{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,24]],"date-time":"2026-04-24T14:40:33Z","timestamp":1777041633823,"version":"3.51.4"},"reference-count":14,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2026,4,24]],"date-time":"2026-04-24T00:00:00Z","timestamp":1776988800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Smart Grid-National Science and Technology Major Project","award":["2024ZD0802403"],"award-info":[{"award-number":["2024ZD0802403"]}]},{"name":"Postdoctoral Fellowship Program (Grade C) of China Postdoctoral Science Foundation","award":["GZC20250329"],"award-info":[{"award-number":["GZC20250329"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Materials"],"abstract":"<jats:p>In ultra-high-voltage GIS and GIL systems, epoxy resin insulators are still the mainstream choice. However, as a thermosetting material, epoxy resin is difficult to recycle after disposal, which limits its environmental benefits. Thermoplastic insulators, due to their recyclability, are potential alternatives. This study focuses on 30% glass fiber-reinforced PET and PA6 materials. Their injection molding behavior, hydraulic pressure performance, and insulation performance were systematically analyzed using Moldflow, ANSYS, and COMSOL, respectively. For injection molding, Moldflow simulations were conducted for filling, packing, and cooling stages. Melt temperature was varied from 260 to \u2013310 \u00b0C (PET) and 250\u2013300 \u00b0C (PA6), while mold temperature was varied from 80 to \u2013130 \u00b0C (PET) and 70\u2013120 \u00b0C (PA6). An optimization objective function, Y = \u0394p\/20 + \u0394x\/0.5 + \u0394s\/1.8, was developed to determine optimal processing parameters. Based on this function, the optimal parameters identified are: PET at 290 \u00b0C melt temperature and 120 \u00b0C mold temperature; PA6 at 250 \u00b0C melt temperature and 70 \u00b0C mold temperature. For hydraulic testing, Moldflow\u2013ANSYS coupled simulations were performed under 2.4 MPa pressure with the compliance criteria of bulk stress &lt; 90 MPa and insert-contact stress &lt; 20 MPa. PA6 passed within a processing window of melt temperature &lt; 270 \u00b0C and mold temperature &lt; 120 \u00b0C. PET failed under all tested conditions, with insert-contact stress ranging from 24.25 to 27.55 MPa, consistently exceeding the 20 MPa threshold. In terms of insulation performance, this paper utilizes COMSOL to study the electric field distribution of thermoplastic insulators in SF6 GIS\/GIL and provides optimization suggestions for insulator geometry design. This study systematically compares the injection molding processes and hydraulic pressure performance of PET and PA6 thermoplastic insulators. These results provide important process insights and design guidance for evaluating thermoplastic materials as potential alternatives to epoxy resin in GIS\/GIL applications.<\/jats:p>","DOI":"10.3390\/ma19091729","type":"journal-article","created":{"date-parts":[[2026,4,24]],"date-time":"2026-04-24T12:29:11Z","timestamp":1777033751000},"page":"1729","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Comparative Study on Injection Molding and Performance of Glass Fiber-Reinforced PET and PA6 Thermoplastic Insulators"],"prefix":"10.3390","volume":"19","author":[{"given":"Yao","family":"Wang","sequence":"first","affiliation":[{"name":"Tai\u2019an Taishan High Voltage Switchgear Co., Ltd., No. 50 Boyang Road, Taishan District, Tai\u2019an 271000, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yuliang","family":"Fu","sequence":"additional","affiliation":[{"name":"Department of Electrical Engineering, Tsinghua University, Beijing 100084, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0009-0007-6078-0191","authenticated-orcid":false,"given":"Xiaofei","family":"Chen","sequence":"additional","affiliation":[{"name":"Department of Mechanical and Electrical Engineering, Beijing Information Science and Technology University, Beijing 100192, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Zehao","family":"Zhang","sequence":"additional","affiliation":[{"name":"Department of Electrical Engineering, Tsinghua University, Beijing 100084, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0890-2220","authenticated-orcid":false,"given":"Weiqi","family":"Qin","sequence":"additional","affiliation":[{"name":"Department of Electrical Engineering, Tsinghua University, Beijing 100084, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2026,4,24]]},"reference":[{"key":"ref_1","unstructured":"Zhiyan Consulting (2026, March 26). Analysis of the Current Situation and Competitive Landscape of China\u2019s Ultra-High Voltage Insulator Industry in 2023. 