Introduction to the waste disposal scheme of black and white glue punching and cutting and the solutions to common problems (the article is reproduced from the die-cutting network)
Our dust-free workshop has two types of punching products, one is formed by secondary punching; Second, it is formed by one time punching.
1： For the products formed by secondary blanking, the process of waste removal is relatively simple, as shown in the following figure:
       
Main components and elements of the process:
1. Three strips of American tape are respectively bonded on the non release surface of the inner frame of the semi-finished product in the stamping process and the PET release film of the two frames;
2. A piece of waste PET film is bonded with the double-sided adhesive surface of the inner frame that has eliminated the PET release film of the inner frame
            
       
       
Operating procedures:
Affix the adhesive tape (1) → remove the PET release film from the inner frame → attach the adhesive tape from the two frames (2), (3) and waste PET (4) → remove the waste through the waste folding plate
Common problems of waste discharge:
1. Leakage discharge; The reason is that the adhesive (1) can not effectively remove all PET release membranes, resulting in leakage If the adhesive and waste PET have been effectively bonded and torn, there are two possibilities: one is that the compression force in the middle section of the machine is insufficient, and the other is that the adhesive itself is not sticky enough; Generally, there is little chance of insufficient adhesion of the adhesive. Therefore, the problem can be solved by increasing the pressure of the compression shaft
2. Glue overflow during waste discharge; There are two reasons for overflow: one is that the colloid surface of the raw material is too thin and the rubber filament is too long; the other is that the waste discharge angle is incorrect
Generally, there are three ways to solve glue overflow: A, add compound release paper for blanking; B. Freeze the material; C. Replace raw materials; D. Adjust the waste discharge angle
Therefore, in case of glue overflow, the waste discharge angle should be adjusted immediately. Generally, the waste discharge angle is 40 ℃ - 60 ℃
3. It is difficult to remove the double-sided adhesive tape at the hand tear position; The reason is that the edge distance is not properly controlled when the materials are compounded, resulting in the waste materials at the hand tear position can not be connected together, which is difficult to remove
The solution is as follows: first, adjust the edge distance of the front end material composite; second, stick a strip of masking tape to the same situation as the inner frame in the same row at the hand tear position, and then stick a strip of masking tape to remove the colloid waste after removing the hand tear position release film
4. During waste discharge, the product absorbs dust and suspended particles in the environment The main reason why the product is easy to absorb dust is the adsorption force generated by the static electricity generated by the friction between the product itself and the machine when the waste is removed; In addition to strengthening environmental control, the following two measures should be taken to eliminate this phenomenon: ① Check the temperature and humidity in the workshop. If the humidity is less than 50%, the humidifier must be turned on immediately to humidify the environment; ② Turn on the ion blower to eliminate the static electricity on the product (as shown in Fig. ④)
5. Pull off the frame release paper or release film of the semi-finished product This phenomenon often occurs when the semi-finished products with thin frames are discharged. The general solutions are: ① Adjust the conveying volume of the stamping process of the products to be larger than required to increase the width of the frames between products, but the width should not be too large; Adjust gradually from small to large, as long as it is found no longer broken ② Adjust the fitting position of the masking tape. Generally, the direction of adjustment is toward the upper and lower borders of the product. The most ideal fitting position is at the edge of the product's hand tear position
2： For products formed once, the process of eliminating waste materials is more complicated than that of secondary forming;
The waste discharge process of once formed products can be roughly divided into three types according to product form
1. Hand tear is on the wide side 2, hand tear is on the narrow side 3, and hand tear is on the side as shown in the figure below
       
The process and basic procedure of waste elimination are the same for the three forms of one-time molding products; First remove the PET release film on the colloid surface of the inner frame and the hand tear position of the product, and then remove the waste of the outer frame and the PET release film on the product
The schematic diagram of waste elimination of products with hand tear position on the wide edge for one-time forming is as follows:
       
Elements and precautions of waste removal process:
1. For this type of product, the frame scrap after blanking must be removed manually before the exclusion operation!
2. When pasting the adhesive tape 2, be careful not to contact other adhesive tapes. The function of adhesive tape 2 is to press the PET release film on the product frame so that it will not pull off the release film of the product frame when removing the waste of the product's inner frame, so as to prevent the product from pulling off as a whole
        
