Month: February 2022

How Robafoam supports new customers

Robafoam is a specialist engineering company that has over 30 years of experience in robotically applying foam seals directly to parts. We support customers from the initial design concept right through to production sign off across multiple services such as sub contract services, lighting sealing solutions, automotive sealing solutions and more. Below are some key stages that Robafoam offer support with.

Initial evaluation of joint design.

Whether it’s a new part in the early design phase or an existing product that is wanting an improved IP rating, the first step would be to evaluate the joint design. Understanding what the joint design is, as well as the assembled gap size, is crucial to deciding the gasket specification. For the majority of IP ratings, the gasket must be compressed to a minimum of 50% and no further than 70%. Controlling the compression is an important factor to ensure the serviceability of the part, if the gasket is over-compressed, the cell structure within the foam material can become damaged and therefore unable to return to the original height.

Our design guide can help designers optimise the joint design to ensure they can achieve the required IP rating. https://www.robafoam.com/wp-content/uploads/2021/07/Robafoam-Design-Guide_Download.pdf

Sample prototype

Once the joint design has been optimised, Robafoam offers free sample processing which allows designers to see what our technology is capable of. We have a dedicated lab facility that uses a 4600 6-axis ABB robot and has the capability of processing parts up to 2m x 3m in size. We are able to apply our gasket direct to any substrate whether it be a type of metal, plastic, or a 3D printed SLA prototype. The only characteristic the substrate must have is thermal stability at 80 degrees due to the gasket being a heat cure material.

Costings and preliminary testing

From the prototype or sample trial, a cycle time and foam weight (gasket weight) will be generated. These two factors are what our costings are based upon. A quote will be issued to the customer at this stage.

At this stage, Robafoam is able to perform some unofficial testing on the sample to ensure the sample gasket is suitable for the application.

Specification refinement

Initial testing can be carried out on the prototype sample. It is important to evaluate how the part assembles with the gasket as well as carrying out IP ratings. Robafoam’s technology has the capability of changing the foam hardness by increasing or decreasing the amount of air entrained within the PU material. Therefore, if the part does not pass the required IP test, we would recommend hardening the foam to increase the compressive force of the gasket. Alternatively, if there are some assembly issues due to the gasket being too hard then we can increase the foam ratio to compensate for this.

Furthermore, the technology has the capability of changing the gasket height in specific areas of a part. If your design has a small out of flat condition in areas, or you require a greater level of compression between fixing points, we can increase the gasket height within these areas. A simple change in robot speed is all that is required.

Design sign off

Once the customer is satisfied with the gasket specification and has completed all the required testing, the design will be signed off and ready for production. Bot ISIR and reference samples will be produced at this stage. Small batch runs are also performed to ensure the production process is refined.

Robafoam Technology – Robafoam Foam Sealing System

Robafoam are specialists in the field of 1K foam sealing. Using our expertise, we design and manufacture entire foam sealing systems, tailoring these for a range of applications including automotive sealing, lighting sealing and more.

The 1K foam sealing technology converts a single part polyurethane (PU) material into a closed cell liquid foam. This is achieved by mechanically entertaining air (or chosen gas) into the material. The chosen level of air entrainment enables a wide range of hardness to be selected.

Designed to work with many materials, to create closed-cell foam. Our technology produces a liquid foam seal that is applied directly to customer components. This unique system requires no in-process purging and has been measured at over 98% availability.

We would like to introduce you the Robafoam Technology.

 

Pump unit single-component sealing material:

The pump unit is a drum where the raw material is stored (20lts pail – 200lts drum). The material can be stored at room temperature and does not require heating prior to the air entrainment. Due to the material requiring 80 degrees to cure, the shelf life is months as the material does not react without the required heat.

The raw material is pumped from the 200kg drum into the Foam unit where the entertainment of air occurs.

Foam creation equipment:

The process takes the raw material from the pump unit and converts it to foam by accurately introducing a measured quantity of compressed air. The amount of air used in this process defines the foam hardness. The more air added, the softer the foam will be. This can be adjusted to create a wide range of shore hardness, depending on the requirements of the customer- We refer to this as foam ratio.

Dispensing valve:

Our 6 axis robot system can apply a gasket to any substrate including plastics, metals, and glass. The level of natural adhesion the foam has to the substrate depends on the dyne value. If there is no natural adhesion, we can use plasma pr-treatment to increase it. Using 6 axis robot, we have the capability of applying a bead to simple flat parts and complex 3D profiles as well as double face applications.

Oven system:

Whether requiring our material for bonding or foam sealing, the PU cures rapidly at temperature 80ᵒC or above. The material itself will cure within seconds at the required temperature, however, what defines the curing time is the heat sink properties of the part. The last section of material to cure is the one that is in direct contact with the part and therefore this face much reach 80ᵒC. The average curing time can be between 3-8 minutes. During the initial enquiry and sample phase of working with a customer, the requirements of the part curing can be adjusted to find the optimal curing time needed for each part.

The flexibility of Robafoam’s oven systems means that they can be customised to work for any requirement or production environment. Ambient to 220ᵒC, our industrial ovens and thermal systems are suitable for material curing, drying, tempering, preheating, and cooling.