The latest development of automatic weight sorting

The latest development and application of automatic weight sorting in packaging logistics quality inspection

1 Why should we use automatic weight sorting scales as the largest potential food consumer in the world? For China, the food packaging industry is undoubtedly one of the most competitive industries. With China's reform and opening-up and accession to the WTO, the world's major food and beverage manufacturing giants have targeted the large market of China's food and beverage consumption. In the face of fierce market competition, in order to maximize the protection of the legitimate rights and interests of consumers, China's General Administration of quality supervision, inspection and Quarantine issued Order No. 43 of the provisions on the metrological supervision of quantitatively packaged goods and the subsequent inspection system for products certified with the "C" mark in 1995 in accordance with the international legal metrology Organization (OIML) No. R87 "net content in packages". OIML officially issued the latest R international recommendation "net content of prepackaged goods" in 2004. China tracked the latest R in 2004, and the National Metrology and testing center in East China was responsible for the revision of China's order No. 43, forming the measures for metrological supervision and administration of products with quantitative packaging (2004 Edition). The above documents not only stipulate the allowable negative deviation of the marked net content of quality quantitatively packed goods, but also are closely related to the weighing and testing equipment of quantitatively packed goods. The international legal metrology group "we have established a factory in China for more than 20 years. The tolerance provisions in the two international recommendations of OIML R61" gravity automatic loading scale "and OIML R51" automatic weight sorting scale "are derived from the allowable negative deviation t of the net content of quantitatively packed goods. OIML R51" automatic weight sorting scale " With the official promulgation of R, the pace of revision has also been accelerated recently. The R51 revision draft was proposed in April 2004. As one of the 24 full member countries of the international legal metrology organization, the national weighing instrument Metrology Technical Committee, after soliciting the opinions of some members, returned China's revision opinions to OIML in time in July 2004. OIML tc9/sc2 working group, after summarizing the opinions of various countries, formed a 4CD (Fourth Committee draft) draft for voting in October 2004. As an indispensable measuring and testing equipment on the packaging and logistics quality inspection line, the selection of automatic weight sorting scales is particularly important. Next, I want to introduce the functional principle, detection methods and standards of automatic weight sorting scale, and explain the importance of its application in packaging logistics quality detection. 2. Classification and principle 2.1 classification and concept of automatic weight sorting scale the latest OIML R automatic catchweighing instrument is defined as:

"automatic weighing scale for weighing pre installed discrete loads or individual loads of bulk objects" is called "automatic weight sorting scale", also known as "automatic weight catching scale" (hereinafter referred to as "sorting scale"). According to the purpose and structure, the sorting scales can be divided into five categories: check weight, weight label, weight price label, vehicle mounted catchweight and vehicle incorporated catchweight. Among the above five types of scales, automatic weight sorting scales (hereinafter referred to as sorting scales) are currently the most popular in the world. Sorting scales are also called "automatic weighing scales". Regardless of the weight checking or sorting function, the sorting scale is a weighing instrument that checks the weight of the weighed articles according to the preset weight range limit for the discontinuous pre installed discrete loads. Items with different weights are selected according to the nominal setting difference. 2.2 applicability of sorting scales with the continuous improvement of people's living standards in China, the market demand for food, beverage, dairy packaging and container goods has increased significantly, and large-scale food, beverage and dairy production plants often need batch automatic assembly line production. There are two types of objects tested by the sorting scale, one is pre packaged goods, and the other is unpackaged goods. When the sorting scale is generally used in the production line of food products, it is installed after the gravity or volumetric automatic loader or filling machine for weight sorting and removing the pre-set unqualified products, or for the grading and classification of the weight sorting of the weighed articles. The weighing accuracy of this scale is higher than that of automatic loader or filling machine. 2.3 structure principle of sorting scale at present, the structure of automatic weight sorting scale at home and abroad is composed of three parts. The first is the front feeding device (feeding belt), metering device (metering belt), and rejection device (rejection belt) of the weighed goods. See the right figure for the appearance. See Table 1 for the structure and main actions of the most typical sorting scale. 3. Measurement requirements for sorting scale (OIML R) 3.1 accuracy level

(1) automatic weight sorting scale used to check the weight of prepackaged goods according to the requirements of OIML R87 international recommendation "net content of prepackaged goods", which is divided into four levels: Xi, XII, XIII, XIIII

in each level, therefore, the treatment of waste plastic particles will become a hot development in the future, including a factor (x) specified by the manufacturer, and the value of (x) should be 1 × 10 k, 2 × 10 k, 5 × 10 K, where k is a positive integer, a negative integer, or zero

(2) it is used for other automatic weight sorting scales, such as weight pricing label scales, postal and conveying scales, and weighing scales used to weigh individual loads of bulk items, which are divided into four levels: Y (I), y (II), y (a), y (b)

a weighing scale can be classified as X or y. For example, a weighing instrument can be operated in two modes, either as an automatic weight sorting scale with class X classification, or as a weight pricing label scale with Class Y classification. 3.2 calibration division value (E)

calibration division value and calibration division number are as described in Table 2: Table 2 3.3 minimum weighing (min)

minimum weighing is manufactured by