Parting line
Where the mold splits decides visible seams and how the part releases.
Large & technical parts
Irregular Hollow Shapes: Machine Configurations
Machine and mold configurations for hollow seats, shaped housings and other irregular parts, with published specifications side by side.
- Typical size
- Part dependent
- Materials
- HDPE · PP
- Machine series
- TDB
- Suggested models
- 2
In short
Irregular Hollow Shapes: what to know
Irregular hollow products, such as mannequins, hollow seats and shaped housings, depend on mold design as much as on the machine. Tongda reviews parting lines, undercuts and wall distribution first, then matches a TDB machine to the part.
Assess parting lines, undercuts, wall distribution and removal from the mold at the start of the project. Tongda’s published application range points to TDB machines for these products.
Typical products
- Plastic mannequins
- Hollow seats and chairs
- Shaped housings
- Leisure and sports products
Materials
- HDPE
- PP
Production process
How the production line works
- Step 01
Prepare the resin
Blow-molding grade resin, masterbatch and regrind are dosed to the product specification.
- Step 02
Extrude the parison
The extruder melts the material and the die head forms a hollow tube of controlled wall thickness.
- Step 03
Close and blow
The mold closes on the parison and compressed air forms the part against the cavity.
- Step 04
Cool and release
The part cools in the mold until it holds its shape, then the mold opens and the part is removed.
- Step 05
Trim and finish
Flash at the neck, handle and base is removed; necks are cut or reamed where required.
- Step 06
Inspect and pack
Weight, dimensions and leak tightness are checked before labeling and packing.
Selection guide
Choosing a machine
Undercuts
Undercuts may need mold slides or a different orientation.
Wall distribution
Deep or stretched areas need parison programming to avoid thin spots.
Finishing
Plan trimming of complex flash lines and any assembly steps.
Machine configurations
Irregular Hollow Shapes line configurations
TDB-80F
≤ 80 LAccumulator-head extrusion blow molding for 50–80 L products, with bottom blowing and a servo motor.
- Stations
- Single
- Clamping
- 440 kN
- Power
- 131.5 kW
TDB-120F
≤ 120 LAccumulator-head extrusion blow molding for 80–120 L products, with bottom blowing and a servo motor.
- Stations
- Single
- Clamping
- 740 kN
- Power
- 131.5 kW
| Model | Stations | Max. volume | Clamping force | Screw | Total power | Max. mold (W × H) | Datasheet |
|---|---|---|---|---|---|---|---|
| TDB-80F | Single | 80 L | 440 kN | 100 mm | 131.5 kW | 800 × 1000 mm | PDF · 2.3 MB |
| TDB-120F | Single | 120 L | 740 kN | 100 mm | 131.5 kW | 900 × 1450 mm | PDF · 2.1 MB |
Suggested starting points from the published range. The final configuration depends on your product drawing, resin, weight and output target.
Quotations, prices and project cases: Tongda irregular-shape product machines on tongdamachine.net ↗
Video & product gallery
Irregular Hollow Shapes
Watch on YouTubeMachine in operation
See the irregular hollow shapes line running
Watch a Tongda machine producing this type of product, from parison extrusion to the finished part. For a video of a specific model or configuration, ask our team.
More machine videos
Questions from buyers
FAQ
Didn't find your answer?
Ask our engineersCan mannequins be blow molded?
Yes. Mannequins and other shaped hollow products are made by extrusion blow molding with purpose-built molds.
Which machine should I choose?
TDB machines such as the TDB-80F and TDB-120F are typical. The size and weight of your part decide the model.
What should I send for a quotation?
A 3D drawing or sample, the material and the required annual quantity.
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