HiSiaddi is an innovative foreign trade service provider driven by dual engines of technology transformation and foreign trade services, with a "1+2+3+4=1" service system and access to PPS raw materials from multiple well-known original manufacturers. As a technology R&D-focused foreign trade enterprise, HiSiaddi has repeatedly proposed PPS formula optimization schemes and application improvement recommendations through technological transformation cooperation with manufacturers and precise market demand insight. Below is a consulting case of HiSiaddi on PPS formula optimization.
For inquiries about formula optimization consulting services, please contact HiSiaddi customer service.
HiSiaddi systematically resolved mass production technical defects covering formula optimization, granulation processes, and end injection molding
The cooperating partner, Nippon Auto Parts Co., Ltd., is located in the Toyota supporting industrial park in Aichi Prefecture, Japan. It is a top Japanese Tier 1 auto parts manufacturer supplying new energy vehicle electronic control connectors, vehicle sensor housings, and power battery insulation brackets to Honda, Denso, and Sumitomo Electric. Its products comply with Japan’s JIS K7194 plastic standard, IEC62477 vehicle electrical specifications, UL flame retardancy, and RoHS environmental control standards. The company’s stable annual procurement volume of modified PPS reaches 290 tons, with long-term fixed sourcing of modified PPS pellets from Toray and Kureha Chemical (Japan).
Due to equipment maintenance at PPS facilities in Japan and South Korea, consecutive surges in raw material prices, and extended lead times of up to 105 days for customized grades from overseas manufacturers, the enterprise launched a localized replacement project for Chinese PPS. After preliminary sample screening, two well-known domestic PPS modification manufacturers were selected, with an initial bulk purchase of 55 tons of two modified PPS grades: 40% glass fiber reinforced PPS for connectors and mineral-filled low-warpage PPS for sensor housings.
After ocean shipment to Japan and warehousing, the client’s two automated precision injection molding lines suffered successive batches of defective products: out-of-tolerance pin hole dimensions on connectors, shell warpage, dense inner wall voids on sensor housings, and exposed glass fiber blooming. The injection molding yield plummeted from 97.5% with original Japanese materials to 51.3%, triggering intermittent shutdowns of multiple automated production lines and massive semi-finished product scrapping. Downstream new Honda auto parts orders faced risks of delay compensation.
The client immediately contacted technical staff from the two domestic suppliers, who could only slightly adjust auxiliary agent proportions based on existing formulas without root rectification of PPS base resin and modification blending processes. Focused on mass production of general industrial products, the factories were unwilling to invest in technical transformation for targeted formula optimization.
Upon recommendation by the Japan Chemical Materials Association, Nippon Auto Parts formally entrusted Shanghai HiSiaddi Technology (HiSiaddi) as a third-party technical foreign trade service provider. Leveraging HiSiaddi’s team of engineering plastic R&D engineers, the team conducted on-site sampling and testing, traced raw material defects, optimized resin formulas and modified granulation processes, and simultaneously assisted Japanese clients in adjusting end injection molding processing parameters to systematically eradicate mass production failures and realize stable mass production replacement with domestic PPS.
Product information: Glass fiber reinforced and mineral-filled modified PPS pellets, HS code 3907999000, export packaging with 25kg moisture-proof laminated kraft paper bags.
The domestic raw material adopted low-cost cross-linked PPS base material with insufficient resin cyclization rate. The content of low-molecular-weight thioether oligomers and residual sulfur salt impurities reached 360ppm, far exceeding Toray’s internal control standard of 80ppm. When raw materials melt at high temperatures during injection molding, small molecules volatilize to form water vapor and gas trapped inside products, creating enclosed voids – the primary inducement of void defects on sensor housings. Meanwhile, the resin’s excessively broad molecular weight distribution leads to wide fluctuation of melt viscosity, resulting in inconsistent melt filling speed under identical injection molding parameters and directly causing out-of-tolerance connector hole sizes.
1. Glass fiber reinforced grade: Alkali-free glass fibers lacked pre-treatment via silane coupling activation. All glass fibers were fed in one concentrated batch through the twin screw, leading to uneven shear dispersion inside the screw, localized agglomeration, and partial glass fiber exposure on product surfaces (glass fiber blooming), impairing connector sealing precision. The formula adopted cheap general-purpose antioxidants that decomposed under long-term 150°C vehicle operating conditions, reducing the product’s thermal aging resistance.
2. Mineral-filled grade: Excessive moisture content in wollastonite and talc powder, paired with imbalanced compound lubricant ratios, left residual internal stress inside modified materials. Stress release under repeated temperature changes caused excessive product warpage, failing to meet dimensional tolerance requirements for precision sensor housings.
The client’s complete injection molding equipment temperature control, screw speed, injection pressure, and mold cooling parameters were calibrated based on the rheological properties of Toray PPS. Domestic modified PPS exhibits obvious differences in melting temperature, crystallization rate, and melt fluidity compared with imported materials, and the original process parameters failed to adapt to the new raw materials, further amplifying defects including warpage, voids, and dimensional deviations. Repeated fine-tuning of injection temperature and cooling time by Japanese process engineers only slightly improved reject rates without permanent root-cause resolution.
After full-parameter testing via third-party thermogravimetry, liquid chromatography, and rheometers, HiSiaddi’s material engineers finalized the rectification plan:
1. Replace base materials: All low-cost cross-linked PPS was replaced with high-cyclization-rate linear high-purity PPS resin. The team collaborated with upstream synthesis factories to optimize polymerization cyclization processes and add a post-vacuum devolatilization step, reducing low-molecular-weight oligomer content from 360ppm to 78ppm and fundamentally eliminating void defects caused by gas precipitation at high temperatures.
