Optics: measuring and testing – By monitoring of webs or thread – For flaws or imperfections
Patent
1993-11-15
1995-05-09
Rosenberger, Richard A.
Optics: measuring and testing
By monitoring of webs or thread
For flaws or imperfections
356238, G01N 2189, G01N 3336
Patent
active
054145201
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to a process for detecting impurities in a textile test material of the yarn, roving or sliver type, in which the test material is subjected to light, the light reflected from the test material is measured and the presence of an impurity is indicated by a change of the reflected light.
In a process of this type known from EP-B-0,197,763, a background surrounding the test material in the manner of a guide slot and likewise subjected to light is provided. The background is co-ordinated with the test material in such a way that the total quantity of light reflected from the test material and of light coming from the background is dependent on the dimensions and density of the test material and on the distribution of the fibers within this. It is thereby possible for a variation in the reflected light to indicate an impurity and not a variation in the dimensions, or in the density or in the fiber distribution in the textile product.
Apart from the fact that in this process, whenever the kind or type of test material is changed, adjustment work involving a relatively high outlay is necessary to adapt the background to the test material, this process is also highly sensitive to the contamination and aging of the background. Moreover, both of these are phenomena which are unavoidable in a textile concern and which constantly occur in that very environment.
Now the invention is to provide a process which requires no coordination of the background with a test material and in which the possibility of any faults caused by the background is therefore prevented.
This object is achieved, according to the invention, in that the test material is illuminated at at least two points, and in addition to the reflection the diameter of the test material or its change is measured, and in that the measurement signals thus obtained are interlinked.
The invention proceeds, therefore, from the fact that the light reflected from a given test material of a 10 given diameter is constant as long as the degree of reflection of the test material does not change, that is to say the latter contains no impurities. The change of the degree of reflection and consequently the presence of impurities, especially of foreign fibers, can then be detected by forming a quantity from the reflection signal and from the diameter signal and by analysing this quantity.
Accordingly, a preferred embodiment of the process according to the invention is characterized in that a quotient is derived from the reflection signal and from the diameter signal and is checked continuously for deviations from an average value.
The invention relates, furthermore, to a device for carrying out said process, with transmission means for illuminating the test material, with reception means for measuring the light reflected and/or absorbed by the test material, and with means for evaluating the measurement signals.
The device according to the invention is characterized in that the transmission means are designed in such a way that a simultaneous illumination of a plurality of points located on the same portion of test material or a multiple illumination of the test material at the same point takes place, and in that reception means are provided for the light reflected and/or attenuated by the test material at said points.
The invention is explained in more detail below by means of three exemplary embodiments and the drawings; in these: of a device according to the invention, embodiment, and according to the invention.
In the exemplary embodiments illustrated in FIGS. 1 and 2, a simultaneous measurement of the yarn diameter and of the reflection on a yarn G is carried out, the measurement signals relating to the same yarn point. The measuring zone is no larger than 0.5 mm. This is because a typical foreign fiber is wound round the yarn, and a typical value for the yarn twist is around 1000 twists per meter. Instead of simultaneous measurement at one yarn point, it is also possible to measure at two points X and Y, store the result of the earlier poin
REFERENCES:
patent: 3461299 (1969-08-01), Felix
patent: 3582661 (1971-06-01), Pijls
patent: 4095905 (1978-06-01), Kuni et al.
patent: 4739176 (1988-04-01), Allen et al.
patent: 4887155 (1989-12-01), Massen
patent: 4948260 (1990-08-01), Felix et al.
patent: 5054317 (1991-10-01), Laubscher
Joss Rolf
Wampfler Hans
Rosenberger Richard A.
Zellweger Uster AG
LandOfFree
Process and device for detecting impurities in a textile test ma does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Process and device for detecting impurities in a textile test ma, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process and device for detecting impurities in a textile test ma will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1710007