US 6,770,158 B2 · Quality management system for pre-processed workpiece

Abstract

A method and system for assessing proper pre-processing and proper welding of polymer workpieces. A visible or infrared radiation source, optionally coupled with optical filters, directs radiation at test wavelengths through a workpiece which is captured by sensors at one or more stations. The system controller determines from the sensor data whether the absorber dye was properly deposited onto the workpiece. The workpiece is then certified weld-enabled within a bandwidth range of the test wavelength. The bandwidth range is determined by absorption spectra and extinction coefficients of the dye or by utilizing multiple test wavelengths. For determining whether proper welds occurred, a further embodiment of the method and system check for spectral characteristics that the dye vehicle did not unduly interfere or occlude the weld. Further spectral data indicates fusing of reflective surfaces, increased transmission and increase photopic transmission.

Claims21

Dependent claims

A method for assessing whether a workpiece having an initial transmission of TINIT has been rendered weld-enabled as defined by a transmission drop ΔPRE to a pre-processed transmission TPRE within a welding zone, the method comprising the steps of:

providing a workpiece with a bulk portion and a surface extending across the bulk portion, wherein at least the surface is made from a first polymer which softens on heating;
transmitting electromagnetic radiation toward the surface in the region of the expected welding zone to be tested;
sensing electromagnetic radiation at a test wavelength passing through the surface of the workpiece and generating a signal representative of transmission;
determining whether the sensed transmission signal is within a range of TPRE as an indication that an absorber dye possessing both strong absorption and a high extinction coefficient was deposited on or above said workpiece surface within the welding zone via a vehicle having necessary viscosity and which avoids undue interference with or occlusion of the welding zone;
and
certifying the workpiece weld-enabled for radiant energy welding wavelengths within a bandwidth range of the test wavelength.

3 more elements

A method for assessing whether a weld-enabled workpiece, having a welding zone formed by a deposition of dye via a vehicle, has been properly or improperly welded to a material evidenced by a transmission gain ΔPOST from a workpiece-material transmission TZONE passing through the welding zone, to a post-processed transmission TPOST, the method comprising the steps of:

providing a workpiece and a material in contact with the workpiece;
transmitting electromagnetic radiation toward the prior location of the welding zone to be tested;
sensing electromagnetic radiation at a test wavelength passing through the workpiece, the prior location of the welding zone, and the material and generating a signal representative of transmission;
determining whether the sensed transmission signal is within a range of TPOST as an indication that the dye has undergone vibronic relaxation followed by exothermic decomposition of at least a portion of said dye in response to inbound radiant energy at a welding wavelength over about 0.1 J/mm2;
and
certifying that the vehicle avoided undue interference with welding zone and that the workpiece and material are properly welded together.

3 more elements

Dependencies are inferred from the claim text.

Quality management system for pre-processed workpiece

Life of this patent

Quality management system for pre-processed workpiece

Life of this patent

Abstract

Claims21