US1005953A - Treatment of lac. - Google Patents

Description

W. A. PREYMUTH.

TREATMENT OF LAG. APPLICATION FILED 001'. 7, 1909.

Patented Oct. 17, 1911. a snnnws-snn'r 1.

W. A. FREYMUTH.

TREATMENT OF LAC.

APPLICATION FILED OUT. 7, 1909..

Patented Oct. 17,1911

3 SHEBTS-SHBET 2.

%%M z W W. A. PREYMUTH.

TREATMENT OF LAG.

APPLICATION FILED OUT. 7, 1909.

Patented 0011731911.

imagin PATENT OFFICE.

WILLIAIYYLADIOPZIF FREYMUTH, or LONDON, ENGLAND.

" 'rnnn'rivmnr on mac.

To all whom it may concern: I

Be it known that I, WILLIA M.AD0LF FREYMUTH, a subject of the King of England, residingat London, in England, have invented certain new and useful Improvements in the Treatment of Lac, of which the following is a specification.

This invention relates to improvements in the treatment of lac and has for its object toprovide a process and apparatus for thewhich is exuded upon the twigs of certaintrees by the 'Taohardia (Oartem'a) Zacca (Kern) Syn: 000cm Zacca, commonlycalled sticklac.

According to this invention a process for treating lac consists in crushing sticklac so that all cells are opened while in admixture with water to produce a pulp, breaking up the dye and animal matter particles by trituration and partially removing the dye by washing, passing the pulp thus treated into an upward current separator and thence to a vanner to remove the remainder of the dye and other impurities, introducing the cleaned lac grain rendered fluid by theapplication of heat into a centrifugal filter and collecting the resultant lac. In some cases, for instance with phunki lac, it will not be necessary to triturate the lac or treat it in an upward current separator but after crushing both the lac and impurities may be fed direct on to a vanner. The separation-of the lac grains from the refuse will then be effected only on the vanner.

One method of carrying the invention into efi'ect will now be described with reference to the accompanying drawing, in which I Figure 1 is a section of the spitzkasten or upward current separator preferably. employed, and Fig. 2 is asection of the centrifugal filter. Fig. 3 isZ a diagrammatic illusr Specification of Letters Patent. Applieationffiled October 7, 1909. Serial No. 521,474.

Patented Oct. 17, 1911.

tration of a complete apparatus according to this invention. Fig. 4 is a detail view.

The sticklac is taken at the stage when the sticks or twigs have been removed. The lac with its. dye and bodies of the coccus and albuminous matter, with dust and ashes, silica, small particles of stick, etc., is mixed with water and treated in a suitable mill 20 or the like which crushes .or breaks it to one definite and required size; an excess of water being present. It should be crushed so that it passes through a mesh of 10 holes to the linear inch, but the size may be varied according to the lac being treated. A larger grain than this will inclose unopened cells, a smaller grain Wlll entail a loss of lac. This pulp after soaking under water for a short time is then circulated from a lowertank to an upper by means of a centrifugal pump 21 during which operation the dye and impurities are beaten loose and dissolved away from the powdered resin of the lac. It is advisable to carry out this operation several times, with succeeding fresh lots of water,

the latter lots to be warm water. In every case each lot of Water should be quickly run off the pulp. It may be advisable to add sand or another abrasive to the pulp to help the scouring effect. To remove the dye and most of the other impurities now held in solution or suspension in the water, the resulting pulp is treated in a special washer. This washer-consists of a spitzkasten l which may be in the form of an inverted cone, or of other shape, being pointed at the bottom and of large horizontal sectional area at the top. This area increases gradually throughout the height, and it may be square, oblong, rectangular, triangular, oval, or circular in horizontal section. The washer may receive the pulp at the top, from one side, or from more than one point behind a battle board, or in the center through a funnel, or the pulp may be introduced from the bottom. The dimensions of the spitzkasten must be arranged to suit each variety of the lac and such dimensions cannot be laid down exactly for every case. One or more pipes enter the spitzkasten at the top or side or bottom and provide a jet of water under a suitable head of pressure, so that the water rises upward from the bottom.

