High Quality Mould Making-2


Second, the mold spray gel coat

Die gel operating process is vital step in mould manufacturing, can even imagine mold gel is the whole mold, after all is in the mold surface layer and structural skeleton gel layer service.

Mould gel need higher than the average product suits to use and cure conditions.

High quality mould surface precision die gel operating and mixing process.

1. Equipment

Using injection equipment coating mold gel is an important link in die manufacturing process.

Appropriate injection pressure to avoid porous flow and gel coats hanging, the phenomenon such as gel separation has important effect.

Gel spray gun, we use the current in the spray gun pot, mix curing agent by manual, ensure the accurate proportion, but gun distribution of jet fan mixture to produce a very fine atomization effect, spraying speed is slower than the pumping system, its working time was limited by gel time of materials.


2. Mould Gel Test

Mould gel of storage period is very strict, in accordance with the gel supplier’s suggestion is very important, in most cases, the producers can ensure quality of gel from the packaging to the use of a specific time.

Therefore, producers and inspectors should always test a barrel gel production date or date code, in order to confirm whether suits in effective use period.

(1) hybrid

Thoroughly with a pneumatic mixer mixing before use each bucket mould gel, and to ensure that all the materials in the barrel are fully mixed, then allow the gel to stay a few minutes to restore to its viscosity, and then to use.

(2) temperature

Verify the gel within the scope of the 21 ~ 28 ℃, the temperature of the temperature is molding process requirements of the appropriate temperature.

(3) gel time

A barrel of mould gel gel time, suppliers are defined. After mould gel into the factory, the quality department must verify the gel time, namely:

A. sample should reach the standard of testing temperature 25 ℃;

B. to join a specified number of curing agent and mixed evenly;

C. recorded from curing to join to the gel time.

(4) viscosity

Need to use gel viscosity BROOKFIELD viscometer testing.

Gel sample temperature is 25 ℃.

A. select the appropriate rotor in samples;

B. viscometer with low speed and high speed;

C. record the readings and translated into viscosity index.

In advanced materials within the factory’s quality is very important, tend to take this important step producers ignored.


3. Stripping Wax, release agent processing

The mould stripping wax or release agent processing.

(1) good grinding, polishing processing, glass fiber reinforced plastic mold is clean, dry with a towel, wait for dry after appearing, in 3 ~ 4 layers of clean cloth bag to the right amount of stripping wax (American ship card R333), using the convolution method of uniform coating on the die surface, wait for 3 ~ 5 minutes, with a clean white towel wipe and hard, until the mirror effect, and placed about 2 hours.

Repeat the above operation, a total of 4 times.

Fifth place more than six hours operation.

Non-slip surface, shape, complicated place after the stripping wax, suggest besmear again release agent for many times.

A. new mould or old mould should with appropriate solvents (acetone, for example) cleaning, make sure the surface of the impurity, wax scale, such as clean, and to dry.

B. will CHEMLEAS PMR with clean gauze is soaked, coating on the mould.

C. after coating, before CHEMLEASE PMR has not yet dry solid, with dry cloth evenly coated to the surface.

D. for the first time to use this product, you must repeat, 4, 5 times, about 10-20 minutes intervals, such as mold area is larger, the coating each after a continuous coating, after the last layer coated must will die with dry cloth to wipe the light, and let stand for an hour or more to use.

E. when using gel can be difficult to coating, the stripping effect is very good reason, apply a small amount of stripping wax, without having to use in the future.

F. if the parting is difficult, to CHEMLEAS PMR coated 1-2 times, so as to save cost and ensure quality.


4. Gel Coating

After the mold coating stripping wax (agent), with a gel coating.

Recommended tooling gel coat thickness is 1 mm, gel is divided into two layers, two complete spraying process, each layer of 0.5 mm thick, sprayed three times, and each layer over the 0.15 mm ~ 0.17 mm.

Tooling gel coat thickness must be strictly controlled and this requires every after spray gel coat again, with a gel foot in many parts of the mold surface precise measuring the thickness of gel layer.

The correct gel coating method is as follows:

(1) spray first pass thickness from 0.15 mm to 0.15 mm mould gel.

(2) and the first time into the vertical direction and the second time spray gel coats, thickness from 0.15 mm to 0.15 mm.

(3) according to the direction of the first pass spray finally again gel, so the first layer of gel coat thickness is 0.5 mm.

(4) in order to avoid cracking or wrinkle, should, after the first coat curing can spray another coat.

Under the normal temperature, curing time was 90 minutes.

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