傳統(tǒng)LED玻璃透鏡出產(chǎn)工藝成型
玻璃透鏡單從透鏡的用途來看，它不僅可以用于LED，也可用于安防、數(shù)碼相機(jī)、鐳射、光學(xué)儀器等領(lǐng)域，材質(zhì)上包括矽膠、PMMA(亞克力)、PC、玻璃等等，但在LED領(lǐng)域方面依然以亞克力和PC為主。 PC的耐熱性比較好，廣泛應(yīng)用于戶外，如LED路燈。亞克力耐熱性稍差，所以一般用于室內(nèi)。
雖然透鏡在國內(nèi)已經(jīng)不是新鮮東西，大改進(jìn)的空間比較有限，但是各個(gè)廠家還在努力摸索。
LED透鏡廠家傳統(tǒng)的玻璃透鏡模壓成型法，是將熔融狀況的光學(xué)玻璃毛坯倒入高于玻璃轉(zhuǎn)化點(diǎn)50℃以上的低溫模具中加壓成形。這種辦法不只簡(jiǎn)單發(fā)生玻璃粘連在模具的模面上，并且產(chǎn)品還簡(jiǎn)單發(fā)生氣孔和冷模痕跡(水紋)，不易取得抱負(fù)的形狀和面形精度。后來，選用特別資料精密加工成的壓型模具，在無氧化氛圍的環(huán)境中，將玻璃和模具一同加熱升溫至玻璃的軟化點(diǎn)鄰近，在玻璃和模具大致處于相同溫度條件下，使用模具對(duì)玻璃施壓。在堅(jiān)持所施壓力的狀況下，一邊冷卻模具，使其溫度降至玻璃的轉(zhuǎn)化點(diǎn)以下。這種將玻璃與模具一同實(shí)施等溫加壓的辦法叫等溫加壓法，是一種對(duì)比簡(jiǎn)單取得高精度，即簡(jiǎn)單精密地將模具形狀外表仿制下來的辦法。這種玻璃光學(xué)零件的制作辦法缺點(diǎn)是：加熱升溫、冷卻降溫都需求很長(zhǎng)的時(shí)刻，因而出產(chǎn)速度很慢。
Traditional Manufacturing Process of LED Glass Lenses
Glass lenses, depending on their purpose, are versatile components used not only in LEDs but also in security systems, digital cameras, lasers, and optical instruments.
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Materials Used
? Silicone, PMMA (Acrylic), PC (Polycarbonate), and Glass are commonly used materials.
? PC:
o Offers good heat resistance, making it suitable for outdoor applications like LED streetlights.
? PMMA (Acrylic):
o Has slightly lower heat resistance, generally used indoors.
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Traditional Glass Lens Molding Process
1. Early Methods:
o Melted optical glass preforms are poured into low-temperature molds at a temperature 50°C above the glass transition point.
o Issues:
? Glass often sticks to the mold surface.
? Common defects include air bubbles and cold mold marks (watermarks).
? Achieving the desired shape and surface precision is difficult.
2. Improved Method:
o Special Precision Molds:
? Manufactured using advanced materials and techniques.
? Glass and molds are heated together to the softening point of the glass in an oxygen-free environment.
o Isothermal Pressing:
? Both the mold and glass are maintained at similar temperatures.
? Pressure is applied to shape the glass, and the mold is gradually cooled below the glass transition point while maintaining pressure.
o Benefits:
? Achieves high precision by accurately replicating the mold surface.
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Limitations
? Slow Production Speed:
o The process requires long heating and cooling times, limiting production efficiency.
Despite these challenges, isothermal pressing remains a reliable method for producing high-precision glass optical components in LED applications and beyond.
