (leaf film) of leafy vegetables is the purple masterbatch added in the film and weather-resistant, heat-insulating, non-dripping masterbatch, blown into a film. The film is slightly bluish-purple, reducing glare, increasing temperature, early growth, high quality and high yield. Suitable for the cultivation of leeks and a variety of green leafy vegetables.
Quartz Sleeve
We provide quartz sleeve for the uv lamp.
The quartz sleeves are probably the most abused components of a UV system, yet they are one of the most critical for delivering UV rays into the water stream.
Sleeves provide a protective barrier around the lamp so that the lamp can operate at its optimal temperature. For the quartz sleeve to maximize a unit`s performance, both the interior and exterior of the sleeve must be cleaned periodically, even in UV units installed in ultra-pure water systems. All quartz sleeves are susceptible to fouling.
Cleaning frequency of quartz sleeves will be site-specific and directly related to water quality. UV systems that are installed in post-reverse osmosis/deionization (RO/DI) locations will require cleaning much less frequently than units installed on raw water or surface water systems. As a general rule of thumb, a post-RO/DI system should have the quartz sleeves cleaned once a year.
Plan on cleaning quartz sleeves quarterly on post-activated carbon systems and more frequently for hard water applications exceeding 5 grains of hardness.
Standard clear quartz glass tube is high quality purity and automatic controlled fusing furnace
It has the characteristics of high purity,strong resistance,high transmission and accurate dimensions,and the OH content 1-20ppm after air of vacuum baking is available.
Quartz Sleeve
Quartz Sleeve, UV Quartz Sleeve, Ultraviolet Quartz Sleeve
Ningbo Sunfine UV lighting Co.,ltd. , http://www.uvlightings.com