Conventional and Modern Lap Preparation Techniques

Last updated on August 8th, 2023 at 12:36 am

Sliver Lap Machine

20 carded slivers in cans are assembled at the back of the machine and led side by side along a polished table, passing through assisting rollers and a stop motion device. They enter the drafting section, which gradationally has three lines of rollers. The slivers are subjected to a draft of about 1.5. After being drafted, the sliver enters a calendar section where they are subjected to a considerable pressure. So, as to make a compact lap with projecting fibres pressed down well to reduce any bindings to licking. Finally in a lap forming section the slivers are wound on a wooden former under pressure. This section is similar to the lap forming unit in scutcher.

In this machine the laps made from the sliver lap machine are drafted, the webs from sliver laps are superimposed, calendered and then wound on to a bobbin for creeling at the comber. The usual draft in this machine is six. Change places are provided for the usual draft alternation. Lap wt/yd is up to 700 grains, total lap weight is up to 20 lbs.  

The carded slivers are first processed in a draw frame. There are three sliver creels for one machine. Each with twenty cans of sliver. The sets of twenty ends are separated into two sets of ten as they pass through the detector rollers and brought together again in a manner which gives a ten ends width, but of double thickness, as they pass through a vertically arranged 2 over 3 drafting system. After drafting the webs are led through pairs of calender rollers and along a table, where they are superimposed calendered and made into a lap.

The draft used in the initial draw frame is 8 and 3.66 at the super lap machine. The total draft is 29.28 and the no. of doublings 480, both being far higher than those on the old system and this is the reason for improvement.

Lap wt up to 35 lbs

Wt/yd up to 1000 grains

Production up to 500 grains