Common blow molding problems and solutions for blow molding

one. Black or black

A small black substance or a short black line on the surface of the transparent part or the transparent part of the part.

machine:

1. The residence time in the barrel is too long.

2. The molten material stays in the blown barrel or in the nozzle flow path.

3. There is a foreign object in the blown barrel.

4. The electric heating ring is loose or weak or electrically unstable, causing the material to degrade.

5. Imperfect nozzles block the nozzle.

6. Improper blow molding conditions.

7. The blown barrel has cracks or screw depressions.

8. The beer machine parts are short of oil.

Mold:

1. The mold inlet is not properly installed.

2. Incorrect exhaust causes burnt material

3. Dirty caused by grease or lubricant

4. The mold size is too small for machine tonnage.

material:

1. Raw materials are contaminated

Beer:

1. Inconsistent processing cycles.

two. Bubble (surface bubble)

During the blow molding process, the fugitive gas is trapped in the future when the surface of the part is formed, causing defects on the surface of the blow molding part.

machine:

1. The blow screw rotates too fast.

2. The screw back pressure is too low.

3. Shooting speed is too fast

4. The injection cycle time is too short.

Mold:

1. The mold temperature is too low.

2. Incorrect nozzle position.

3. Insufficient exhaust or clogging at the exhaust.

material:

1. The nozzle material (re-grinding material) is too rough.

2. A volatile material is used.

3. The material is not dry enough and the blown material is wet.

Three. Baking

The defects of surface cloud spots are common in the nozzle position, and sometimes there are weak physical properties in the common defect areas around the obstacles of the flow channel.

machine:

1. Blowing is too fast.

2. The melting temperature is too high or too low.

3. Blowing pressure is too low

4. The diameter of the nozzle is too small.

5. The nozzle temperature is too low.

Mold:

1. The mold temperature is too low.

2. The diameter of the nozzle is too small.

3. Incorrect nozzle position.

4. The mold wall is insufficiently cooled.

5. Too sharp corners, especially the nozzle area.

material:

1. The material is too moist.

Beer:

1. Inconsistent machine blow molding cycle.

Deformation

The state of being bent like a bow may be a convex or concave shape, or may be caused by a different shrinkage rate from the surface to the other side of the part.

machine:

1. The mold opening speed is too fast.

2. The thimble system is uneven or not parallel.

3. The cooling time is too short.

4. Parts "packaging" error.

Mold:

1. The melt temperature is too low.

2. Inconsistent mold temperature

3. The nozzle is in the wrong position.

Beer:

1. After processing the beer, the processing of the parts is improper.

Fives. Fracture

The tendency of plastic parts to break or break under certain abnormal environmental conditions, sometimes parts can be destroyed.

machine:

1. Incorrect blow screw design.

2. The blow molding cycle is too short.

3. Use an inappropriate, wrong nozzle.

4. The injection pressure is too high, and the screw speed or blow speed is too fast.

5. The temperature of the melt at the nozzle is too high

6. The blow molding pressure is too low.

Mold:

1. Inlet design restrictions.

2. Condensation of rubber in the flow channel

material:

1. Melt temperature is too low

2. The rubber is too moist

3. The performance of the rubber particles is degraded.

Beer:

1. The blow molding cycle is inconsistent.

six. bubble

The gas zone enclosed in the plastic part is different from the bubbling on the surface. It is often caused by a trapped gas or air bag, but it may also be caused by shrinkage.

machine:

1. The blow molding temperature is too high.

2. The blow molding pressure is too low.

3. The shot time is too short.

4. Material was not replenished in time.

5. Wrong melt temperature tuning.

6. Faster shot speed.

7. Abnormal blow molding pressure.

Mold:

1. The inside of the flow channel is damp.

Beer:

1. Inconsistent blow molding cycle.

Seven. Charred

A small black burn scar or black scar on the surface of the blow molded part usually occurs at the end of the rubber flow path or at the end of the blind hole.

machine:

1. Too fast blow speed or excessive blow pressure.

2. Blowing pressure is too high.

3. The screw rotation speed is too high.

4. The wrong compression ratio of the screw.

5. Wrong melt temperature control.

6. Excessive barrel temperature.

7. The diameter of the nozzle is too small.

Mold:

1. Wrong exhaust system.

2. Wrong water inlet (size position).

material:

1. The mixing ratio of the nozzle material is too high.

Beer:

1. Inconsistent blow molding cycle.

Eight. Spend color points

The surface arc and dot defects of the blow molded parts caused by the lack of plasticity can also be caused by incorrect colorant distribution (cloth).

machine:

1. Barrel temperature is too low

2. The mold temperature is too low.

3. The screw speed is too slow.

4. Wrong screw compression ratio.

5. Wrong blow temperature control.

material:

1. Excessive use of nozzle material.

Beer:

1. Inconsistent blow molding cycle.

nine. Poor gloss

Defective areas like clouds or fog often appear on the surface of transparent parts.

machine:

1. Barrel temperature is too low

2. The clamping pressure is too low.

3. The screw speed is low.

4. The gap between the barrel wall and the screw is too large.

Mold:

1. The mold is not evenly fed.

2. The surface of the mold is not shiny.

3. The mold temperature control is not good.

material:

1. The blow molding material is too moist.

Beer:

1. The blow molding cycle is inconsistent.

ten. Dirty

The presence of an external object or the material of a non-blown part results in defects in the blow molded part.

machine:

1. Oil leakage or lubricating oil dripping.

Mold:

Use too much lubricant.

material:

1. Use the wrong nozzle material.

2. The blow molding material is too moist.

Beer:

