Para Pedia

10
Jul

Paraffin waxes in household chemicals

 

Paraffin waxes in household chemicals

Various grades of macro- and micro crystalline paraffin waxes are used in household chemicals. The main consumers for paraffin waxes are polishes and candles. Paraffin waxes are used as additives in many polishes, and a substantial part of candle material is paraffin wax.

 Polishes with paraffin wax as an additive

Polishes are materials which, on the one hand, increase the gloss of the treated surface or restore its initial gloss, and on the other hand, protect the surfaces against mechanical and chemical effects, and thus prolong the service life of the object. Solvent-containing, liquid polishes have a cleaning effect, too.

Polishes containing considerable amounts of paraffin waxes include floor, furniture, shoe and automobile polishes. Polishes usually contain several kinds of natural and synthetic waxes, paraffin waxes, resins, solvents, auxiliary agents and water. As well as the requirements of the consumer, cost of the components is an important factor in the formulations. This is one of the reasons for the tendency to replace a part of the relatively expensive natural and synthetic waxes by less expensive paraffin waxes. The origin of natural waxes is diversified: carnauba wax, for example, is obtained from a palm, bees-wax is produced by the insect, and crude montan wax is extracted from lignite. Refined montan wax, chemically transformed into acid esters or partly hydrolyzed, is widely used. The synthetic waxes include products obtained by esterification of fatty acid fractions from the oxidation of macro- and micro crystalline paraffin waxes, as well as polyethylenes. Suitably selected paraffin waxes improve gloss, but greater amounts may result in an opaque surface. Another important factor in the choice of the solid components and their ratios is the requirement to form a mechanically resistant film.

Floor polishes

Paraffin wax is used for floor polish coatings as serve the purpose of preventing water, vapor and air penetrating into the floor and protecting the flooring against wear. Wood floors are usually coated first with a priming paraffin wax layer, and subsequently, if necessary, with a liquid polish. After evaporation of the solvent, the film remaining is rubbed to produce a gloss. Solid floor polishes are pastes or solvent-less polishes. Liquid polishes yield either surfaces requiring rubbing for gloss formation, or yield directly glossy surfaces after drying

Solid floor polishes

Floor pastes are usually manufactured from carnauba or some corresponding wax, montan wax, macro crystalline paraffin wax and ceresin. The paraffin waxes, which are softer than the former waxes, ensure proper consistency of the paste and increase solvent retention capacity. The carnauba wax content seldom exceeds 12 wt-%. Since wood absorbs paraffin waxes readily, their content is kept around 10 wt-%. Within these general ranges the formulations for floor pastes vary widely.

An important characteristic of paraffin waxes in polishes is solvent uptake. Even if the structure of the product after manufacture is a perfect gel, cracks may be formed in the course of storage, and the spreading properties of the wax may deteriorate. This is the result of poor solvent retention of the waxes. ‘This disadvantage

hardness of the paraffin wax constituents and significantly improve gel formation even in small amounts. In turn, solvent uptake of paraffin waxes is low, but solvent retention is excellent. Thus, relatively high amounts of paraffin wax combined with small amounts of montan wax-based synthetic waxes yield readily gelling pastes with good solvent retention.

Liquid floor polishes

With liquid floor polishes a gloss is obtained by rubbing the film formed after applying the polish. The components of the polishes are the same as those of pastes, the only difference being the solvent content. The solids content of liquid floor polishes varies between 8 and 15 wt-%. The most widely used components of floor polish emulsions are bees-wax, carnauba wax, candelilla wax, japan wax, and macro- and micro crystalline paraffin waxes. An example of a formulation for a liquid emulsion floor.

Furniture polishes

The duty of furniture polishes is to remove dust and other dirt from the surface of the furniture and to increase its gloss. The five large groups of furniture polishes are furniture oils, oil-in-water type emulsions, wax emulsions, furniture pastes and silicone-containing furniture polishes. Paraffin waxes are used in two of these groups, in wax emulsions and in furniture pastes. The most widely used solid components of wax emulsions are carnauba wax, beeswax, macro- and micro crystalline paraffin waxes, stearic acid and various estersed synthetic waxes.

