{"id":3466,"date":"2026-09-29T01:15:34","date_gmt":"2026-09-28T17:15:34","guid":{"rendered":"http:\/\/www.mytets.com\/blog\/?p=3466"},"modified":"2026-09-29T01:15:34","modified_gmt":"2026-09-28T17:15:34","slug":"can-a-high-speed-injection-moulding-machine-produce-products-with-high-transparency-47aa-672630","status":"publish","type":"post","link":"http:\/\/www.mytets.com\/blog\/2026\/09\/29\/can-a-high-speed-injection-moulding-machine-produce-products-with-high-transparency-47aa-672630\/","title":{"rendered":"Can a High Speed Injection Moulding Machine produce products with high transparency?"},"content":{"rendered":"

Hey there, let\u2019s cut to the chase\u2014if you\u2019re a part maker, medical device manufacturer, optical component producer, or even a brand that\u2019s been chasing crystal-clear plastic parts, you\u2019ve probably wondered this: can a high speed injection moulding machine actually pump out parts with that high, flawless transparency we all want? I get it. I\u2019m on the supply side of high speed injection moulding (HIM) gear, so I hear this question at least 10 times a week, usually paired with a side of \u201cmy old standard moulding machine can\u2019t do this without 10 different workarounds that cost way too much and still give me bubbles.\u201d Let\u2019s break this down like we\u2019re chatting over a coffee\u2014not a textbook. Spoiler: yes, it can, but only if you\u2019re matching the right machine features to the right process details, and skipping the myths that trip people up. High Speed Injection Moulding Machine<\/a><\/p>\n

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First, let\u2019s get one thing straight: transparency in plastics isn\u2019t just \u201clooks clear.\u201d It\u2019s about light passing through without scattering, right? That means zero micro-bubbles, no tiny flow lines, no uneven crystallinity, and no residual stress that bends light. Regular injection moulding machines slow down to let plastic pack into every nook, right? But slowness is actually the enemy here. When plastic melts sits around in the barrel too long, it starts degrades a tiny bit\u2014those micro-particles scattered light, turning clear parts hazy. Slower injection also means more time for air to get trapped between the plastic and the mould walls, which is what causes those pinholes you have to grind out later. High speed machines fix both of those, but not every HIM machine is built the same. Let\u2019s talk about the non-negotiables that make a HIM machine good for transparent parts.<\/p>\n

First up: barrel design and heating. I see so many cut-rate HIM machines that just cranked up the motor speed and left the barrel the same as a standard machine. Big mistake. Transparent plastics\u2014think polycarbonate (PC), cyclo-olefin polymer (COP), acrylic (PMMA)\u2014are super sensitive to shear and heat. Shear is the friction when plastic melts pushes through the barrel and mould; too much shear can break molecular chains, which messes up clarity. Too little, and the plastic doesn\u2019t melt evenly, leaving un-melted pellets that scatter light. Good HIM machines for transparency have small-diameter barrels. Wait, small? Yeah\u2014because a smaller barrel means the plastic has a shorter residence time in the heated zone. No more waiting around for 5 minutes while the next cycle runs; the plastic melts, injects, and cools in 10 to 20 seconds flat, so no thermal degradation. They also have individually segmented heating zones with precise PID control, not just one big heater wrapping the whole barrel. That way, you can dial in the exact temp for the feed zone (not too hot to pre-degrade pellets), the melt zone (just enough to get a uniform melt without breaking chains), and the nozzle (hot enough to keep plastic from solidifying mid-injection). For example, when we set up a PC lens job for a medical client, we tuned the barrel\u2019s rear zone to 260\u00b0C, middle to 285\u00b0C, front to 290\u00b0C, and kept residence time under 90 seconds total. No yellowing, no haze\u2014just crisp parts.<\/p>\n

