With the rapid development of mold manufacturing technology, mold has become an important part of today's manufacturing technology. Now the mold manufacturing technology is also moving towards accelerating information-driven, to improve the manufacturing flexibility, agile manufacturing and systematic integration of the direction of development. In order to be able to create high-quality molds and in view of the current domestic manufacturing mold technical level and quality, mold manufacturing process is now described as follows, for your reference.
First, the conditions for manufacturing mold
In a dirty environment is not able to create high-quality mold, yin and yang mold manufacturing area should be highly clean, must be higher than the production area of the maintenance and management standards, so at the beginning of mold manufacturing, Good mold manufacturing area of dust and cleaning work.
2.Clean compressed air
Pure, dry gas supply is another element of the manufacture of high-quality mold, gelatin surface will appear a lot of pinholes and pitting, to pay a lot of labor to repair, so that the quality of the mold will be great influences. The air compressor needs to be housed in a favorable environment and equipped with an effective air dryer and oil-water separator.
Temperature: in the manufacture of male and female mold the whole process should always maintain the same ambient temperature, that is 21 ~ 28 ℃.
Humidity: humidity on the gel coat and resin curing a great impact, the ideal humidity range of 40 to 60, if the mold when the relative humidity of more than 65, should wait until the appropriate production conditions and then construction.
4.The selection of raw and auxiliary materials
Selection of high quality raw and auxiliary materials, is to create high-quality mold of the important conditions. The cost of raw and auxiliary materials used to make the mold is only a small percentage of the total cost and can not be used to save the use of the product resin or the overstocked material and the inferior material.
5.To develop a reasonable modeling schedule
Arranging the appropriate tooling schedule is one of the factors that makes a good mold. Whether using the traditional method of laying, or the choice of new low-shrinkage system, the time required by the chemical and chemical properties of these raw and auxiliary materials, determined to take shortcuts or accelerated process, will have a negative impact on the quality of the mold The
Second, the mold gel coat spray
Mold gel coat operation process is a crucial step in mold manufacturing, and even imagine the mold gel coat is the whole mold, all the post-layer and structural skeleton are for the mold surface gel coat service.
Mold gel coat requires higher use and curing conditions than the general product gel coat. High-quality mold surface requires a very sophisticated mold gel coat operation and mixing process.
The use of spraying equipment coated mold gel coat mold manufacturing process is an important part. Appropriate spray pressure to avoid porous and gel coat sag, gel coat color separation and other phenomena have an important impact.
We are currently using the W-77 gun in the spray gun, the curing agent through the manual mixing to ensure the exact ratio, but the spray gun spray fan-shaped mixture of the distribution of a very fine atomization effect, spraying faster than pumping The system is slow and its working time is limited by the gel time of the feedstock.
2.Mold gel coat inspection
The shelf life of the mold gel coat is very demanding, and it is important to follow the recommendations of the gel coat supplier. In most cases, the producer can guarantee the quality of the gel coat from the packaging to a specific time. Therefore, the producer and the inspector should always test the production date or date number of the gel coat in order to confirm whether the gel coat is in the effective period of use.
Use a pneumatic stirrer to thoroughly mix each barrel of mold gel coat before use and ensure that all the material in the bucket is completely mixed and then allow the gel coat to stay for a few minutes to return to its own viscosity and then use it.
Verify that the temperature of the gel coat is in the range of 21 to 28 ° C, which is the appropriate temperature required for the molding process.
⑶ gel time
The gel time of the barrel gel coat per barrel is clearly defined by the supplier. After the mold gel coat into the factory, the quality inspection department must check the gel time, namely: A, the sample should reach the standard test temperature 25 ℃; B, add the specified amount of curing agent and mix well; C, recorded from curing to join To the time of the gel.
Need to use BROOKFIELD viscometer test gel coat viscosity. The temperature of the gel coat sample is 25 ° C.
A, select the appropriate rotor placed in the sample;
B, viscometer to low speed and high speed rotation;
C, record the reading and convert it into viscosity index.
It is very important to carry out the quality control of the mold material in the factory, and the producers often ignore this important step.
3.Stripping wax, release agent treatment
The mold is subjected to stripping wax or release agent treatment.
⑴ the water mill, polished glass steel mold clean clean, dry with a towel, to be dry through, with 3 to 4 layers of clean gauze wrapped on the amount of stripping wax (US boat license R333 No. 8), using Round evenly coated on the mold surface, wait 3 to 5 minutes, wipe with a clean white towel, until the mirror effect, placed about 2 hours. Repeat this operation a total of 4 times. The fifth operation is placed for more than 6 hours. Anti-slip surface, the shape of the complex place after the removal of wax, it is recommended to apply a number of release agent again.
⑵ A, new mold or old mold should be the appropriate solvent (such as acetone) cleaning, be sure to surface impurities, wax scale, etc. to clean, and to dry.
B, the PMR with a clean gauze soaked, coated on the mold.
C, after coating, in the PMR has not yet dry before, with a dry cloth evenly coated to the surface.
