YAOAN PLASTIC MACHINERY CO.,LTD

How to Completely Eliminate Internal Voids, Surface Bubbles and Latent Micropores in TPU Thick‑Sheet Extrusion (For Supercritical Foaming Pre‑cursor Sheets)

Key Premise: Any tiny pores in the pre‑cursor sheet will develop into large bubbles, cell rupture, uneven cell distribution and blistering scrap during supercritical autoclave foaming. TPU pre‑cursor sheets must achieve zero internal voids, no entrapped air and no volatile‑induced pores. Pores mainly originate from four sources: moisture / low‑molecular volatiles in raw materials, air entrapment at feeding section, gas entrainment during melt conveying, and gas precipitation upon cooling. Practical process control measures are provided below by process sequence. 1. Raw Material Section: Pores Induced by Moisture Hydrolysis & Volatiles (Most Common Cause) TPU absorbs moisture readily; water generates CO₂ under high temperature and forms bubbles inside melt. Mandatory Drying Specification Polyester TPU: 80～85 ℃, 2.5‑4 h; Polyether TPU: 85～90 ℃, 3‑4 h Target moisture content: ≤300 ppm, preferably controlled within 200 ppm. Prohibitions: Open hopper feeding; drying air shall be dehumidified instead of ordinary hot air; dried pellets shall be conveyed via insulated hoppers to prevent re‑moisture absorption. Re‑grind Material Control Crushed re‑grind edges absorb moisture faster due to larger specific surface area. Re‑grind ratio ≤20%; re‑grind material must be re‑dried. Screen crushed material to remove dust which entrains air. Additives Nucleating agents, talcum powder and color pigments are moisture‑prone; pre‑dry powder additives in advance. 2. Feeding Section: Prevent Air Entrapment from Solid Pellets (Easily Overlooked for Thick‑Sheet Extrusion) Air trapped among loose pellets may be encapsulated by forward‑flowing melt and form elongated internal voids if not vented in time. Adopt forced feeding (loss‑in‑weight feeder preferred) to avoid bridging and pulsating feeding from gravity free‑fall. Keep moderate low temperature at extruder feed zone: Maintain pellets in solid state for compaction; air is forced backward out of hopper by screw compression. Excessively high feed‑zone temperature causes premature melting, seals pellet gaps and traps air inside melt. Match screw feed‑zone channel depth and compression ratio for TPU: Apply moderate compression ratio for gradual compression and reserve sufficient venting window. 3. Extruder Main Unit: Vacuum Degassing System — Eliminate Gases inside Melt (Core Configuration) Drying only removes free water. Low‑molecular oligomers, process‑generated small molecules and residual monomers of TPU can only be removed by vacuum venting. Configuration Requirements At least one vacuum venting zone; dual‑vent configuration for premium lines. Vacuum degree: ≥‑0.095 MPa. Equip vacuum pump with water‑gas separator plus condenser to avoid back‑flow contamination from water vapor and oil mist. Vent port design: Melt shall generate continuous surge flow to renew melt surface for sufficient gas escape. Avoid melt sealing the vent port. Apply deep screw channel at vent section to maintain low melt pressure. Taboo: Excessively high melt pressure at vent zone → gases cannot separate out, latent pores are carried into pre‑cursor sheets. Optimize temperature profile to suppress thermal degradation Small‑molecule gases are generated by over‑heated TPU degradation: Avoid local overheating along barrel zones; melt temperature controlled within 190～220 ℃ (adjust per hardness grade). Adopt low‑shear screw design to reduce shear‑induced temperature rise. Shear overheating is a hidden gas source. 4. Melt Conveying & Die Section: Avoid Secondary Air Entrapment and Pressure Fluctuation Highly polish melt pipelines and die interior without dead corners to prevent degraded gas‑generating stagnant material; perform regular purging. Install static mixer upstream of die Homogenize melt temperature and pressure, eliminate local low‑pressure zones where dissolved gases precipitate into bubbles. Maintain stable and sufficient melt back‑pressure Establish continuous stable back‑pressure throughout extrusion. Severe pressure fluctuation triggers instantaneous local low pressure and precipitates dissolved gas. Avoid excessive back‑pressure which causes shear‑induced thermal degradation. Prevent partial die lip blockage and carbonized build‑up; fallen degraded deposits bring entrapped air. 5. Three‑Roll Calendering Section: Surface Bubbles & Skin Blisters Bubble defects may occur after melt exits die, not only generated inside extruder: Uniform die discharge across full width to avoid air entrapment by turbulent local melt flow. Complete melt lamination onto rolls; no air shall be trapped between melt and roll surface. Adjust die horizontal level, three‑roll gap and haul‑off speed matching. Implement gradient roll temperature: Do not set the first cooling roll too cold. Sudden quenching forms solid skin prematurely and locks internal gases inside sheet as subsurface pores. Apply gradual cooling to provide escape window for internal gases before skin solidification. 6. Practical Troubleshooting Sequence when Pores Occur Verify raw‑material moisture content and confirm drying performance. Inspect vacuum system: vacuum degree, pipeline leakage, melt blockage at vent port. Lower feed‑zone temperature to improve solid conveying and backward venting. Match screw speed and haul‑off speed to stabilize melt pressure. Reduce local over‑heating to mitigate thermal degradation. Optimize three‑roll temperature and lamination condition to eliminate entrapped air. 7. Extra Critical Requirements for Supercritical‑Foaming‑Grade TPU Pre‑cursor Sheets Minor subsurface pores are acceptable for general extrusion, but not for foaming pre‑cursor sheets. Even micron‑scale latent pores act as preferential cell nucleation sites inside autoclave, resulting in uncontrolled foaming ratio, mixed big/small cells and sheet hole defects. On‑line inspection: No visible voids on cross‑section of cut sheets. If available, perform boiling water test: soak pre‑cursor sheet in 90 ℃ hot water for 30 min; no surface blistering indicates no dissolved gas or micro‑pores inside. Shut‑down specification: Purge melt completely for long‑term shutdown to prevent accumulated degraded small molecules inside barrel, otherwise pores persist after restart. 8. Rapid Root‑Cause Identification for Typical Pore Defects Elongated through‑thickness voids: Air entrapment at feeding, insufficient venting Fine dispersed micro‑bubbles: Excessive moisture / insufficient vacuum, volatile precipitation Sporadic irregular large bubbles: Local melt over‑heating and degradation Subsurface skin‑only bubbles: Air entrapment at three‑roll stack, premature skin solidification Periodic intermittent bubbles: Unstable feeding, screw pulsation, intermittent vacuum‑line leakage

