How to mafacture mannequins in factory?

To manufacture top-quality mannequins, it is necessary to reach excellent standards from three aspects: factory hardware, management level, and personnel training. Solid and effective work must be done in the selection of mold materials, reasonable arrangement of process regulations, and quality inspection.

1. Conditions for manufacturing molds:

1. Environmental conditions

Temperature: The ideal temperature range is 21-28°C. In the process of manufacturing the original mold and the mold should always maintain such an ambient temperature. The matrix material used in mold manufacturing should have the best chemical reaction process. Environmental factors are not suitable, which will prolong or speed up this process and adversely affect the performance of the mold.

Humidity: Humidity has an important effect on the curing of gel coat and resin. If the relative humidity is greater than or equal to 70% when making the mold, it will have an adverse effect on the curing of the matrix material. You should be cautious and wait until the appropriate production conditions or adopt Dehumidification measures.

2. Perfect workshop management

The mold manufacturing workshop should have storage conditions for chemical products, equipment for controlling temperature and humidity, and a clean work site. In terms of management, it is necessary to divide the fixed area according to the process flow, complete control documents such as process specification card, work instruction, and quality tracking card, and record detailed records.

3. Compressed air

Pure and dry air supply is another element for manufacturing high-quality molds. A small amount of water or oil in the trachea will have an important impact on the mold gel coat. It needs to be matched with an air compressor placed in a good environment, and equipped with an effective air dryer and oil-water separator, as well as a voltage stabilizing and regulating system.

4. Raw materials

Choosing the highest quality raw materials as much as possible is another important condition for manufacturing high-quality FRP molds. The cost of raw materials used to make molds only accounts for a small percentage of the total cost, so don't try to save.

5. Arrange a reasonable process

Whether using a traditional layup method or a low shrinkage system, the time required is determined by the curing characteristics of these materials. Attempts to take shortcuts or speed up the process will adversely affect the quality of the mold.

6. Well-trained technical workers

The so-called well-trained means to have basic knowledge and professional skills of common sense, have good behavior habits, and be able to consciously regulate personal behavior.

2. Material selection:

A. Original mold material

The original mold is the most important prerequisite for manufacturing high-quality FRP molds. The choice of the base material of the original mold is mainly based on the mold type and size, as well as the experience gained when making different types of molds. Based on the principle of layup thermodynamics, to eliminate defects such as different densities, seams, screw holes and other defects of the original mold surface material, there must be a layer of uniform heat transfer speed and a certain rigid material as the substrate of the surface treatment material. On the kind of substrate, use easy-grinding materials to correct the accuracy and smoothness of the contour size of the original mold surface, and use an air-drying gel coat with a high-gloss surface to obtain a high-gloss surface of the original mold.

The accuracy, smoothness, and brightness of the contour size of the original mold surface directly determine the quality of the FRP mold.

To ensure the accuracy and smoothness of the contour size of the original mold surface, materials with the following characteristics are required:

1. Air-dry jet type, can quickly accumulate a certain thickness

2. Low clearance hole, easy to polish and modify

3. Good temperature resistance

To ensure the high brightness of the original mold surface, materials with the following characteristics are required:

1. Air-dry jet type

2. Low clearance hole, easy to water abrasion

3. Good temperature resistance

4. Smooth and delicate surface

B. The requirements of the original mold surface release material

1. Ensure demolding

2. Does not affect the surface brightness of the original mold

3. The release material is not transferred to the mold

C. Mold material:

The most important measure of the production level of the mold is the brightness, smoothness, gloss, and surface porosity of the mold gel coat surface. This is determined by the level of technology. The length of the mold surface quality retention time, which is commonly referred to as the mold life, is determined by the properties of the mold material.

Mold gel coat:

Mold gel coats currently mainly include vinyl mold gel coats and isophthalic unsaturated polyester mold gel coats.

The resin structure of the mold gel coat gives the final mold surface mechanical strength, brightness, weather resistance, chemical resistance and flexibility.

The operation process of mold gel coat is a crucial step in mold manufacturing. Mold gel coat is the entire mold, and all post-layup and structural skeletons serve the mold surface gel coat layer.

Mold gel coats require higher use and curing conditions than general product gel coats. A high-quality mold surface requires a very precise mold gel coat operation and mixing process.

Therefore, the performance of mold gel coat materials, environmental control equipment, and technological level are the keys to determining mold production.

