11 points about the analysis of plastic structures

1. Regarding the analysis of plastic structures, we first understand the relevant conditions of plastics such as name, manufacturer, grade, molding shrinkage, fluidity, heat sensitivity, mold requirements, conditions, etc.

2. Whether any unreasonable mold structures can be improved, and whether the items changed in the previous design have been modified in the plastic part drawing.

3. Which molding method to use?

4. Whether there are existing molds available for some commonly used plastic parts (such as gears, gearboxes, battery boxes, etc.).

5. Plastic Structures Forming analysis.

• Whether the outer surface of the plastic part is formed on a movable mold or a fixed mold.

• Whether the parting surface, penetration surface, and collision surface are ideal. Whether the slope of the insertion surface is sufficient, preferably 3°~10°.

• Whether the parting line on the surface of the plastic part can be accepted by the customer.

6. Analysis of plastic structures

• Whether the wall thickness is reasonable, whether the part of the plastic structure is seriously asymmetrical, how to overcome the deformation caused by the serious asymmetry of the plastic part, and how to overcome the shrinkage marks when the plastic part is locally thick.

• Whether the part  of the plastic structures will shrink and sag on the surface due to too concentrated heat and not easy to cool, which side will the sag appear on, and whether there is a solution

• What is the height of the rib and its ratio to the wall thickness

• Whether the wall thickness of the root of the self-tapping stud is too large, and how to solve it if it is too large.

7. Feed analysis

• How to choose the form, quantity, position, size, etc. of the gate, how to achieve a balance of feeding, and whether the selection of the gate position will cause deformation of the plastic part.

• Whether the gate form used will cause flow marks, serpentines o,r uneven color (such as fuzzy, foggy, etc.) near the gate, and how to avoid it.

• Analyze the position where the weld line appears, and try to make the weld line form on their face that is not stressed or not important. It is advisable to set up an exhexhaustedoove or a cold slug hole near the weld line.

• Is it necessary to add auxiliary runners? With the setting of auxiliary runners and cold slug holes, will it have adverse effects on the appearance and color of the plastic part surface, such as shadows, fog, and s left after cutting the gate, etc.? Is it necessary to set up an overflow tank?

• If the wall thickness of the plastic part is uneven, the ideal way to feed the material is from thick to thin.

• Mold flow analysis should be performed when the melt flow is difficult to determine.

• If there are mesh holes in the plastic parts, is it necessary to set up auxiliary flow channels or breathable inserts because of the large material flow resistance at the mesh holes?

8. Evaluation of the lateral concavity-convexity plastic structures

• Which side of the plastic portion has the lateral bump, and can the structure be strengthened without using the lateral core-pulling mechanism?

• How to avoid having the inclined push rod make contact with the mold core, self-tapping hollow studs, reinforcing ribs, or other plastic part structures when it is pushed out.

• If the plastic component will be dragged out and distorted by lateral core pulling, what preventative measures are available, and whether it is essential to utilize delayed core pulling or add a push rod to the lateral core pulling mechanism?

9. Release analysis.

• Whether the customer has special requirements for launching the system, such as method, size, location, quantity, etc.

• Whether the demoulding slope is sufficient, whether there is any problem in pushing out, whether there is a special requirement for the demoulding slope on the plastic part drawing, whether it is necessary to ask the customer to increase the demoulding slope, and the tightness of both sides of the moving and fixed molds Which side of the force is greater, is it sure that it will stay on the side with the push-out mechanism, if not sure, what countermeasures are there?

• Whether a large deep cavity plastic part will produce a vacuum when it is pushed out, what countermeasures are there, and whether it needs to be pushed out pneumatically.

• For transparent plastic parts (such as PMMA, PS, etc.) or plastic parts with side wall etching, can the demoulding slope be made larger?

• To prevent the plastic parts from being scratched during demolding, the larger the demoulding slope, the better, but the increase of the demoulding slope, will it cause difficulty in assembling the plastic parts, or produce shrinkage dents and shrinkage deformation.

• To prevent the top from being pushed out, has the customer stipulated to delay the push out for the partial push rod?

• Pay special attention to the push-out position of transparent plastic parts.

10. Coordination between plastic parts

• Whether the tolerance of the dimensions required for matching with other plastic parts meets the requirements, especially paying attention to the influence of the draft angle on the assembly of plastic parts.

• Whether the parting line is appropriate, whether it will affect the appearance, and whether the flash and burrs will affect the assembly.

11. Others

• Where is the benchmark of the plastic part drawing?

• Whether the possible deformation and warpage of plastic parts are fully predicted, and whether there are countermeasures.

• Whether there are sharp corners and sharp edges in the plastic part drawing, whether it will affect the fit with other plastic parts after rounding, and how large the rounded corner R can be.