Mold Verify Report (TVR) is based on the products acquired from mold testing to assess whether corresponding molds reach the requirement through the measurement thereof. Since one mold is usually provided with a plurality of cavities and certain differences always occur for plastic parts molded in different cavities, the TVR, therefore, should not only be based upon mold No. and testing No., but also be related with cavity No.. The quality verification of injection products includes:

  1. Appearance and Surface Quality Verification

The appearance and surface quality of injection products refers to the quality characteristics that can

be visually sensed by human beings, such as the geometric modeling, color and glossiness as well as surface defect of injection products. The verification standard for the appearance and surface quality of injection products should be determined in accordance with the size, use and part of the products, for example, the requirement for the appearance quality of exposed part of the products after assembly is higher and stricter than that of the unexposed part. Usually the appearance quality of injection products is not represented with statistic data but with substantial samples within the allowable limit of appearance defect. When sampling the degree of allowable limit of appearance and surface quality of injection products, overhigh requirement will unavoidably increase the difficulty and cost of mold designand manufacture; meanwhile, much stricter requirement will be imposed upon the setting of injection technics and corresponding parameter control of injection equipment; moreover, the productivity thereof shall be definitely reduced to a certain extent. All these will be ultimately reflected in the price of products. Thus, if the appearance defect (except for cracks) is not extremely obvious, the products can be deemed as qualified.

  1. Dimension and Tolerance Verification

The external dimension and precision verification of injection products should be circumscribed in

a required measurement environment (temperature and humidity), wherein special tools and instruments for measuring plastics (for products without much requirements for dimension precision, the measurement condition can be less strict), as well as suitable measurement method should be adopted to avoid deformation of plastics during the process. The measurement for external dimension and precision of injection products mainly aims at those parts easily distorted and warped, which accordingly influences the external precision, parts with special requirement for assembly and positioning, and those which are deformable and damageable under stress during assembly.

  1. Performance Verification

The performance verification of injection products mainly includes verification for mechanical

intensity, heat resistance, weather and age endurance, environmental stress and crack resistance, chemical resistance, electric property as well as optical performance of transparent products etc, wherein the mechanical intensity verification comprises such content as verification for tensile strength, impact strength, bending strength, falling test, fatigue intensity as well as comprehensive intensity of hot and cold circulation etc.