Let's learn the inspection standards for injection molding products!

1. Inspection environment:

Place the product to be inspected at a position of 0.8-1m under a 40W fluorescent lamp or a 60W ordinary light bulb. In the direction of 45 degrees to 135 degrees, the two eyes are 30-50 cm away from the product to be inspected, and the front visible portion stays 3-5 s, and the other faces are 2-3 s.

2, product inspection strictness distinction:

Class I products refer to products that do not need to be painted, such as DVR, wall box cover, satellite switch rubber tray, PHLIPS customer antenna, etc., which have high surface requirements; Class II products refer to products that need to be painted and indoors. Antenna products (large plastic parts, cheap, exported to some less developed countries and regions such as Africa, South Asia).

3, the same product different position strictness distinction

3.1, A side visible in the normal product operation, such as the product cover, front end and interface.

3.2. Surfaces that are not normally visible in normal product operation, such as the side of the product.

3.3. The surface of the C surface that is not visible in normal operation, such as the bottom surface of the product.

3.4, D face refers to the non-exposed surface of the product structure, such as the inner and inner structural parts of the product.

4, product failure classification

4.1. Fatal Defects: Experience and judgment indicate unqualified conditions that are caused or unsafe to individuals who use, maintain, or rely on the product.

4.2. Severe Defects: Not a fatal defect, but in order to achieve the intended purpose, it is likely to cause a product failure or a failure to greatly reduce the efficiency of use.

4.3. Light defects: In order to achieve the intended purpose, it is impossible to greatly reduce the efficiency of use of the product, but there is a non-conformity that has little impact on the product.

5, injection molding products specific product inspection defect classification

5.1. Material defects: The materials are used incorrectly, containing miscellaneous materials, and the raw materials (heavy defects) are used without a large proportion.

5.2, appearance:

Appeared in the B-side, C-side and Class II products of Class I products, scratches, shrinkage, flow patterns, chromatic aberrations, whitening (light defects) which are not obvious on the A, B and C faces.

There are obvious scratches, shrinkage, flow patterns, chromatic aberrations, whitening, and weld lines and material heads (heavy defects) that affect the assembly.

Product structure (assembly) defects: The product cannot be assembled with the matching parts, which affects the defects of use (heavier failure). For example, after the upper and lower covers are assembled, the misalignment is serious, the thread is not matched, the column is cracked after the screw is locked, and the hole of the punching rod is cracked.

Product performance defect: A defect (heavy defect) that causes the product to fail to meet the intended function of the design. For example: paint lacquer falling off, plating plating peeling off, steel hardness, strength is unqualified, electrical connection is broken, short circuit, attenuation reflection is not up to standard.

Packaging defects: It may cause scratch quality problems in the product or the corresponding protective film and plastic bag (heavy defect).

6, the overall principle of judgment

6.1. In the production process of injection molded parts, the concept of “zero defect” is used to inspect the products and control the production, and help the workshop to analyze the causes of defects.

6.2. The finished product injection molded parts are manufactured according to the customer and product type. If there are light defects in the appearance, they can be received without affecting the assembly.

6.3, as long as the color difference is not wrong, the color difference of the supporting products is not acceptable.

6.4. Defective products that cause poor assembly (cracking of the punching rod hole, slippage of the locking screw hole, charring, column deformation affecting assembly, joint joint large, broken, buckle not tight, misalignment) shall be refunded.

7. Inspection techniques for injection molded parts

7.1, surface appearance:

No burrs, weld lines, bubbles, water patterns, deformation, scratches on the surface.

Look at the color difference (pay attention to the combination).

Look at the feed inlet for no strain or delamination.

There is no repair on the trimming edge.

7.2, structural parts

There should be no plugging holes in the screw column and through hole, and the holes (large and small) are deformed, whitened and welded.

There must be no cracks or breaks in the joints.

Threads must not be slippery or twisted.

7.3, trial installation, test spray.