What are the acceptance standards for the appearance of plastic injection molds


In order to ensure that the mold can produce qualified […]

In order to ensure that the mold can produce qualified products, it is put into production normally, to ensure the service life of mold production, and meet the production and use requirements of product design. The specification recognizes the standards of molds in terms of product quality, mold structure, injection molding process requirements, etc., and evaluates mold quality accordingly.
1. Appearance, size and fit of molded product
Defects on the product surface are not allowed: lack of material, burnt, top white, white line, peaking, blistering, whitening (or cracking, breaking), baking, and wrinkles.
Welding mark: Generally, the length of circular perforated weld mark is not more than 5mm, and the length of special-shaped perforated weld mark is less than 15mm. The weld mark strength can pass the functional safety test.
Shrinkage: Shrinkage is not allowed in obvious areas, and slight shrinkage is allowed in unobvious areas (not feeling dents).
Modification: Generally, the flatness of small products is less than 0.3mm, and the assembly requirements must be guaranteed.
There should be no air lines or material flowers in the obvious appearance, and the product generally should not have bubbles.
The geometric shape, size and accuracy of the product should meet the requirements of the official and effective mold drawing (or 3D file). The product tolerance should be based on the tolerance principle. The shaft size tolerance is a negative tolerance, and the hole size tolerance is a positive tolerance. Customers have requirements. As required.
Product wall thickness: The product wall thickness is generally required to be an average wall thickness, non-average wall thickness should meet the requirements of the drawing, and the tolerance should be -0.1mm according to the characteristics of the mold.
Product coordination: surface shell and bottom shell coordination: the surface misalignment is less than 0.1mm, and there should be no scratching. The holes, shafts and surfaces that have the matching requirements must ensure the matching interval and use requirements.
2. Mold appearance
The mold nameplate has complete contents, clear characters and neat arrangement.
The nameplate should be fixed on the mold foot near the template and the reference angle. The nameplate is reliable and not easy to peel off.
The cooling water nozzle should be made of plastic block, if the customer requires otherwise, please follow the requirements.
The cooling water nozzle should not protrude from the surface of the mold base.
The cooling water nozzle needs to be processed with counterbore. The counterbore diameter is 25mm, 30mm and 35mm. The orifice is chamfered and the chamfer should be consistent.
The cooling water nozzle should be marked in and out.
Mark English characters and numbers should be greater than 5/6, and the position should be 10mm directly below the tap. The handwriting should be clear, beautiful, neat, and evenly spaced.
Mold accessories should not affect the lifting and storage of the mold. During installation, there are exposed oil cylinders, faucets, pre-reset mechanism, etc., which should be protected by supporting legs.
The support leg should be installed with screws passing through the support leg and fixed on the mold base, and the excessively long support leg can be fastened on the mold base with a machined external threaded column.
The size of the ejector hole of the mold should meet the requirements of the specified injection molding machine. Except for small molds, one center cannot be used for ejection.
The positioning ring should be fixed and reliable. The diameter of the ring is 100mm and 250mm. The positioning ring is 10-20mm higher than the bottom plate. Unless otherwise requested by customers.