Plastics/Calculating Shot size/weight
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Question
Hi Robert,
We are an injection molding company based on the border of NSW and Victoria in Australia. We are looking to run a new product, and we need to calculate whether one of the machines we currently have is able to run it, or whether we'll have to source the product from somewhere else. The product is 450 x 350 x 23 mm plastic tray. The machine is JSW350 Tonne and the screw diameter is 86mm
We need to calculate the shot size and clamping force. We have a formula, but we are not quite sure about it. Do you think you would be able to offer any help to enable us to calculate these measurements?
Kind Regards,
Bob
Dear Bob,
You are probably using the projected area method for calculating the required locking force depending on the material that you are going to make the product from will determine the amount of locking force that you apply to calculate the required locking force based on material PP you need around 630 tons if you do not have intrusion available of the machine.
There is also a method of using the injection piston diameter to work out the above.
Shot weght if possible weigh a product if not some cad packages work out the weight for you, remember do not use more than 2/3 of the total shot weight of the machine.
regards,
Robert.
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Answers by Expert:
Robert Tomlinson
Expertise
Tooling design,design for manufacture,tooling procurement,machine design,machine procurement,
Processes injection moulding,injection blow moulding,extrusion blow moulding, process control,productivity improvement,Quality,Decoration,Assembly,Automation.Thin wall moulding expert.
Experience
Recent and past projects. ?Designed various closures for a new type of composite tube and assisted company in bringing the product to market one design now in use by a major high street retail group a second design is currently moving into the production phase. ?Assisted a company in procuring sheet materials for a construction project. ?Identified source of a foreign plastic body for a major manufacturer of food products. ?Outsourced the manufacture of a building product reducing the cost of manufacture by 10%. ?Provided technical assistance to a manufacturer of blank car registration plates which improved production and reduced rejects. ?Provided interim management for a manufacturer of composite GRP tubes and structures. ?Carried out commercial due diligence and technical appraisal of a manufacturer of plastic products on behalf of the buyer a major investment group. ?Provided technical assistance to a major producer of closures with a hot runner and colour change problem. ?Provided technical assistance with a problem regarding a mould tool and hot runner system processing PET. ?Carried out research and development of a patented testing system for a major pharmaceutical manufacturer. ?Designed and implemented a manufacturing cell that produced annual savings of over £35k. ?Designed and project managed a transfer system of mouldings from the point of manufacture to the warehouse that reduced labour and eliminated bottle necks. ?Increased the production of aerosol caps by 16% at a leading European manufacturer which resulted in an increase of 600k components per day. ?Invented, designed and implemented an automatic part rejection system that reduced labour and customer complaints at a closure manufacturer. ?Set up joint venture between Indian and UK manufacturer. ?Designed auto engine support mounting bracket that reduced cost of manufacture. ?Designed planned preventative maintenance system for a manufacturer that reduce downtime by 10%. ?Reduced the cost of machine spares by 10% for an injection moulding company. ?Designed an automatic water cooling evacuation system as part of a single minute exchange of die project. ?Carried out procurement of replacement plastic pump parts for a Saudi Arabian company. ?Carried out appraisal and valuation of plant for a company prior to them purchasing a company. These are only a few of the successful projects that have been undertaken by Plastic Moulding Solutions since it?s formation if you require assistance then please do not hesitate to contact us to discuss your requirements.
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