Logistics Practice

Author: Zhao Meng Compiler/Nationality:
Publisher:
Publishing Date: 2004-08-01
Features:
(V) Test Methods for Individual Packaging Performance
To ensure quality, the following tests can be conducted for various individual packaging methods:
Cleanliness test, vacuum retention test, pressure retention test, cyclic exposure test, heat sealing test, and product adaptability test (all refer to JIS Z 0303).
III. Inner Packaging
Inner packaging originally refers to the packaging of two or more individual packages (direct packaging for the product) or the application of waterproofing, moisture-proofing, and cushioning measures to larger products from an unprocessed state, or the application of pressure bars, supports, etc., to directly fix them on the outer packaging container to prevent the product from moving. The above content is collectively referred to as inner packaging. Therefore, for inner contents, the anti-rust and moisture-proof measures described in individual packaging are equally applicable to inner packaging. There is no significant difference in function between individual packaging and inner packaging, though their implementation methods differ. The choice between individual packaging and inner packaging can be made freely, with the overall goal being convenience. Inner packaging can be broadly categorized functionally as follows:
(1) Chemical protection inner packaging
① Waterproof;
② Moisture-proof.
(2) Physical protection inner packaging
① Cushioning;
② Fixation.
(I) Waterproofing
For large wooden boxes like frame crates, due to the characteristics of wood (especially its low modulus of elasticity, resulting in large deformation, and significant shrinkage that does not change with moisture content), completely sealing the wooden box itself as packaging is nearly impossible. Even if it were constructed like woodworking products, it would incur high costs, making it unsuitable for transport packaging. Thus, in such cases, the appropriate approach is to line the inner surfaces of the wooden box's sides and ends with waterproof materials, use tar paper or similar methods for rough waterproofing on the top cover, and achieve complete waterproofing through floating bags (Floating Bags), bags, or sealed inner packaging.
Methods for waterproofing inner packaging:
1. Inserted sealing
Use flat processed paper or plastic film, or waterproof bags. The materials are shown in Table 3-13. When using packaging polyethylene film, use heat bonding to form a bag shape, apply waterproof adhesive to the sealing area, and fold the two pieces together after bonding. For grades II and III, adhesive may not be needed; instead, fold and bond with a cloth tape wider than the sealing width by 25 mm or more. The method for making the inner liner for the outer box:
Material length = 2 × (outer box length + 10 cm),
Material width = (outer box height + 10 cm) × (outer box width + 10 cm).
However, the dimensions of the outer box are the largest inner dimensions, and X is the clearance when placed in the outer box. When the outer box's length, width, and height are less than 1 m, X is 7 mm; when they are 1 m or more, X is approximately 15 mm. The method for making the inner box when packaging the product:
Material length = product length + product height + 8 cm,
Material width = 2 × (product width + product height) + 8 cm.
2. Large bags
For mechanical items, use waterproof bags to cover or fully encase them for waterproofing, especially when fixed to a base. In such cases, the floating bag method used for moisture-proof packaging may also be employed. Sealing can also be achieved using tape or heat sealing.
3. Inner boxes with galvanized iron (JIS G 3302) containers
When using a container made of galvanized iron with a thickness of 0.3 mm or more, bend the sheet material and solder it with soft solder. The sealing area is soldered. However, when overlapping waterproof paper for sealing, apply adhesive to a width of 5 cm or more and bond it. Alternatively, use bonding materials equivalent to or better than cloth tape (NDS Z 04021).
4. Waterproof corrugated boxes
When using waterproof corrugated boxes for inner packaging, use cloth tape (JIS Z 1524, width 50 mm or more) to the outer joints of the container. Other sealing areas also use cloth tape.
5. Waterproof grade
In NDS Z 0008 (Waterproof Packaging Methods), waterproof grades are specified as a basis for waterproof design (see Tables 3-14 and 3-15). Based on the waterproof grade, selecting waterproof materials can lead to more reliable packaging.
This refers to the overall inspection of the packaging after the product packaging is fully completed. The main focus is on the transport packaging part, judging the quality, quantity, and specifications of the inner contents, as well as ensuring the completeness of documents, the rationality and reliability of transport packaging, and the completeness and clarity of packaging markings. The appearance of the packaging unit should be clean, standardized, and aesthetically pleasing.
Packaging unit inspection includes checking the inner contents and packaging containers, packaging accessories, packaging fixation methods, and sealing or nailing methods before sealing. After sealing and nailing, an overall inspection of appearance and markings is conducted, along with testing the structural strength of the packaging. The most easily overlooked aspect of packaging unit inspection is the visual inspection. Some exported mechanical and electrical products have tilted packaging boxes, incorrect labeling, or non-standard placement of labels or spray coatings, leading to rejection by foreign merchants, damaging national reputation, or causing packaging unit damage during shipment. Therefore, every item must be carefully checked.
(VI) Sampling Inspection
Sampling inspection is based on the principles of mathematical statistics. According to a determined sampling plan, a sufficient number of products are randomly selected from a batch of products for inspection. The inspection results are compared with judgment standards to estimate and determine the quality of the batch, and to decide whether to accept or reject it. Sampling inspection is a method of determining whether a batch of products is qualified based on the quality of the samples. Both the supplier and the customer have certain experience with this method. For products with stable quality, mass production, multiple inspection items, or destructive and high-cost inspections, sampling inspection is both economical and scientific.
GB/T 2828 (Sampling Procedures and Tables for Inspection by Attributes) is applicable to the inspection of packaging quality for continuous batches. Generally, normal single sampling is used, and adjustments may be made if the quality is stable.
In sampling inspection, the Acceptable Quality Level (AQL) is the maximum process average defect rate that can be accepted. It is usually determined through negotiation between the producer and the user. For packaging unit inspection, AQL can be taken as 4%.
The inspection level determines the relationship between the batch size and the sample size. Under normal circumstances, general inspection level II can be used.
After determining these conditions, the sampling plan can be selected from the sampling table based on the batch size.