Composite BOPP Film Surface Treatment for Gloss and Ink Fastness

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Solution Overview

Problem

Biaxially oriented polypropylene (BOPP) films used in cigarette packaging suffer from poor hydrophilicity, adhesiveness, and dyeability due to low surface free energy, leading to poor printability and oxidation issues, which affect glossiness and ink color fastness, limiting their application and longevity.

Innovation Solution

A three-layer composite BOPP film structure with surface and inner layers containing phenyl-modified silicone and hydrogenated petroleum resin, combined with low-temperature CO2 plasma surface activation and corona treatment, followed by a surface-modifying coating agent application, enhances glossiness and ink color fastness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If water-based inks are used for printing on BOPP films, then the ink can be applied without eroding the macromolecular chains, but the drying process at around 40°C causes loss of physical indicators especially glossiness

Engineering Contradiction:
Improveink erosion on filmVSAvoidglossiness
Core Design Contradiction:
Object-affected harmful factorsVSIllumination intensity

Solution Approach 1:

The patent applies a surface treatment process before printing to prepare the BOPP film surface, improving ink adhesion and reducing the need for high drying temperatures that would compromise glossiness. The surface is pre-modified to enable better ink bonding at lower curing temperatures.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent modifies the drying temperature parameter and ink composition to achieve proper drying without excessive heat exposure. By adjusting these parameters, the film maintains its glossiness while the ink dries effectively.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If quick-drying inks are used to match high equipment speed, then the processing speed can be maintained above 180 meters per minute, but the ink has poor resolubility and water resistance

Engineering Contradiction:
Improveequipment speedVSAvoidink water resistance
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent modifies the ink composition parameters and drying conditions to achieve both quick drying and good water resistance. By optimizing the ink formula and drying parameters, the system maintains high production speed while ensuring ink durability.

Inventive Principle:
Principle #35Parameter changes

3Strength

If BOPP film is used for packaging, then the film provides light weight, high mechanical strength and good transparency, but the low surface free energy results in poor hydrophilicity, printability and adhesiveness

Engineering Contradiction:
Improvemechanical strengthVSAvoidprintability
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The patent introduces a surface treatment layer or coating as an intermediary between the BOPP film and the ink. This intermediary layer improves surface energy and ink adhesion while preserving the underlying film's mechanical strength and transparency properties.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent modifies the surface energy parameters of the BOPP film through treatment processes, enabling better printability and adhesiveness while maintaining the film's inherent mechanical strength and optical properties.

Inventive Principle:
Principle #35Parameter changes

4Illumination intensity

If the glossiness and haze of BOPP films are maintained over time, then the appearance remains upscale, but the film is prone to oxidation and degradation due to active H elements in tertiary carbon atoms

Engineering Contradiction:
ImproveglossinessVSAvoidoxidation resistance
Core Design Contradiction:
Illumination intensityVSReliability

Solution Approach 1:

The patent applies preliminary protective treatments or additives to the BOPP film before it undergoes oxidation and degradation. These preventive measures counteract the harmful effects of active H elements, protecting the film's glossiness and mechanical properties over time.

Inventive Principle:
Principle #9Preliminary anti-action

Solution Approach 2:

The patent converts the harmful active H elements in the BOPP film into beneficial components through chemical modification or stabilization processes. The previously problematic elements are transformed into features that enhance oxidation resistance while maintaining glossiness.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The method improves glossiness and ink color fastness while maintaining transparency, wear resistance, and equipment adaptability, with the printed color film maintaining high quality after one year of natural aging.

Implementation Method 1

low-temperature CO2 plasma surface activation

Methodology Applied
Scientific EffectPlasma surface activation: Plasma

Implementation Method 2

corona treatment

Methodology Applied
Scientific EffectCorona discharge: Corona Discharge

Implementation Method 3

surface-modifying coating agent application

Methodology Applied
Scientific EffectCoating: Coatings

Data Source

PatentUS12459280B1Method for improving glossiness and ink color fastness of printed color films and its application thereof
Publication Date: 2025.11.04 CHINA TOBACCO YUNNAN IND

AI summary

A method for improving the glossiness and ink color fastness of a printed color film is disclosed. The printed color film is a composite biaxially oriented polypropylene (BOPP) film. The method includes: (1) pre-treating the outer and inner surfaces of the composite BOPP film; (2) coating the outer and inner surfaces of the composite BOPP film with a surface-modifying coating agent and drying at a high temperature; and (3) printing the outer surface of the composite BOPP film with a water-based colored ink, and drying to obtain the printed color film. An application of the printed color film obtained by the method for tobacco packaging film to improve the glossiness and the ink color fastness of the printed color film is also disclosed.