The subject innovation relates generally to the field of vehicle interior flooring systems and more particularly, to systems and methods of manufacture and molding of vehicle interior flooring material and insulation systems.
Today, many products are manufactured by way of molding. The process usually involves shaping pliable raw material using a rigid frame or model called a “pattern,” also oftentimes referred to as a “mold.” A “mold” often refers to a hollowed-out block that can be filled with a liquefied plastic, glass, metal, ceramic materials, or the like. In manufacturing, the liquid hardens or “sets” inside the mold, adopting the shape of the mold's inner surface. Once hardened, a release agent is typically used to effect removal of the hardened/set substance from the mold.
Injection molding is a manufacturing process for producing items from materials such as thermoplastic and thermosetting plastic materials. In most instances, the thermoplastic or thermosetting plastic material is inserted into a heated container, mixed, and forced (or injected) into a mold cavity often using a two-part mold. Thereafter, the material cools and hardens to the configuration of the mold cavity.
Molds are most often constructed from metal, usually either steel or aluminum, and precision-machined to form the features of the desired part. Injection molding is widely used for manufacturing a variety of parts, from the smallest component to a vehicle flooring system (i.e. floor mats) to entire vehicle body panels. Another form of molding is referred to as reaction injection molding or RIM. This type of molding is similar to injection molding however, thermosetting polymers are used in place of plastics. These thermosetting polymers require a curing reaction to occur within the two-part mold. Common vehicle components manufactured via RIM include bumpers, air spoilers, and fenders.
In addition, producing acoustical insulators and liners for vehicle applications via a mold and molding process to attenuate sound have been developed with limited success. These insulators typically rely upon both sound absorption, i.e. the ability to absorb incident sound waves and transmission loss, and the ability to reflect incident sound waves, in order to provide sound attenuation.
The following presents a simplified summary of the specification in order to provide a basic understanding of some aspects of the innovation. This summary is not an extensive overview of the innovation. It is not intended to identify key/critical elements of the innovation or to delineate the scope of the innovation. Its sole purpose is to present some concepts of the innovation in a simplified form as a prelude to the more detailed description that is presented later.
The innovation disclosed and claimed herein, in one aspect thereof, discloses a vehicle flooring system that includes a single-sided mold component and a spray application component that facilitates application of a liquefied mixture into the single-sided mold, wherein the application results in a vehicle flooring product.
In yet another aspect, the innovation discloses the use of a foil or other type of heat deflector that can be molded into the flooring system that deflects heat away from a vehicle's occupant compartment.
In yet another aspect, the innovation disclosed and claimed herein, in one aspect thereof, discloses an acoustical performance of a double wall sound system expressed in terms of sound transmission loss (STL). The innovation utilizes design techniques that generate example embodiments including a wear surface layer, a mass-filled layer, and a de-coupler layer. The innovation discloses factors that influence the performance of the sound system for use in the commercial vehicle industry and describes methods to determine which factors have the most influence on the STL performance and optimal design configurations.
In another aspect, the innovation discloses a method of geometric shapes, surface treatment and composite manufacturing to create reduced localized stiffness and low strain energy for improve acoustic reduction and barrier properties of a combined double wall constrained layer system.
In another aspect, the innovation discloses a molded acoustic and vibration insulator or liner for a vehicle is provided that includes a first layer a second layer disposed on the first layer. The second layer has a textured bottom surface to facilitate attenuation of sound and/or vibration.
In yet another aspect, the innovation discloses a mold that facilitates the manufacture of a molded acoustic and vibration insulator or liner for a vehicle is provided that includes a first mixture a second mixture disposed on the first mixture. The second mixture has a textured bottom surface to facilitate attenuation of sound and/or vibration.
To the accomplishment of the foregoing and related ends, certain illustrative aspects of the innovation are described herein in connection with the following description and the annexed drawings. These aspects are indicative, however, of but a few of the various ways in which the principles of the innovation can be employed and the subject innovation is intended to include all such aspects and their equivalents. Other advantages and novel features of the innovation will become apparent from the following detailed description of the innovation when considered in conjunction with the drawings.
The innovation is now described with reference to the drawings, wherein like reference numerals are used to refer to like elements throughout. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the subject innovation. It may be evident, however, that the innovation can be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form in order to facilitate describing the innovation.
While specific characteristics are described herein (e.g., thickness), it is to be understood that the features, functions and benefits of the innovation can employ characteristics that vary from those described herein. These alternatives are to be included within the scope of the innovation and claims appended hereto.
As described above, in a reaction injection molding (RIM) process, two parts of a polymer are mixed together and subsequently injected into a mold under high pressure, e.g., using an impinging mixer. The mixture is left in the mold for a period of time sufficient for the mixture to expand and for the curing reaction to complete.
Additionally, if desired, reinforcing agents can be added to the mixture prior to injection. This process is often referred to as reinforced reaction injection molding (RRIM). For example, reinforcing agents such as glass fibers can be added into the mixture so as to enhance strength of the final product. For this reason, it will be appreciated that RRIM is often used to produce rigid automotive panels. A subset of RRIM is structural reaction injection molding (SRIM), which uses fiber mesh as a reinforcing agent. In accordance with SRIM, the fiber mesh is first arranged in the mold and then the polymer mixture is injection molded onto the mesh.
