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Vacuum pouring plant
Vacuum
news Fine control leak valve: This may ,be used to admit gases other than air into the vacuum chamber or to accurately control a required leak rate. High- and low-tension power supplies: These are mounted in the cabinet and monitored by ammeters mounted in the instrument panel. Dynavac High Vacuum Proprietary Limited, Australia Circle number 50 on Reader Enquiry Service
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Vacuum pouring plant
A resin vacuum pouring or casting plant developed in the Electronics Division of the Atomic Weapons Research Establishment for laboratory and production use is now available commercially from S & J Engineering (Henley) Limited. The plant consists of several interchangeable parts, allowing specialised plant to be provided easily and quickly. Modifications and extensions required at any later date, can be readily accommodated. The plant is designed for manufacturing bubble-free mouldings for encapsulated electronic assemblies or other applications using epoxide and similar resins. Pouring is carried out in a vacuum chamber, fitted with an armoured glass or acrylic door, sealed by atmospheric pressure. An electrically heated turn-table, fitted inside the chamber, can be raised, lowered, indexed and locked in any position. Resin is fed from a heated conical mixing vessel mounted above the chamber. The vessel has a stainless steel liner of 3 litres capacity, or a disposable polypropylene liner of 1 litre capacity. A motordriven blade mixes the resin, and the same motor controls the release of the mix by operation of a bung valve in the neck of the mixing vessel. The resin is released via an externally controlled “n p” valve, into the moulds placed on the turntable in the main chamber. Alternative equipment is available for simplified pouring and mixing. A “transfer funnel” with a manually operated bung valve can be fitted on the top of the vacuum chamber. This is used for pouring directly into the moulds, or for transferring resin into tipping cups inside the chamber which are controlled by a tilting handwheel mounted outside. Combinations of sub-units provide versions
Because of the extreme care taken with material selection, surface finish and constructional technique, exceptional performance is said to be achieved. Pump-down time of a clean, empty chamber to 5 i: lo-& torr is 4 min or better, the guaranteed ultimate vacuum being better than 1x 1Om6torr. The unit consists of: Vucrrrtm chamber: Glass cylinder, 12 inch diameter, 14 inch high, fitted with metal top suitable for the simple addition of specialised electrical feed-throughs. A clear Perspex outer shield is fitted around the chamber for protection. Pumping system: This consists of a WOD4/3 4 inch fractionating oil diffusion pump backed by a Dynavac 6 two-stage air-ballast rotary oil-sealed pump. The backing pump is positioned for vibration-free operation. Vacuum valving: The high-vacuum valve mounted between the vacuum chamber and the diffusion pump is a Dynavac WBV4/3 manuallyoperated baffle valve. The roughing line valve is manually operated and the backing line valve is solenoid-operated for protection in event of power failure. Vucuum gauge: The vacuum gauge is a CG106 combination thermistor/ionization gauge reading 10 to 1Omstorr on one scale and 2 x lo-$ to 1 x 1O-6torr on the other scale. The thermistor gauge head is mounted to read the backing pressure and the ionization gauge head reads the chamber pressure. Chamber jigging: The jigging has been specially designed to offer maximum flexibility and can be arranged in a wide variety of ways. It consists of an adjustable specimen carrier, adjustable carbon evaporation assembly including automatic feed carbon rods and vapour shield, and an adjustable shadow casting tungsten filament assembly with vapour shield. A movable arm into the vacuum chamber is also provided. This can be utilized to operate a shutter assembly for more exacting specimen preparation. Zon-bombardment facilities: High-voltage glow-discharge cleaning facilities are supplied as standard. Intensity of discharge can be controlled by means of a variable transformer. The high-voltage power supply cannot be operated unless the chamber is under vacuum. 392
Vacuum
pouring
plant
ranging from a simple bench mounted unit, to a free-standing unit incorporating a mounting frame with vacuum pump, vacuum valves and electrical control panel, etc. These control panels are similarly designed on an interchangeable sub-unit basis, for ease of servicing and addition of further temperature controls, timers etc. Strip-chart recorder units are available for providing a record of material exotherms etc. The plant is constructed by using a wide range of sub-assemblies according to the arrangement that is required. The basic principles are well proved and the system of interchangeability is believed to be unique. The advantage of the system is said to be the degree of flexibility provided by the range of sub-assemblies, the permutations of which meet many different specifications. S % J Engineering (Henley) Limited, UK Circle number 51 on Reader Enquiry Service