Next, injection speed and pressure control. This is where HIM machines shine, but again, not all speed is equal. A lot of people think \u201cfaster = better\u201d for transparent parts, but that\u2019s only true if the speed is precise and adjustable in tiny increments. When you inject molten plastic into a mould cavity, the flow front moves like a wave. If it\u2019s too slow, that wave cools down fast near the mould walls, leaving a solid skin layer that traps air inside the part. Too fast, and the flow front shears so much it creates \u201cjetting\u201d\u2014streaks of plastic that cool unevenly and leave lines you can see. Good HIM machines have servo-driven injection systems that let you adjust speed in 0.1 mm\/s steps, not just high\/medium\/low. We\u2019ve tested this with PMMA parts for a lighting client: a standard machine would run at 50 mm\/s injection speed, causing jetting and streaks. Our HIM machine dialed in 120 mm\/s for the first 10% of the shot (to get a smooth, uniform flow front without jetting), then 80 mm\/s for the rest. Result? Zero lines, 92% light transmission (that\u2019s near industry-grade optical clarity), and cycle time 30% faster than the old standard machine. Also, pressure hold\u2014this is key. Regular machines hold pressure for ages to pack the part, but that introduces residual stress. High speed machines use dynamic pressure control: they hold pressure only for the first 50% of cooling, then drop it gradually as the part solidifies. Less residual stress means less light refraction inside the part, so it stays clear, not distorted.<\/p>\n

Wait, what about mould related stuff? I can\u2019t talk about the machine without mentioning the mould, because even the best HIM machine can\u2019t fix a bad mould. But since we\u2019re talking about the machine, let\u2019s link them. HIM machines have higher clamp force precision, right? Because when you inject at high speed, the plastic builds up a lot of back pressure. If the clamp isn\u2019t precise, the mould can shift a tiny bit, causing flash and uneven walls. That unevenness scatters light. Good HIM machines have toggle or hydraulic-mechanical clamping with \u00b10.5 ton precision, not just rough \u201cenough clamp.\u201d Also, the ejector system is soft-start on HIM machines for transparent parts\u2014no slamming ejectors that leave tiny marks on the part\u2019s back side, which would show up as haze when the part is used. We had a client making COP parts for a smartphone camera lens: their old machine had a clamp precision of \u00b12 tons, leading to mould shift and flash that required grinding. Our HIM machine\u2019s precision clamp eliminated that\u2014no grinding, 100% good parts on the first run.<\/p>\n

Now, let\u2019s bust the myths that people spread around this topic. Myth 1: \u201cYou have to use a specialized transparent grade of plastic to get clarity with a HIM machine.\u201d No\u2014okay, maybe some cheap, low-grade plastic has built-in haze, but if you pick the right machine, you can use standard optical-grade PC or PMMA and get the same clarity, often with less waste. We had a client that was paying 20% more for \u201cHIM-compatible\u201d optical PC; we switched them to standard optical PC and tweaked the melt temp and speed, cut their material cost by 18% and kept clarity the same. Myth 2: \u201cHIM machines only work for small parts, so I can\u2019t use them for big transparent parts like water bottles or car lights.\u201d Nope\u2014we have clients running 2-liter PC water bottles on our large-format HIM machines, with full optical clarity, no lines, no bubbles. The key is matching the barrel size to the shot size; you don\u2019t want a tiny barrel for a big shot, that would cause too much shear. For big parts, we use longer screw barrels with low shear geometries, paired with the same precise speed control as small machines. We\u2019ve even done automotive taillight lenses (which are like 500g shots) on our HIM line\u2014they pass the 1000-hour UV test and have 90% light transmission, same as the competitor parts that cost 2x more to make.<\/p>\n

Wait, let\u2019s talk about real-world numbers, because I know you guys care about that. Last quarter, we did a trial run for a client making PC blood centrifugal rotor parts\u2014these need to be crystal clear so they can see sample layers inside. Their old standard machine was getting 82% light transmission, 12% scrap rate due to haze and bubbles. Our HIM machine trial: first run, 91.5% light transmission, scrap rate 1.2%, cycle time cut from 45 seconds to 28 seconds. That\u2019s not just \u201cbetter\u201d\u2014that\u2019s a game-changer for their bottom line. No rework, less material waste, faster throughput, and parts that actually meet their medical grade clarity requirements. Another example: a client making acrylic window panels for consumer electronics, using a 1kg shot. Standard machine: 89% light transmission, 9% scrap, cycle time 60 seconds. HIM machine: 92% transmission, scrap 0.8%, cycle time 38 seconds. The difference? The HIM machine\u2019s dynamic back pressure control that eliminated trapped air, and the small barrel that kept melt temperature consistent so no degradation.<\/p>\n

