Delaware Valley Corporation was asked to submit ideas for a carpet to be used as a decorative covering for a lower panel on the inside of mini-van doors that had the ability to be vibration welded to the door panel substrate. Drawing on Delaware Valley’s experience in automotive applications, our extensive knowledge in the secondary processing of our products and the thermal bonding technology that we had been instrumental in introducing to the Needle Punch Industry in the early 1990’s, in the matter of weeks, we were able to provide a working prototype fabric to suit the requirements of the client.
Critical to this success was our ability to present to the Vibration Welding process a virgin polymer fabric devoid of any non-polymeric binders or stiffeners, such as SBR or PVA, typically used to give the Needle Punched fabric its stability. Such binders would have interfered with the co-melting of the carpet to the polymer door panel substrate. Our solution for fabric stability was to mix into the higher melt a low melt variant of the fabric structural polymer, that, when heated to its specific melting point, acted as the binder to give our fabric its stability. Using the same polymer as that of the door panel substrate assured a complete welding of the carpet to the door panel
The day following the Customer request, utilizing a drawing they had provided to us of the door panel, we sent the customer hand cut fabric parts. Our 100% polymer approach welded completely the first time. Although the welding proved successful, there were some additional adjustments required in order to perfect the fit and finish of our fabric in their application.
Within two weeks, our Project Lead went to the Customer’s facility with many additional samples cut using a prototype die which incorporated the findings of the trial with the initial hand cut sample fit.
After several days of trials incorporating adjustments to the welding machines suggested by our Project Lead, the finish of the part was deemed acceptable for use. During these trials it was discovered that the thickness of the fabric was critical to the ability of the welding process to control the melt of both the carpet and the door panel; too thick and the weld was inconsistent, too thin and the fabric melted to an unacceptable finish. While the client continued with additional “tweaks” to their welding machines our Project Lead returned home to Delaware Valley to mitigate the fabric distortion caused by the vibration welding with a new die design.
The program, awarded to Delaware Valley for its entire product life, provided millions of successful parts that are on sliding mini-van doors on the roads today.