YLTpacking: Common Mistakes in Flexible Bag Making

1. What should I do if the heat sealing of the bag making machine is incomplete and the contents leak or deteriorate?Reason: poor anti-pollution heat sealability of the film,The main reason is that the resin used in the inner sealing layer is not suitable.Countermeasures: Use a film with good anti-pollution heat sealability. Generally speaking,LDPEHas moderate contamination resistance heat sealability,EVAexistVAWhen the content is large, it has good anti-pollution heat sealing performance,LDPEIt also has good anti-pollution heat-seal properties, and ionic resins and metallocene polymers have excellent anti-pollution heat-seal properties. 2, What should I do if the seal of the bag making machine is brittle and brittle?reason:(1) The heat sealing temperature is too high; (2)Too much pressure;(3) The heat sealing time is too long; (4) the edge of the upper sealer is too sharp or the teflon covering is damaged; (5) The silicone rubber of the bottom seal is too hard; (6) During the compounding and curing process, a portion of the adhesive penetrates into the interior of the film. Due to the influence of the penetration of the adhesive, the toughness (impact resistance) of the substrate decreases and the brittleness increases; (7After the plastic composite packaging bag is cooled and placed, the heat sealing strength has increased, and it also has a tendency to become brittle.Countermeasures: (1) According to the heat sealing characteristics of the material of the inner sealing layer, select the appropriate processing temperature, pressure and heat sealing time; (2) Improve the surface state of the upper heat sealing knife and make the surface of the sealer flat; (3) wrapped with PTFE cloth intact; (4) Select the appropriate hardness of the silicone rubber pad. 3, What should I do if the bag is warped after heat sealing?reason:(1) The thickness of the composite film is inconsistent; (2) The heat sealing temperature is too high or the heat sealing time is too long; (3) In the longitudinal heat sealing knife part, the running track of the composite film is not straight; (4) Insufficient cooling; (5) The aging time is not enough; (6) The surface substrate film has poor heat resistance; (7During the lamination process, the tension matching of the composite substrate is not properly controlled, resulting in residual stress after curing and shaping, especially when the thickness of the composite film is thin, such failures are more likely to occur.Countermeasures: (1) to adjust the tension of the floating roller; (2) Select the inner sealing substrate with low temperature heat sealability; (3) Adjust the heat sealing temperature to a suitable temperature; (4) is fully cooled; (5) is fully ripened; (6) re-select the surface substrate film; (7) Adjust the tension of each part of the composite processing equipment, and try to make the retraction rate of the two composite substrates equal. 4, What should I do if the outer contour of the heat sealing surface is not clear? (The knife pattern is not clear)reason:(1) Short cooling time; (2) Poor contact of the cooling plate; (3) Since the silicone pad is heated, the edge part is melted; (4) Longitudinal heat sealing force is uneven; (5) The edge of the heat sealing knife is uneven and dull.Countermeasures: (1) to adjust the cooling time; (2) to adjust the cooling plate; (3) to replace or adjust the heat sealing knife; (4) to prevent edge melting caused by overheating of the silicone pad. 5, What should I do if the heat sealing strength is poor?reason:(1) the adhesive in the composite film has not been sufficiently hardened; (2)