Part I Basic mold information (customer\type\rubber\product and mold size\steel)
Part II Product description and requirements (difficulties in product molding and demolding)
Part III Mold structure design (pouring\parting\ejection reset\cooling\mold action)
Part IV Mold manufacturing and processing (NC\EDM\WC\mold saving\assembly, etc.)
Part V Injection molding process (baking material requirements\mold temperature\material temperature\injection molding cycle\clamping force\injection pressure)
Part VI Summary

1. This product is a transparent plastic part, clamping line and appearance quality requirements are very high.
2. Average wall thickness is only 2.3mm, and customer requires a molding cycle of 70S.
3. Customer accepts front mold undercut adopting spring front mold structure, large side undercut of drawer rear mold adopts large lifter driving small lifter structure.

1. A plate original body uses 2711 pre-hardened steel; B plate material is 1.2311.
2. The lower mold thickness, slide and other forming parts use 2711 pre-hardened steel, of which lifter is nitrided to a depth of 0.15 and hardness is HRC50~52.
3. Except for AB plate, mold base uses medium carbon steel 1050; mold base standard parts use HASC0 equivalent specifications.
4. Hot runner uses Mold-Master needle valve hot nozzle, two-point water entry; junction box and power/electrical couple socket use HARTING specifications.
5. Large slide oil pump uses PARKER oil pump; quick plug nozzle uses STAUBIL specifications.

 

This drawer product is a transparent part with complex weld lines and structural clamping lines. During mold forming, multiple positions need to be removed and buckled.

 

Mold-Master needle valve hot nozzle is used, and water is entered at two points; water entry position has been verified by MoldFlow analysis.

 

1. Parting surface design: Pull out from R corner of the product, with smooth transition at the corner, without step corners.
2 Thin steel position processing at insertion point: Two insertion positions of front mold are inserted for easy maintenance.

 

1. Combined lifter structure:
Lifter is designed into three sections. Large lifter in the middle is obliquely ejected under ejection drive, while small lifters on both sides have an angle difference with large lifter in demolding direction (angle of small lifter is smaller than that of large lifter); large lifter uses structural angle in horizontal direction between large and small lifters, and drags small lifters on both sides through "T"-shaped bar to shrink inwards while ejecting obliquely; structure is mature and reliable, and has great promotion significance.

 

2. Sliding position lifter structure:
Large slider moves outward, and slider lifter is blocked by block fixed on B plate, so that it moves upward under action of slider inclined groove to escape undercut; block is disengaged from slider lifter, and slider lifter moves outward with large slider to complete demolding. Structure is mature and reliable, and has promotion significance.

 

3. Spring-type front mold structure: (front mold slide)
Front side of drawer is inverted, and front mold adopts a spring-type front mold structure; length of front mold slide is 670mm, so there are inclined guide pillars on both sides for guidance, and there are four sets of springs in the middle of slide for front mold to pop out; in addition, there are three sets of mountain screws at both ends and the middle of slide to limit.

 

4. Ejection and reset system:
Push square and inclined ejection, ejection is safe and convenient to take out; because oil pump slide has strict sequence requirements when opening and closing mold, oil pump slide is equipped with a card to control action sequence.

 

5. Cooling system:
Front mold original body makes mold cool quickly, each slide has a separate water supply for inclined ejector and hot nozzle, and the overall cooling is sufficient.

 

6. Other structures:
Product has a large projection area of about 1755CM2, there is no gap between A and B plates to make pressure-bearing surface sufficient. Four sides are designed to be square.

 

<I>. Precautions for NC processing:
1. In view of large processing depth of lower die, principle of segmented roughing should be adopted, and different tool lengths, processing allowances and cutting depths should be set to ensure safety and efficiency.
2. In view of fact that the lower die push square groove is easy to bounce knife, an arc transition should be added at the corner of push square groove to avoid sudden changes in processing direction. On the side of push square groove glue position, allowance should be appropriately increased or surface should be moved horizontally to prevent knife from bouncing.
<II>. Precautions for EDM processing:
1. Push square around lower die should be loaded into lower die for electro-etching to prevent wire from being clamped at push square.
2. When electro-etching the lower die, it should be electro-etched one by one in one direction to avoid processing grading.
3. Carbon open roughing is used for large allowance part of lower die, a large spark position is used, and discharge allowance is appropriately increased.
<3>. Precautions for wire cutting:
Perform wire cutting process after NC processing, and pay attention to correct number of collisions according to auxiliary benchmark provided by NC processing.

 

Material baking conditions: 80ºC, 2~4 hours. Mold temperature 40~80ºC, this product is recommended to take the larger value to reduce influence of weld lines.
Injection molding should be as high-speed as possible and reasonably pressure-maintained to reduce shrinkage holes. During mold trial, clamping force is 650 tons, injection pressure is 950kgf/cm2, injection pressure is 7 seconds, cooling time is 18 seconds, and ejection stroke is 105mm.
Product beer molding cycle is 53 seconds.

1. Combined lifter structure: While large and small lifters are ejected obliquely, large lifter drags small lifters on both sides through "T"-shaped bar to shrink and demold inward. This structure is novel and creative.
2. Cooling system, pouring system, and ejection system are reasonably designed. „
3. The overall structure is compact, simple and suitable, action is safe and reliable. „
4. The overall processing is reasonable (less EDM in non-glue part), assembly process is reasonable, and it is easy to replace
(two thin steel parts are used as inserts, which are easy to replace)