YAOAN Achieved Fruitful Results in Chinaplas 2025

CHINAPLAS 2025 has successfully concluded! YAOAN achieved fruitful results with abundant overseas order intentions and in-depth business negotiations during the exhibition. We showcased our newly upgraded PEEK & POM rod extrusion line, which supports high-efficiency mass production with a capacity of producing 58 PEEK rods in one single run. This optimized dual-purpose extrusion equipment features stable molding accuracy, low internal stress, easy screw cleaning and outstanding batch consistency, perfectly meeting the high-volume and high-precision production demands of high-performance engineering plastic rods. In addition, we exhibited our professional PP thin sheet extrusion line. It is designed for ultra-thin sheet production with a processing thickness range of 0.15mm to 0.7mm and a maximum product width of800mm. The equipment delivers uniform thickness, smooth surface and excellent flatness for finished PP sheets, ideal for various flexible packaging and industrial thin sheet applications. During the exhibition, our latest PEEK & POM high-efficiency rod extrusion line (58 rods one run) and 800mm width PP thin sheet extrusion line attracted numerous professional overseas buyers from all over the world. We conducted in-depth technical exchanges and business negotiations with global customers, secured a large number of intentional orders and reached multiple preliminary cooperation agreements. Thanks for all partners’ trust and support! YAOAN keeps focusing on independent R&D and technological innovation, and provides stable, high-efficiency and cost-effective plastic extrusion equipment and one-stop production solutions for global clients.

Unleash the Power of the Horse with YAOAN!

The Year of the Horse is here, and it’s time to accelerate!   At YAOAN, we believe that 2026 is all about momentum. Just as a galloping horse emodies speed and grace, we are committed to moving forward with agility and purpose in the coming year. Whether it's driving innovation, fostering meaningful partnerships, or achieving new milestones--we are ready to run the race. To our amazing clients, partners, and fans: Thank you for being part of our journey. Wishing you a year filled with endless energy, bold achievements, and prosperous days ahead! Events News Cases Contacts Contacts:Mr. Ryan Tan Tel:86-138-25752088         Chat Now Mail Us Send  

YAOAN Plastic Machinery Shined at Chinaplas 2025 with Excellent Medical Extrusion Solutions

