Reducing Risk with Solidworks Plastics

Reducing Risk with Solidworks Plastics

W&S has utilised SolidWorks as our choice of CAD software for many years and after a recent comprehensive review, we upgraded our subscription to include the Plastics add in.

With a long history of using the industry standard plastic injection molding simulation software we understand and promote the benefits of running simulations prior to commencing the expensive process of making a tool.

The following are some examples of how we have used the features of SolidWorks Plastics and Simulations for the benefit of our customers.

Warp
The SolidWorks Plastics software provides many excellent reports but the one that we have found to be very impressive is “Warp”.
It allows graphical representation in three separate axis as well as total warp.
The ability to set a reference point, or plane, anywhere on the part allows measurement of the effect of warp at points of interest.
A feature of the software is the ability to save a copy of the part in its warped state.
We can supply part models which are representative of the final shape after molding.
Assemblies can be recreated with these realistic models to visualise how parts will mate. Any issues can be quickly visualised and measured. This provides a high level of surety over the part design prior to cutting metal.
An example of where we have used this is; whilst preparing a quotation for a project we suspected that one component would warp.
We ran a full Plastics Analysis and the Warp result confirmed our suspicion.
We included a warning in our quotation with advice to review the part design.

Warped Part 01

This part is the lid of a housing for an electronic device and when assembled has a LCD attached to it. Had it been manufactured without resolving the warp issue, the housing would not have been able to be assembled and the LCD would have been distorted.

Air Traps

When preparing a DFM for a part recently we captured a flow issue in a TPE over mould.
The Solidworks Analysis determined that the TPE would have an air trap that would effect the quality of the part.

The air trap would have stopped the flow front from knitting and therefore created a hole.
With the designers authority, we moved the injection gate location to a position that improved the fill.

Fortunately this early intervention resulted in molded parts that were perfect and all stakeholders were saved the inconvenience, time and cost of tool modifications that otherwise may have been required.

Short Fill

During the preparation of another quotation, it was noticed that a part had a very thin wall section and long flow path.
A Plastics Analysis was conducted and determined that the part would not fill completely.
Our quotation included a warning and the recommendation that the part design and material selection be reviewed before proceeding to manufacture.

Finite Element Analysis

FEA allows us to simulate the effect of forces, static or dynamic, on parts or assemblies.
Cyclic forces and variations in temperature can be simulated.
Your part and assembly designs can be analysed to determine how they will perform in use. Design improvements can be made and the analysis can be rerun allowing improvements before prototyping.

Saving time during validation process

An element of the simulation process is the creation of a chart that shows increase in weight of the part during the packing stage of the injection molding process.
We include this chart in the information package supplied to our process engineers for the tool trails and validation process.
It is used to determine an accurate starting point when conducting the gate freeze study, an element of the scientific molding process that we employ when validating a new or modified tool.

Design for Manufacturing Reviews

When awarded a project we conduct full design for manufacture studies (DFM) for each part. These include plastics simulations and include recommendations for solutions to problems that are found.
All recommendations are tested by modifying part models and rerunning the SolidWorks Plastics simulations.

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