Spezial-MaschinenfabrikHans Kürschner GmbH & Co. KG

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The Production of Natural Waxes Based Candles on Halfautomatic, Automatic and Continuously Working MoldingMachines

Presentation Abstract:

1.Kind of raw materials.2.Sources of renewable raw materials for natural waxes.3.Market trends of natural waxes based candles. 4.Machines and equipment for the production of natural waxes

based candles.5.Features of half-automatic, automatic and continuously working

molding machines6.Discussion

1.Kind of raw materials

In recent years not only has the consumption of candles increased, but also the demand for higher quality candles.

The smoke-free clean burning of candles without dripping can be achieved with the environmentally friendly natural waxes. The unlimited sources of natural waxes and price increases of paraffin has made this product more and more attractive for the candle manufacturers and consumers.

To name these stearic acid products “natural waxes” sounds much more positive to the users.

The word stearic “acid” falsifies in common use of language the beneficial features of the product.

Stearin is at normal temperatures a solid crystalline mixture of different fatty acids. Clear stearin has a chain with 18 C atoms which are saturated by hydrogen. The formula is C18 H36 COO.

The fatty acids consist mainly of palmitin and stearic acid.

1.Kind of raw materials (cont.)

The source materials for stearin are vegetable and animal based fats and oils.

The stearin types differ in their contents of palmitin and stearic acid. A speciality is that the temperature at which the product becomes soft and the congealing point are nearly identical – the temperature is in the range of 52-60°C (125 – 140°F).

Natural waxes therefore have practically no “soft phase” which allows very good temperature stability in tropical areas.

Because of their crystalline structure, all stearines have a very opaque –non transparent – appearance.

The fact that stearine has an average melting energy of 51 cal/g compared to 39-44 cal/g of paraffines and that the burning heat is lower compared to paraffin – due to the smaller quantity of C-atoms – the amount of melted wax around the base of the wick is lower.

Another natural wax is beeswax. This wax however is based on wax acid ester, distorts easily and gets sticky at higher temperatures.

We will not include beeswaxes in today’s presentation.

2.Sources of renewable raw materials for natural waxes.

The animal based stearin is produced from live stock tallow or fish oil. The vegetable based stearin is mainly produced from botanical oils with soybean base or palm and coconut oils.

The live stock tallow based stearin has only C16 and C18 chains whilst fish oil based stearin has C20 and C22 chains.

3.Market trends of natural wax candles.

The good quality for candle making and the attractive price of natural waxes have made this product more attractive. The price differs very much on the quality and the source.

Other advantages for natural wax candles which increase the consumption apart from the price advantage are:

Generally you must use more color – special pigment based colors - but can achieve very intensive coloreffects. With the right mixture of palmitin and stearineunique surfaces are created. These candles are very popular.

Paraffin and stearine can be blended in any ratio. At more than 5% stearine, a highly intransparentappearance occurs. Very shiny and even surfaces can be achieved. At more than 25% stearine, the body of the candle becomes solid and very inflexible. The candle breaks and does not bend before breaking.

4. Machines and equipment for the production of natural wax candles

At higher stearine concentrations or at 100 % stearinematerials only the molding process is applicable for candle production.

If cooling from liquid to solid is too rapid, the crystalline structure does not appear and the candle gets cracks.

At high stearine concentrations, extremely care must be taken when cooling – the capacity of the machine is limited to the necessary cooling time.

The chemical structure of the stearine is the reason for the fact that the crystals orientate vertically if the are in touch with metals. A very good release of the candle from the molds is achieved with this effect.

4. Machines and equipment for the production of natural wax candles (cont.)

As stearine is very aggressive, only special materials must be used in mold production to ensure a long machine life.

For cylindrical candles special aluminium alloys can be used. The mold itself should be slightly tapered for easier release of the candle. For tapered candles almost 100 % tin alloys can be employed with success.

