Decorative Sheet Embossing Depth Ratio for Molding

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Decorative resin molded articles with irregularity shapes tend to lose their high realistic design feeling and surface smoothness during the molding process due to heat and pressure, as the irregularities become gentle or small, and existing techniques struggle to maintain these features effectively.

Innovation Solution

A decorative sheet with a transparent resin film layer having an irregularity shape where the depth of the recess and the thickness from the start point to the opposite surface satisfy a specific ratio (d/T × 100 = 5 to 10%), which is formed by embossing and optionally filled with a support film to maintain shape and smoothness post-molding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If embossing is performed to form an irregularity shape on the decorative sheet, then a high stereoscopic feeling and depth feeling are achieved, but the irregularity shape becomes gentle or small under heat and pressure during molding, impairing the realistic design feeling

Engineering Contradiction:
Improveirregularity shapeVSAvoidrealistic design feeling
Core Design Contradiction:
ShapeVSManufacturing precision

Solution Approach 1:

The patent applies preliminary action by forming the irregularity shape through embossing on the decorative sheet before the injection molding process. This pre-formed irregularity shape serves as a master pattern that will be replicated onto the resin molded article, ensuring the stereoscopic feeling and depth feeling are transferred accurately during molding.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent uses copying by transferring the irregularity shape pattern from the decorative sheet to the resin molded article through the injection molding process. The decorative sheet acts as a master template, and the resin material copies this pattern, reproducing the stereoscopic effect on the final product surface.

Inventive Principle:
Principle #26Copying

2Shape

If the irregularity shape is formed deeply to enhance stereoscopic feeling, then high realistic design feeling is achieved, but the irregularity shape may come out to the surface under heat and pressure during molding, impairing smoothness

Engineering Contradiction:
Improveirregularity shape depthVSAvoidsurface smoothness
Core Design Contradiction:
ShapeVSStress or pressure

Solution Approach 1:

The patent applies parameter changes by optimizing the depth of the irregularity shape within a specific range (5-50 μm) to balance the stereoscopic feeling with resistance against deformation during molding. This controlled depth parameter ensures the irregularity is deep enough to create visual depth but shallow enough to maintain surface smoothness under molding pressure.

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If a resin layer is provided to suppress deterioration of realistic design feeling, then high realistic design feeling is retained after molding, but further improvement is desired indicating increased complexity

Engineering Contradiction:
Improverealistic design feelingVSAvoidlayer structure
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent uses a thin film approach by employing a decorative sheet with an irregularity shape formed directly on a transparent or colored resin film. This thin film structure maintains the realistic design feeling through the embossed pattern while avoiding the need for additional thick resin layers, thus reducing overall structural complexity.

Inventive Principle:
Principle #30Flexible shells and thin films

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 a decorative sheet and molded article with a high irregularity impression, stereoscopic feeling, and excellent surface smoothness, while preventing cracking under load or bending, thus retaining a high realistic design feeling and maintaining surface integrity post-molding.

Implementation Method 1

a method is known in which embossing is performed from the top of a design layer formed on a transparent resin film to the transparent resin film side to form an irregularity shape

Methodology Applied
Scientific EffectEmbossing:

Implementation Method 2

an irregularity shape formed on the decorative sheet becomes gentle or small under heat and pressure during injection molding in an insert molding method etc.

Methodology Applied
Scientific EffectThermal stability:

Data Source

PatentEP3202565B1Decorative sheet
Publication Date: 2024.09.25 DAI NIPPON PRINTING CO LTD
  • EP3202565B1 patent drawingFigure 1~2
  • EP3202565B1 patent drawingFigure 3

AI summary

Provided is a decorative sheet that, due to an asperity profile, creates a highly textured impression, such as a contoured impression, three-dimensional impression, impression of depth, and the like, even after being molded, and that has exceptional surface flatness. This decorative sheet has a layer that includes at least a transparent resin film layer, the layer that includes at least the transparent resin film layer having on one surface thereof an asperity profile having recesses that reach the transparent resin film layer, and includes an area in which the depth (d) of the recesses of the asperity profile, and the thickness T from the start point of the depth (d) to the surface on the opposite side from the surface that has the asperity profile in the layer that includes the transparent resin film layer, satisfy the relationship (d)/T × 100 = 5-10, and is intended for use as a decorative resin molded article in which a molding resin is laminated to the surface having the asperity profile.