PU leather common pitfalls and solutions

Synthetic Leather International Network January 12 hearing: in the production process, PU leather common pitfalls are: pinhole, spot, orange peel, drag lines, floating loose, now wove pad injury, the pattern is not clear, light dumb uneven and so on.

First defect：Pinhole

Cause

1, a mixed solvent evaporation too fast;

2, the furnace temperature is too high.

Solution

1, adjusting solvent formulations;

2, due to lower furnace temperature, especially the first set oven temperature.

Second defect: Spot orange peel

Cause

1, the bottom fabric uneven shrinkage;

2, the surface layer of the primer solvent made up.

Solution

1, the end of the fabric adjustment formula, the major base coat appropriate to add a layer of surface liquid type glue.

A, adjusting solvent formulations;

B, appropriate to accelerate the speed and reduce swelling time;

C, addition of polyethylene plastic surface phenoxy or a crosslinking agent.

Third defect: Tow line

cause

1, a blade opening foreign body;

2, paint unevenness.

Solution

1, the elimination of foreign body;

2, an increase in agitation, the pigment evenly, filtered through the young network.

Fourth  defect: Pine float

cause

1, fit gap is too large, insufficient bonding pressure;

2, the base material is too thin;

3, Fabric Wool cloth too long.

Solution

1, adjust the gap, increase the bonding pressure;

2, thick base material, an appropriate increase in the coating amount of the adhesive layer;

3, appropriate to reduce the length of plush fabric.

V. defect: Line fabric grain

cause

1, fit the gap is too small, fit pressure is too large;

2, incomplete drying;

3, the curing time is not enough.

Solution

1, high-speed gap, reducing the bonding pressure;

2, the speed appropriate to reduce or increase the appropriate oven temperature;

3, an appropriate extension of aging time, especially in winter; or increase the amount of crosslinking agent and accelerator.

Sixth defect: Pad injury

cause

1 periodically pad injury: A, a production process roller or the pressure roller outstanding foreign body; release paper paper at the end of a foreign body.

2, the quality inspection did not find until only the use of units found uncooked good.

Solution

1, A, clear the roller or the pressure roller to highlight differences; B, remove the paper bottom foreign matter.

2, an appropriate increase in the amount of crosslinking agent and accelerator, or consider choosing other kinds of grades of crosslinking agents and accelerators.

VII. Defects: Pattern unclear

cause

1, fit the gap is too small, fit pressure is too large;

2, the release paper use too many times, the paper pattern is unclear.

Solution

1, adjust the fit clearances and pressure;

2, removal of part of the release paper pattern is unclear.

VIII. Defects

Dumb light unevenness

cause

1, the release paper piling up for too long, some moisture.

2, the release paper use too many times, the paper pattern uneven surface of the light dumb.

Solution

1, first empty paper go once, release paper and drying;

2, removal of light dumb uneven portion release paper.