Automobile polishes

The duties of automobile polishes are manifold: they cleanse the car body and the metal decorating elements from dirt, e.g. dust, oil spots, etc., they restore the initial gloss and smoothness of the varnish, and form a thin continuous film that will protect the varnish coat against weathering for some time. In addition to the usual waxes, paraffin waxes, plasticizers, emulsifiers and solvents, automobile polishes also contain abrasive powders, which remove dust particles adhering strongly to the surface and cause roughness. Such strong adhesion is the result of paint and varnish softening by the heat of sun radiation or by the heat of the motor.

Shoe polishes

Shoe polishes are required to protect and shine the leather. They form flexible, glossy wax films resistant to water, dust and the effects of weather. As well as various natural waxes, paraffin waxes are also being used in the manufacture of shoe polishes. An accepted terminology is hard and soft shoe polishes. However, these attributes do not refer directly to the hardness of the waxes or paraffin waxes present, but to other properties, such as solvent uptake, solvent retention, consistency, film-forming properties, drying time, etc. The attribute “hard” refers, in this respect, to waxes such as carnauba wax, hard macro crystalline paraffin waxes and ceresins, candelilla wax, while “soft” applies to waxes such as crude montan wax, bees-wax, japan wax and various micro crystalline paraffin waxes. As a substitute for natural waxes, many synthetic waxes are being used at present.

In the formulation of shoe creams the proper proportion of hard and soft materials is of particular importance. Hard materials jn themselves are unsuitable for manufacturing shoe creams having paste-like consistencies. The soft waxes act as binders for the hard waxes and also as a binder between the paraffin waxes and solvent. On the other hand, hard waxes and hard paraffin waxes are imperative from the viewpoint of shine. In addition to the above solids, shoe creams that are aqueous emulsions contain oleic acid, stearic acid, borax and triethanolamine as well as sodium and potassium soaps.

Candles

One of the oldest fields of application for paraffin waxes is in the manufacture of candles. Paraffin waxes were first used for this purpose in the middle of the last century. The composition of candles is defined by their intended use, by climatic factors and by the specific demands of the consumers. The most important processes are : mechanized moulding using cylindrical moulds, dipping and pouring. The illumination power of pure paraffin wax candles per mass unit is higher, owing to the pure hydrocarbon composition, than that of candles containing other components besides paraffin waxes. However, pure paraffin wax candles have several disadvantages. Their low melt viscosity causes excessively high amounts of melt being picked up by the capillaries of the wick, and consequently the flame tends to soot. Candles made of macro crystalline paraffin waxes with low softening points may bend and adhere to one another under the effect of their own weight. Candles made of higher softening point waxes, on the other hand, will be difficult to light in cold weather, the flame will tend to blow out, and repeated lighting will again be difficult, because the heat of the igniting flame will not be satisfactory for easy melting of the candle material. For this reason, the majority of candles are manufactured from blends of macro crystalline paraffin waxes and stearic acid. Also, bees-wax, micro crystalline paraffin waxes (ceresins), vegetable and synthetic waxes are used. Macro crystalline paraffin waxes having melting point between 48 and 54 “C are suitable for candle manufacture. So-called composite candles made of paraffin wax and stearic acid contain 5 to 15 wt- % stearic acid, which can, however, be substantially higher in candles manufactured for hot climates. Even candles made of pure stearic acid are being manufactured.

The melting point of composite candles is around 50 “C. The melting point of commercial stearic acid is 55 to 60 “C. The melting point of the blend is lower over the total concentration range than that of the individual constituents. The melting point minimum is around the 50/50 wt- % ratio of the constituents and is lower by 6 to 9 “C than that of the pure paraffin wax. However, softening starts at a higher temperature than that of the pure paraffin wax. Church candles, in contrast to other candle types, contain a Paraffin wax and higher share of bees-wax, sometimes exceeding 50 wt-%.

