What are the process characteristics of acrylic lenses?

Acrylic lens can choose casting, injection molding, extrusion, hot forming, laser engraving, laser cutting and other processes. So what are the characteristics of these processes?

1, casting molding

Casting is used to form plexiglass plate, bar and other profiles, that is, the body body polymerization method to form profiles. The products after casting need to be post-treated. The post-treatment conditions are holding heat for 2h at 60℃ and 2h at 120℃

2. Injection molding

Injection molding selection of suspension polymerization of granular material, molding in the general plunger or screw injection machine. Table 1 shows the typical process conditions of polymethyl methacrylate injection molding. Process parameters Screw injection molding machine plunger injection molding machine cylinder temperature 180-200 180-200 middle 190-230 front 180-210 210-240 nozzle temperature ℃180-210 210-240 Mold temperature ℃40-80 40-80 injection pressure MPa 80-120 80-130 pressure MPa 40-60 40-60 screw speed RP.M-1 20-30 injection products also need post-treatment to eliminate internal stress, treatment in 70-80℃ hot air circulation monotonic box, processing acrylic rod time depending on the thickness of the product, generally need about 4h.

3. Hot forming

Thermoforming is the process of making plexiglass sheet or sheet material into various standard shape products. The blank cut into the required standard is clamped on the mold frame, heated to soften it, and then pressed to tighten the mold surface to get the same shape as the surface, and the product is obtained by trimming the edge after cooling and shaping.

The pressure can be selected by vacuum drafting or direct pressure on the punch with a profile. Thermoforming temperature can refer to the temperature planning recommended in Table 3. When CHOOSING FAST VACUUM low draft forming products, it is advisable to choose the temperature close to the lower limit, the deep draft products with messy shape should choose the temperature close to the upper limit, and the normal temperature should be used in general.