玻璃透镜模压成型的工艺分析

夹层玻璃镜片模压成型法，是将熔融状态的光学镜片毛胚倒进高过夹层玻璃转换点50℃之上的超低温磨具中充压成型。这类方式 不但非常容易产生夹层玻璃黏连在磨具的模表面，并且商品还非常容易造成出气孔和冷模印痕（皱褶），不容易获得理想的样子揉面形精密度。之后，选用材料精密机械加工成的压型板磨具，在无空气氧化氛围的自然环境中，将夹层玻璃和磨具一起加温提温至夹层玻璃的变软点周边，在夹层玻璃和磨具大概处在同样温度标准下，运用磨具对夹层玻璃施加压力。接下去，在维持所施压力的情况下，一边制冷磨具，使其温度降至夹层玻璃的转换点下列（夹层玻璃的变软点时的夹层玻璃黏度约为107.6泊，夹层玻璃的转换点时的夹层玻璃黏度约为1013.4泊）。这类将夹层玻璃与磨具一起执行等温充压的方法叫等温加压法，是一种较为非常容易得到 高精密，即非常容易高精密地将磨具样子表层拷贝出来的方式 。这类夹层玻璃电子光学零件的生产制造方式 缺陷是：加温提温、制冷减温都必须较长的时间，因而生产制造速率比较慢。以便处理这个问题，因此对于此事方式 开展了成效显著的改善，即在一个压模设备中应用多个磨具，以提升生产率。殊不知非球面磨具的工程造价很高，选用好几个磨具必然导致成本费过高。对于这类状况，进一步科学研究开发设计出与原先的镜片毛胚成形标准较为相仿一点的非等温加压法，进而提升每一个磨具的生产制造速率和磨具的使用期。此外，也有人已经科学研究开发设计把由熔化炉中流出去的夹层玻璃立即高精密成形的方式 。夹层玻璃毛胚与模压成型品的品质有立即的关联。按大道理，绝大多数的光学镜片都可以用于压模成成形品。可是，变软点高的夹层玻璃，因为成形温度高，与磨具略微一些反映，导致磨具的使用期很短。因此，从模具材料非常容易挑选、磨具的使用期可以增加的见解考虑，应开发设计合适超低温（600℃上下）标准下模压成型的夹层玻璃。殊不知，开发设计的合适超低温模压成型的夹层玻璃必不可少合乎可以廉价地生产制造毛胚和不带有环境污染的化学物质（如PbO、As2O3）的规定。

Process Analysis of Glass Lens Precision Molding
The glass lens precision molding method involves pouring molten optical glass blanks into low-temperature molds that are heated to a temperature 50°C above the glass transition point. Pressure is then applied to shape the glass. However, this method has several issues:
1. The glass tends to adhere to the mold surface.
2. The products are prone to defects such as air bubbles and cold mold marks (wrinkles).
3. Achieving the desired shape and surface precision is difficult.
To address these challenges, precision-machined molds made from specialized materials were introduced. The process involves heating both the glass and the mold together in an oxygen-free atmosphere to a temperature near the softening point of the glass. Under these conditions, where the glass and mold are at nearly the same temperature, pressure is applied to the glass using the mold.
Afterward, while maintaining the applied pressure, the mold is cooled to a temperature below the glass transition point.
• At the softening point, the viscosity of glass is approximately 10⁷.⁶ Poise.
• At the transition point, the viscosity is approximately 10¹³.⁴ Poise.
This process, known as the isothermal pressing method, allows for high precision and accurate replication of the mold's surface.
Disadvantages:
• The heating and cooling steps require a significant amount of time, resulting in low production efficiency.
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Improvements to Increase Efficiency
To improve production efficiency, multiple molds were incorporated into a single molding device. However, the high cost of aspheric molds makes this approach expensive.
Development of Non-Isothermal Pressing:
A non-isothermal pressing method was developed to address this issue. This method adjusts the conditions to be closer to those used for molding lens blanks, increasing production speed and extending mold lifespan.
Direct Precision Molding from the Melting Furnace:
Research is also being conducted to develop a method where glass flows directly from the melting furnace into precision molds, bypassing intermediate steps.
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Glass Blanks and Molded Products
The quality of glass blanks is directly related to the quality of the molded products. In theory, most optical lenses can be molded into finished products.
Challenges with High Softening Point Glass:
• High softening point glass requires high molding temperatures, which can react slightly with the mold, shortening its lifespan.
Solutions:
To address this, glass suitable for low-temperature molding (around 600°C) is being developed. Such glass must meet the following criteria:
1. It must be cost-effective for blank production.
2. It must not contain environmentally harmful substances such as PbO or As₂O₃.