Acrolab was asked by a client to assist them with the development of an automated, rapid cure process for producing a series of Carbon Fiber Reinforced Plastic (CFRP) parts utilizing ISOMANDREL® technology.
Acrolab’s ISOMANDREL® technology was utilized to create this new manufacturing process
The first step was to understand the client’s requirements and develop a project outline. After a detailed consultation and discussion, we focused on the design of a manual production cell for the proof of concept. Once proven, the next step would require building an automated system. The core technology for the cellular manufacturing system was centered on Acrolab’s ISOMANDREL® technology in conjunction with extensive application research by the Acrolab team.
ISOMANDREL® Technology in Development Since 2010
Acrolab has developed new and discrete processes on a custom basis for manufacturers across a broad range of industry sectors. The mass production of CFRP parts currently requires the use of industrial ovens and ISOMANDREL® technology presents a new opportunity for manufacturers to adopt a new technology that would replace or enhance their existing production processes.
The new manufacturing process using Acrolab Isomandrel technology cures the composite faster resulting in a more efficient and cost-effective production cycle.
ISOMANDREL® Rapid Cure of CFRP Part – Proof of Concept
Acrolab developed a solution for our client based on our specialty in two-phase heat transfer technology along with application knowledge and expertise in developing an enhanced manufacturing process for composite (CFRP) part production utilizing our ISOMANDREL® technology. In order to develop the manual production cell for CFRP part manufacturing, Acrolab’s engineering team invested a significant amount of time researching:
- the appropriate and optimal resin and fiber materials,
- defining the winding schedule,
- choosing the appropriate winding machine,
- designing the Isomandrels for various part configurations,
- designing special tools,
- calculating the heat up rate, and
- curing parameters and the cooling rate to integrate all the equipment used during the full production cycle.
Building an Automated CFRP Part Manufacturing System
After the concept development of the manufacturing system, there were several meetings with our client to examine the feasibility of transforming the manual production cell proof-of-concept into an automated CFRP production process.
At this phase of the project, Acrolab was required to integrate our ISOMANDREL® technology into the clients existing manufacturing process of CFRP parts, keeping in mind the characteristics of various materials and the various part configurations provided by the client.
The Importance of Scheduling, Temperature, and Curing Times
During the development of the manual production cell for CFRP part manufacturing, we were able to better understand the curing cycle (schedule, temperature and time) for the client’s CFRP parts and the mechanical properties of the finished parts as they relate to the schedule, process temperature, and curing times.
Temperature Settings for the Heating & Cooling Stages in the Curing Process
One of the key factors in this process was developing the proper schedule for curing parts by ensuring that the temperatures were properly set for both the heating stage and cooling stage to optimize the curing process. The mechanical properties of the CFRP parts depend on the chosen resin and fiber materials, the winding schedule and angle, the curing temperature and time plus many other factors.
To identify the curing behavior of the CFRP parts, pre-preg materials were investigated and on our recommendation, the client selected the pre-preg tape used for the study. A special Isomandrel, including the relevant extraction jigs, were designed and built. Combining the use of the Isomandrel, the pre-preg material, and the induction heating system, we carried out several wrapping and curing tests to document the curing behavior of the selected pre-preg.
Testing of the Production CFRP Parts
To examine the mechanical properties of the composite parts cured at various temperatures and curing times, the samples were sent out for testing. Three ISOMANDRELS® were used for the CFRP parts and were designed and sourced from local suppliers. One of the part designs provided by the client was significantly more challenging than the others. A lot of time and effort was spent on this unique CFRP part and ultimately the ISOMANDREL® for this unique part and the accompanying extraction tools were carefully worked out.
We studied the thermal characteristics of the ISOMANDREL® and a set of suitable inputs/parameters were established for the induction system based on experimental results from using the ISOMANDREL®.
A detailed technical report summarizing the manufacturing system design which included the ISOMANDRELS®, enhanced tooling designs, equipment selection and testing procedures. The experimental results obtained were prepared and submitted to the client. From here the client was able to assess the feasibility of incorporating an automated CFRP Part manufacturing process into their current production environment.