One-piece is shot and blow in the same machine is completed, injection molded preform is cooled to below the crystallization temperature range, but remains in a state of thermo-elastic, and finally blowing into bottles. One-piece and two-stage is divided into two kinds. PET grain dryer use high temperature air is dehumidified, circulation in the hopper. Dry air, the dew point temperature must be between -29 ℃ and -40 ℃. Temperature of the dryer was set at between 177 ℃ and 182 ℃, dried for about four hours.įirst, injection molding processing system to a preform , which is fired into the mold cavity to melt, and then rapidly cooling, the preform temperature below the crystallization temperature range, made of transparent preform a second step of the preform is heated, it is higher than the glass transition temperature, and then extended, blow molding and cooling. Before preform injection molding, PET grain must be dried to a moisture content of 0.05% or less, so that it can create a good non-crystalline transparent preform. PET is a hygroscopic material, if the moisture content is too high, will produce at a high temperature hydrolysis process, the PET molecular chains and thermal decomposition of acetaldehyde, reduce physical and mechanical properties, the crystallization rate of speed, when the Preform Injection, will Preform partially crystalline bleaching, affecting the quality of the product. PET is a polymer, the most important feature is its molecular weight, molecular weight is the number of uniform molecular PET molecular chains, the number of molecules of longer chain link, the better the physical properties of PET. PET is a crystalline resin, a specific gravity of about 1.4, a melting point of 245 ℃, the molding temperature between about 290 ~ 315 ℃. Usually used in the manufacture of PET plastic container grain, must pay attention to the following features: (1) molecular weight (2) acetaldehyde content (3) the content of diethylene glycol (4) a carboxyl group (5) the percentage of total polymer ( 6) Melting point (7) a glass transition point (8) the degree of crystallinity. Polyethylene terephthalate (of PET) , having the features: (1) excellent in gas barrier properties (2) pressure resistance, creep resistance (3) Impact resistance (4) transparency, surface gloss (5) itself is odorless and Paul fragrance security (6) on food hygiene, and beautiful, easy molding, has been widely used in food containers. Here are some notes for the PET preform injection molding process, for all my friend, much know-how experience, much near to the perfect production. The final result is that the bad quality &bad production of PET preform in the customer factory, which will waste the money &energy &time of all. And in order to reduce the sell cost, many manufacturers also present the general purpose injection molding machine with C type of screw &big shot weight, while they obviously ignored to bring the important notes to the customer before they make a decision focus on the PET PREFORM PRODUCTION. This product compiles with food contact regulations, so it can be used in all types of packaging.Many friends would like to adopt the general purpose injection molding machie to produce the PET preform. NTC SLU, being a colouring specialist, can include it in the production of PET dyes, either as a masterbatch or liquid. This product does not interfere with the preform colouring. – In liquid form, with dosing through a 0.2% pump during injection. – In masterbatch form, with a recommended dosage of 2%. We have two presentations of this product: – increases the speed of the preform in the blowing rail, which increases production by preventing jams in the blowing line, thus providing less friction resistance. The Slider for PET preforms, due to its nature, brings several improvements during the injection blow moulding process, such as : NTC SLU’s Slider Colorpet, for PET preforms, thanks to its unique formulation, allows the preforms to slide relative to each other by repositioning themselves inside the bag, increasing the amount of preforms that can be stored in an octavin by 20%. Octavins with large empty spaces caused by the geometry of the preform create the need for space, decreasing the profitability of the warehouse and increasing transport costs. One of major disadvantages of PET preform manufacturers is the large space required to store this material. A new development for injection moulding of PET preform s, adding to our list of additives and colorants for polymers and resins.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |