More Info - Supavent
Supavent is a proven product which addresses a number of quality issues facing rotational moulders all over the world. The La Plastecnica vent range, which now includes Smartvent, provides simple yet effective solutions to the whole industry.
Expected Results
Supavent was developed after extensive modelling of the moulding process and production trials. It is a partial one-way valve that speeds the sintering process by reducing porosity, improving surface finish and potentially reducing cycle times. Users of Supavent will see a reduction in second rate product or scrap, and, due to the flexible nature of Supavent, part shrinkage will not be restricted.
Supavent’s results display high repeatability.
Venting Pressure Dynamics
Effective venting is critical to the success of rotational moulding. During the cooking cycle, small positive pressures in the mould can potentially reduce either the oven temperatures or the cycle time – or both.
The cooling stage is the most important part of the cycle when it comes to venting. Enabling sufficient air to enter the mould will prevent the formation of vacuums that are responsible for part-line blowholes and contribute towards part warpage.
Approved Mould Volumes and Materials
Due to the variations in form and usage of rotational moulding tools, the 13mm (1/2”) and 19mm (3/4”) Supavents are approved for use in moulds of up to 100 litres (25 gallons) and 150 litres (40 gallons) in volume respectively[1]. You can take a number of simple steps, however, to enable Smartvent to be used in moulds of much larger volumes – please contact us for details. In addition, some moulders have developed techniques which allow them to use multiple Supavents in larger moulds.
Supavent has been approved for use in polyethylene, polypropylene, nylon and PBT systems. Trials with other polymer systems are currently under way.
Use Within Existing Systems
Supavent is larger than the nominal diameter, and will fit snugly into a 13mm (1/2”) or 19mm (3/4”) hole without any further fixing procedures. You can easily incorporate Supavent into active pressurisation systems using a 10mm or 15mm OD feeder tube. Please contact us if you have any further questions.
Economic Benefits and Life Expectancy
Under standard moulding conditions, Supavent will last for more than 10 moulding cycles. Therefore, Supavent will cost the customer less than $0.20 per part produced.
It is not uncommon for moulders to incorporate a scrap rate of about 5% in their costings. If Supavent reduces the scrap rate by 25%, then the vent pays for itself in any part that costs more than $16.00. And this is only one of the potential benefits! Further benefits may include reduced cycle times, lower processing temperatures and less reliance on operator expertise.
Fitting Instructions
See Fitting.
[1] Assuming, among other things, that the mould is sealed while the internal air is heated from 20 to 200oC.