| 摘要 |
<p>A vacuum is set up in a bag formed from a film of heat weldable material. The opposite ends at the opening of the bag are brought towards each other so that the mouth is opened. A steam feed nozzle is introduced into the bag and the ends of the month mouth are pulled apart so that its edges close over the nozzle. Steam is fed into the bag, the nozzle is withdrawn whilst the ends are still stretched, and the edges are welded to seal the mouth of the gas. Whilst the steam is being injected, radiant heaters maintain the temp. at the mouth of the bag above that at which steam condenses and below the point of which the material of the bag becomes plastic. The method is simple, quick, efficient and ensures that foodstuffs can be stored safely.</p> |