10
Jul

Paraffin waxes,liquid paraffin applications

 Paraffin waxes & liquid paraffin applications

The areas of direct application of paraffin wax and  micro crystalline paraffin waxes

  1. Applications in the paper industry.
  2. Applications in household chemicals (polishes, creams, candles, etc.).
  3. Application in cosmetics.
  4. Applications in the food industry and in agriculture (cheese-coating, poultry processing, fruit preservation, etc.).
  5. Miscellaneous applications of paraffin wax(matches, textiles, electrical industry, pyrotechnics, pencil manufacture, precision casting, wax emulsions for building construction, etc.).
10
Jul

Paraffin waxes in paper industry

Paraffin waxes in the paper industry

Although the use of plastics steadily increases in packaging, cellulose-based papers, cardboard and corrugated paperboard still remain the most important packaging materials. Besides other additives, paraffin waxes and wax-containing auxiliary products are largely used for improving the properties of paper, cardboard and corrugated paperboard. The packaging industry is one of the most important consumers for direct applications of paraffin wax. This is due mainly to the following factors: – paraffin waxes are inexpensive, – they are available in practically unlimited quantities, – their grades do not vary. In fields where the paraffin waxes themselves are not capable of meeting the necessary requirements, their functional properties can readily be improved by the addition of natural or synthetic waxes or polymers. Such products can be utilized in the paper industry using simple and rapid operations. Paraffin waxes, with suitably selected plastics additives, have favorable properties : good adhesion, permanent gloss, impermeability to water and water vapor, broad ranges within which viscosity, plasticity and mechanical strength may be varied. Para& waxes are used in the paper industry especially for impregnation, coating and laminating. In addition, paraffin waxes are used as additives to paper sizes.

 

(A) Paraffin waxes for impregnation

Impregnation is used both during paper manufacture and for the finishing of the paper. Paper has a capillary structure which causes it to absorb moisture. This property is often inconvenient and can be mitigated by impregnation with various additives, e.g. paraffin waxes. The formed paper web can also be impregnated by leading it, by means of guide rolls, through the solution or melt of the impregnating material. Shaped paper products, such as containers, etc., can also be subjected to impregnation. The impregnating substance uptake is defined by the above-cited conditions. It usually varies between 3 to 35 g/m2. The substances suitable for impregnation are macro- and micro crystalline paraffin waxes, their blends, and modified low melt-viscosity paraffin waxes containing a maximum of 10 wt-% polymer. The polymers used for this purpose are polyethylene, polyisobutylene, ethylene-vinyl acetate copolymer.

