Black wrapping film and preparation method thereof

Abstract

The invention discloses a black wrapping film and a preparation method thereof. The black wrapping film is prepared from the following raw materials: 37 to 99.6 parts of linear low density polyethylene, 0 to 50 parts of metallocene linear low density polyethylene, 0.2 to 10 parts of black masterbatch, 0.2 to 10 parts of viscosity-increasing masterbatch, 0 to 30 parts of reclaimed material; whereinthe black masterbatch is prepared from 40 to 70 parts of polyethylene, 20 to 55 parts of carbon black, 5 to 30 parts of polyethylene wax with number average relative molecular mass of 1000 to 4000; the viscosity-increasing masterbatch is prepared from 40 to 70 parts of polyethylene and 30 to 60 parts of polyisobutene in parts by mass. The raw materials are uniformly mixed to prepare the wrappingfilm by adopting a film casting method, wherein the temperature of film forming is 170 to 290 DEG C, the temperature of a cooling roller is 15 to 35 DEG C and the speed ratio is 1.01 to 1.2. Accordingto the invention, relatively less viscosity-increasing masterbatch is used, the better viscidity is obtained, the release of the viscidity is quick, the delivery cycle is greatly shortened; meanwhile, the reclaimed material is adopted, the cost is lower, the environment influence is less, the preparation method is simple and convenient, the requirement on production equipment is low and easy to control, and the preparation method is suitable for continuous production.

Description

technical field [0001] The invention relates to the technical field of stretch films, in particular to a black stretch film and a preparation method thereof. Background technique [0002] Stretch film, also known as stretch film and heat shrinkable film, was the first in China to use PVC (polyvinyl chloride) as the base material, DOA (dioctyl adipate) as the plasticizer and self-adhesive to produce PVC stretch film. Due to environmental protection issues, high cost (compared to PE (polyethylene), relatively large proportion, small unit packaging area), poor stretchability, etc., when PE stretch film was produced in China from 1994 to 1995, it was gradually eliminated. PE stretch film first uses EVA (ethylene-vinyl acetate copolymer) as self-adhesive material, but its cost is high and tasteful, and later developed with PIB (polyisobutylene) and VLDPE (very low-density polyethylene) as self-adhesive material , The substrate is now dominated by LLDPE (linear low-density polyet...

AI Technical Summary

Problems solved by technology

At present, the black stretch film needs to be stored for about 30 days from production to use before it can have a certain viscosity, and the amount of tackifier masterbatch added in production is also large, resulting in a corresponding increase in cost, and often many customers require shorter delivery Cycle time and high cost performance

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