Injection Production Technology Of EVA

Modern plug production is divided into two types: one-time injection molding and traditional molding.

Injection parts: storage ingredients, materials, Lina, R0LL operation, outgoing, crushing, pumping, drying, ejection, constant temperature setting, washing and checking, packing and paying.

Stereotype

EVA: materials, rate comparison, grinding, weighing inspection, paying library.

Finalize the design: material requisition, finalize the type, check the finished product, pay the library.

Ejection part

Raw material formula

1. take 33 metric 11D real white EVA as an example:

EP2288; DF810 plastic grain; DF940 plastic granule; TT magnesium carbonate, titanium dioxide; Si Ling; ZNO-80 masterbatch; JTR-M50 foaming agent; group green gel; EVA1375 red glue.

Formula function:

Plastic granules: the main ingredients of raw materials.

Company's orders: external lubricants, easy to release.

ZNO-80 masterbatch: reduce foaming temperature so that it can be foamed at 140 degrees.

Bridging agent: make plastic colloid cross-linking produce space network structure, make material tenacity.

Foaming agent: nitrogen, ammonia and a small amount of carbon dioxide are produced during the heating process, resulting in the formation of micro pores.

Titanium dioxide, cyan gum, 375 red glue: through proper proportions, the initial embryo after foaming can reach the color requirement.

DF810, DF940 plastic grain and TT magnesium carbonate: improve the physical properties of the initial embryo.

Recipe reaction mechanism

1. the foaming agent is decomposed by heat to produce nitrogen, ammonia and a small amount of carbon dioxide, which makes the pores of the crosslinking body elastic.

2. the bridging agent is decomposed by heat to produce active radicals, replacing the hydrogen ions of polymers, so that polymers are active and cross-linked into three dimensional network structures with toughness.

What is EVA foam injection molding technology?

Through the EVA mixture formula, we use the principle of linear expansion of the ejection molding machine and the reduction of the die cavity to achieve the required foaming body, which includes melting, mixing, flow, crosslinking, foaming, expansion and contraction to achieve the purpose of forming the EVA.

It mainly consists of three main elements of interaction.

Injection control -- die design -- formulation stability

Two. Materials.

The finished ejected EVA material is stacked together with the whole hand and placed in the prescription material to be inspected.

The inspector should check the ingredients thoroughly.

The requisition personnel should confirm whether the ingredient is normal.

The ingredients personnel and inspectors can sign the ID card after the material can be taken out of the warehouse.

Three. The Lina machine

1. principle of work: after two rollers are rotated and the wall is extruded, the glue is fully dissolved and mixed.

2. operational matters:

The drugs should be first in first out and dry in place, not on the floor or in damp places.

The preheating temperature is set to 70 degrees.

The first mixing time is 9-10 and the temperature is 100-105 degrees.

When temperature reaches 100-105 degrees, add foaming agent and bridging agent.

The second stage mixing time is 3-4 minutes and the temperature is 105-115 degrees.

Clean the machine when changing the material or color.

Four.ROLL machine

1. principle of operation: the tearing of the compound through the rotation of two rollers can make the compound more fully mixed.

2. operational matters:

Turn on the lubricating oil pump before starting, then turn the lubricating oil into the oil groove of the roller and turn on the motor.

The roller temperature is set at 60-70 degrees, and the measurement is not more than 75 degrees.

After unloading the material, ROLL was cut two times below 6-8mm thick, and then thinner after 1.0-1.5mm, then 5 times after 6-8mm.

Five. Film out machine.

1. operational matters:

The temperature of the ROLL roller of the discharging machine is set to 60-65 degrees, and the measurement is not more than 75 degrees.

The film thickness is 1-1.5mm

Material length 80cm, width 40cm

The material can be crushed into 6h.

Six. Grinder.

The material can be crushed to 6h.

At least three hands were smashed in batches.

The machine can not be crushed in 30 seconds after starting the machine. The material in the material tank must be crushed to prevent shutdown.

When changing the color system, clean the machine thoroughly and open the cooling water when producing.

Seven. Granulator

1. principle of operation: when the glue enters the screw, it melts. As the screw passes through the mesh, the cutter is cut laterally, and the cooling water comes out, forming granular.

2. operational matters:

It is necessary to warm up before the machine is produced. When the temperature reaches 30 of the set temperature, it can turn on the machine, so as to avoid the pressure and cause safety hazard.

The temperatures are set at 1-84 degrees; 2-85 degrees; 3-85 degrees; 4-90 degrees; 5-85 degrees; 6-90 degrees; 7-90 degrees.

The temperature of the cooling water is below 50 degrees, and the size of the material should be even.

The EVA in the screw should be finished before shutting down.

Eight. Drying

Bake: 35-40 degrees; time: 30-240 minutes.

Baking must be recorded in form.

Nine. Ejection

The shooting control conditions are set according to the requirements of shoe type: take 2210 as an example: the mold temperature is 165 degrees plus minus 5 degrees, and the holding time is 300 seconds.

Use the sword cloth, bamboo slice and air gun to clean the mold.

Ten. Constant temperature oven

1., the working principle: the stereotyping oven works according to the temperature of the constant temperature tester. When the actual temperature is lower than the set temperature, the heating tube is automatically heated. On the contrary, it uses the fan to discharge heat and automatically controls the speed to stabilize the temperature at last.

2. operation settings:

The five paragraph is 60-55-50-45-40 respectively.

3. operation requirements: the first embryo product should be taken away from the mold within 3 seconds and sent into the oven within 18 seconds.

Eleven.PH wash.

1. the water temperature is 35-45 degrees.

2. after the water washing machine is finished, tap the water drops gently, and then check the ratio of the finished products according to the check board.

3. when packaging, no mixed mixing phenomenon will occur.