       
3. In order to exclude the design of the inner frame adhesive of the product, if the fitting effect of waste PET can meet the requirements, consider reducing one tape to save costs; The positions of the two tapes can be adjusted accordingly to meet the waste discharge requirements
Operating procedures:
Remove the waste from the outer frame → stick American glue 1,2,3 → remove American glue 1 (hand tear PET release film) and PET release film from the inner frame of the product → stick American glue 4.5.6. and waste PET → remove the waste through the waste folding plate
Solutions to common problems:
1. Leakage discharge; The reason is that the adhesive (1) can not effectively remove all PET release membranes, resulting in leakage If the adhesive and waste PET have been effectively bonded and torn, there are two possibilities: one is the insufficient pressure of the middle section of the machine, the other is the insufficient viscosity of the adhesive itself, and the third is the improper fitting position of the adhesive; Generally, there is little chance of insufficient adhesion of the adhesive. Therefore, the problem can be solved by increasing the pressure of the machine and adjusting the position of the adhesive 4.5
2. Glue overflow during waste discharge; There are two reasons for overflow: one is that the colloid surface of the raw material is too thin and the rubber filament is too long; the other is that the waste discharge angle is incorrect
Generally, there are three ways to solve glue overflow: A, add compound release paper for blanking; B. Freeze the material; C. Replace raw materials; D. Adjust the waste discharge angle
Therefore, in case of glue overflow, the waste discharge angle should be adjusted immediately. Generally, the waste discharge angle is 40 ℃ - 60 ℃
3. Broken glue; The reason for glue breaking is mainly that the adhesive 3 is too close to the product frame when sticking, and the glue on the inner frame of the product is pulled off when removing the glue. The second reason is that the punching depth of the product is not enough, and the glue is not completely cut off, which causes tearing when discharging In general, the probability of non penetration is relatively small; Therefore, when the product frame is broken, you can adjust the waste adhesive and move the position of the adhesive about 2 mm inward
4. Pull off the whole product; The main reason for this undesirable phenomenon is that the pressure of the machine shaft is too high or the colloid itself is too thin Therefore, when the product is pulled off as a whole when passing through the waste discharge fold plate, the pressure of the machine's compression shaft can be reduced. If it is determined that it is a raw material problem, the material can be replaced immediately. Another possibility is that the auxiliary materials used in the product are too loose (less likely)
The schematic diagram of waste elimination for products with hand tear position at narrow edge in one-time forming is as follows:
       
The waste removal method of this type of one-time molding product is basically the same as that of the product with one-time molding hand tear on the wide edge. The difference is that there is a change in the position when pasting the adhesive 1.2.3. But the basic principle is always that the pasting position of adhesive 2 must be on the wide edge of the product to ensure that the PET release film of the outer frame will not be pulled off when removing the PET release film of the inner frame
See the figure above for specific waste removal
In addition, the waste discharge method of this type of product can be the same as that of the product with hand tear on the wide edge for one-time molding, provided that the frame of the product is not easily broken by the masking tape
The schematic diagram of waste elimination of products with hand tear position at the side of primary molding is as follows:
       
As shown in the figure above, for this type of product, when the frame waste is eliminated, the pasting position of the adhesive 2 will be at the extreme edge of the product. Before punching the product, pay close attention to whether the width of the frame at the hand tear position can accommodate the width of the adhesive. If so, the pasting position of the adhesive can be at the hand tear position; If not, the gluing position of adhesive 2 can only be operated as shown in the figure above
In addition, there is another way to remove waste materials for the products with hand tear at the side of the molding. That is, if the product frame at the fitting position of masking tape 2 shown in the above figure is too narrow, which makes the masking tape unable to fit effectively, the method shown in the following figure can be used:
       
As shown in the above figure, the following problems must be paid attention to during operation:
① Photo The fitting position of the masking tape must not change, and must be pressed to the hand tear position of the product, otherwise, the PET release film at the hand tear position cannot be removed smoothly; Besides removing the PET release film at the hand tear position, it is also necessary to remove the waste PET release film of the inner frame.
② The applicable product for waste elimination in this method is that the hand tear position is on the side and the position of the hand tear position shall be within the width of the inner frame and shall not exceed this range.
③ There are some exceptional product types in our existing products, for example, the product hand tear position is located on the side of the product but exceeds the width of the product inner frame; This type of product is not easy to complete the machine waste discharge operation under the existing waste discharge method of our company; If similar problems are encountered in production, which makes normal operation impossible, try all the above methods to eliminate waste materials, or immediately communicate with the engineering quality department to improve the process.
Note: The waste disposal methods and exception handling methods for the three different types of products mentioned in this plan are basically the same, but the difference is that the adhesive bonding position changes. Please pay attention to the flexible application of field operators and quality management personnel.