The base paper used by carton manufacturing enterprises in our country，If you divide it by place of origin，It can be simply divided into imported base paper and domestic base paper;If according to the variety of base paper to divide，It can be divided into cowhide cardboard (also known as cowhide box cardboard in China), corrugated base paper, and whiteboard paper for high-grade packaging and printing, hanging kraft paper, coated kraft paper board, etc。Due to the rapid development of China's carton industry, the demand for base paper is rising year by year, especially coated kraft paper board, because it has the advantages of both kraft board paper and coated whiteboard paper, but also has the strength of kraft board paper and the printability of whiteboard paper, so the import volume is significantly increased。Although the overall quality of domestic base paper has been greatly improved in recent years, there is still a gap compared with the quality of foreign base paper, and even if individual paper mills can reach the same level abroad, but in some low-gram weight, high-strength kraft paper and corrugated paper production, due to limited capacity, it can not meet the demand。Most still depend on imports。For the imported base paper, China's inspection and quarantine departments have specific provisions: in accordance with the provisions of the Commodity Inspection Law, the commodities listed in the category list must be inspected by the inspection and quarantine institutions or their designated inspection departments, and may not be sold and used without inspection。Most of the carton base paper imported from China is a legal inspection of goods, so it must be inspected。At present, when the inspection and quarantine department inspects these papers, the inspection standards followed are roughly as follows:

　　1.Standards mandatory by laws and regulations or other inspection standards that must be implemented;

　　2.If laws and regulations do not have mandatory standards or other inspection standards that must be implemented, they may be tested according to the standards agreed upon in the contract between the two parties。(If the mandatory standards of laws and regulations are lower than those stipulated in the contract, the standards stipulated in the contract shall be implemented);

　　3.In the absence of the above two points, the inspection can be conducted in accordance with the standards of the producing country, relevant international standards or the standards designated by the national inspection and quarantine authority。If there is no suitable test standard, the approved internal method standard is selected。 In our actual inspection process, we found that most domestic users do not have enough agreement on the quality terms of imported base paper in the trade contract, or even no agreement, they often only recognize the brand and origin, and ignore the quality fluctuations of the product itself。The first half of this year，There are several batches of imported paper with quality problems found by our inspection and quarantine department，However, because the customer did not agree in advance in the contract to receive the quality requirements and inspection standards，It is difficult for the inspection and quarantine department to issue the unqualified certificate，It brings trouble for customers to claim and return their own claims，因此，We urge companies importing base paper to include quality clauses in their contracts，To protect their own profits.The specific inspection contents of paper include: safety, health, environmental protection, quality, quantity, weight, packaging and other items。Due to space constraints, we only introduce its routine physical detection items and the method standards used。

　　1.Appearance inspection:

　　The appearance inspection of paper is one of the important inspection items, which is generally composed of on-site sampling inspection and laboratory inspection by inspectors。The appearance defect of paper not only affects the appearance of paper, but also affects the use of paper。We use the test method standards: ISO, TAPPI standards, as well as SN/T0874-2000 and national standards GB/T1541 dust degree detection。Mainly adopt the light inspection, the head-up inspection, the squint inspection and the hand touch inspection。The paper surface is required to be smooth and clean, and folds are not allowed。

　　2.Physical property test

　　Before carrying out the physical performance inspection work, the paper must be pretreated with constant temperature and humidity according to the standard, because different paper needs to be tested differently, here are mainly listed several:

　　(1) Whiteboard paper

　　Good whiteboard paper generally requires a tight texture, smooth surface, consistent thickness, no lint on the paper, good absorption, and small expansion rate, and can adapt to the requirements of multi-color overprinting。In order to meet the requirements of making boxes, the white board paper should also have the characteristics of large stiffness and good folding resistance。The main import countries are: South Korea, Indonesia, the United States, Japan, etc., especially the quality of Japanese white board paper is good。The test items are: quantitative, thickness, whiteness, smoothness, breaking length, breaking resistance, folding resistance, sizing degree, stiffness and IGT。

