Stamping copy

To break through the bottleneck in the commercialization of optical plastic products, optical plastic products can be stamped

Copy (Bossing Method) Copy. In summary of the above, the overall program of the coherent experiment is as follows:

1. Electroform the mother sheet.

2. Emboss the thermoplastic material with an electroform. There are two kinds of imprinting methods, one for rolling and the other for flat pressing.
Rolling-type electroformed master mold is placed on one of the heated rollers, and the thermoplastic material to be pressed is sent to the two rollers and stamped with the mother mold after heating. Cool to complete the copy.


2. Flat pressure type

The principle is similar to the rolling method. Two embossing stencils are used to replace the roller in the roller type. The electroformed master mold and the thermoplastic material to be embossed, such as acrylic, are put together in two. Blocks are preheated between templates, fully preheated and imprinted for a period of time under a constant pressure, and rapidly cooled to complete the copying process. Flat-press masters are generally thicker than roll-types because they must maintain their flatness and resist repeated thermal expansion and contraction. The advantage of this method is that it is relatively easy to imprint a large size area, and the requirement for the thickness of the imprinted material is not as strict as the rolling type, allowing a small amount of change, and the quality of embossing is better than that of a rolling type. Yes, and its equipment is much cheaper than roller type, but its disadvantage is that the imprinted material is bulky, requires more heat, and the thermal conductivity is not good, so the warm-up time is long, and the stamping master and the Embossing materials need to be tightly adhered to, which prolongs the production time, so the production rate cannot be compared with the rolling type. Here we use Polycarbonate (PC) as the plastic injection molding material for optical plastic products. Polycarbonate has good heat resistance (about 130 degrees C), high impact strength and transparent appearance; it has a wide range of applications. Good weather resistance, but the price is expensive. The characteristics of the performance at the time of injection molding are as follows:

1. Since the molding shrinkage is small (about 0.6%) and the rigidity is high, it is relatively easy to show the exact size. However, the forming method is difficult.
2. It belongs to polymer and it is not easy to burn.
3. The resin has poor fluidity during molding. The mold length and thickness L/T ratio is 140. Large gates and runners are more suitable. Increase the temperature during forming (the barrel temperature is approx. 300°C). 4. Because it is easier to bite, the mold must be plated.

The feature of injection molding of optical plastic products is that it is a high-precision, high-productivity molding manufacturing method that uses high pressure to evenly fill the molding plastics at every corner, plane or concave surface of the mold.


Plastic optical plastic products in the forming process is to pay special attention to the thermal reaction and residual stress deformation characteristics. The shape of the molded product must meet the required dimensional accuracy: In particular, molded products that have a simple shape and which produce a uniform molding shrinkage should pay particular attention to changes in load, temperature, and environment that occur during use. The shape should maintain the required appearance; pay attention to the uniformity of the wall thickness, if too thick, easy to produce dents. Basically, it is more appropriate for the optical plastic product to be ejected in the mold to maintain a low pressure state (to avoid residual stress on the molded product). This is the main reason for finding the best conditions for the shape of the entity. When the filling operation in the mold is finished, the pressure that has been ejected will fully act to cause the pressure in the mold to drop rapidly. Therefore, the pressure must be changed immediately. This is what we call maintenance pressure and it needs to be maintained for some time. Optical plastic products Plastic injection molding To prevent the occurrence of dents, the general countermeasures are to reduce the molding shrinkage, that is, to increase the molding pressure, and to increase the duration of the injection and pressurization. At the same time, the cushioning material can be increased to ensure that the pressure can be maintained. The buffer material means the material that is equivalent to the reduction of the volume of the resin in the mold during the pressing process, so that it is cooled. The design of molded articles of optical plastic products has a close relationship with the molds, in order to improve quality and reduce costs; therefore, before and after the development of the molds, this study was performed on a computer to simulate the optical plastics in the injection molding process. To find problems. In order to modify the mold design or molding operating conditions, reduce production costs and mold design man-hours, improve product quality. Computation of Pressure of Imprinted Optical Plastic Products

First, the implementation steps of imprinting optical plastic products are as follows:

1. Place the acrylic or plastic plate in a hot environment for a while.
2. Apply pressure P_e Emboss the optical plastic product master on acrylic or plastic board.
3. Keep pressure for a while.
4. Remove acrylic or plastic plates and cool in cold air.

Second, the pressure of the printing optical plastic product is calculated

The pressure P_e can be given an initial value by the lower bound theory and the upper bound theory, and then finally obtained by a simple fuzzy control system.

three. Imprinting control method

Define the implementation parameters of flat-press imprinted optical plastic products as follows:
1. Place the acrylic or plastic plate in ambient T_c heating time_1 seconds
2. Applying Pressure P_e to Emboss the Master Mold of Optical Plastics on Acrylic or Plastic Plates
3. Maintain pressure time_2 seconds
4. Remove the acrylic or plastic plate and cool the time_3 seconds in the cold air. Ambiguity in process variables B = T_c, P_e, time_1, time_2, time_3
The characteristic set A = F_d, F_e, F_l, F_c, F_s, F_p
Let it correspond to fuzzy parameters such as f_1,f_2,f_3...., and its membership function is
Mu_1 ,mu_2, mu_3....
Here
F_d is the emboss depth
F_e is an edge collapse
F_l is the case of surface indentation
F_c is imprinted fog
F_s is the spot on the embossed surface
F_p uses the so-called alpha cut value for the case of surface depressions, and fuzzy control can be used to obtain appropriate process parameters.
The IF-THEN rule of fuzzy control is as follows:
Rule 1: If the condition of the surface indentation is light, F_l is severe, check the imprint depth F_d.
If the emboss depth F_d is small, the pressure P_e, the temperature T_c increase, and the time time_1 decreases. Rule 2: If the situation of light surface indentation F_l serious, and the embossed depth F_d, the edge of the case of collapse F_e are large, then increase the time time_2, time_3, reduce the pressure P_e
.
Rule 3: If the surface haze situation F_c is severe, reduce the pressure P_e, the time time_2, and the temperature T_c.

Rule 4: If there are many spots F_s on the embossing surface, increase the time time_3.
Rule 5: The condition of the surface depression F_p is severe and the edge of the case is collapsed F_e is large,
Then reduce pressure P_e, time time_2.