How to solve the sticking problem of polyethylene

  • Detail

How to solve the problem of adhesion of polyethylene stretch packaging film

polyethylene used as stretch packaging film. The first thing to check is that some resins made of bamboo powder mainly include LDPE and LLDPE. Stretch packaging film needs to have a certain degree of adhesion before packaging. The stretch packaging film with high content of PVC and vinyl acetate has self adhesion. In the flat film method, the film can be bonded by the sudden cooling of the cooling roll. However, LDPE and LLDPE stretch packaging films prepared by blow molding lack self bonding and expose more particles

two methods can be used to solve the problem of film bonding

1. Add tackifier

common tackifiers include glycerol monooleate, polybutylene, random PP, EVA, etc. The tackifying effect of polybutene is relatively outstanding. When the addition amount is 3%, the film can still maintain the adhesion when stretched 200 ~ 300%. However, due to the high viscosity of polybutene, it is difficult to measure the hopper, so the master batch must be made first

with the development of palletized packaging, the requirements for the adhesion of stretched film have changed, that is, it is required to produce stretched packaging film without adhesion on the outside, so as to avoid the sticking phenomenon caused by the direct contact of packages due to the absence of pallets and the tearing phenomenon of film caused by sticking

eva is generally blended to increase viscosity. Because EVA has good adhesion, EVA and LLDPE are co extruded to obtain EVA as the inner layer. LLDPE is an outer stretch packaging composite film, which also meets the requirements of single-sided bonding

2. Hot melt bonding

in order to solve the bonding problem and adapt to the requirements of pallet free packaging, hot melt bonding has been developed, that is, the usual hot sealing. EVA is blended with LLDPE or a total of 3 The heat sealing stretch packaging film can be produced by increasing technological transformation and extrusion. However, if EVA and LDPE are blended to produce stretch packaging film, 8~12% EVA must be added to obtain effective heat sealing, and the adhesion problem caused by EVA is not suitable for pallet less packaging, so coextrusion method is suitable. Another solution is to seek new materials to replace EVA and LLDPE Blends, because it has good heat sealing and no adhesion

note: the reprinted content is indicated with the source. The reprint is for the purpose of transmitting more information, and does not mean to agree with its views or confirm the authenticity of its content

Copyright © 2011 JIN SHI