Stickies are tacky substances contained in the paper pulp

Pulp (paper)

Pulp is a lignocellulosic fibrous material prepared by chemically or mechanically separating cellulose fibres from wood, fibre crops or waste paper. Wood pulp is the most common raw material in papermaking.-History:...

 and process water systems of paper machines. Stickies have a large tendency to make deposits on the processing equipment in certain stages of the papermaking

Papermaking

Papermaking is the process of making paper, a substance which is used universally today for writing and packaging.In papermaking a dilute suspension of fibres in water is drained through a screen, so that a mat of randomly interwoven fibres is laid down. Water is removed from this mat of fibres by...

 process. Contamination

Contamination

Contamination is the presence of a minor and unwanted constituent in material, physical body, natural environment, at a workplace, etc.-Specifics:"Contamination" also has more specific meanings in science:...

s of paper

Paper

Paper is a thin material mainly used for writing upon, printing upon, drawing or for packaging. It is produced by pressing together moist fibers, typically cellulose pulp derived from wood, rags or grasses, and drying them into flexible sheets....

 that that are classified as tacky are also called stickes. The main sources for stickies are recycled paper, waxes, and soft adhesives.

Composition

Stickies are an indefinite mixture of organic compounds, with the main part being different esters. The components might stem from:

• Printing inks
• Coating binders (synthetic latex
  Latex
  Latex is the stable dispersion of polymer microparticles in an aqueous medium. Latexes may be natural or synthetic.Latex as found in nature is a milky fluid found in 10% of all flowering plants . It is a complex emulsion consisting of proteins, alkaloids, starches, sugars, oils, tannins, resins,...
  
  )
• Waxes
• Hot melt adhesive and unsupported pressure sensitive adhesive
  Pressure sensitive adhesive
  Pressure sensitive adhesive is adhesive which forms a bond when pressure is applied to marry the adhesive with the adherend...
  
  s
• Plastics
• Wet strength
  Wet strength
  Wet strength of paper is a measure of how well the fibreweb is holding together upon a force of rupture. Wet strength is routinely expressed as the ratio of wet to dry tensile force at break.-Mechanism:...
  
   resins
• Pitch
  Pitch (resin)
  Pitch is the name for any of a number of viscoelastic, solid polymers. Pitch can be made from petroleum products or plants. Petroleum-derived pitch is also called bitumen. Pitch produced from plants is also known as resin. Products made from plant resin are also known as rosin.Pitch was...
  
  
• Papermaking
  Papermaking
  Papermaking is the process of making paper, a substance which is used universally today for writing and packaging.In papermaking a dilute suspension of fibres in water is drained through a screen, so that a mat of randomly interwoven fibres is laid down. Water is removed from this mat of fibres by...
  
   additives

Properties

Stickies that passes through a slotted plate screen of 0.10 - 0.15 mm are called micro stickes. Micro stickies can be finely dispersed (100 µm - 100 nm), colloidal (100 - 10 nm) or molecular dissolved ( < 10 nm). Macro stickies are those who retain as a screening residue. The reason for this classification is that macro stickes are easy to remove from the deinked pulp in the deinking

Deinking

Deinking is the industrial process of removing printing ink from paperfibers of recycled paper to make deinked pulp.The key in the deinking process is the ability to detach ink from the fibers. This is achieved by a combination of mechanical action and chemical means. In Europe the most common...

 process with filtration. Micro stickies follows the pulp to the paper machine and might agglomerate

Agglomerate

Agglomerates are coarse accumulations of large blocks of volcanic material that contain at least 75% bombs...

 and cause problematic deposits.

Stickies have often thermoplastic

Thermoplastic

Thermoplastic, also known as a thermosoftening plastic, is a polymer that turns to a liquid when heated and freezes to a very glassy state when cooled sufficiently...

 properties.

Chemical-physical alterations like pH

PH

In chemistry, pH is a measure of the acidity or basicity of an aqueous solution. Pure water is said to be neutral, with a pH close to 7.0 at . Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline...

, temperature

Temperature

Temperature is a physical property of matter that quantitatively expresses the common notions of hot and cold. Objects of low temperature are cold, while various degrees of higher temperatures are referred to as warm or hot...

 and charge

Charge (physics)

In physics, a charge may refer to one of many different quantities, such as the electric charge in electromagnetism or the color charge in quantum chromodynamics. Charges are associated with conserved quantum numbers.-Formal definition:...

 changes might cause colloidal destabilization and agglomeration

Agglomeration

In the study of human settlements, an urban agglomeration is an extended city or town area comprising the built-up area of a central place and any suburbs linked by continuous urban area. In France, INSEE the French Statistical Institute, translate it as "Unité urbaine" which means continuous...

 of micro stickies.

Stickies control

Several methods are used to control them are used:

• Alteration of the physical properties, like using recycling friendly paper coatings,
• Avoidance of troublesome components that causes stickies,
• Removal by more effective deinking
  Deinking
  Deinking is the industrial process of removing printing ink from paperfibers of recycled paper to make deinked pulp.The key in the deinking process is the ability to detach ink from the fibers. This is achieved by a combination of mechanical action and chemical means. In Europe the most common...
  
   process, like improved screening, cleaning, washing and flotation,
• Passivation with process additives like fixation agent
  Fixation agent
  A fixation agent is a chemical that is capable to fixate one substance to another substance that the first substance have little affinity to.-Pulp and paper production:...
  
  s,
• Prevention by washing wires or protecting equipment parts with chemicals.