CN108918579A - A kind of method for automatic measurement of film shrink rate - Google Patents
A kind of method for automatic measurement of film shrink rate Download PDFInfo
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- CN108918579A CN108918579A CN201810462258.1A CN201810462258A CN108918579A CN 108918579 A CN108918579 A CN 108918579A CN 201810462258 A CN201810462258 A CN 201810462258A CN 108918579 A CN108918579 A CN 108918579A
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- film
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N25/00—Investigating or analyzing materials by the use of thermal means
- G01N25/16—Investigating or analyzing materials by the use of thermal means by investigating thermal coefficient of expansion
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B11/00—Measuring arrangements characterised by the use of optical techniques
- G01B11/02—Measuring arrangements characterised by the use of optical techniques for measuring length, width or thickness
Abstract
The present invention relates to a kind of method for automatic measurement of film shrink rate, including：Film sample is fixed using the film stationary fixture based on negative-pressure adsorption method, utilizes the film sample image under industrial camera acquisition light-source system illumination；It is pre-processed using film sample image of the image processing and analyzing system to acquisition, removes the interference in film graphics and noise；Identify that film sample image boundary, Measured Boundary length simultaneously carry out data-optimized by image analysis system；Film sample boundary length according to step (1)-(3), before measurement is toasted respectively and after baking.The present invention solves the problems, such as that film difficulty or ease are quickly fixed using negative-pressure adsorption principle, using computer vision technique, realizes the automatic measurement of film heating anterior-posterior length, and fast and accurately calculate the percent thermal shrinkage of film, meets professional standard and accurate, reliably.
Description
Technical field
The present invention relates to thin film physics performance detection technical field, the film proposed for film heat shrinkable characteristic is surveyed
Amount method, the method for automatic measurement of specifically a kind of film shrink rate.
Background technique
Film refers to by a variety of high molecular materials molding a kind of plastic material by the technical process such as co-extrusion, stretching,
Have many advantages, such as that transparency and glossiness are high, material non-toxic, molecular structure stabilized, and have the function of completely cutting off smell and moisture.
In view of this, film has been widely used in the industries such as food packaging, cigarette packaging.Film shrink rate refers to film one
Determine under the conditions of temperature and the change rate of certain time inside dimension, it is one important technology index of film characteristics.Film is heated
The characteristic of contraction directly affects the beauty of product outsourcing, and percent thermal shrinkage appropriate can be such that product outsourcing has tightlier, more evenly
It is wrapped, avoid package cover from generating fold and pack the problems such as incomplete；Heat sealability is combined, to guarantee that packaging has
Good abutting effect.
The percent thermal shrinkage of film has an important influence the products such as food, cigarette, and the percent thermal shrinkage of film detects and controls
It is one essential link of Related product production process.In general, measurement means and work that each enterprise or testing agency use
Tool differs greatly, and the uncertainty of test process is larger, so that data comparativity is poor between each enterprise or testing agency, very
Hardly possible is realized and is accurately controlled to cigarette film packing material quality.
The test method of existing film shrink rate is mainly manual measurement, it is main according to be State Quality Supervision Bureau and
The national standard GB/T 10003-2008 of national administration commission's joint publication《General applications Biaxially oriented polypropylene (BOPP) film》
The test method, defined film shrink test method are：First along thin-film width direction uniformly cut 100mm ×
100mm square sample marks and accurately measures horizontal, film on longitudinal direction length, is then placed on film sample and is stained with
It on the pallet of talcum powder, is put into baking oven and heats 5 minutes, take out the ruler after measurement is heat-shrinked after being cooled to experimental situation temperature
It is very little, calculate horizontal, longitudinal percent thermal shrinkage.There are following main problems for manual measurement method：(1) operator is measured using Steel Ruler
Film length, human interference is big, and measurement accuracy is low；(2) measurement process is complicated for operation, cannot calculate the heat with recording sheet automatically
Shrinking percentage, low efficiency and large labor intensity.
Related researcher has been directed to the research of the film shrink rate measurement method with automatic detection function.