In Fig. l of the accompanying drawings, a convenient form'of spitzkasten is shown by way of example. In the arrangement shown, the sides 1 f the spitzkasten are provided on their upper edge with a trough 2 for the removal of the water. Within the spitzkasten is mounted a funnel ,3 which 5 may be supported by arms such as4 and is adjustable vertically by means of screws 5. This funnel 3 expands slightly at the bottom as shown. A vertical water supply pipe coccus bodies, filaments, dust, fluff, etc., and 2 0 the-semi-soluble albuminous matter, are carried upward and over. theedge of the spitzkasten and are removed by the trough 2. The heavier lac having a specific gravity of about 1.3 is lifted by the current of water until, owing to the widening of the spitzkasten, its weight overcomes the upward force of the water and brings it'down again;

it is caught andwhirled up again, and again falls; so that the contents of the spitzkasten consist of (first) a small zone of iron sand or other impurities with a specific gravity.

heavier than lac which falls to the bottom,

(second) a zone of clean powdered lac and- "water, (third) a zone of lighter particles '35 traveling upward of both lac and impurifourth) a zone where the ,lac falls back and the lighter refuse flows on? upward to the top where it is carried away by the water overflowing. In certain cases, -40 owin'g 'to gases of decomposition and fermentation, a large quantity of curd or float willrise, carried upward by bubbles ofgasu This in the ordinary course will flow olf ties, and

- the top of the spitzkasten. Arrangements however can be made to skim this or andsave it. A small discharge cock 7 is providedat the bottom to intermittently dis- I charge 'the sand, etc. A larger discharge pipe or outlet is provided in the side or bot- I tom of the spitzkasten by which the cleaned seed lac may be discharged as required by means of the cock or valve 8. A cock 9 may also be provided higher up, by which the lighter particles of seed-lac and coccus bodies in the third zone may be intermittently removed, such cock connecting with a second spitzkasten 10 as shown. This sp' kasten 10 has a similar adjustable funnel\l\ and is provided with a cook 12 at the ttom forthe removal of the smaller seed-lab, water being admitted under a suitable pressure by the pipe 13. To further remove some impurities which are discharged with the .se'ed-lac, the latter maybe fed on to a vanner 22 where the impurities,

being either lighter or heavier than lac, will be separated. Having washed the seed-lac in the spitzkasten as above described the water is next strained oil and, the seed=lac dried. When dry this seed-lac is ready 7 either for sale as seed-lac or to be melted and further refined to button lac or shellac. It may be advisable to feedthe dry seed-lac on to a dry vanner or separator to remove impurities. To further refine the lac it is introduced into" a centrifugal filter. This filter, as shown in Fig. 2, comprises a basket .14 which may be either perforated or solid and which is fixed to and rotates with the shaft 15; the latter being driven from underneath by apparatus not shown. Surrounding the basket isv an outer casing 16 provided withjinlet and outlet conduits 17" and 18 respectively by which air heated'to the required temperature may-be circulated through the apparatus. The seed-lac is in-- troduced into the basket of the centrifugal while the whole apparatus is maintained at a temperature of from 120 to 140 C. At this point it is found that the lac, which con-. '90 tains roughly :2% impurities, animal remains and albumin, 5% wax, 93% lac resin, becomes completely fluid, that is to say,-all its constituent parts are melted. It is found that the various constituents 95 of the lac have different melting points, for

instance, thepure lac resin is fluid only atfrom 120-14.0? 0., whereas the wax remains still in a fluid condition at,80 C. By this invention the lac and the wax are both melt- .0 ed and filtered through the centrifugal fil ter at a temperature sufiicient to melt both\ ingredients, lVhile still in a fluid'condition they are run oil'- into a convenient agitator and allowed to cool gradually, while undergoing agitation, to about 80 C. It is found that by this means a homogeneous mass is formed which, while it is perfectlyv clear-and a good color, is in a plastic condition and can be suitably handled for any purpose for which it may be required.

Referring to the treatment of the lac in the centrifugal, if the basket be of the porous type a filter-cloth or medium will be provided coverin the perforations therein.