2023. Available online: https:\/\/www.chyxx.com\/industry\/1161612.html."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"607","DOI":"10.1049\/hve2.12243","article-title":"Advanced insulating materials contributing to \u201ccarbon neutrality\u201d: Opportunities, issues and challenges","volume":"7","author":"Li","year":"2022","journal-title":"High Volt."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"518","DOI":"10.1109\/TDEI.2023.3235699","article-title":"Eco-Friendly Thermoplastic Alternatives to Epoxy Resin for Support Insulators","volume":"30","author":"Zhang","year":"2023","journal-title":"IEEE Trans. Dielectr. Electr. Insul."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1280","DOI":"10.1109\/TDEI.2020.008724","article-title":"Pultruded thermoplastic composites for high voltage insulator applications","volume":"27","author":"Volk","year":"2020","journal-title":"IEEE Trans. Dielectr. Electr. Insul."},{"key":"ref_5","unstructured":"Bessede, J., Huet, I., Kieffel, Y., Aeshbach, H., Braeuer, F., Pohlink, K., Dahoun, A., Etienne, S., and Hiver, J. (2005). Annual Report Conference on Electrical Insulation and Dielectric Phenomena, National Academy of Sciences-National Research Council."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"415501","DOI":"10.1088\/1361-6463\/ace455","article-title":"Glass fiber network reinforced polyethylene terephthalate composites for support insulators","volume":"56","author":"Liang","year":"2023","journal-title":"J. Phys. D Appl. Phys."},{"key":"ref_7","unstructured":"Liu, S.Z. (2013). Research on Molding Process of Thick-Walled Injection Molded Products, Qingdao Technological University."},{"key":"ref_8","first-page":"113","article-title":"Effect of cooling rate on shrinkage and sink mark formation of HDPE thick-walled products","volume":"39","author":"Chen","year":"2010","journal-title":"Plastics"},{"key":"ref_9","unstructured":"ALBIS (2026, March 26). Material Datasheet Ultramid B3EG6. Available online: https:\/\/www.albis.com\/de\/products\/download\/doc\/zh\/SI\/basf\/UltramidB3EG6.pdf."},{"key":"ref_10","unstructured":"BASF (2026, March 26). Product Information Petra 130 BK 112. Available online: https:\/\/pmtools-na.basf.com\/products\/dspdf.php?type=iso&param=Petra+130+BK112&autospec=1."},{"key":"ref_11","first-page":"1740","article-title":"Compact design of 550 kV basin-type spacer in gas insulated switchgear (Part I) Structure optimization","volume":"37","author":"Wang","year":"2022","journal-title":"Trans. China Electrotech. Soc."},{"key":"ref_12","first-page":"9","article-title":"Regulation of electric field distribution in GIS\/GIL basin insulators based on comprehensive optimization of geometric shape\/dielectric distribution","volume":"40","author":"Wang","year":"2020","journal-title":"Proc. CSEE"},{"key":"ref_13","first-page":"69","article-title":"Design and research on operational reliability of UHV DC GIL","volume":"60","author":"Li","year":"2024","journal-title":"High Volt. Appar."},{"key":"ref_14","unstructured":"Li, B. (2015). SF6 High Voltage Equipment Design, China Machine Press. [4th ed.]."}],"container-title":["Materials"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1996-1944\/19\/9\/1729\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,4,24]],"date-time":"2026-04-24T12:38:18Z","timestamp":1777034298000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1996-1944\/19\/9\/1729"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,4,24]]},"references-count":14,"journal-issue":{"issue":"9","published-online":{"date-parts":[[2026,5]]}},"alternative-id":["ma19091729"],"URL":"https:\/\/doi.org\/10.3390\/ma19091729","relation":{},"ISSN":["1996-1944"],"issn-type":[{"value":"1996-1944","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,4,24]]}}}