近幾年來氣體輔助射出成型技術,已被射出成型業界所認同,而廣為應用,隨著技術的成熟應用層面也相對越廣,對於準確性,穩定性及操作性的要求也隨之提高,本論文針對業界之需求,發展並尋找最佳的控制方式oPLC使用在氣體射出系統的穩定性具備自我偵測能力,故障率低,操作容易及設備成本較低等優點,而PC具備強大的運算能力,擴充性強及結合上層管理系統等優勢o本論文分別使用PLC控制方式,PC控制方式以及結合PC與PLC實際應用在氣體輔助射出系統及成型o本論文中也對Cinpres,Airmold及本實驗室研發的GPRIS做穩定性及重複性的測試,比較在高壓及低壓下的反應特性o在壓力誤差方面,以Airmold系統最佳;本系統在不同的比例範圍有不同的誤差量,誤差約0-5bar;而Cinpres系統誤差最大,此乃導因於其系統利用體積控制方法受限於增壓氣流量與外洩狀況所影響,相對於Airmold及Cinpress系統o本實驗室研發的GPRIS可以提供最完整之即時動態監控功能,誤差之部份則是受限於氣壓閥體本身功能特性oGPRIS系統在應用時可提供使用者最精確之成型條件數據,在PC與PLC系統方面,PC部份負責資料參數及回饋訊號監控,而PLC負責現場操作控制閥體,此種方式使得各控制機體能各司其職,可以達到最佳化與多元化的控制o

Gas-assisted injection molding(GAIM) process,being an innovative injection molding process,has recently become a popular technology in the thermoplasticinjection molding industry.As the technology becomes maturely and widelyapplies,the requirements of accuracy,repeatability and setability of the process are necessary.The paper proposed a suitable control to fulfill such requirements and may be helpful in designing practicable application.PLC(Programmable Logic Controller) has the advantages of easy operating,self-detecting,high reliability and low cost.PC(Personal Computer) has the advantages of high calculating speed,extensive I/O and easy communicating with the management system.The paper first applies both PLC and PC individually to control an injection molding unit.In order to obtain optional solutions,PLC and PC are grouped together.PLC is used as a controller responsible for the data analysis and calculation.A laboratory designed gas injection unit GPRIS has been tested under the proposed control strategies to study the stability and repeatability of gas pressure response performances.The results are compared with two other commerical units,Airmold and Cinpres.It is found that the GPRIS has excellent performances of gas pressure response.