5. Features of half-automatic, automatic and continuously working molding machines

As far back as the Middle Ages people took molds, tightened a wick and filled the mold with wax. Still single molds with the wick fixing are still available today with a lot of different

shapes for smaller candle quantities.

5. Features of half-automatic, automatic and continuously working molding machines (cont.)

To achieve higher outputs, molds were rowed together and molding machines created.

Before the First World War, most candles were produced on these manual or half-automatic machines to achieve “industrial sized” outputs.

These machines were upgraded more and more, the materials of the molds improved and there are still machines around today which have been operating for more than 50 years.

The machines available have the following functions as minimum outfit:

1. Preparation of the machine with wick arrangement

2. Correct wick spool placement

3. Wick feeding with the wickneedle

4.Knotting of several wicks together on the table and pouring in the wax, cooling – get the first candle to the clamping frame.

4.wick cutting by use of cutting tool

5.swivelling of clamping unit and discharge of candles manually from the clamping device

6.cake cutting off by scraping tool

7.swivelling of clamping unit back down in open position

8.ejection of candles by means of upward movement of the pistons via

9.handwheel and clamping of candles in the clamping device

10. re-start - pistons are again down in starting position

Then starting with the procedure:

1.preheating temperature is reached, pistons are in starting position, one batch of candles are clamped in the device, wick is tight from these candles down to the wick tubes

2.pouring of liquid wax into moulds - by means of liquid flow downward the moulding table - wax supply by kettle or by a tank above the machine with hose to trough of the table

3.cooling - cold water circulation by opening the valves till the wax is frozen

Upgrading to automatisation:

1. Electrical gear motor for raising and lowering the pistons

2. Automatic scraping mechanism of cake

3. Pneumatically operated pouring-in system

4. Wax supply tank mounted over the machine

5. Temperature control system for 2 water temperatures

6. Programmable electronic control system to ensure automatic sequence of the machine functions

All the above machines are water cooled and hot water preheat.

The circulating water causes at high gloss surfaces or mottled textures irregularities – this can be avoided with a very smooth cooling process.

Here air-cooled molding machines are on the market.The air is blown through a heat exchanger and circulates round the molds and the bottom channel of the machine.

Function and design of this air cooled moldingmachine:

1.manual wick centring by means of wick centring device above the molds

2.hot water circulation at heat exchanger by opening the valves – the blower blows through the heat exchangerand the hot air heats the moulds till the preheating temperature is reached, pistons are in starting position.

3.pouring of liquid wax into moulds – by means of liquid flow downward the moulding table - wax supply by kettle or by a tank above the machine with hose to trough of the table

4.cooling – cold water circulation at heat exchanger by opening the valves –the blower blows through the heat exchanger and the cold air cools themoulds till the wax is frozen. Second pouring might be necessary

5.manual cake cutting off by scraping tool

6.ejection of candles by means of upward movement of the pistons via motordriven ejection system. Discharge of candles from the table

Re-start – pistons are again down in starting position

The continuos operating molding machines are mainly rotary molding machines with several mold segments (9-15) which rotate with each 72 to 213 molds – at natural waxes you achieve 2,5 revolutions/hour at 23 mm diameter or appr. 5.500 candles continuously per hour.

The machine consists of:

1. steel-welded round support frame (to be used as water tank)

2. wick spool rack for wick spools with max. 3.5” dia., 8” long

3. hydraulic rotary drive unit for the mold table

4. wick cutting station

5. knife station for removal of wax overpour

6. hydraulic lifting drive unit for the candle ejection

7. table with mold segments with moulds

8. rubber clamps to take up the candles

9. automatic water distributor for preheating and cooling (2 water temperatures)

10. electric – hydraulic – pneumatic installation

11. programmable control system SIEMENS S-7

12. continuos candle take-off and transfer system which takes over the candles from thecandle clamping units of the machine, conveys them horizontally and transfers them onto the lowering unit which turns the candles by 90° before laying row wise the candles down on a transport belt. Followed optional with the candle base saw, the candle base melting machine the candle overdippingmachine.