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news Fine control leak valve: This may ,be used to admit gases other than air into the vacuum chamber or to accurately control a required leak rate. High- and low-tension power supplies: These are mounted in the cabinet and monitored by ammeters mounted in the instrument panel. Dynavac High Vacuum Proprietary Limited, Australia Circle number 50 on Reader Enquiry Service
card
Vacuum pouring plant
A resin vacuum pouring or casting plant developed in the Electronics Division of the Atomic Weapons Research Establishment for laboratory and production use is now available commercially from S & J Engineering (Henley) Limited. The plant consists of several interchangeable parts, allowing specialised plant to be provided easily and quickly. Modifications and extensions required at any later date, can be readily accommodated. The plant is designed for manufacturing bubble-free mouldings for encapsulated electronic assemblies or other applications using epoxide and similar resins. Pouring is carried out in a vacuum chamber, fitted with an armoured glass or acrylic door, sealed by atmospheric pressure. An electrically heated turn-table, fitted inside the chamber, can be raised, lowered, indexed and locked in any position. Resin is fed from a heated conical mixing vessel mounted above the chamber. The vessel has a stainless steel liner of 3 litres capacity, or a disposable polypropylene liner of 1 litre capacity. A motordriven blade mixes the resin, and the same motor controls the release of the mix by operation of a bung valve in the neck of the mixing vessel. The resin is released via an externally controlled “n p” valve, into the moulds placed on the turntable in the main chamber. Alternative equipment is available for simplified pouring and mixing. A “transfer funnel” with a manually operated bung valve can be fitted on the top of the vacuum chamber. This is used for pouring directly into the moulds, or for transferring resin into tipping cups inside the chamber which are controlled by a tilting handwheel mounted outside. Combinations of sub-units provide versions
Because of the extreme care taken with material selection, surface finish and constructional technique, exceptional performance is said to be achieved. Pump-down time of a clean, empty chamber to 5 i: lo-& torr is 4 min or better, the guaranteed ultimate vacuum being better than 1x 1Om6torr. The unit consists of: Vucrrrtm chamber: Glass cylinder, 12 inch diameter, 14 inch high, fitted with metal top suitable for the simple addition of specialised electrical feed-throughs. A clear Perspex outer shield is fitted around the chamber for protection. Pumping system: This consists of a WOD4/3 4 inch fractionating oil diffusion pump backed by a Dynavac 6 two-stage air-ballast rotary oil-sealed pump. The backing pump is positioned for vibration-free operation. Vacuum valving: The high-vacuum valve mounted between the vacuum chamber and the diffusion pump is a Dynavac WBV4/3 manuallyoperated baffle valve. The roughing line valve is manually operated and the backing line valve is solenoid-operated for protection in event of power failure. Vucuum gauge: The vacuum gauge is a CG106 combination thermistor/ionization gauge reading 10 to 1Omstorr on one scale and 2 x lo-$ to 1 x 1O-6torr on the other scale. The thermistor gauge head is mounted to read the backing pressure and the ionization gauge head reads the chamber pressure. Chamber jigging: The jigging has been specially designed to offer maximum flexibility and can be arranged in a wide variety of ways. It consists of an adjustable specimen carrier, adjustable carbon evaporation assembly including automatic feed carbon rods and vapour shield, and an adjustable shadow casting tungsten filament assembly with vapour shield. A movable arm into the vacuum chamber is also provided. This can be utilized to operate a shutter assembly for more exacting specimen preparation. Zon-bombardment facilities: High-voltage glow-discharge cleaning facilities are supplied as standard. Intensity of discharge can be controlled by means of a variable transformer. The high-voltage power supply cannot be operated unless the chamber is under vacuum. 392
Vacuum
pouring
plant
ranging from a simple bench mounted unit, to a free-standing unit incorporating a mounting frame with vacuum pump, vacuum valves and electrical control panel, etc. These control panels are similarly designed on an interchangeable sub-unit basis, for ease of servicing and addition of further temperature controls, timers etc. Strip-chart recorder units are available for providing a record of material exotherms etc. The plant is constructed by using a wide range of sub-assemblies according to the arrangement that is required. The basic principles are well proved and the system of interchangeability is believed to be unique. The advantage of the system is said to be the degree of flexibility provided by the range of sub-assemblies, the permutations of which meet many different specifications. S % J Engineering (Henley) Limited, UK Circle number 51 on Reader Enquiry Service
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