1. Look at the appearance: the appearance of the fruit bag must be smooth and smooth, all the bonding parts of the adhesive bag should be firm, the upper right corner should be fastened, the lower vent hole should be obvious, and the needle size of the hand-stitched bag should be large and uniform for ventilation. The outer color of the outer bag paper is yellow-green; The inner surface of the outer bag is painted black, which requires uniform light tightness. If there are many light spots exposed, it is unqualified outer bag paper. The inner bag paper is red or dark red, generally it is matte paper coated with wax on one side, and the wax surface should be uniform.

2. Soak in water: when the fruit bag is poured with water, the water on the paper surface is water droplets, indicating that the water on the paper surface is good waterproof, and the water on the paper surface is flaky, indicating that the water resistance is poor; Water soaked the paper, indicating that the water resistance is worse; Soak the fruit bag in water for 24 hours, observe the wet speed of the fruit bag and the deformation degree after water drying, and check whether there are black spots on the surface of the outer bag paper. If there is large deformation, black exposure and fast wetting speed, they are all unqualified paper bags.

3. Try by hand: hold the fruit bag with your left hand, and stretch it with your right hand into a simple shape. After taking out your hand, look in from the mouth of the bag to see if the vent hole at the bottom of the bag is open. If the vent hole is stuck, or if there are too many holes (more than 3) or too large (more than 15mm), you can't use it. At the same time, check whether the inner bag is broken. If it is broken, you can't use it.

Extended information:

Precautions:

1. Observe whether the purchased fruit bags have trademarks and manufacturers. Only the quality of fruit bags produced by regular manufacturers can be guaranteed. The quality of fruit bags produced by some small factories is poor, which can not only improve the efficiency, but also often delay the production.

2. Check the water resistance and air permeability of the fruit bag. The water resistance is tested by simple soaking method. The good fruit bag is not easy to break after being soaked in water for more than 8 hours. However, the poor quality fruit bag will be broken and deformed after being soaked in water for more than 8 hours.

3. Correct selection of specifications and sizes of fruit bags. The apples planted in production are mainly large fruit varieties, and the specifications of fruit bags selected in fruit tree production are 15cm wide and 19.5~2cm high, so that the size of fruit bags can cover apples over 9.5cm. If the paper bag is too small, the fruit will burst easily if it is too big, while if it is too big, it will cause waste.

4. Look at the appearance quality of the fruit bag. Choose fruit bags with fine workmanship, no glue opening, no nails falling off and moderate ventilation holes.

Baidu encyclopedia-fruit bag paper