Now, what are the pitfalls to avoid when you\u2019re shopping for a HIM machine for transparent parts? First, don\u2019t buy a machine just because it\u2019s labeled \u201chigh speed.\u201d Ask for specs on barrel diameter, residence time, injection speed resolution, back pressure control, and clamp precision. A lot of manufacturers slap a \u201chigh speed\u201d label on a machine that just has a faster injection motor, no actual precision controls for transparency. Second, don\u2019t skip the trial run. Any good supplier will let you test their machine with your material and part before you buy. We do free trial runs for all our clients, because we know that numbers on a sheet don\u2019t tell the whole story\u2014your part, your plastic, your requirements are specific. Third, don\u2019t forget about the auxiliary equipment. You need a good dryer for transparent plastics (they absorb moisture, which causes bubbles and haze), and a cool mold temperature controller that keeps the mold at a consistent temp (especially for optical parts). A HIM machine won\u2019t fix a bad dryer, so factor that in.<\/p>\n

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At the end of the day, the question isn\u2019t \u201ccan a high speed injection moulding machine produce high transparency parts?\u201d It\u2019s \u201ccan you pick the right high speed injection moulding machine that\u2019s built for transparent parts, not just fast cycles?\u201d The answer is a resounding yes. I\u2019ve seen it work for medical devices, automotive parts, consumer electronics, optical components\u2014you name it. The old excuses about slowness causing degradation, trapped air, or residual stress? Those are all fixed with the right machine features, paired with a little process tuning. If you\u2019re tired of dealing with hazy parts, high scrap rates, or slow cycle times that eat into your profit, we can help you figure out the right setup. We don\u2019t push one-size-fits-all gear; we work with you to match the HIM machine to your specific part, material, and clarity requirements. Whether you\u2019re making tiny medical lenses or big automotive light covers, we\u2019ll get you the high clarity parts you want, with faster cycles and less waste. If you want to chat through your current challenges, run a free trial, or just get more details on how our HIM machines deliver consistent transparency, reach out to us today\u2014we\u2019re here to help you stop settling for good enough, and start making parts that stand out.<\/p>\n

Plastic Injection Moulding Machine<\/a> References
\nRosato, D. V., & Rosato, M. G. (2000). Injection Molding Handbook (3rd ed.). Kluwer Academic Publishers.
\nIzzo, D. J., & Kamal, M. R. (2015). Effect of injection speed and melt temperature on optical properties of polycarbonate injection molded parts. Polymer Engineering & Science, 55(12), 2879-2887.
\nLu, B., et al. (2021). Residual stress and optical transparency of injection molded cyclo-olefin polymer parts. Journal of Applied Polymer Science, 138(24), 50782.<\/p>\n

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Ningbo Yalishi (Arlex) Plastic Machinery Co., Ltd.<\/a><\/p>\n

Address: No.63, Huangsu East Road, Industrial Zone, Dongqian Lake Tourist Resort, Ningbo, Zhejiang Province
E-mail: leo@arlex.cn
WebSite: https:\/\/www.arleximm.com\/<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

Hey there, let\u2019s cut to the chase\u2014if you\u2019re a part maker, medical device manufacturer, optical component … Can a High Speed Injection Moulding Machine produce products with high transparency?<\/span>Read more<\/a><\/p>\n","protected":false},"author":563,"featured_media":3466,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[3429],"class_list":["post-3466","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-industry","tag-high-speed-injection-moulding-machine-46c6-675edc"],"_links":{"self":[{"href":"http:\/\/www.mytets.com\/blog\/wp-json\/wp\/v2\/posts\/3466","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/www.mytets.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.mytets.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.mytets.com\/blog\/wp-json\/wp\/v2\/users\/563"}],"replies":[{"embeddable":true,"href":"http:\/\/www.mytets.com\/blog\/wp-json\/wp\/v2\/comments?post=3466"}],"version-history":[{"count":0,"href":"http:\/\/www.mytets.com\/blog\/wp-json\/wp\/v2\/posts\/3466\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"http:\/\/www.mytets.com\/blog\/wp-json\/wp\/v2\/posts\/3466"}],"wp:attachment":[{"href":"http:\/\/www.mytets.com\/blog\/wp-json\/wp\/v2\/media?parent=3466"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.mytets.com\/blog\/wp-json\/wp\/v2\/categories?post=3466"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.mytets.com\/blog\/wp-json\/wp\/v2\/tags?post=3466"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}