Shenzhen, China – Yao An Plastic Machinery Co., Ltd., a leading innovator in plastic processing equipment, was proud to announce its participation in Chinaplas 2025, Asia’s premier international plastics and rubber trade exhibition. The company showcased two groundbreaking technologies: the high-performance PP sheet production line, featuring precision winding for flawless roll formation, and the advanced TPO medical-grade spiral winding tube extrusion system, designed to meet stringent healthcare standards. **Revolutionizing PP Sheet Production** At Booth K23, Hall 8, Yao An highlighted its PP (polypropylene) sheet extrusion line, engineered to deliver exceptional efficiency and consistency. The machine’s standout feature—neat winding technology—ensures tightly wound, uniform rolls of PP sheets, minimizing material waste and maximizing downstream processing efficiency. Ideal for food packaging, industrial materials, and consumer goods, this innovation underscores Yao An’s commitment to precision and sustainability. **Pioneering Medical-Grade TPO Extrusion Solutions** In response to growing global demand for reliable medical equipment, Yao An debuted its TPO (thermoplastic polyolefin) medical spiral winding tube extrusion equipment. This system produces lightweight, durable, and biocompatible tubing critical for respiratory care devices. Engineered for high-speed production without compromising quality, the equipment adheres to medical standards, making it a trusted choice for healthcare manufacturers worldwide. **A Testament to Innovation** "Chinaplas 2025 offered a platform to demonstrate how Yao An integrates technology with industry needs," said Mr. Ho, CEO of Yao An Plastic Machinery. "Our PP sheet line and TPO medical extrusion systems reflect our dedication to solving real-world challenges—whether enhancing production efficiency or supporting global health initiatives." **About Yao An Plastic Machinery Co., Ltd.** With over two decades of expertise, Yao An specializes in designing and manufacturing customized extrusion solutions for packaging, automotive, medical, and industrial sectors. The company’s R&D-driven approach ensures cutting-edge technology, robust aftersales support, and a client-centric philosophy. **Visit Us at Chinaplas 2025**  

Holiday Notice of Chinese New Year 2025

Dear customers: The Chinese New Year is approaching, according to the notice of the General Office of the State Council, and in conjunction with the actual situation of the company, our company's Spring Festival holiday arrangements are as follows: January 21st to February 5th. During the holiday, order production and delivery will be suspended, please plan your order requirements in advance, we apologize for any inconvenience this may cause you. Thank you for your continued cooperation and we wish you a prosperous new year!

Lantern Festival celebrated at Dalang

People perform dragon dance at Dalang Town of Dongguan city, Guangdong Province, Feb. 24, 2024. People across the country celebrated the Lantern Festival on Saturday amid a festive and bustling atmosphere. The theme lanterns incorporate seasonal flowers, showcasing the characteristics of southernChina. Considering that the Lantern Festival falls on a weekend this year, the popularity of lantern-related cultural and tourism activities has soared across the city. People perform Hanfu at Dalang town of Dongguan city In addition to lanternshows, various themed activities are also abundant.Please enjoy the pictures as below:  

Happy Chinese New Year 2024

In the past, people pasted paper cutouts on windows facing south and north before the Spring Festival. Paper cutouts are colored lucky red, with beautiful and exaggerated patterns. They express hopes of a merry and prosperous life, in line with the Spring Festival theme. Spring couplets are paired phrases, typically seven Chinese characters each, written on red paper in black ink, and pasted on each side of a door frame. Sometimes a phrase of four or five characters is affixed to the top of the door frame as well. It's tradition across China to hold a lavish feast to celebrate the New Year. Chinese try very hard to make this family event, often traveling long distances. In Northern China a traditional dish for the feast is jiaozi. They are shaped like old Chinese ingots, symbolizing wealth. Southern Chinese eat niangao (sticky rice cake) on this special day, because niangao sounds like "yearly higher", symbolizing improvement.People set off firecrackers to celebrate the coming of the New Year, as well as to drive away evil. On the first day of the lunar New Year, Chinese wish each other good luck and happiness in the New Year. It is customary for the younger generation to visit their elders and wish them health and longevity. People who are unable to visit their friends or relatives send a WeChat red packet or a text message instead of paying a New Year's call. The red packet is a red envelope with money in it, which ranges from one to a few thousand Chinese yuan. Usually the red packet is given by adults and elderly to young children in New Year days. It was believed money in the red packet would ward off evil spirits and keep children healthy.Digital red packets have gone viral in recent years, and "grabbing red packets" has become an extremely popular game on WeChat.

Canton Fair 2023 comes to live again

Well-known as the Canton Fair, China Import and Export Fair has been held biannually in Guangzhou every spring and autumn since 1957. Regarded as the largest scale, the highest level, Canton Fair presents the most comprehensive exhibition covering the widest range of industries and sectors, as well as the richest products and commodities. The Canton Fair likes a golden business bridge, linking insightful overseas buyers with high-quality domestic exhibitors. During the past three years, the Canton Fair was severely impacted by the COVID-19 and had to hold only on "cloud". This year, free from the impact of COVID-19, Canton Fair 2023 YAOAN, one of the best plastic machinery manufacturer in China, will attend Canton Fair 2023, the first phase. Our booth number: 18.1 D01-02 We will bring our plastic sheet extrusion machine to attend this fair. Show time: 15 to 19, April, 2023