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This Project is about Die Casting Parts Vibratory Finishing Automotive Parts in Pakistan Company Zahoor Die Casting. The outcome of the project saves 60-70% of manual finishing cost.
The cooperation for international business is not easy to start. One of the reasons is that people cannot physically see and hear each other. The only way available is email, WhatsApp/WeChat/skype, phone call, or a video chat. As a result, efficient communication between the two parties is essential.
1. We receive an inquiry and start the contact
In September 2014, we received a question from ZDC company who make aluminum die casting parts for Honda Motor.
At present, they use wheel grinding to polish smaller size aluminum die casting parts. However, the process is dust and dirty, time-consuming.
They are considering a way to improve the process and save time and labor costs.
Also, ZDC shows the parts’ photos before and after dies casting in their current wheel grinding process.
2. Sample delivery and understand product requirement
To better understand parts surface requirements, Imran sends me a technical drawing of all workpieces and production volume in one day.
The information on product geometry is essential to select media size without lodging problems.
The right combination of media and parts is easier for details and media separation.
The production volume together with shift number is essential to decide the machine size.
3. Sample received with confirmed with customer requirement
The workpieces were received one week later. When I open the parcel, I found the workpieces have massive edges and heavy burr, which hard to remove by any mass finishing process.
I talk with Imran if we can do the process after those big burr removed by wheel grinding machine.
Otherwise, if the mass finishing process removes burr, the whole parts completely deform. Imran agreed with my point.
After a short telephone meeting, we agreed: the parts with heavy casting edge from mold need to remove before the mass finishing process. We use the traditional wheel grinder to remove the rough edge and burr in our factory.
4. How we select the machine, tumbling media and polishing compound
4.1 How we select the machine
- The workpiece size is medium size with an extensive production volume. So, a batch-based centrifugal barrel finishing machine cannot be considered.
- The processing time will be extended for several hours, so a continuous surface finishing machine is not suitable for the application.
- The part surface requirement is critical, so we want to keep parts-on-parts contact to a minimum level. The high energy centrifugal disc machine with speed 150-180rpm will leave surface scratch and hit. As a result, a centrifugal disc finishing machine is not considered in this application.
- A vibratory finishing machine with a frequency converter (Variable Frequency Drive) is suggested in the application.
4.2 How to select tumbling media
- Based on the surface requirement, oxidation layer after casting need to remove and grinding mark need move as well, a media with grinding and cutting function is desired
- Because aluminum is a softer metal material, the plastic press can make the right balance between a smooth surface and effective cutting
- Consider the size of plastic media to prevent lodging and make enough surface contact on workpieces surface.
- After smoothing with plastic media, the zirconia ball gives the plastic surface a mirror shining function without making a dent on the part surface.
- Holder B1 parts have the hole for screw diameter 2mm, to prevent zirconia ball stuck in the parts, 3-4mm zirconia ball size is good.
4.3 How we decide the polishing compound
- Grinding compound LC-13 is suggested to make the Die Casting Parts Vibratory Finishing smooth and lubricative, the media and combination protect parts on parts hit and give it a smooth surface
- Polishing compound H-3 is the next step to make product mirror shining; HM-3 is a neutral chemical with a slight acidic property. Add HX-0 cleaning compound in the polishing process to remove dirt on the metal surface
5. Die Casting Parts Vibratory Finishing result for aluminum die casting parts
The polished aluminum dies throwing parts is send back to Imran with express for confirmation. He will receive the sample in 3-5 days.
6. Sample received with ZDC
7. Order prepared
The first order to be prepared is three machines, including two pcs of 600L vibratory finishing machine and one pcs of 400L vibratory finishing machine. The 600L machine is for the first step smoothing process with plastic media, and the 400L machine is for the second step polishing with zirconia ball.
Production time is significant. For ordinary goods, production time about 20-25 days. Some specially customized goods take much longer time because of mold, raw material, design, etc.
I informed Imran that the goods would be ready about 30 days after payment confirmation.
The shelf life of media and compound is very long. But it’s not necessary to order a significant amount for the first time. I suggest Imran make an order for a 3-4 month consumption of plastic media and polishing compound.
Imran agreed, and the order, including vibratory machine, tumbling media, and polishing compound is prepared.
Later, when we consider full container loading with a 40′ container, Imran wants to put as many goods as possible because the shipping cost is fixed.
Plastic media bags are put inside the vibratory bowl to save space for polishing compound. Imran is happy about the idea.
8. Payment Term
Because this is the first time to do business, both of us is very careful with the payment term. We usually do the payment 30% in advance. And after goods finished, we will take the photo for confirmation before the customer makes the final payment.
Imran insists on LC at Sight 100% and he adds us 2% to total amount to change the way of payment. We finally agreed on this term with our bank guarantee. Bank consultant makes the suggestion to correct terms to prevent misunderstanding.
After 1 week and over the weekend, we get the formal notification from the bank that for the arrival of LC. Imran send me the draft almost the same time and he is very eager to see the goods ready soon.