1. Insufficient packaging and processing, resulting in inadvertent operation.

eleven. Fracture pattern

Cracks in the blow molding material are common in the vicinity of the dissolved wire, such as blow molding inserts, column positions or other holes, and the brittleness can sometimes be referred to as fracture.

machine:

1. Internal stress effects.

2. The cooling time is too short.

Mold:

1. Use too much lubricant.

2. The etched lines are not enough or uneven.

3. Wrong runner and gate design.

material:

1. Use the wrong nozzle material.

2. The blow molding material is too moist.

Beer:

The blow molding cycle is inconsistent.

twelve. Surface crack

The cracks on the surface of the blow molding parts are very small cracks, often like nets but cracks that are split like spider webs.

machine:

1. It is not suitable to use the clamping force of the beer machine.

2. The cooling time is too short.

3. Blowing speed or shot time is insufficient.

4. The barrel blowing temperature is too high.

Mold:

1. The entrance is large.

2. The mold temperature is low.

3. Dirty surface of the mold

4. The Tsui Tsui runner design is wrong.

material:

1. The blown material is contaminated.

2. The blown plastic is too moist.

Beer:

1. Bad (operational) habits.

thirteen. Delamination

The surface of the blown part of the surface is delaminated or separated, and it can also appear like a fish scale.

machine:

1. The shot speed is too slow.

2. Blow molding is not enough.

3. Shooting glue, holding time is too short.

4. The barrel melt temperature is too low.

Mold:

1. The mold temperature is too low.

2. Sharp water nozzle corner.

3. Mold runners and gates are too large,

material:

1. The nozzle material is contaminated.

2. External material or auxiliary material influence.

3. The blow molding material is too moist.

Beer:

1. Bad (operational) habits.

fourteen. Pollution (dispersion)

The primary color of a plastic material changes, often caused by overheating, mechanical shearing, or chemical reactions.

machine:

1. The nozzle has a large diameter.

2. The glue injection time is long.

3. The barrel time is too high.

4. The nozzle temperature is too high.

5. The blow cycle time is too long.

6. Wrong screw design.

Mold:

1. The mold temperature is wrong.

2. Not enough (minutes) is cold.

3. Insufficient exhaust.

material:

1. Blowing material contamination.

Beer:

1. The blow molding cycle is inconsistent.

fifteen. Batch peak

The extra rubber is thrown out of the mold, usually at the weld line or parting line, but it can also appear at the point where the two surfaces meet.

machine:

1. Blowing pressure is too large

2. Long shot time

3. The barrel temperature is too high (WeChat search kinggle_song)

4. Long blow molding cycle

5. The beer machine has insufficient clamping force

Mold:

1. Wrong part line

2. The mold support is not enough

3. Insufficient exhaust.

4. The nozzle sleeve is too long

5. Incorrect stack size.

Beer:

1. Incorrect blow molding cycle.

sixteen. Flow pattern

Linear defects (or ring-shaped corrugations near the nozzle) are present on the surface of the blow molded part, often indicating the direction of flow of the material in the mold front.

machine:

1. Insufficient injection pressure

2. Insufficient time for injection

3. The barrel melt temperature is too low.

4. The melt temperature at the nozzle is too low

5. The blow cycle time is insufficient.

Mold:

1. The mold temperature is too low

2. The water inlet is too small.

3. Insufficient exhaust.

material:

1. Wrong material flow rate

2. Blow lubrication is not enough.

Beer:

1. The blow molding cycle is inconsistent.

Seventeen. Dumb

The surface finish of the parts is dark, often caused by the filler speed being too fast, and the wrinkles are generated when the blown surface of the mold is rubbed.

machine:

1. Blowing pressure is not enough

2. The shot time is too short.

3. The barrel temperature is too low.

4. The nozzle temperature is too low.

5. The blow cycle time is short.

Mold:

1. The mold temperature is too low.

2. The water inlet is too small.

3. Incorrect water inlet position.

4. Insufficient exhaust.

5. The mold surface is not enough.

6. The surface of the mold is dirty.

material:

1. Poor fluidity.

2. Too moist.

Beer:

The blow molding cycle is inconsistent.

Eighteen. Spray pattern (snake pattern)

a serpentine formed on the surface of the blown part when the melt flows into the front mold

machine:

1. The rate of fire is too fast

2. The barrel melt temperature is too high or too low.

3. The nozzle is too small.

4. The temperature at the nozzle is not enough.

Mold:

1. The mold temperature is too low.

2. The gate is too small.

3. The nozzle is in the wrong position.

4. The nozzle flow path is too long.

material:

1. Poor flow rate.

Beer:

Bad habits of operation.

XIX. Water mark

During the blow molding process, the two streams cannot be merged. This phenomenon is often in the vicinity of the hole or the obstruction, which can cause the blown part (bearing force) to weaken.

machine:

1. The barrel temperature is too low.

2. The clamping pressure is insufficient.

3. The injection pressure or the injection speed is too low.

Mold:

1. The mold temperature is too low.

2. The nozzle is too small.

3. The nozzle is not in the right position

4. The nozzle junction area is too long.

material:

1. The flow rate is wrong.

Beer:

Bad habits of operation.

twenty. Flower strips

The surface of the blow molding part is spread out into strips of material, and the surface of the blown surface is sometimes called a flower strip.

machine:

1. The barrel temperature is too high.

2. The screw speed is too fast.

3. The nozzle is too small, too hot or has obstacles.

4. The nozzle has a large diameter.

5. There are air or gas in the circle.

6. The oven is not clean or contains water.

Mold:

1. The water inlet is too small.

2. There are obstacles in the water outlet.

3. The mold gate is broken.

material:

1. Too moist.

2. The rubber is dirty.

Beer:

Bad habits of operation.