(B) Paraffin waxes in coatings

In coating, a film is formed directly on the surface of the paper, without applying an adhesive between the film and the paper. In addition, the film is an unbroken, glossy, flexible, smooth layer, it is waterproofing and impermeable to water vapor. The equipment developed for melt-coating is based on rollers, discharge devices or nozzles. For high-viscosity hot-melt coating special discharge slots, so-called curtain-coating equipment has been developed, forming a film curtain under which the shaped products pass and become coated. The melt uptake is controlled according to the viscosity of the melt and the porosity of the paper material; 10 to 20 g/m2 paraffin wax application yields a continuous layer. Three types of melt are used for coating : – paraffin waxes with a maximum 10 wt-% polymer content, with melting points only slightly higher than that of the paraffin wax, and with low melt viscosity ; – waxes and paraffin waxes with 20 to 35 wt-% polymer content (so-called hot-melts), having higher melting points than those of the former type, and medium melt viscosity values ; – extrusion coating materials with high melting points and high melt viscosity. For coating with paraffin wax products it is expedient to use suitable blends of macro- and micro crystalline waxes. The macro crystalline waxes lend gloss, light color, stiffness and transparency to the coating, the micro crystalline waxes provide low permeability to water vapor and fatty substances, adhesion and high flexibility. The particularly important duty of the micro crystalline wax components is to preserve impermeability to water vapor of packaging materials (corrugated paperboard for machines, instruments, food, containers, cups, etc.) under the effect of mechanical loads. The difference in water vapor permeability between macro- and micro crystalline paraffin waxes is scarcely detectable. However, the papers coated with these waxes show significant differences, since micro crystalline waxes, owing to their higher flexibility, form layers more resistant to mechanical effects. For this reason, paraffin wax products for the paper industry always contain micro crystalline waxes. According to whether their function is coating or increase of hardness, Rumberger stipulated the requirements listed in Table 111-2 for micro crystalline paraffin waxes. Waxes for coating originate from residual oils, and improve the melting point and the vapor proofing properties of the macro crystalline waxes. Micro crystalline waxes for improving the hardness and melting point of macro crystalline waxes are products obtained from tank waxes or petrolatum by DE-oiling. The surface gloss obtained with paraffin wax products can be increased with hard waxes as additives. The further advantages of these components consist (a) in their anti-blocking property, i.e. surfaces placed one on one another do not stick together; and (b) in their flexibility, ensuring that the film does not crack during use. The product ensures good mechanical strength for the raw paper. It improves resistance of the papers to cracking, and reduces their permeability to water and water vapor. Owing to the optimum oil content, the wax layer has a high flexibility and smooth surface. Due to the high drop melting point, packaging paper treated with the product can also be used in warm climates. The low viscosity of the melt allows simple processing. Among polymers containing paraffin wax products, the three-component products consisting of polyethylene, macro crystalline paraffin wax and micro crystalline paraffin wax are prominently good. Such polyethylene waxes mix readily with paraffin waxes at temperatures around 110-120 “C, and only slightly increase the melt viscosity of the paraffin waxes. Increased gloss can be observed with percentages of the additive as low as 2 wt-x, and the blocking temperature is also higher. To achieve the gloss, melting point, blocking temperature, abrasion resistance and flexibility required in specifications, 3 to 5 wt-% of the polyethylene additive must be used. Still higher gloss is obtained by 6 to 10 wt-%.   and a suitably chosen polyethylene wax are presented. Macro- and micro crystalline paraffin waxes worked well for the safe sealing of flasks and containers used to pack goods sensitive to air and moisture.

Milk cartons, butter and ice-cream cartons, containers for deep-frozen food, etc. require coatings allowing the filling of the containers at higher temperatures, and, therefore, higher melting points of the product used for coating. The characteristics of such products, also used for coating packaging materials for bread, meat, candies, etc., are listed . The paraffin wax products contain polyethylene wax.

plastics products are stronger than those obtained with paraffin wax-based products. However, in many cases the latter are preferable for this very reason, because the lower seal strengths allow the package to be opened without also destroying the whole packaging material. This is an important advantage when the content of the package is not consumed all at once, e.g. for bread packages. The strength of the seal depends both on the adhesion forces between the paper and the paraffin wax, and on the cohesion forces within the paper and the paraffin wax. These forces can be controlled by the temperature and time of the sealing operation, by the amount of wax applied, by the cooling speed after hot sealing, by the composition of the wax product and by the grade of the paper.

(C) Paraffin waxes for lamination

Lamination is the bonding operation of two or more webs, films or foils made of the same or of different materials (paper, metal foils, plastics films, etc.). Lamination allows the combination of the advantages of different types of packaging materials and the minimizing of their disadvantages. They are suited for strong, transparent packaging materials impermeable to fatty substances, gases and aromas. The adhesives are varnish resins, rubbers, etc.; – hot-melt lamination eliminating any use of solvents. The adhesives are paraffin waxes, micro crystalline waxes, paraffin waxes with polymer additives. The adhesive is applied from a heated tank onto one web, which is then joined with the other web, and finally the adhesive is solidified by passing over cooling rollers. This lamination procedure allows high speeds. Excellent packaging materials for e.g. macaroni, biscuits, cakes can be manufactured; – so-called stretch-lamination, in which paper is laminated with heat-plasticized, considerably stretched plastics film. Among hot-melt adhesives, waxes and paraffin waxes alone yield only low bond strengths, but this can substantially be improved by adding synthetic thermoplastic adhesives. The viscosity of the melt is controlled by temperature. Compositions whose viscosity are suitable within the 120 to 200 “C temperature range lend themselves readily to processing. The most widely used laminates manufactured by the hot-melt process are combinations of paper with aluminum foil, paper with cellophane and paper with plastics films. The grade of the micro crystalline paraffin waxes used as components of hot melt adhesives depends on the area of application. For instance, if porous layers are to be bonded, micro crystalline wax with good cohesive properties is required, with low oil content and no low-melting fractions. Such wax will not cause stains on the surface of the packaging material, and the low-melting fractions will not exude.

