Molding process and mould for reducing internal stress in PC lens production

Abstract

The invention relates to a molding process and a mould for reducing internal stress in PC lens production. The molding process comprises the following steps: slow mold merging-low pressure-positioning-moving forwards-ejection-compression, mold merging and simultaneously ejection-mold locking at high pressure-pressure maintaining-feeding-cooling-mold opening-push out-push backwards-slow mold merging; the adoption of processes of moving forwards and ejection between the processes of slow molding and mold locking at high pressure can reduce the generation of the internal stress; the mould comprises a fixed bolster plate arranged on a mounting plate for the fixed bolster plate, and a moving bolster plate arranged on a mounting plate for the moving bolster plate by a supporting plate, wherein a fixed clearance is reserved between the moving bolster plate and the supporting plate which are supported on a same parallel surface by a guide pole, and a strong spring is arranged between the moving bolster plate and the supporting plate for positioning; as the capacity of a mould cavity is adjustable, the material has bigger liquidity in the mould cavity when in ejection, so as to discharge bubbles in time, and significantly reduce the generation of the internal stress; therefore, the qualification rate of products is improved greatly.

Description

Technical field: [0001] The invention belongs to the lens processing industry, and relates to a lens processing method, in particular to a process and a mold for reducing internal stress in the process of producing PC lenses by adopting multi-stage clamping and compression functions. Background technique: [0002] In the traditional PC lens processing technology, its production process is as follows: [0003] 1. Slow mold clamping - low pressure - high pressure mold clamping (mold fully closed); [0004] 2. Seat in and out; [0005] 3. Pressure keeping—feeding—cooling—mold opening (after mold opening)—ejection—ejection retreat—slow mold closing; [0006] The molds matched with this process are as follows: figure 1 As shown, it includes the fixed side formwork A, which is installed on the fixed side formwork installation plate B, and the movable side formwork C, which is installed on the movable side formwork installation plate E by means of the support plate D, wherein th...

AI Technical Summary

Problems solved by technology

[0016] The disadvantages of the above process and equipment are: due to the non-adjustability of the mold cavity volume, the fluidity of the material in the mold cavity is poor. In addition, due to the characteristics of the lens (myopia) being thick in the middle and both sides, it is easy to appear in the injection molding process. Insufficient filling and long bonding lines and other defects, and in order to improve this defect, it is necessary to use faster injection speed and higher injection pressure in the injection molding process, and this is prone to bubbles, flashes and larger Product defects such as internal stress directly affect the quality of the lens, and this process consumes a lot of energy

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