In response to amplification, clients often ask first for price or term, but the retrofitter should first check the size of the drum, system pressure, de-pumping, heating and molding needs. Only by quantifying these conditions can the standard screws have an interpretable boundary with the choice of a dedicated screw.

Old machine upgrades are the easiest to ignore system matching. New screws must be compatible with the needs of old drums, drives, brakes, heating, nozzles, control of travel and molds. Any build-up, speed-up or material upgrade should first measure the status quo, then determine whether the single replacement, plasticization component upgrade or the full retrojection of the unit. 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 discussion in this paper is on the size of drums, system pressure, de-pumping, heating and mold requirements, which must correspond to the customer ' s current production conditions and not be limited to the maximum values in machine samples.

The feasibility assessment of the full set of reductive units may be used as the main line in the project advance, and an evaluation of the sale, design, process and customer participation may be arranged. The evaluation focused on the completeness of the input data, whether the assumptions were confirmed by the client, whether the mechanical interfaces were matched, how standards and specialized programmes were selected, and who provided the acceptance data.

The main risk to the scene is that expanding the diameter reduces pressure and may exceed mechanical space. 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.

At the time of acceptance, it is recommended that the primary indicator be capacity, pressure and mechanical safety residuals, and that the temperature, screw velocity, back pressure, measurement position, buffer position, injection peak pressure and continuous sample weight be simultaneously recorded in the drums. At least three reasonable process points, low, medium and high, are covered to confirm that the programme is not effective under a single parameter. The sales proposal should answer three questions at the same time: why this selection was made, which conditions had changed and which were re-selected, and how the customer validated the results. By making these three issues clear, the replicability can move from a trade in spare parts to a traceability technology project.