For the replacement of old screws, customers often ask first for price or maturity, but the seller of spare parts should first check the table name, the size of the screw, the wear and tear performance and the current raw materials. Only by quantifying these conditions can the standard screws have an interpretable boundary with the choice of a dedicated screw.

The core of the demand phase is not to immediately give a screw model, but to convert the client ' s product target into a calculable data. Product weights, project sizes, wall thickness, flow ratio, number of lacquers, flow weights, material plates and target cycles must be placed in the same record; if one of them has not been identified by the customer, it should be clearly marked as a hypothesis and the sales calibre should not be mistaken for final technical condition. 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.

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. The focus of discussion in this paper is on platform plates, screw sizes, wear and tear and current raw materials, which must correspond to the customer ' s current production conditions and cannot be quoted only for the maximum value in the machine sample.

In the context of this project, it is proposed to use the concept of “cross-checking of information with dismantling machines”. First, to determine whether the available data support the choice, then to calculate the volume of reductive, pressure and plasticization, and finally to discuss the geometry, front-end components and material handling of the screws. If the standard scheme is able to cover the window, priority should be given to the standard configuration; if the risk of a connection end or a non-reversible component mismatch following the nominal model remains, a dedicated structure is proposed, with an indication of the increased costs, delivery period and expected benefits.

The main risk of the scene is that the use of a nominal model may have a connection end or a non-reversible component. The issue of whether or not to be derived from a screw should first be excluded from drying, heating ring, thermal voltage, nozzles, reversible rings, wear and tearing of the material drums and changes in process parameters. The use of exclusions is more reliable than the direct replacement of components and also protects the time and cost of both the seller and the client.

The focus of the validation is the installation of a pass rate and the stability of the test machine. The test shall use the actual material and representative moulds of the client, retaining the batch number, dry condition, ambient temperature and sample number. When compared to old schemes, equipment, moulds and major process conditions other than screws should be as consistent as possible. With the continued accumulation of project data for the replacement of old screws, the equipment manufacturer could gradually establish a package, a trade package and an aircraft-type menu to allow sales to quickly identify general and special conditions, while at the same time placing a truly complex project in a timely manner for evaluation by an application engineer.