Such as in 103308548 A of patent CN《A kind of cigarette packaging film percent thermal shrinkage measurement method》In, film is cut into elongate strip
Then shape measures the heat-shrinkable of film using pulling force and length variation, but the measurement method is only applicable to measurement elongate strip
Shape film, limitation is big, and is unable to the heat-shrinkable of the vertical and horizontal of accurate response sheet film, with standard GBT 10003-
2008《General applications Biaxially oriented polypropylene (BOPP) film》Regulation is not consistent.In patent CN 205593949U《Utilize optics
The device of image technique measurement film sheet percent thermal shrinkage》In, it describes the film shrink rate based on optical imagery technology and surveys
Amount method, but film can generate fold and distortion during heating, and the patent does not consider the feelings of film fold and distortion
Film aid or fixing means under condition.In addition, it is described in the patent based on film graphics recognition methods, in poor light
Thin film boundary can not be effectively identified in environment, at the same time, which still relies on traditional method of scoring, and film pretreatment process is numerous
It is trivial, and line width and the line depth of parallelism can directly contribute the inaccuracy of measurement.In patent CN106324019A《Film shrink rate changes
Into measuring method》In, the method for film heating is merely depicted, and measurement method is not illustrated.
In conclusion film associated production and being badly in need of one kind now using enterprise or testing agency and can comply with standard, fastly
Fast, accurate measurement method.
Summary of the invention
The purpose of the present invention is being directed to film shrink rate measurement process, a kind of film heat receipts are proposed
The method for automatic measurement of shrinkage solves the problems, such as that film difficulty or ease are quickly fixed using negative-pressure adsorption principle, and is regarded using computer
Feel technology, realizes the automatic measurement of film heating anterior-posterior length, and fast and accurately calculates the percent thermal shrinkage of film, meets row
Industry standard and accurate, reliable.
What the present invention was achieved through the following technical solutions：
The present invention is a kind of method for automatic measurement of film shrink rate, including the use of negative-pressure adsorption method, film is smooth
Be fixed in film fixed platform, then using light-source system provide uniformly suitable intensity of illumination, recycle computer view
Feel technology, acquisition identification film picture simultaneously carry out pretreatment and image analysis measurement to image, finally carry out data-optimized meter again
It calculates, to realize the measurement of film vertical and horizontal both direction size and calculate film automatically according to the formula of percent thermal shrinkage
Percent thermal shrinkage.
The negative-pressure adsorption method is that multiple apertures are had in film fixed platform, the negative pressure hair below film fixed platform
Raw device generates negative pressure, is passed to negative pressure in film sucker by closed conduit, to realize that film fixed platform has adsorption energy
Power, this solves the problems, such as that film heating generates fold and is difficult to quick flat booth on the stationary platform, and Kong Zhi in fixed platform
Diameter is and suitable adsorption capacity to be arranged less than 1mm, avoids and generates deformation of thin membrane because of absorption and influence the feelings of measurement accuracy
Condition.
The light-source system be include LED light emitting source, light source fixing seat and uniform light board etc., light source fixing seat is by light emitting source
Be fixed between image collecting device and film fixed platform, LED light emitting source generate illumination light, uniform light board be by the light of light source more
It is evenly distributed in acquisition space；It provides intensity by light-source system properly, uniformly to illuminate, to increase the clear of thin film boundary
Clear degree, to solve the problems, such as that transparent membrane boundary is indiscernible.
Image preprocessing process is as follows：
(1) interference and the noise in film graphics are removed first；
(2) film graphics color difference carries out difference enhancing processing, to increase the discrimination of film Yu film fixed platform；
(3) thin film boundary is identified using film and film fixed platform image color difference, it is sufficiently sharp in the process
The characteristics of property opposed flattened with the continuity and thin film boundary of thin film boundary, more accurately to identify thin film boundary；
(4) image in addition to film is rejected by thin film boundary.
