Non-Aqueous PVC Dampening Coatings for Automotive NVH
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Solution Overview
Problem
Automotive manufacturers face challenges in achieving substantial vehicle weight reductions without compromising noise, vibration, and harshness (NVH) performance, especially in body and closure panels, due to the conflict between weight reduction and NVH requirements, which are typically addressed through innovative damping treatments and panel geometry optimization.
Innovation Solution
Non-aqueous, sprayable, and heat-curable dampening compositions comprising PVC homopolymer or copolymer, plasticizers, platy and spherical fillers, modified epoxy resin, adhesion promoters, and substrate wetting agents, applied to oily metal substrates and cured at automotive e-coat bake conditions, forming an interpenetrating network for enhanced adhesion and vibration dampening.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional dampening treatments and panel geometry optimization are used to maintain NVH performance, then NVH performance is improved, but vehicle weight increases
Solution Approach 1:
The invention changes the chemical composition parameters of the dampening material by using a non-aqueous solvent system with specific plasticizers (phthalate and benzoate) and PVC resin ratios, enabling the coating to achieve optimal dampening properties at thinner applications, thus reducing weight while maintaining NVH performance
Solution Approach 2:
The invention creates a composite material system combining PVC homopolymer or copolymer with plasticizers, fillers, and modified epoxy resin that provides enhanced dampening efficiency per unit weight, allowing weight reduction while maintaining or improving NVH performance
2Strength
If non-aqueous sprayable dampening compositions are applied to oily metal substrates, then adhesion is improved, but curing complexity increases due to heat treatment requirements
Solution Approach 1:
The invention merges the dampening coating application with the existing automotive e-coat bake process, combining two curing operations into one. The coating is cured simultaneously with the e-coat at temperatures of 130-190°C for 10-60 minutes, eliminating separate curing steps and reducing overall process complexity despite the heat treatment requirements
Solution Approach 2:
The modified epoxy resin acts as an intermediary component that facilitates adhesion to oily substrates while being compatible with the heat cure process, bridging the gap between the non-aqueous solvent system and the metal substrate
3Reliability
If thicker dampening coatings are applied to enhance vibration dampening properties, then NVH performance is improved, but vehicle weight increases
Solution Approach 1:
The invention optimizes the plasticizer content (phthalate and benzoate plasticizers) and PVC resin ratio to achieve maximum dampening efficiency at minimal thickness. The specific parameter adjustments in the formulation allow the coating to deliver required NVH performance with reduced material quantity, directly addressing the weight versus performance trade-off
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 compositions exhibit excellent adhesion to oily steel and aluminum metals, providing high vibrational dampening properties and remarkable physical properties, suitable for automotive body and closure panels, while maintaining NVH performance and facilitating weight reduction.
Implementation Method 1
a non-aqueous sprayable and curable dampening composition for automotive body and closure panels which cures to form a cured product, comprising, consisting essentially of and/or consisting of: (a) a PVC homopolymer resin and/or a mixture of a PVC copolymer resin; (b) a phthalate plasticizer and a benzoate plasticizer
Implementation Method 2
a modified epoxy resin; (e) an adhesion promoter... forming an interpenetrating network for enhanced adhesion and vibration dampening
Implementation Method 3
an adhesion promoter... The compositions exhibit excellent adhesion to oily steel and aluminum metals
Implementation Method 4
The compositions are applied to the oily coated metal substrates, which are subsequently exposed to a heat treatment at a temperature in the range of about 130-190 degrees Centigrade for a period of about 10-60 minutes
Implementation Method 5
Polymers possess viscoelasticity and provide dampening performance... The alternating stress cause cyclic deformation of the viscoelastic material. This, along with molecular interaction within the material, forces the mechanical energy to be dissipated in the form of thermal energy
Data Source
AI summary
A non-aqueous sprayable and curable dampening composition for automotive body and closure panels which cures to form a cured product, including: (1) a PVC homopolymer resin and/or a mixture of a PVC copolymer resin; (2) a phthalate plasticizer and a benzoate plasticizer; (3) a filler component, wherein the filler component comprises one or more spherical fillers and/or one or more platy fillers; (4) a modified epoxy resin; (5) an adhesion promoter; and (6) a substrate wetting agent.