　　(2) cowhide cardboard

　　Kraft cardboard, our country is called box board paper, is one of the main paper types of carton paper。Domestic box board paper is divided into excellent products, first-class products, qualified products three grades。The texture of kraft paper must be tough, high rupture resistance, ring compression strength and tear, in addition to having high water resistance。Due to the difference in process and materials, in general, the quality of most imported kraft paper is better than that of domestic kraft paper, especially the quality of cattle card produced in the United States。The test items are: quantitative, thickness, tightness, rupture resistance, rupture index, ring compression strength, transverse annular pressure index, breaking length, tearing degree, sizing degree, moisture, banner quantitative difference, transverse folding resistance and so on。

　　(3) The detection items of coated kraft cardboard and lined kraft paper are reference kraft cardboard and whiteboard paper。

　　(4) Corrugated base paper

　　Corrugated base paper is one of the important components of corrugated board。Corrugated base paper requires good fiber bond strength, flat paper surface, good tightness and stiffness, and a certain degree of elasticity to ensure that the carton made has shockproof and pressure resistance。In addition, the moisture index should be controlled, the moisture is too small, the paper is brittle, and the corrugated processing will break;Excessive moisture and soft paper will bring difficulties to processing and forming。The water content of general paper should be controlled at about 10%。Domestic corrugated base paper is divided into A, B, C, D four grades。

　　The test items are quantitative, thickness, tightness, breaking resistance, ring compressive strength, transverse ring compressive index, flat compressive strength, breaking length, sizing degree, moisture and so on。The methods used for detection mainly include: GB, SN, ISO, TAPPI, SCAN, JIS, etc。Here is a simple example of our country's test standards:

　　1.GB/T451.2-2002 "Quantitative Determination of Paper and board"

　　2.GB/T451.3-2002 "Determination of Thickness of Paper and board"

　　3.GB/T453-2002 "Determination of tensile strength of paper and board (constant rate loading method)"

　　4.GB/T454-2002 "Determination of paper breakage"

　　5.GB/T455-2002 "Determination of tear degree of paper and board"

　　6.GB/T456-2002 "Paper and board smoothness determination (Buick method)"

　　7.GB/T457-2002 "Determination of folding resistance of paper (Schauber method)"

　　8.GB/T458-2002 "Determination of air permeability of paper and board (Schopper method)"

　　9.GB/T459-2002 "Determination of elasticity of paper and board"

　　10.GB/T462-2003 "Paper and board moisture determination"

　　11.GB/T13024-2003 "Box Board"

　　12.GB/T13023-1991 "Corrugated Base Paper"

　　13.SN/T0874-2000 "Inspection Rules for Import and Export Paper and Board"

　　The above mentioned are some of the more conventional carton paper detection methods, with the rapid development of science and technology and people's increasing concern for environmental protection, carton paper is developing in the direction of functional and environmental protection。Such as anti-corrosion, anti-bacteria, anti-oil, high temperature and other functional paper。At present, China's national standards for this kind of special paper are not complete, some are being modified and formulated in the process, the detection of this kind of paper, inspection and quarantine departments generally refer to the relevant international standards, export country standards or manufacturers' standards。In addition, some of the base paper used for food packaging cartons must also meet the relevant health standards in our country, which is now the focus of our inspection and quarantine work, because it is directly related to the health and safety of our people。The inspection standards involved in these papers are mainly:

　　1.GB11680?D89 Hygienic Standard of Base Paper for Food Packaging

　　2.GB18192-2000 "Liquid Food aseptic Packaging paper based Composite Materials"

　　3.GB18706-2002 "Liquid food preservation packaging paper based composite materials (roof package)" For some printed and used in food packaging paper must also detect the content of related heavy metal elements, such as lead, chromium, cadmium, mercury, etc。

　　In addition, EU countries now strictly control the total content of heavy metal elements in imported packaging cartons。The scope of testing involves a wide range, including the carton itself, box nails, adhesives, contents, and so on。Relevant testing standards are:

　　1.DDENV12498:1998 Paper andboardintendedto comeintocont act with food stuffs .Determination of cadmium, leadand chromiuminana queous extract (Determination of Cadmium, Leadand Chromiuminana Queous extract from Paper and Board in direct contact with food);

　　2.Paperandboardintendedtocomeintocontactwithfoodstuffs DDENV12497:1998.　Determinationofmercuryinanaqueousextract "(" the direct contact with food, paper and cardboard mercury determination of water extraction");With the strengthening of people's environmental awareness，All countries in the world have their own restrictive laws and regulations on imported packaging，Our carton manufacturers should pay special attention when conducting international trade，To prevent unnecessary damage。