Image analysis system analytic process is as follows：
(1) film picture and its boundary are identified and analyzed, determine the horizontal and vertical of film, avoided because placing
Film, is then adjusted on XY coordinate by the error of inclination and generation as horizontal and vertical, so that it is laterally consistent with X-axis, it is longitudinal
It is consistent with Y-axis, facilitate and carries out length scribing line measurement；
(2) film graphics are equidistantly marked with multiple groups boundary length line by vertical and horizontal；
(3) length (such as horizontal and vertical respectively take N group data) for measuring its each group length line, then carries out data-optimized
(such as abnormality value removing method), and averaging remaining data obtain final size value, in this way reduction differentia influence, it is ensured that
The accuracy of data.
Film shrink rate measurement method, main operational steps are as follows：
1) by the film sample before baking it is smooth spread with negative-pressure sucking film fixed platform on, then utilize work
Industry camera acquires the film sample image under light-source system illumination；
2) instrument utilizes computer vision technique, and the film graphics of heating front and back are acquired by industrial camera, utilize image
Processing analysis system automatic measurement, the size value for calculating the film sample before baking are respectively that L1 is horizontal, L1 is vertical, and stores
Come；
3) take out film sample send baking oven to toast by requirements of the national standard；
4) by 1) and 2) the step of, the film sample value after measurement baking is that L2 is horizontal, L2 is vertical；
5) according to percent thermal shrinkage calculation formula T=(L1-L2)/L1 × 100%, instrument calculate automatically film it is longitudinal and
The percent thermal shrinkage of lateral both direction, and display and save.
If the film sample size before baking is cut using instrument, can be straight by fixed dimension value if size is consistent
It connects and is input in instrument, can reduce 1) with 2) two steps, measure more quick, easy in this way.
The advantages of the present invention over the prior art are that：
(1) present invention innovation proposes a kind of film shrink rate measurement method, overcomes traditional-handwork measurement method people
To interfere the disadvantages of big, measuring accuracy is low, cumbersome.
(2) by computer vision skill, using image processing and analyzing system and data-optimized, measurement essence can be greatly improved
Degree.
(3) present invention by image processing and analyzing system and software processing, it can be achieved that thin film boundary Automatic-searching, reduce because
Measurement and error caused by the out of plumb of boundary, also can be avoided error caused by due to placing inclination or different location.
(4) present invention can carry out data record, storage automatically, and can calculate film shrink rate automatically, convenient
Measurement data is searched, counts and is saved.
(5) present invention is by negative-pressure adsorption method, solves the whole fixation problem of film difficulty or ease quick flat, this method is simple, it is quick,
Reliably.
(6) present invention may be implemented to reduce people compared with conventional method to the quick and precisely measurement of film shrink rate
For measurement error；With 103308548 A of patent CN《A kind of cigarette packaging film percent thermal shrinkage measurement method》It compares, solves this
Method is only capable of measuring the problem of strip film；With 205593949 U of patent CN《Film sheet is measured using optical imagery technology
The device of percent thermal shrinkage》It compares, the present invention uses negative-pressure adsorption method, solves to deform after film is heated and consolidate with fold difficulty or ease
Determine problem；Light-source system has also been devised in the present invention, solves what thin film boundary caused by thin-film transparent property was difficult to accurately identify
Problem.Described in summary, the present invention have high degree of automation, measurement it is accurate, easy to operate, calculating, testing efficiency is automatically stored
The advantages that high.
Detailed description of the invention
Fig. 1 is system structure of the invention, 1. film fixed platform, 2. light-source system, 3. industrial camera, 4. film sample
5. image analysis processing system.
Fig. 2 is thin film boundary identification and length line scribing line figure, 6. boundary length lines.
Fig. 3 is working-flow figure of the invention.
Specific embodiment
1, attached drawing 2 and Fig. 3 are described in detail specific implementation content of the invention with reference to the accompanying drawing：
1) it spreads the film sample 4 before baking is smooth in the film fixed platform 1 with negative-pressure sucking, it is negative using band
The film fixed platform 1 of aperture is pressed, the image of the film sample 4 under light-source system 2 illuminates then is acquired using industrial camera 3；
2) computer vision technique is utilized, the film graphics of heating front and back are acquired by industrial camera 3, utilize image procossing
5 automatic measurement of analysis system, the size value for calculating the film sample before baking are respectively that L1 is horizontal, L1 is vertical, and stores；
3) take out film sample send baking oven to toast by requirements of the national standard；
4) by 1) and 2) the step of, the film sample value after measurement baking is that L2 is horizontal, L2 is vertical；
5) according to percent thermal shrinkage calculation formula T=(L1-L2)/L1 × 100%, calculate automatically respectively film it is longitudinal and
The percent thermal shrinkage of lateral both direction.
The course of work of the method for the present invention is described in detail below with reference to a case study on implementation：
Case study on implementation one：
Film fixed platform appearance is dyed into black or dark color, to increase the contrast of thin film boundary and fixed platform,
To apparent identification thin film boundary, accurate for measurement is provided safeguard, as shown in Figure 2.
Case study on implementation two：
After the film sample image procossing that industrial camera obtains as shown in Fig. 2, first by its 20 parts (centre is equal part),
Then measurement each divides lines length value (numerical value is as shown in table 1 below), then its abnormality value removing (is such as rejected the smallest by 5
A value and maximum 5 values), the average value of remaining data (shown in table 2) after rejecting finally is calculated, obtains final measured value
(L2 indulges cross=94.53=90.16 and L2), and counted using film shrink rate calculation formula T=(L1-L2)/L1 × 100%
Film shrink rate (assuming that L1 indulges cross=100=100 and L1) is calculated, T indulges=(100-90.16)/100 × 100%=
9.84%；T cross=(100-94.53)/100 × 100%=5.47%.It is this to be measured by multiple groups, it can effectively exclude exception
Value avoids measurement error, improves measurement accuracy, and can measure the length of vertical and horizontal simultaneously, shortens time of measuring.
Above embodiments are provided just for the sake of the description purpose of the present invention, and are not intended to limit the scope of the invention.This
The range of invention is defined by the following claims.It does not depart from spirit and principles of the present invention and the various equivalent replacements made and repairs
Change, should all cover within the scope of the present invention.
Claims (6)
1. a kind of method for automatic measurement of film shrink rate, which is characterized in that include the following steps：
(1) film sample is fixed using the film stationary fixture based on negative-pressure adsorption method, acquires light source system using industrial camera
Film sample image under system illumination；
(2) it is pre-processed, is removed dry in film graphics using film sample image of the image processing and analyzing system to acquisition
It disturbs and noise；
(3) identify that film sample image boundary, Measured Boundary length simultaneously carry out data-optimized by image analysis system；
(4) the film sample boundary length according to step (1)-(3), before measurement is toasted respectively and after baking；
(5) according to percent thermal shrinkage calculation formula, the percent thermal shrinkage of film vertical and horizontal both direction is calculated separately out.
2. a kind of method for automatic measurement of film shrink rate according to claim 1, it is characterised in that：It is described to be based on bearing
The film stationary fixture of platen press includes film sucker and negative pressure generator；Negative pressure generator generates negative pressure, will by closed conduit
Negative pressure passes in film sucker, to realize the absorption of film.
3. a kind of method for automatic measurement of film shrink rate according to claim 1, it is characterised in that：The light source system
System includes LED light emitting source, light source fixing seat and uniform light board；Light source fixing seat by LED light emitting source be fixed on image collecting device with
Between film platform, LED light emitting source generates illumination light, provides suitable brightness for acquisition space, uniform light board is by the light of light source
Being distributed in more evenly acquires in space.
4. a kind of method for automatic measurement of film shrink rate according to claim 1, it is characterised in that：Image preprocessing
Process is as follows：
(1) interference and the noise in film sample image are removed first；
(2) difference enhancing processing is carried out to treated in (1) film sample image color difference, thus increase film sample image with
The discrimination of film fixed platform；
(3) thin film boundary is identified using film sample image and film fixed platform image color difference, is filled in the process
Point using thin film boundary continuity and thin film boundary opposed flattened property the characteristics of, more accurately to identify thin film boundary；
(4) image in addition to film is rejected by thin film boundary.
