Introduction of processing technology standards for valve bags
The valve bag is currently the most popular packaging bag on the market. The material is fed from the top or bottom valve port, and the material is filled into the bag from the valve bag by filling, and the bag is sealed by internal sealing or external sealing. Package. Afterwards, it can be stored and transported by stacking. It is a packaging form that is more suitable for the operation and storage of bulk cargo with small cargo and large total volume, and the valve bag plays a key role in it.
Appearance quality and craftsmanship of valve bag
1. Printing: It is required that the layout must conform to the design, the cleaning depth of graphics and text should be consistent, and the printing position should be accurate without errors.
2. Bag shape: The whole is square and there is no obvious skew.
3. The inner cavity of the paper bag: flat, no wrinkles, and firm heat sealing.
4. Surface: flat, no wrinkles, no obvious stains.
5. Bonding: The bonding position is flat, without blistering, degumming, wrinkles or composite peeling torn paper fibers.
6. Seal: The width of the non-adhesive side of the seal is less than 8 mm, the paste is flat, and there is no leakage around it.
7. Valve bag: the upper left valve and inner valve bag on the front of the printing surface; the valve bag is not allowed to be installed or reversed; the inner chamber of the valve bag must not be stuck, and the bonding position of the valve bag is not allowed to leak; the valve bag is installed to prevent powder leakage.
8. Bottom: The bottom of the upper and lower bottoms are not allowed to leak the bottom, the seal is missed or upside down, and the upper and lower bottom seals must be firmly pasted (peel the torn paper fiber).
9. Properties of fluorescent substance: The fluorescent area shall not exceed 5 cm.
If there is one serious defect or three minor defects in the above process standards for the appearance quality of the valve bag, it is regarded as a substandard product.
Valve bag size and material requirements
1. Valve bag size deviation: bag length error ±10mm; bag width error ±5mm; bag height error ±5mm; valve port width ±5mm.
2. Material and structure requirements
(1) Valve pocket with microporous structure
First layer: 90g/m2 white stretchable kraft paper
Second layer: 1.5-2.0c HDPE plastic film (10cm hole in the middle of the bag body) perforation length = paper bag length
Three-layer and four-layer: 90g/m2 natural stretch kraft paper (perforated)
(2) Non-porous structure valve pocket
90g/m2 white stretchable kraft paper
1.5-2.0cHDPE plastic film (non-porous)
90g/m2 natural stretch kraft paper (without holes)
90g/m2 natural stretch kraft paper (without holes)
(3) Valve port material: The valve port is made of 70g/m2 or 80g/m2 natural stretchable kraft paper, lined with LDPE film.
3. Hot-melt adhesive sealing: hot-melt adhesive inner valve pocket, the valve mouth is made of 70g/m2 or 80g/m2 natural extensible kraft paper, lined with 20g full circle closing tissue paper, and the sealing strip at the valve mouth is transferred and glued by 30mm.
4. Weight: the weight deviation of the finished bag is ±4%, the base paper is 90g/m2, and the weight deviation is ±5g/m2.
The above is the introduction of the processing technology standard of valve bags. In addition, our company specializes in the production of various types of valve bag bag making machines and bottom paste machines, which are used to produce valve bags of various sizes and specifications. If necessary, please feel free to contact us. .