The lac which, elther before or after entering the basket, is rendered fluid by heat will be forced through the cloth by the centrifugal action, the impurities remaining behind. The lac after being forced through the cloth will impinge upon :the outer 16 but will not solidify owing to the heat of the casing. This lac, free from impurities, will run down the walls of the and will flow out therefrom through the conduit 19. 2

If a solid basket is usedthe liquid lac is. caused by the centrifugal force to flow to the sides, driving the refuse away from the center of the basket and against the walls. The cleaned, purified lac packing it tight v of the invention is not departed from.

- similar to the ordinary sausage machine.

- ing fed in hot at one end and cooling tothe forms 0 still remain in a homogeneous state.

' shown in the drawingh'gAfter the purifie i at the exit.

- additipnal matter to the lac resins and wax.

is therefore-forced over theedge of the has} ket which will be conveniently turned in, a

lac leaves the centri al machine in it preferably consists of a screw or blade-con veyer 23- working in a cylinder 24 having, if desired, fixed blades therein somewhat;

liquid form it is run into an agitatorvwhiclix.

able hot liquid t us keeping the material in the conveyer at the required tem rature until ,itis dlscharged at the end. The cylinder may, however be unheated, or have only aportion of it heated, the material berequisite temgerature by the time it arrives f necessary, a portion of the conveyer may be artificially cooled to regulate the temperature. Such a construction is illustrated in Fi 4 in which the outer chamber 25 is divi ed into two sections by a transverse partition, each of said compartments being provided with independent supply and discharge pipes. The conveyer may be set to work evel or upward or downward. After treatment the result' plastic mixture is stretched, rolled, stampe or mani lilated into any of the marketable ac. Y The process may also be used for mixing Suhadditionalmatter may-be added in a. powdered solid or other form before or durtemperature at which if thelac and wax are heated to such temperature and filtered no separation takesplace, and if suitable care is taken while cooling the mixture it will Although theaction of the centrifugal filmore'fully' explain the'workin 7 process, it forms no art of the resent invention, but forms -t e subject 0 a concuri rent application.' I H A modification may be made in car this invention into. efiect provided the spirit -1 the mixture and mechanically mixing frgeduced below thea-melting oint of The cylinder is preferably entirely surrounded by outer cylindrical chamber which is heated. b steam, hot air or a suitmatter," mechanically.

and means for seeing the lacithro h-the J Vl7l1at'. [-v claimas m invention and desire to secureby i. atent is:-

1. The herein described process of treat- 1 ing lac in heating lac wax and lac as resin to etheruntil-a temperature is reached at whic both are molten, and then the ingredients together the temperature is all the edints and the mixture comes lastie. LThe herein described process 0 treatin lac consisting inheating lac wax and lab ,rsin'fto etheruntil'a temperature is reached at Win51 both are -1 Qolten, adding other the W ients together and cooling t;hje mixture untll the temperature is reducedflbelow the'meltmg point of all the ingredients andlt-becomes lastic." P 3. The herein described apparatus for treating lac compigsinga pulping vessel, an agitating and tnt rating vessel, an" upward "current separator, '11.. vanner, a mixing apparatus .in which purified lac 1s allowed. to become plastic, and means for assmg the lac through the several parts 0 the appa- Fratus for the required treatment. p 4. The1 herein describedflapparaetgiss91 for j-treatin ac com nsmg' ap plngv ,an agitatii zg and trituratmg' vessel, an upward current separator, a vanner, eentnfugal filter, a mixing appar us 1n whlchthe pu1 '1-. fied liquid lac is allow to become plastic, 85 several parts. 0 thezapparatus for 0 required treatment. I mg the mixing. There is however a critical 5. The hereinsdeseribed apparatusior treating lac comprising a mechan cel m1x-- ing device, means for heating the mixing de- 00 vice, and means for regulating the heat so that one end ma be maintained at a temperature at whic the lac is-molten and, the 7 other end at a temperature at which-the lac is lastic. I r 96 testimony whereof I have signed-my name'to this specificationin thepresenoejof two subscribing wrttm momranian. or. n

H. D. deficit.

Images