When the project involves PET and PBT, the screwdriver programme must start from the customer ' s real-life job. Vendors of packaging and electronic equipment need to organize water-bearing, crystallization, steroid ratio and cycle into a set of verifiable, calculable and traceable input conditions.

The name of the raw material can only be classified as the first layer, and what really determines the screw configuration is the viscosity, melting point, thermal stability, humidity, filling and additive of the specific plate. Vendors should obtain material forms and identify whether the customer uses raw, retroactive or retroactive formulations to discuss generic, grinding, corrosive or lower shear structures. Calculates the nominal value to be converted to the actual condition. The machine often uses PS as a reference for the gel weight, which should be revised by density when using other raw materials; the weight of the product should be added to the main course, traffic separation and a reasonable buffer. The larger the diameter of the screw, the greater the theoretical capacity, but the pressure of injections per unit area under the same hydraulic pressure or servo system will decline and the resolution of the measurement of the small amount of the aerosol may also be variable.

It is recommended that customer information be broken down into five groups: products and moulds, raw materials, platforms, process objectives and existing problems. Product end logs of single weight, flowway, number of caves, wall thickness and appearance levels; ratio of feedstock end recorder number, melting finger, filling, flame retardation and retrofitting; terminal logs of tonnage, voltage, screw diameter, maximum travel, injection pressure and plasticization. All data are sourced and are marked, drawn, physical, measured or estimated by clients. The focus of the discussion here is on the water content rate, the crystal status, the percentage of the product and the periodicity, which must correspond to the customer ' s current production conditions and not be limited to the maximum values in machine samples.

From a sales management point of view, associated configuration drying systems, screws and temperature control should form a standard process that can be used again. Each project saves original needs, computations, final drawings, test modelling data and client feedback, and can call on experience in the event of a similar machine or material, but there is still a need to reconcile key differences and not to copy the historical configuration directly.

The cost of the misconfiguration is not only the screw itself, but also the cut-off, the waste of raw materials, the testing of molds, the delay in delivery and the credibility of customers. Precautionary measures around hydrolysis and downscaling due to poor drying and uneven plasticization are more economical than re-routing after problems have arisen; the vendor can then move from a mere offerer to a partner capable of taking on technical screening.

It is recommended that the main indicator be the water-bearing rate, viscosity and appearance, and that the temperature of the drums, screw speed, back pressure, measurement position, buffer position, injection peak pressure and continuous sample weight be synchronized. At least three reasonable process points, low, medium and high, are covered to confirm that the programme is not effective under a single parameter. Therefore, PET and PBT should not follow the simple logic of “symmetrically-system”. Only by accounting for products, feedstocks, tonnages, voltage, screw diameter and target cycles will the standard screws have a clear scope of application and the dedicated screws have a reasonable design basis and return on investment.