Traditionally, flooring products (e.g., mats) for vehicles were manufactured using adhesives and glues to bond stock materials together. These materials were later die-cut or overlayed with an injected top surface. To the contrary, the innovation described herein, in aspects thereof, provides for a spray-applied top surface. In particular embodiments, the spray “skin” may employ a mixture of urethane and polyurea. One particular aspect employs a mixture of urethane and polyurea (e.g., approximately 5% urethane and 95% polyurea) in the spray mixture. In another embodiment, the spray mixture may employ a 100% blend of urea that includes a percentage of barium sulfate (BaSO4). The barium sulfate is used as a filler and sound deadening material. Thus, it is to be appreciated that the composition of the spray mixture may be any suitable mixture that facilitates the objectives of the innovation disclosed herein.
The novel manufacturing system (and method) of the innovation provides for clarity in the finished product aesthetics above that of conventional manufacturing techniques. In particular aspects, the innovation provides for in-molded features and components such as textures and logos as desired. For example, a desired logo or other treatment (e.g., grain type) can be provided on the A-side of the flooring product. In addition, localized areas of the A-side can include carpet. Once the carpet is in place the spray mixture can be applied in a normal process with a less amount (approximately 1.0-1.5 mm) being applied to the carpeted areas. This will create a bond of skin to the carpet and creates a barrier over the B-side of the carpet so foam will not transfer through during the reaction.
Additionally, the innovation can provide for variable thickness in the flooring product. It will be appreciated that this variable thickness can enhance wear-ability as well as assist in audible and thermal reduction, e.g., from road noise and engine/exhaust components respectively.
In accordance with the innovation, a spray can be employed to manufacture a flooring product, such as but not limited to a floor mat. The innovation further employs a single-sided mold that has a draft angle of approximately 90 degrees to facilitate the removal of the finished flooring product. In other words, the method can be described using the perspective of zero degrees as a shear condition. In aspects, the single-sided mold includes a vertical wall ninety degrees to the main horizontal surface. In conventional injection processes, a male/female tool is used, which with zero degrees, generates shear upon the vertical portion. The innovation alleviates this effect by employing a spray application process. In other words, the spray process uses a single-sided tool for this application, which lends to greater flexibility in design and alleviates from shearing. Accordingly, endless three-dimensional capabilities are possible with this unique manufacturing system and method.
Referring to
The mold component 104 can be comprised of a single-sided mold. In addition, the single-sided mold can include surface treatments that will be transferred to a top surface (A-side) of the flooring product to enhance aesthetics or functionality of the molded product. For example, a logo, ridges, a grain type structure, etc. can be applied to the top surface of the single-sided mold, described further below in reference to
At 202, a single-sided mold is provided. It is to be understood that because the novel flooring manufacturing system employs a spray component described above, a single-sided (or single-part) mold is all that is required to manufacture the flooring product. At 204, a spray mixture is prepared to apply to the single-sided mold. At 208, the spray mixture is cured for a predetermined period of time and removed from the single-sided mold.
It will be understood that optional acts can take place at 210 and 212. For example, at 210, a foil(s) or other temperature deflector/insulator can be embedded into the flooring product. It will be understood that a molded-in foil can enhance occupant comfort by blocking or shielding heat from entering the vehicle, e.g., cab of a long haul truck. Additionally, at 212, a surface treatment (e.g., logo, pattern such as graining or logo) can be applied so as to enhance aesthetics as well as functionality of the flooring product, see
As described herein, the spray mixture can be a blend of urea that includes barium sulfate, a combination of urethane (e.g., approximately 5%) and polyurea (e.g., approximately 95%), etc. Those skilled in the art will understand that polyurea is a type of elastomer that is derived from the reaction product of an isocyanate component and a synthetic resin blend component through step-growth polymerization. In accordance with the innovation, the mixture can be sprayed into a mold (e.g., single-part mold) or directly upon a floor surface (e.g., metal, backing material). As described herein, when sprayed into a mold, it will be appreciated that, because a single-sided mold is used, shear can be alleviated as would be present in a conventional two-part molding process.
On the other hand,
Referring to
For example, although,
In order to determine which of the mixtures or layers noted in
Three factors were considered in the experiment: 1) ratio of wear surface to mass-filled layer density; 2) mass-filled layer thickness; and 3) de-coupler density. One constraint on the total thickness of the part was that any decrease in the layer thickness of the mass-filled layer lead to a proportional increase in the wear surface layer. There were three levels for each factor whose range represented realistic manufacturability.
The predicted double-wall decoupled frequency for a nominal mass sample is 305 Hz. A previous study which showed both theoretically and experimentally that the presence of an air gap, difficult in flooring application, and the method of mounting the foam layer to panel are critical to the STL performance of the double wall system. Furthermore material properties closely related to the solid phase of the foam are much more influential to the STL performance than the fluid phase properties of the foam in the current foam panel boundary condition.
Following indices which are widely in use in DOE methodology are summarized. Standard deviation (SD) in the Taguchi method which is to be minimized is a measure of the variability of the STL response due to noise or uncontrolled effects. Signal to noise ratio (S/N) is a measure of robustness used to identify and optimize the control factors that reduce STL variability of the product by minimizing uncontrolled effects. The index Cp is the ratio of the range of the control limits to the six sigma variation of the design which represents dispersion. A related index Cpk measures both the spread and the non-centering of the design.
STL curves were produced in a test facility following recommended practice SAE J1400-10. Samples were mounted between a source reverberation chamber and an adjacent receiving anechoic chamber. These samples were mounted in a sealed frame and were mounted against a metal panel facing the noise source. Differences between the average sound levels in the source and receiving room along with a measured correlation factor lead to the STL curves.
During preparation of the foam de-coupler layer 706 the skin 708 forms against a surface of the mold. The skin 708 largely affects the STL, as shown in
The STL curve is made up of nineteen ⅓rd octave center band amplitudes ranging from 125 to 8000 Hz. In order to break up the analysis into more manageable sections this frequency range is divided into four ranges shown in Table 1 below.
A Taguchi analysis demonstrates the optimum performance for each factor and frequency range in Table 2 as well as the influence of a specific factor.
For example, a high density de-coupler is preferable at the lower frequency ranges whereas a low density de-coupler is superior at the two higher frequency ranges. In the current study there are changes in resin chemistry at different foam density levels. The de-coupler density at all 4 frequency ranges has a much larger contribution to the STL response than the other two factors, the effective mass in the top good section of the double wall. Larger mass in the top good section can be achieved through higher loading of the filler material in the mass-filled layer (ratio of wear surface to mass-filled layer density) or by increasing the mass-filled layer thickness whichever is preferential.
STL response curves are reduced to the main effects of the mean in
The interface between the molded floor mat de-coupler skin and the cab structure remains an important area to balance performance trade-offs. Some commercial vehicle manufactures may choose to keep the foam skin if water absorption is a more important concern than acoustical performance. It may be possible to modify this stiffness in the molding process by adding surface texture to the tool. The mechanism by which surface modification shifts the double wall resonance is still being explored, perhaps by effectively adding small air gaps between the foam and cab structure or modifying the localized dynamic stiffness.
The STL graphs in
The design variation is optimized with respect to a specific target. This target usually takes the form of a STL curve, but is easily converted to an average value in a frequency range as previously described. For illustrative purposes, the improved design target for frequency range 4 is 3 dB greater than the current design average: Improved Designaverage,R4=Current Designaverage,R4+3 [dB]. It is expected that the improved design can be achieved with the same optimum levels from Table 1 and the Signal to Noise (S/N) Ratio in Table 3 below.
The current design (S/N Ratio: −9.4, SD: 7.4, Cp: 1, Cpk: 0.86) is improved significantly to the improved design (S/N Ratio: −1.7, SD: 3.1, Cp: 2.4, Cpk: 2.4). Optimizations can be further improved with cost models to customize the design depending on the needed acoustical improvement in each frequency range balanced with the cost of increasing weight, raw material, or manufacturing.
With reference to
The input parameters may be input into a flooring product configuration management component 1708 of the computer system 1700 where the information is processed. The flooring product configuration management component 1708 may include several processing components, such as but not limited to a receiving component 1710, an analysis component 1712, and a configuration component 1714. The receiving component 1710 receives the information from the input parameters and sends the input information to the appropriate component within the flooring product configuration management component 1708. The analysis component 1712 analyzes the information from the input parameters to determine an optimum flooring product configuration. Finally, the configuration component 1714 configures the flooring product based on the resulting information from the analysis component 1712.
The information from the flooring product configuration management component 1708 is output in the form of a specification. For example, the optimum flooring product configuration may be output in the form of a flooring product specification 1716, which is used to fabricate the part.
What has been described above includes examples of the innovation. It is, of course, not possible to describe every conceivable combination of components or methodologies for purposes of describing the subject innovation, but one of ordinary skill in the art may recognize that many further combinations and permutations of the innovation are possible. Accordingly, the innovation is intended to embrace all such alterations, modifications and variations that fall within the spirit and scope of the appended claims. Furthermore, to the extent that the term “includes” is used in either the detailed description or the claims, such term is intended to be inclusive in a manner similar to the term “comprising” as “comprising” is interpreted when employed as a transitional word in a claim.
This application is a Continuation-in-Part of pending U.S. patent application Ser. No. 13/420,112 entitled “VEHICLE FLOORING SYSTEM” filed on Mar. 14, 2012 and claims the benefit of U.S. Provisional Patent application Ser. No. 61/453,436 entitled “VEHICLE FLOORING SYSTEM” and filed on Mar. 16, 2011. The entireties of the above-noted applications are incorporated by reference herein.
Number | Date | Country | |
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Parent | 13420112 | Mar 2012 | US |
Child | 13626468 | US |