Mold gel coat construction process equipment

The use of spray equipment to coat the mold gel coat is an important part of the mold making process. Two types of spraying equipment can be used, one is typically used for product gel coat spraying, and the other is an air atomized pressure spray can. Both types of equipment can produce high-quality gel coat surfaces. But in operation, you must consider the following points:

For typical gel coat spray equipment, the curing agent is injected into the raw material by internal mixing or external mixing. These spray guns are easy to use and are usually more efficient than spray cans. However, it should be noted that if the proportion and distribution of the curing agent are deviated, the transmission system has problems or the fan-shaped mixture is not well distributed, it may cause gel coat defects.

Many moldmakers choose to use an air atomized spray can to eliminate deviations in the production process. In the spray can gun, the curing agent is manually mixed to ensure accurate proportions. In addition, the distribution of the fan-shaped mixture produces a very fine atomization effect, but the spraying speed is slower than the pumping system, and its working time is limited by the gel time of the raw materials.

a, mix

Use a pneumatic agitator to mix each bucket of mold gel coat thoroughly before use, and make sure that all the materials in the bucket are completely mixed. Do not use manual mixing, and do not reduce the completeness of the mixing because you are afraid of air mixing into the mold gel coat. Make sure that the gel coat at the bottom and the sides of the bucket can also be completely mixed. Then, before use, allow the gel coat to stay for a few minutes to restore its own viscosity and defoam.

b, temperature

Check whether the temperature of the gel coat is within the range of 23-28°C. If it is not within the range, measures should be taken.

c. Test and select the performance of curing agent in different types of materials and in different processes.

d. Gel time

The next step of the gel coat quality inspection is to verify the gel time, which will prove whether the mold gel coat is within the specified range. The process of verifying the gel time is simple and does not require any equipment.

1. The test sample should reach the standard test temperature of 25°C;

2. Add the specified amount of curing agent and mix well;

3. Record the time from the curing agent added to the gel.

The gel coat supplier will recommend equipment and provide detailed instructions to guide users to conduct gel coat quality inspection in their own factories. Quality inspection of mold materials in the factory is very important and can be regarded as part of the molding process.

After applying the release agent on the original mold, it is time to start spraying the gel coat. Two layers of gel coat are sprayed separately. The thickness of the mold gel coat needs to be strictly controlled. This requires that the thickness of the gel coat layer must be accurately measured in many places on the mold surface after each spray of the gel coat.

The correct gel coat operation method is as follows:

1. Spray the mold gel coat with a thickness of about 0.15-0.2mm in the first pass.

2. Spray the second gel coat in a direction perpendicular to the first pass.

3. Spray the gel coat for the last time according to the direction of the first pass. Now the thickness of the entire layer of gel coat is 0.5-0.6mm.

4. After the first layer of gel coat is cured (usually the mold gel coat is cured in 90-120 minutes), another layer of gel coat can be sprayed. This gel coat cannot exceed two-thirds of the thickness of the first gel coat.

4. Spray the second layer of 0.3-0.4mm gel coat in the same way as the spray method of the first layer of gel coat (steps 1 and 2 above).

The spraying of the gel coat follows the principle of difficult first, easy first, groove first, flat surface, and try to avoid local over-thickness. In the case of unsatisfactory spray angle, the auxiliary method of hand brushing first can be used.

Three, mold layer

The mold gel coat needs two hours to three and a half hours, that is, the initial setting time of the mold gel coat in an ideal state is 50 minutes, and the curing time is 100 minutes. After the second layer of gel coat is cured, the base layer can be laid. There are two common layup methods for making FRP molds. One is the traditional multi-step layup method, and the other is the fast and low shrinkage system layup method.

a. Traditional mold laying method A, raw materials:

1. Mold resin

The mold resin should have a high heat distortion temperature and low shrinkage. M-phenyl resin, vinyl resin and DCPD resin can all be used as mold resin.

Vinyl polyester resin has high solid content, thixotropy, and has been promoted to have excellent process performance, low shrinkage performance; excellent mechanical properties, thermal degradation performance, and chemical resistance. It has superior strength retention at high temperature and high heat distortion temperature. When making high-end molds

As the first choice for mold materials, to ensure the surface quality of the product depends on the mold gel coat, and to ensure the stability and consistency of the product quality, it depends on the performance of the mold resin.

2. Glass fiber reinforced materials

The surface felt is often used as the first layer of reinforcement because of its fine fiber, convenient infiltration and easy defoaming.

Chopped strand mat is an ideal reinforcement material for molds, because it can minimize the printing of fiber lines.

3. Quality Assurance

In order to ensure that the mold resin meets the quality requirements, the quality inspection must be performed like the mold gel coat.