Ultrapolymers New development: Pump chamber for cottages / holiday houses

New development: Pump chamber for cottages / holiday houses

When the tool was made three materials were evaluated for the pump chamber
    Material A: density 935, mfr 7,0
    Material B: density 935, mfr 6,0
    Material C: Lupolen 3621 MRM: density 935,5, mfr 7,5

The rotomoulder monitored the following properties:
    - Oven time, until bubble free products
    - The internal surface of the product
    - The filling of material around inserts
    - The displacement of the part where the venting of chamber is fitted
    - The filling of the threads
    - Warpage
    - Wall thickness distribution
    - Ease of demoulding


The rotational moulder did not have a lot of advanced laboratory equipment, but managed to make a good evaluation using “simple” tools:
The internal surface was evaluated and documented with the loupe and camera:


The filling around inserts and the filling around threads were evaluated with the folding rule and the camera:


The pinholes and the filling of threads were evaluated visually under the loupe.
The warpage was evaluated with the folding rule:


The wall thickness was measured in critical areas of the chamber:

The displacement of the vent was measured with the folding rule:

Finally parts of the tank were tested with a drop test:


Based on this evaluation the customer made this spider diagram to visually judge the performance of the different materials:


Based on this evaluation it was easy for the rotomoulder to choose Lupolen 3621 MRM for their new product.

Although material density and MFR is identical – different materials will behave differently in your operation. Look at the total production economy – including oven time, product handling and customer satisfaction. If you do your homework – it will pay off in the long term.


For further contact please contact UltraPolymers European Technical Development Manager Ronny Ervik: [email protected]