Abstract: A vehicle interior panel (10) includes a decorative covering (16) with a non-visible tear seam that forms a deployment opening through the covering during airbag deployment. The tear seam is formed by mechanical piercing of a skin layer (20) of the covering using a piercing tool (30) having a compound chamfer (40). Such piercing tools allow the mechanical piercing process to produce non-visible and functional tear seams in polymeric materials and non-polymeric materials such as leather, including materials with relatively low elastic recovery characteristics. Tear seams formed in this manner can offer larger processing windows, lower manufacturing and equipment cost, and/or shorter cycle times when compared to other methods such as laser scoring.

Abstract: A vehicle interior panel includes a decorative covering with a non-visible tear seam that forms a deployment opening through the covering during airbag deployment. The tear seam is formed by mechanical piercing of a skin layer of the covering from the decorative side. The skin layer is formed from a self-healing material, allowing a piercing tool to form microholes that are smaller than the effective piercing diameter of the tool without the need for subsequent processes intended to otherwise hide the formed tear seam. Tear seams formed in this manner can offer larger processing windows, lower manufacturing and equipment cost, and/or shorter cycle times when compared to other methods such as laser scoring. Tear seam function may also be improved and/or more predictable.

Abstract: A panel for use over a vehicle airbag includes a skin layer with a tear seam formed therein. The skin layer is made from a material that includes a polymer matrix and one or more transmissivity-reducers in the form of microflake fillers or fillers having a monomodal particle size distribution. The transmissivity-reducers are included in an amount that reduces the transmissivity of light through the material to reduce variation in laser scoring processes and also in an amount that does not substantially alter the mechanical properties of the polymer matrix. Skin layers made from these materials can be used in laser scoring processes of TPO coverings that are thinner than previously known.

Abstract: A vehicle interior panel (10) includes a decorative covering (16) with a non-visible tear seam that forms a deployment opening through the covering during airbag deployment. The tear seam is formed by mechanical piercing of a skin layer (20) of the covering using a piercing tool (30) having a compound chamfer (40). Such piercing tools allow the mechanical piercing process to produce non-visible and functional tear seams in polymeric materials and non-polymeric materials such as leather, including materials with relatively low elastic recovery characteristics. Tear seams formed in this manner can offer larger processing windows, lower manufacturing and equipment cost, and/or shorter cycle times when compared to other methods such as laser scoring.

Abstract: A non-visible tear seam can be formed in a vehicle interior panel in a mechanical piercing process with a piercing tool that radially supports a needle during the process. The radial support enables the use of higher gauge needles and the formation of non-visible microholes through a visible surface of the panel. The piercing tool is capable of forming each of the microholes of the tear seam individually and may be disposable and/or may be configured with a replaceable needle.

Abstract: A method of making a vehicle interior panel includes irradiating a covering layer material in a manner that reduces the strength of the material while preserving the thickness of the covering layer. An irradiated portion of the covering layer is arranged to at least partially overlie an airbag door region of an underlying substrate to help define the location of an airbag tear seam. The irradiation process can be carried out using an electron beam or ultraviolet light. Natural or synthetic organic materials may have their chemical structures altered by irradiation in a manner that reduces the strength of the material, thus reducing or eliminating the need for stress-concentrating features in covering layers and enabling non-visible tear seams to be formed in high strength materials like leather.

Abstract: A vehicle interior panel includes a decorative covering with a non-visible tear seam that forms a deployment opening through the covering during airbag deployment. The tear seam is formed by mechanical piercing of a skin layer of the covering from the decorative side. The skin layer is formed from a self-healing material, allowing a piercing tool to form microholes that are smaller than the effective piercing diameter of the tool without the need for subsequent processes intended to otherwise hide the formed tear seam. Tear seams formed in this manner can offer larger processing windows, lower manufacturing and equipment cost, and/or shorter cycle times when compared to other methods such as laser scoring. Tear seam function may also be improved and/or more predictable.

Abstract: A panel for use over a vehicle airbag includes a multi-layer covering disposed over a substrate outer surface. The covering includes a decorative skin layer and a foam layer between the substrate and the skin layer. The covering also includes a tear seam provided at a pre-determined location for an airbag deployment opening. The foam layer has one or more material properties that vary between the substrate and the skin layer. The density of an outside layer of the foam layer may be greater than the density of an inside layer of the foam layer to improve tear seam function. The covering layers may be bonded to each other without the use of additional adhesive material. The tear seam may be formed by laser scoring and may have at least a portion that extends into the foam layer and may further extend into the skin layer.

