Window Tint Meter | What Are the Advantages of PO Film in Greenhouse?
PO membranes have the best overall performance and are the newest agricultural membranes with the best market prospects and the fastest promotion speed. Although they have excellent performance, they are extremely expensive and rarely used.
1. What are the advantages of PO membranes?
(1) The highest light transmittance
The light transmittance of the PE film is 90%, the light transmittance of the EVA film is 85%. The light transmittance of the PO film can reach more than 95%, which is not possible with ordinary films, so by comparing the light transmittance of the agricultural film, it is easy to judge whether it is PO film.
(2) Excellent anti-fogging and dripping properties
The PO film can be maintained for a long time through the de-fogging technology of the special process. Until the shed film is replaced, it can be said that with the life of the agricultural film, this is also impossible for other agricultural films. To test the anti-fogging and dripping properties of the shed film, the PO film can be covered on a drinking glass filled with boiling water to determine the state of the de-fogging and defogging. If you want to judge the stability of the mist removal droplets, you can use plastic tape to repeat the drip surface of the mucous membrane. If it is a good film, the mist removal droplets will not decrease. If it is a defective film, after two or three times, the mist removal flow. The drop function will decrease or even disappear.
(3) Better physical properties
The material of the PO film is the softest, the EVA is slightly hard and the PE film is obviously hard. The PO film has strong tensile strength, is not easy to penetrate. With a hand pull, the shed film of different materials can be easily judged. Especially under high temperature conditions, the properties of PO membranes are more stable. Ordinary PE film and EVA film have a melting point of only 120 ° C. If they are scalded with boiling water, the properties of the agricultural film will change significantly and quickly become soft. However, the melting point of the PO film is 180 ° C. The properties do not change much after boiling.
(4) Longer service life
Regardless of the thickness, most of the other types of shed films are changed once a year, otherwise it will cause a poor environment in the shed due to the decrease in light transmittance and the deterioration of the mist removal and drip, which will seriously affect the normal growth of vegetables. The PO film with the same thickness can be replaced every 2 years or even 3 years because of its better light transmittance and fog removal. Of course, the service life of agricultural film is closely related to the thickness of agricultural film. Agricultural film that you want to use for many years must ensure a certain thickness. Generally speaking, the effective use period is 1-2 years, and the thickness of the shed film can be 0.08-0.10 mm; the effective use period is 2-3 years and the thickness of the shed film is mostly 0.12-0.15 mm. Some multi-span greenhouses use 0.15 mm PO film and the service life can even reach 5 years. At present, the 0.08mm agricultural film is the minimum thickness of commonly used agricultural film. If it is in a region with more wind, it is better to use a film with a larger thickness!
2. PO film transmittance detection method
To detect the transmittance of PO film, LS116 window tint meter can be used. The LS116 window tint meter adopts the parallel light path of the light source and the receiver condenser design with a resolution of 0.1 %, The accuracy is better than ± 1%, and conforms to the CIE photopic luminosity function standard. It is a high-precision window tint meter. The measurement principle is to use a visible light source to irradiate the measured substance. The sensor detects the incident light intensity of the light source and the light intensity after passing through the measured substance. The ratio of the transmitted light intensity to the incident light intensity is the transmittance.
When using the LS116 window tint meter, you can directly use the two probes to to clamp the two sides of the measured object. The two probes can be automatically attracted together. The window tint meter can automatically measure without pressing the button. The transmittance is expressed as a percentage If you want to save the current test data, press the "HOLD" button of the instrument to store it. The window tint meter can store up to 9 sets of test data.
Overall, the performance of the PO membrane is the best choice for the greenhouse membrane. At present, the price of domestically produced PO membranes on the market has been greatly reduced. The normal thickness (0.09-0.10 mm) per square meter price is 1.5-2.0 RMB, which is the first choice for the cultivation of melon vegetables and nightshade vegetables in northern areas.
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