When the project involves a multi-module shared platform, the screw programme must start from the customer ' s real production mission. Note plastics programme engineers are required to organize the minimum and maximum product weights covered and the different material windows into a set of verifiable, calculable and retroactive input conditions.

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.

Technical communication distinguishes between three types of objectives that must be met, desired improvement and acceptable. It is necessary to meet the hard boundary of the item for the determination of equipment and screws, and it is hoped that the improvement item will be used for the comparison of standards and specialized programmes, while the acceptable item will help to control costs and deadlines. This would avoid stacking all requirements on a screw and would make it easier for clients to understand the real value of each configuration. The focus of the discussion here is on the minimum and maximum product weights and the different material windows, which must correspond to the customer ' s current production conditions and cannot be based solely on the maximum values in machine samples.

In the context of this project, the idea of “building a matrix of moulds and finding common process windows” is proposed. 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 formula is able to cover the window, priority should be given to the standard configuration; the risk of long stays for minor products if only the maximum model option remains, with a dedicated structure and an indication of increased costs, delivery periods and expected benefits.

Special vigilance is needed to allow for the long stay of minor products only on the basis of the maximum mould. Many of the post-sale disputes arise from inconsistencies between the design input and the actual production conditions, such as the customer ' s replacement of the raw material number, the increase in the return rate or the transfer of the screw to another set of moulds, while still requiring the maintenance of the original acceptance results. The configuration of the boundary and change management should therefore be included in the technical document.

It is recommended that the client set clear upper and lower limits around the use of the voltage and the time of the switch, rather than simply " running properly". Quantification criteria may include measurement of time fluctuations, extremely poor product weights, number of black dots, change time, hourly production or ton wear and tear, with specific projects choosing indicators that really affect business outcomes. 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. Clearing up these three issues would make it possible to move from a spare parts trade to a traceability technology project.