(d) Paraffin waxes as additives to paper sizes

Paraffin waxes are used for sizing to reduce the moisture absorption of paper. Paraffin waxes or their emulsions used as additives promote the uniform distribution of the size in the fibrous structure of the paper, since the wax particles separate the resin adhesive particles from one another, thus preventing their agglomeration. Another advantage of adding paraffin wax is that it compensates the effect of the resin adhesives to mix with the various pigments. Thereby print ability is improved and efficiency of printing is increased. Also, the addition of 1 to 5 wt-% paraffin wax results in a substantial moisture repellent effect, owing to an increase of the surface tension of the adhesive. It is preferable to introduce the paraffin waxes into the system as emulsions containing usually 35 to 50 wt-% of solids. Particle size in the emulsion varies between 0.5 and 5 pm. Micro crystalline paraffin waxes or blends of micro- and macro crystalline waxes with melting points between 50 and 65 “C are used for these emulsions.

22
Apr

Articles

ARTICLES

Fruits (Apple) Polishing By Wax

If you walked out into an orchard, picked an apple from the tree and rubbed that apple on your shirt, you would notice that it shined – you’ve just polished the natural wax that an apple produces to protect its high water content. Without wax, fruits and vegetables like apples would lose their vital crispness and moisture through normal respiration and transpiration – eventually leaving them soft and dry.

After harvest, apples are washed and brushed to remove leaves and field dirt before they are packed in cartons for shipping to your local market. This cleaning process removes the fruit’s original wax coating or polishing, so to protect the fruit many apple packers will re-apply a commercial grade wax. One pound of wax may cover as many as 160,000 pieces of fruit; perhaps two drops is the most paraffin wax covering each apple.

Waxes have been used on fruits and vegetables since the 1920s. They are all made from natural ingredients, and are certified by the U.S. Food and Drug Administration to be safe to eat. They come from natural sources including carnauba wax, from the leaves of a Brazilian palm; candellia wax, derived from reed-like desert plants of the genus Euphorbia; and food-grade shellac, which comes from a secretion of the lac bug found in India and Pakistan. These waxes are also approved for use as food additives for candy and pastries. (Now you know why your chocolate bars melt in your mouth but not in your hand…yes, it is because of paraffin wax.)

The commercial waxes do not easily wash off because they adhere to any natural wax remaining on the fruit after cleaning. Waxed produce can be scrubbed with a vegetable brush briefly in lukewarm water and rinsed before eating to remove wax and surface dirt. (Using detergents on porous foods like apples is not recommended!) ”

 

How to calculate how much Paraffin wax to use

You’ve got your mould or your container and you’re ready to make some candles but how much Paraffin wax do you need?

Find out more about the different Paraffin waxes available. Specially paraffin oil content.

It’s easy to work out.

1-Fill the container or mold with water (if it’s a mould, cover the hole with your finger) to the proper level

2-Tip the water into a measuring jug, round up to the nearest 10ml or

3-so Deduct 20%

That’s the number of grams of Paraffin wax to use

For example if your container takes 250ml of water, you would use 200g of Paraffin wax (250-50).

This is because 1ml of water weighs exactly 1 gram (for the nerds amongst you this is because a kilogram is defined as the weight of 1 litre of water). So 250ml of water weighs 250g. However, Paraffin wax is slightly less dense than water so you need to deduct 20% or so to get the right weight in Paraffin wax