2. Refined adjustment of modified formulas:
o Glass fiber reinforced grade: General cheap hindered phenol antioxidants were replaced with a composite high-temperature resistant antioxidant system, paired with amino silane pre-activated electronic-grade alkali-free glass fibers to adapt to long-term high-temperature vehicle service environments.
o Mineral-filled grade: Optimized the ratio of wollastonite to ultrafine talc powder and precisely fine-tuned internal and external lubricant addition ratios to reduce internal molding stress and mitigate warpage under temperature cycling.
Two gradient trial batches (50kg and 300kg) were produced successively and shipped to Japanese laboratories for physical property verification.
HiSiaddi guided partner modification factories to deploy an independent dedicated modification production line isolated from general material production to avoid cross-contamination, and optimized the complete twin-screw production process:
1. Restructured main and side segmented feeding architecture: Resin was fed through the main feeder, while glass fibers and mineral fillers were uniformly added through multiple side feeders to boost uniform filler dispersion within the resin matrix and eliminate filler agglomeration and glass fiber blooming.
2. Rezoned screw temperature control: feeding section 270°C, melting section 288°C, homogenization section 295°C, die head 290°C. A medium-low speed gentle shear process was adopted to reduce glass fiber shear fracture.
3. A low-temperature hot air circulation drying process was added post-granulation to strictly control pellet moisture content below 0.015%, avoiding voids generated by water vaporization at high temperatures.
HiSiaddi compiled Chinese-Japanese bilingual process guidance manuals and remotely assisted Japanese process engineers in optimizing injection molding parameters separately for the two grades:
1. Glass fiber reinforced connector material: Overall barrel temperature reduced by 4~6°C, mold temperature raised from 130°C to 145°C, injection speed slowed, holding time extended, and mold water circuits optimized to improve cooling uniformity, stabilizing filling consistency and controlling aperture dimensional tolerance.
2. Mineral-filled sensor housing material: Moderately reduced screw speed and extended in-mold cooling time for products to slowly release internal molding stress and mitigate housing warpage deformation.
72-hour continuous small-batch prototype production verified all dimensional and appearance indicators of connectors and sensor housings fully met standards.
1. Fixed-source supply chain control: HiSiaddi locked fixed suppliers of linear high-purity PPS resin. Glass fibers, mineral fillers, and antioxidants all adopted equivalent Japanese-compliant raw materials, with exclusive grades PPS-JP-GF40 and PPS-JP-MF35 designated separately for the client. Each batch came with full DSC, rheology, and ash content COA testing, establishing a full-batch traceability ledger. After optimization, the unit purchase price decreased by 25.8% compared with Toray’s original materials, and delivery lead time was shortened from 105 days to 38 days.
2. Compliance support: HiSiaddi completed REACH pre-registration, SVHC screening, and Japan METI Chemical Substance Control Act notification for the two PPS grades. Japanese-English bilingual SDS safety data sheets were compiled in compliance with Japan’s JIS and CLP standards. Moisture-proof anti-static export packaging was optimized with printed GHS compliant labels. Domestic customs declaration pre-review and Nagoya Port clearance document filing in Japan were completed in advance to guarantee smooth export and subsequent cargo delivery.
The remaining 49 tons of original inventory PPS were sent back to the factory in batches for formula and process rectification, then shipped in two batches to Nagoya, Japan. After rectified raw materials were put into mass production, the yield of the two core injection molding lines rebounded to 97.2%, restoring full-load production capacity. The client successfully delivered Honda supporting component orders on schedule, reducing losses from scrapping and production shutdowns equivalent to over 14.8 million Japanese yen. Third-party laboratory testing by the client confirmed that the optimized domestic PPS comprehensive performance matched Toray’s equivalent specifications, satisfying all access standards for Japanese vehicle components.
In Q4 2025, Nippon Auto Parts Co., Ltd. signed an annual framework procurement agreement with HiSiaddi, locking in an annual customized PPS procurement volume of 275 tons with sustained adoption of the optimized two-grade formula. Building on mature technical cooperation, the client raised new R&D demand for hydrolysis-resistant modified PPS for power battery insulation housings, entrusting HiSiaddi to coordinate upstream factories for formula development and sample production.
Backed by this benchmark rectification case for a leading Japanese auto parts enterprise, HiSiaddi leveraged the client’s industry resources to successively connect with two Korean Tier 1 component manufacturers supporting Hyundai and Kia. The full-chain technical service model of "raw material formula optimization + modification process rectification + end process guidance" was replicated, delivering multiple batches of PPS samples and mass production orders and consolidating HiSiaddi’s technical service advantages in the East Asian vehicle modified PPS foreign trade track.
The core conflict in this case lies in domestic modified PPS manufacturers’ habitual mass production of standardized products using low-cost base materials and general auxiliary agents, lacking capabilities for refined formula and modification process optimization targeting precision Japanese vehicle components. Objective performance gaps exist between domestic raw materials and imported counterparts, compounded by the client’s retention of original factory-matched injection molding processes. Multiple overlapping factors triggered mass production rejects.
Breaking away from the traditional foreign trade model limited to raw material intermediation, HiSiaddi conducted end-to-end troubleshooting and rectification covering four dimensions: resin base material, modified formula, granulation production, and client-side injection molding. It resolved the urgent crisis of production line shutdown and order breach for the client and locked in high-end Japanese end clients through technical services. Amid intensified global supply chain volatility for vehicle engineering plastics and tightening automotive material regulations worldwide, empowering foreign trade with technical services represents the core path to break through low-price competition and cultivate high-end overseas clients.
For inquiries about formula optimization consulting services, please contact HiSiaddi customer service.
+86-13120989737 
info@hisiaddi.com 
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