D, the first use of this product, to be repeated 4-5 times, each interval of about 10-20 minutes, such as the larger mold area, each coating can be continuous coating after the last layer of coating with a dry cloth Mold wipe bright, and put it aside for more than an hour.
E, a use, the gel coat may be difficult to coat, this is the effect of stripping too good, can be coated with a small amount of stripping wax, do not have to use.
F, if the mold is more difficult, then PMR coated 1-2 times, so you can achieve cost savings and to ensure the purpose of quality.
4.Gel coat spray
After the mold is painted on the mold, the gel coat is sprayed. It is recommended that the thickness of the mold gel coat is 1mm and the gel coat is divided into two layers. The spraying process is completed in two steps, 0.5mm thick and sprayed three times, and 0.15mm ~ 0.17mm. The thickness of the mold gel coat needs to be strictly controlled, which requires that after each spray gel coat, have to use plastic feet in the mold surface in many places to accurately measure the thickness of the gel coat layer.
The correct gel coat spray method is as follows:
⑴ spray the first time the thickness of 0.15 mm ~ 0.17 mm mold gel coat.
⑵ and the first pass into the vertical direction of the second spray gel coat, the thickness of 0.15 mm ~ 0.17 mm.
⑶ and then the direction of the first pass spray the last time gel coat, so that the first layer of gel coat thickness is 0.5 mm.
⑷ In order to avoid cracking or wrinkling, should be cured in the first layer of gel coat, in order to spray another layer of gel coat. At normal temperature, the cure time is 90 minutes.
Third, the mold layer
Gel spray after 1 hour to 3 hours, such as gel coat after curing, the surface of the case of non-stick, the laying. We currently use the traditional multi-step paving method.
A, mold resin
Mold resin has a high heat distortion temperature and low shrinkage, we basically use mica resin, vinyl resin.
B, glass fiber reinforced materials
The chopped mat is a very good mold reinforcing material, it can minimize the printing of the fiber lines. Compared to knitted fiber mats and fiber weaving products, the advantages of chopped mats are more prominent.
C, quality inspection
In order to ensure that the mold resin to meet the requirements, but also like the mold gel coat as a quality inspection. Including: material storage period, mixing tests for each batch, and testing gel time and viscosity.
2.The first floor
Mold layer is the first layer from the beginning of the paste system. The first floor of the quality requirements are very high, to avoid all the mold after the completion of the repair or damage to the possibility of gelatin. According to the complexity of the shape of the mold, the first layer of the mold when the choice of 30 grams of 2 surface blanket, 300 grams of 2,450 grams of 2 chopped mat, laminated with iron roll must be carefully rolled to ensure that all Bubbles have been rushed and guaranteed a reasonable ratio of resin to fiber. When the first layer of curing, to do a thorough and comprehensive inspection of the laying, including all the corners, surfaces and other possible problems. Such as the discovery of bubbles and other defects, must be careful to remove the bubble, and repair the wound again.
Laminated process is generally M450 × 4 ~ 5 + RX × N, small mold about 8mm thick, large mold to ensure that about 15mm. Producers must strictly enforce the lamination process and timetable.
A good way to develop a pavement plan is to observe the changes in the pasteurian hardness. When the thickness of the laminate reaches a fully cured hardness of 80% to 90%, the next layer can be carried out. When using the Pasteurizer to measure the hardness of the pavement, pay attention to the need to record multiple readings and calculate the average, and as a hardness value. This method eliminates the data error due to the difference in curing time, and the laying of this method is usually faster than the laying time schedule.
Fourth, the mold outside the structure
When the mold is finished, the next step is to make the external reinforcement of the mold. The purpose of the reinforcement structure is to make the external force on average to the mold surface, preventing the mold surface deformation. Mold gel coat crack the most basic reason is the deformation of the mold, because of this, the design of a rigid mold structure will greatly prevent the gel coat dry.
Regardless of the structure of the steel frame or the plywood of the plywood, it should be suspended at 14 feet above the mold floor. If the structural frame is directly connected to the mold surface, different heat transfer will cause the mold surface to be printed. In addition, do not place part of the foam, laminate or other insulating material between the structural layer and the surface. The bonding between the structure and the laminate is preferably glass, but do not use braided cloth to prevent printing.
When the frame structure is fully cured, the mold can be stripped. The first step will cut the edge of the mold neatly, and then use a number of stripping wedge are inserted into the yin, between the male mold, even force (not alone to prevent damage to the mold), and use the rubber hammer tapping the various stress concentration ( Iron beating), and finally completely stripped.
Six, mold processing
After stripping, carefully check every part of the mold, any surface defects should be noted and marked out. In the ideal state, the mold does not need to polish the surface, only the mold surface can be polished, the general mold can not be achieved to achieve the ideal state, it had to follow the traditional method of grinding the mold.
Guolan specializes in professional mold manufacturing, mold, injection, spray to the assembly of one-stop service, and the implementation of strict quality control procedures, starting from the mold raw materials to the final delivery, each link are strictly control, So that the rationality of the mold design, production accuracy, die life and quality of injection products have reached your requirements for your production of high-quality molds and mold injection products.