Two-Line 2K Chain Guard
De Woerd produces amongst other things chain guards for bicycles and approached Momexx with the request to design and produce a mould for a more efficient production of their chain guards.
Problemstatement
A chain guard consists of two components, which were previously produced by two separate moulds. The products of the first mould were manually assembled into the second mould after which the complete product was spray-casted.
Though there was a big problem with the fitting and closing between the two components due to a rather large time gap between the spray-casting of the first and second component. To solve this problem the best way possible, the first components were heated before assembled into the second mould. However, this is very time consuming, expensive and therefore not the ideal solution. It was the challenge for Momexx to find a more efficient solution for the production of two-line 2K chain guards.
Flow Analysis
For the appearance of the chain guard is was important to keep the flow-lines as much as possible on the non visible side of the product. There were extensive flow analyses made to achieve this. The analysis demonstrated how the hot- and cold runner beams should be installed in order to realize the required stream with the diversity of tube diameters.
Machinery and craftsmanship
Many of the parts of the mould were constructed by milling due to a high degree of accuracy, product shape and costs. Hereby the machinery is being used for as much as 24 hours a day, whereby unmanned at night. This also holds account for spark-erosion cutting.
Multiple parts are also produced in China with similar high quality machinery (f.e. Nak 80 of Assab) and materials.
Moulds
With this specific case Momexx uses her expertise in the area of 2 components (2K) moulds. Hereby a robot is used to place the products.
One of the biggest challenges is the fitting of the mould within the machine sizes, thereby taking into account the shot weight and the perfect placing of the products with the robot. A specific characteristic of this mould is that there are slides put into the front mould, and therefore a perfect placing of the products has been possible.
End product
The production process of De Woerd has been improved and stabilized by the delivery of this 2K mould. Moreover they have realized a cost reduction and therefore the investment in the new mould has been profitable.