Injection Molded Polymeric Interlayers for Safety Glazing

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional methods for producing multiple layer glazings, such as laminated safety glass, are labor-intensive, time-consuming, and energy-intensive, posing safety concerns and increasing production costs and time.

Innovation Solution

The use of injection molding to form polymeric interlayers directly between two rigid substrates, employing low molecular weight polymers, multiple injection points, and heated substrates to facilitate the injection of polymer into the narrow space between glazing substrates, allowing for the rapid and inexpensive formation of multiple layer glazings.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional autoclave lamination is used to combine polymeric sheets and rigid layers, then safety glazings can be produced with improved impact resistance and glass retention, but the process becomes labor intensive, time consuming, and energy intensive

Engineering Contradiction:
Improveimpact resistanceVSAvoidproduction time
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent combines multiple conventional lamination steps (assembly, de-air, autoclave) into a single integrated injection molding process. The polymeric interlayer is injected directly between glass layers in a closed mold, eliminating separate de-air and autoclave operations, thereby reducing production time while maintaining safety performance

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The injection molding process serves multiple functions simultaneously: it forms the polymeric interlayer, bonds it to the glass layers, and creates the final laminated structure in one operation. This multi-functional approach replaces several specialized steps, improving productivity without compromising reliability

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If conventional autoclave lamination is used to combine polymeric sheets and rigid layers, then safety glazings can be produced with improved impact resistance and glass retention, but the process becomes labor intensive and poses safety concerns

Engineering Contradiction:
Improveglass retentionVSAvoidmanufacturing safety
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent replaces the thermal-mechanical autoclave system with a controlled injection molding system. Instead of using high temperature and pressure in an autoclave, the process uses controlled polymer injection under pressure in a closed mold, reducing safety risks while maintaining the bonding and glass retention functions

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Strength

If conventional lamination process is used with multiple steps (assembly, de-air, autoclave), then complete bonding can be achieved, but the process becomes energy intensive and time-consuming

Engineering Contradiction:
Improvebonding strengthVSAvoidthermal energy consumption
Core Design Contradiction:
StrengthVSUse of energy by moving object

Solution Approach 1:

The patent merges the bonding function into the injection molding process itself. The polymer is injected in a heated mold cavity, and the bonding occurs during the injection and cooling phases, eliminating the need for separate de-air and autoclave heating steps, thereby reducing total energy consumption while achieving complete bonding

Inventive Principle:
Principle #5Merging (Combining)

4Manufacturing precision

If manual trimming of interlayer sheet is performed to match glass edges, then precise fit can be achieved, but the operation requires manual labor and limits throughput

Engineering Contradiction:
Improveedge fit precisionVSAvoidthroughput
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent performs the fitting action preliminarily by injecting the polymer directly into the mold cavity between pre-positioned glass layers. The polymer automatically fills the gap and bonds to the glass edges, eliminating the need for subsequent manual trimming operations and enabling continuous automated production

Inventive Principle:
Principle #10Preliminary action

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

This method simplifies the production process, reduces costs, and enhances safety by eliminating the need for extensive fabrication procedures, while enabling the production of high-quality multiple layer glazings with improved efficiency and reduced energy consumption.

Implementation Method 1

injecting a polymer melt into said gap

Methodology Applied
Scientific EffectPressure gradient: Pressure Gradient

Implementation Method 2

heated substrates to facilitate the injection of polymer

Methodology Applied
Scientific EffectThermal energy: Heating

Implementation Method 3

after cooling, the resulting multiple layer panel functions as a safety panel

Methodology Applied
Scientific EffectCooling: Cooling

Data Source

PatentEP2057010B1Method for producing injection molded multiple layer glazings
Publication Date: 2011.08.03 SOLUTIA INC
  • EP2057010B1 patent drawingFigure 1
  • EP2057010B1 patent drawingFigure 2
  • EP2057010B1 patent drawingFigure 3

AI summary

The present invention is directed to the use of injection molding to form polymeric interlayers (16) directly between two rigid substrates (12, 14) that are positioned so that after injection of the melted polymeric, material and after cooling, the resulting multiple layer panel functions as a safety panel that can be used in any appropriate conventional safety glazing application. Methods of the present invention utilize a relatively low molecular weight polymer, multiple injection points, mold compression, and/or a heated substrate in order to facilitate the injection of polymer into the relatively narrow space between glazing substrates that is typically found in safety glazings.