Abstract: A vehicle interior panel for use over an airbag includes a substrate having an airbag door region and a decorative covering disposed over the airbag door region. A tear seam is formed in the decorative covering along a path having an end portion that is non-orthogonal with respect to a hinge side of the airbag door region. The tear seam path may include a central portion that lies along a side of the airbag door region opposite the hinge side, along with end portions that form obtuse included angles with the central portion. In some cases, the end portions diverge from a perimeter of the airbag door region and may generally extend along high deployment stress regions of the covering. Tear seams formed along such a path may reduce airbag inflation energy losses associated with tearing the covering material(s) during airbag deployment.

Abstract: A vehicle interior panel for use over an airbag includes a decorative covering with a grain-coordinated tear seam. The decorative covering includes a visible surface with a grain pattern formed therein, and individual stress risers of the tear seam a located at valleys of the grain pattern. Holes cut through a skin layer of the decorative covering in this manner have reduced visibility, due in part to light reflection characteristics at the grained surface that tend to form shadowed areas in the grain valleys. A method for forming a grain-coordinated tear seam includes determining the location of peaks and/or valleys of the grain pattern and forming a majority of the stress risers at determined valley locations.

Abstract: A vehicle interior panel for use over an airbag includes a substrate having an airbag door region and a decorative covering disposed over the airbag door region. A tear seam is formed in the decorative covering along a path having an end portion that is non-orthogonal with respect to a hinge side of the airbag door region. The tear seam path may include a central portion that lies along a side of the airbag door region opposite the hinge side, along with end portions that form obtuse included angles with the central portion. In some cases, the end portions diverge from a perimeter of the airbag door region and may generally extend along high deployment stress regions of the covering. Tear seams formed along such a path may reduce airbag inflation energy losses associated with tearing the covering material(s) during airbag deployment.

Abstract: A covering for use over a vehicle airbag includes a skin layer and an attached foam layer. The foam layer is constructed from a polymer-based material that includes a polymer portion and an additive, and the additive may be selected to affect the energy transmission characteristics of the foam layer material when the covering is subjected to a laser scoring process that uses a laser light beam having a characteristic wavelength. The additive may decrease the amount of light energy transmitted through the material at the characteristic wavelength to limit the amount of energy leakage from one cut location to another during laser scoring. The decrease in light transmission through the material may be accompanied by an increase in the light absorption of the material, an increase in the amount of light reflected by the material, and/or an increase in a laser cutting rate of the material per unit energy.

Abstract: A covering for use over a vehicle airbag includes a skin layer and an attached foam layer. The foam layer is constructed from a polymer-based material that includes a polymer portion and an additive, and the additive may be selected to affect the energy transmission characteristics of the foam layer material when the covering is subjected to a laser scoring process that uses a laser light beam having a characteristic wavelength. The additive may decrease the amount of light energy transmitted through the material at the characteristic wavelength to limit the amount of energy leakage from one cut location to another during laser scoring. The decrease in light transmission through the material may be accompanied by an increase in the light absorption of the material, an increase in the amount of light reflected by the material, and/or an increase in a laser cutting rate of the material per unit energy.

Abstract: A panel for use over a vehicle airbag includes a multi-layer covering disposed over a substrate outer surface. The covering includes a decorative skin layer and a foam layer between the substrate and the skin layer. The covering also includes a tear seam provided at a pre-determined location for an airbag deployment opening. The foam layer has one or more material properties that vary between the substrate and the skin layer. The density of an outside layer of the foam layer may be greater than the density of an inside layer of the foam layer to improve tear seam function. The covering layers may be bonded to each other without the use of additional adhesive material. The tear seam may be formed by laser scoring and may have at least a portion that extends into the foam layer and may further extend into the skin layer.

Abstract: A panel for use over a vehicle airbag includes a skin layer with a tear seam formed therein. The skin layer is made from a material that includes a polymer matrix and one or more transmissivity-reducers in the form of microflake fillers or fillers having a monomodal particle size distribution. The transmissivity-reducers are included in an amount that reduces the transmissivity of light through the material to reduce variation in laser scoring processes and also in an amount that does not substantially alter the mechanical properties of the polymer matrix. Skin layers made from these materials can be used in laser scoring processes of TPO coverings that are thinner than previously known.

Abstract: A panel for use over a vehicle airbag includes a non-visible tear seam for forming an airbag deployment opening. The tear seam may be formed by laser cutting through a panel substrate and into a panel covering using multiple laser power levels and may be formed at an angle of 85 degrees or less with respect to the substrate. Using multiple laser power levels can increase the accuracy and consistency of the residual wall thickness of the covering, and forming the tear seam at an angle of 85 degrees or less can improve tear seam function during deployment.