5. a kind of method for automatic measurement of film shrink rate according to claim 1, it is characterised in that：Described image point
Analysis system analytic process is as follows：
(1) film sample image and its boundary are identified and analyzed, determine the horizontal and vertical of film sample image, avoids
Because of the error placing inclination and generating, then film sample image is adjusted on XY coordinate as horizontal and vertical, so that horizontal
It is longitudinal consistent with Y-axis to consistent with X-axis, facilitate and carries out length scribing line and measure；
(2) the length line of N group frontier distance is marked by vertical and horizontal to film sample image；
(3) it carries out data-optimized after measuring the N group length and averages, obtain final size value, in this way reduction difference shadow
It rings, it is ensured that the accuracy of data.
6. a kind of method for automatic measurement of film shrink rate according to claim 1, it is characterised in that：The heat is received
Shrinkage calculation formula is T=(L1-L2)/L1 × 100%, and wherein L1 is film sample boundary length before toasting, after L2 is baking
Film sample boundary length.
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| Application Number | Priority Date | Filing Date | Title |
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| CN201810462258.1A CN108918579B (en) | 2018-05-15 | 2018-05-15 | Automatic measurement method for film heat shrinkage rate |
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| CN201810462258.1A CN108918579B (en) | 2018-05-15 | 2018-05-15 | Automatic measurement method for film heat shrinkage rate |
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109894378A (en) * | 2019-04-09 | 2019-06-18 | 湖北三环锻造有限公司 | The hot forging online automatic detection method of knuckle |
| CN110211088A (en) * | 2019-04-16 | 2019-09-06 | 广州超音速自动化科技股份有限公司 | Improvement type diaphragm film-making automatic testing method, electronic equipment and storage medium |
| CN111307853A (en) * | 2019-11-29 | 2020-06-19 | 宝燕工业科技(南通)有限公司 | Device for testing heat shrinkage property of biaxially oriented polypropylene film and use method thereof |
| CN111380901A (en) * | 2018-12-27 | 2020-07-07 | 贵州中烟工业有限责任公司 | Method, device and equipment for testing shrinkage rate of cigarette film and readable storage medium |
| CN113189135A (en) * | 2021-04-27 | 2021-07-30 | 中国节能减排有限公司 | Method for measuring thermal shrinkage rate of adhesive film |
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| CN103308548A (en) * | 2013-07-06 | 2013-09-18 | 国家烟草质量监督检验中心 | Measuring method of thermal shrinkage rate of cigarette packaging film |
| CN103358594A (en) * | 2013-07-12 | 2013-10-23 | 泉州市汉威机械制造有限公司 | Plastic packing bag making process |
| CN205397502U (en) * | 2016-03-07 | 2016-07-27 | 盐城华星光电技术有限公司 | LCD liquid crystal glazing correcting unit |
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| JPH06144856A (en) * | 1992-11-06 | 1994-05-24 | Asahi Glass Co Ltd | Method for measuring very small amount of thermal shrinkage of plate glass |
| CN1609603A (en) * | 2004-11-22 | 2005-04-27 | 上海利浦应用科学技术研究所 | Image testing method for chemical fibre thermal contraction rate and testing apparatus thereof |
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111380901A (en) * | 2018-12-27 | 2020-07-07 | 贵州中烟工业有限责任公司 | Method, device and equipment for testing shrinkage rate of cigarette film and readable storage medium |
| CN109894378A (en) * | 2019-04-09 | 2019-06-18 | 湖北三环锻造有限公司 | The hot forging online automatic detection method of knuckle |
| CN110211088A (en) * | 2019-04-16 | 2019-09-06 | 广州超音速自动化科技股份有限公司 | Improvement type diaphragm film-making automatic testing method, electronic equipment and storage medium |
| CN111307853A (en) * | 2019-11-29 | 2020-06-19 | 宝燕工业科技(南通)有限公司 | Device for testing heat shrinkage property of biaxially oriented polypropylene film and use method thereof |
| CN111307853B (en) * | 2019-11-29 | 2022-08-19 | 宝燕工业科技(南通)有限公司 | Biaxial stretching polypropylene film heat shrinkage property testing device and using method thereof |
| CN113189135A (en) * | 2021-04-27 | 2021-07-30 | 中国节能减排有限公司 | Method for measuring thermal shrinkage rate of adhesive film |
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