Multilayer Label Facestock with Machine Direction Orientation

Solution Overview

Problem

Current label facestocks are not environmentally friendly and lack adequate properties for labeling applications, particularly in terms of conformability and mechanical strength.

Innovation Solution

A machine direction oriented multilayer facestock is developed, comprising a core layer and two skin layers with different compositions, where the second skin layer includes propylene homopolymer, hydrocarbon resin, styrene block copolymer, and low density polyethylene, and is stretched in the machine direction by a longitudinal force to achieve the desired properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If conventional single-layer or symmetric multilayer facestocks are used, then manufacturing simplicity is maintained, but conformability and mechanical strength are inadequate

Engineering Contradiction:

Improvemechanical strengthVSAvoidfacestock structure complexity

Core Design Contradiction:

StrengthVSDevice complexity

Solution Approach 1:

The facestock is divided into three distinct layers: a core layer providing mechanical strength and two skin layers providing conformability and adhesive bonding. This segmentation allows each layer to be optimized for its specific function, with the core layer containing polypropylene copolymer for strength and the skin layers containing polyethylene and grafted polyolefin for conformability and adhesion.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention uses composite materials by combining different polymers in a multilayer structure. The core layer uses polypropylene copolymer, while the skin layers use polyethylene and grafted polyolefin, creating a composite material system that achieves both mechanical strength and conformability that neither material could provide alone.

Inventive Principle:

Principle #40Composite materials

2Reliability

If environmentally friendly materials are used in facestock, then recyclability is improved, but mechanical properties and conformability may deteriorate

Engineering Contradiction:

Improveenvironmental friendliness and recyclabilityVSAvoidmechanical strength

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

The invention uses composite materials by combining different polymers in a multilayer structure. The core layer uses polypropylene copolymer, while the skin layers use polyethylene and grafted polyolefin, creating a composite material system that achieves both mechanical strength and conformability that neither material could provide alone.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The invention changes the physical and chemical parameters of the polymer materials by using copolymers and grafted polyolefins instead of simple homopolymers. This allows optimization of both mechanical properties and environmental compatibility, as the copolymer structure provides better flexibility and adhesion while maintaining recyclability.

Inventive Principle:

Principle #35Parameter changes

3Strength

If the facestock is stretched to improve orientation and mechanical properties, then tensile strength increases, but conformability may decrease

Engineering Contradiction:

Improvetensile strengthVSAvoidconformability

Core Design Contradiction:

StrengthVSEase of operation

Solution Approach 1:

The facestock is divided into three distinct layers: a core layer providing mechanical strength and two skin layers providing conformability and adhesive bonding. This segmentation allows each layer to be optimized for its specific function, with the core layer containing polypropylene copolymer for strength and the skin layers containing polyethylene and grafted polyolefin for conformability and adhesion.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the facestock have different properties: the core layer is designed with high strength characteristics, while the skin layers are designed with high conformability and adhesion characteristics. This local quality differentiation allows the facestock to exhibit both high tensile strength and good conformability simultaneously.

Inventive Principle:

Principle #3Local quality

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 solution provides an environmentally friendly label facestock with improved conformability and mechanical strength, suitable for various labeling applications, including self-adhesive labels, while maintaining cost-effectiveness and recyclability.

Implementation Method 1

stretching the facestock in machine direction by a longitudinal force by a first roll and a second roll at a stretch ratio of 4:1 to 8:1

Methodology Applied

Scientific EffectPlastic deformation: Deformation

Implementation Method 2

the temperature of the first roll is lower than temperature of the second roll

Methodology Applied

Scientific EffectThermal softening: Heating

Data Source

PatentEP2874814B1A label facestock

Publication Date: 2016.05.25 UPM RAFLATAC OY

Figure 1a~1c
Figure 1d~1e
Figure 1f

AI summary

The invention relates to a multilayer facestock (100) of a label, and to a label having a multilayer facestock (100), wherein the facestock (100) is machine direction oriented and comprises a core layer (101), a first skin layer (110) and a second skin layer (105). The second skin layer (105) comprises propylene homopolymer, hydrocarbon resin, styrene block copolymer, and low density polyethylene. The invention also relates to a method for manufacturing such facestocks (100). The invention further relates to a use of the facestock (100) for self- adhesive labels.