How To Prevent Pet Bottle Preform Strain Defects

Stress-strain analysis is a very important quality inspection method that determines the stress and strain of a stressed PET material. The test was performed on a photoelastic strain gauge. This process is very important for the production of high quality PET bottles. How do Pet Bottle Preform get stress and strain defects? In the manufacture of PET bottles, the initial stage of PET bottle material experience was the "injection stretch blow molding" process. This process is divided into four phases: 1. injection The molten polymer flows into the injection chamber through the hot runner block and produces a preform. After a specific set of times, the injection mold and the preform held in the neck carrier were rotated to 90 degrees. 2. Stretch Once adjusted to the correct temperature, the preform can be stretched. When the preform is in the area of ​​the blow mold, the mold is closed and the stretch rod is introduced to longitudinally stretch the preform. 3. blow After stretching, the preform is blown circumferentially using two stages of air pressure. 4. Exempt After a certain period of time, when the mold cools, it opens and the preform is removed through a drop chute or robotic device. During stretch blow molding, the preform can incorporate various stress distributions or strains on itself. This defect can interfere with the thickness distribution and performance required for the final bottle. Since thickness distribution is one of the most important criteria in bottle production, strain can be considered a major quality barrier to PET bottle manufacturers. The stress analysis of pet bottle preforms is carried out by observing the macroscopic view of the mechanical properties of the material. It is assumed that the observed stress is related to the strain (deformation) of the material. This deformation can be detected by photoelastic methods on a photoelastic strain gauge. The photoelastic process describes a change in the optical properties of a preform having mechanical deformation. It determines the strain in the PET preform by providing a stress profile around the discontinuities in the preform. A skilled photoelastic instrument detects small stresses or strains in the product and helps manufacturers test the quality and transparency of PET preforms before final production. Jilian Plastics produces a series of high quality and durable 5-Gallon Pet Preform products. Welcome customers who need it to contact us.