Mold trial report, mold trial process

I have done it in an injection molding factory before, and the process is different for each one. The basic process is as follows: 1. Preparation in the early stage (raw materials, equipment, personnel, drawings) 2. Arrange special personnel and special planes to test the mold, the first piece generally needs to be confirmed by three engineers together (mold factory, injection molding factory, and main engine factory), if the first piece is satisfied with the state, it is necessary to produce a small batch to verify whether the state is stable (generally 200) 3. Record relevant data.

This process is generally the mold trial process of the injection molding processing plant.

Raw material handling, feeding, dispensing, beer tasting, recording parameters.

The outline is as follows:

1. Description of the product defective.

2. Bad causes.

Analysis (mold reason, molding specific reason).

3. The improvement plan for the bad reasons, such as the sticking mold, the corresponding improvement plan is the mold polishing, or the moving mold brushing, etc., should describe in detail the modification position, how to repair. It is advisable to attach a repair drawing so that it can be traced back later.

4. Improve effect evaluation. Whether there is any impact on the mold or molding, and whether there is any impact on the product. whether there is any impact on customer use, etc.

5. The participation of relevant personnel should be signed, and the measures of each link should have a planned time.

1. Insufficient plastic parts: mainly due to insufficient material supply, poor flow of melt filling, excessive inflation and poor exhaust, etc., resulting in dissatisfied filling cavities, incomplete plastic parts appearance or incomplete individual cavity filling.

2. Dimensional instability: mainly due to poor mold strength, poor precision, unstable working of the injection machine and unstable forming conditions, etc., the size of the plastic parts is unstable.

3. Bubbles: due to excessive inflation or poor exhaust in the melt, the residual gas in the plastic parts is small or in a series of cavities (note that it should be distinguished from vacuum bubbles).

4. Collapse pit (dent) or vacuum bubble: due to poor pressure holding and feeding, uneven cooling of plastic parts, uneven wall thickness and large plastic shrinkage.

5. Excessive flash: due to poor mold clamping, too large gap, too good plastic fluidity, and too much material is added to extrude excess flakes along the edge.

6. Poor welding: due to the low temperature of the material when the melt is diverted and converging, the resin and the admixture are not miscible and other reasons, the melt is poorly welded when it is converging, and obvious fine seams are produced along the surface or inside the plastic parts.

7. Corrugation on the surface of the plastic part: because the melt material does not flow neatly along the surface of the mold, fills the cavity, but flows in a semi-cured fluctuation shape on the cavity surface or the melt material has a stagnant phenomenon.

8. Poor demoulding: due to the over-filling effect, poor demoulding performance of the mold, etc., it is difficult to demould the plastic parts or the plastic parts are deformed and cracked after demoulding, or the residual direction of the plastic parts does not meet the design requirements.

9. Mica flake layered peeling: due to the mixing of foreign materials or low mold temperature, the shear effect of the melted material is too large when it flows along the surface of the mold, which makes the material peel off in a thin layer and the physical properties are reduced.

10. Gate sticking mold: due to the mechanical resistance in the gate sleeve, the cooling is not enough or the pulling rod fails, so that the gate sticks to the gate sleeve.

11. Poor transparency: due to the poor contact between the melt material and the surface of the mold, there are small holes on the surface of the plastic parts, which cause the light to radiate randomly or the plastic to decompose, there are foreign body impurities, or the surface of the mold is not bright, so that the transparency of the transparent plastic is poor or uneven.

12. Silver wire markings: due to the presence of moisture or inflation in the material, and too much volatiles, the melt material is subjected to excessive shearing action, and the melt material is poorly sealed with the surface of the mold, or it is rapidly cooled or mixed with foreign materials or decomposed and deteriorated, so that the surface of the plastic part appears along the direction of the material flow with silver-white luster needle-like stripes or mica flake markings.

13. Warpage and deformation: internal stress caused by residual stress, shear stress, cooling stress and uneven shrinkage during forming; Poor demoulding, insufficient cooling, insufficient strength of plastic parts, mold deformation and other reasons, so that the shape of plastic parts distortion, uneven warping or shape hole deviation, uneven wall thickness and other phenomena.

14. Cracks: Due to excessive internal stress of plastic parts, poor demoulding, uneven cooling, poor plastic performance or poor design of plastic parts and other drawbacks (such as deformation), fine cracks occur on the surface of plastic parts and near the feed port, or cracking or cracking does not occur under load and solvent action.

15. Black dots and black bars: due to the decomposition of plastics or flammable volatiles in the material, air and other decomposition and combustion under high temperature and high pressure, the combustible matter is injected into the plastic cavity with the melting, and black spots and black streaks appear on the surface of the plastic parts, or charcoal-like burns along the surface of the plastic parts.