TREES TO TISSUE

Image1.png

The following facts and figures are designed to give you a brief and greatly simplified understanding of papermaking and paper uses.    Whilst it is streamlined, the basis of the information is such that when faced with a buying situation and presented with differing types and qualities, you will be armed with enough facts to talk with some authority on most types of tissue paper placed before you.

It should also be noted that the following is only concerned with soft tissue and hygiene paper - not stationery or newspaper or packaging, etc., although certain facts are common to all papers.



The Markets

All tissue products are made to meet the needs of today's market. There are two markets:

RAW MATERIALS

Paper is made from plant fibres and most are made from soft wood trees that grow well in the UK and in colder countries further north. Soft wood trees make the best paper products:  in the main, Pine or Eucalyptus trees are best  - the latter has a longer fibre, but we do not have enough of them in the UK so we have to buy raw material in the form of wood pulp from other countries. The trees grow quickly (10-12 years) which enables us to harvest the timber in such a way that we should never run out of the raw material that is needed to make soft tissue.

All wood pulp manufacturers grow trees just like a farmer would grow his wheat in a managed and responsible manner -  if we haven't got a crop,  you have no toilet paper?  For every tree that is cut down 3 are replanted but note that rain forest trees are no good for soft tissue and are mostly used for furniture, building homes, packaging or just burnt.

Wood pulp mainly comes from North America or Scandinavia and there is no question that the relevant Governments would not allow anyone to operate a replanting program that will ensure future jobs and prosperity and economic growth for their country.

What we must remember about a tree is that throughout its growing cycle, a tree produces life giving oxygen, while an old and decaying tree consumes it.

So as you can see there are greater benefits when mature/decaying trees are harvested in a controlled way, just like a farmer with his wheat, that he harvests every year, wood pulp manufacturers have to wait 10 years.

Bleaching is a cleaning process of the fibres and the aim is to achieve a brighter white pulp, There are different methods used today for bleaching; ECF {elementary chlorine free {where chlorine dioxide is used, and TCF {totally chlorine free} where ozone, oxygen and hydrogen peroxide is used.

Chemicals that are used in the process as well as the functional chemicals are assessed from an environmental, occupational health and safety and product safety point of view.

The used functional chemicals are:

Wet strength agent.
Dry strength agent.
Dye if coloured.
Fixing agent.
Fluorescent whitening agent.
Glue if used.
Softeners.

 The process chemicals are:

Antipitch.
Protection agent.
Yankee coating
Defoamer
Dispersing agents and surfactants
pH and change control
Retention aids

Recycled paper can be produced from collected newsprint, magazines, office and manufacturing waste. The paper is washed and treated with chemicals under high temperature and then filtered. Different fibres demand different process and this determines the end product properties.

image2.jpg

PULP
In order to make paper we start with fibres from various types of plants, trees, sugar beet - each having their own characteristics. The pulp is generally made in two ways:-

This is primarily a grinding operation turning the raw material into very short fibre lengths and leaving the impurities still contained in the fibres. This is a cheap way of creating fibre but due to its length, the strength and softness properties are low.

 
Typical Mechanical pulp fibre

image3.jpg

The raw material is taken and cooked until each of the fibres separate and all the impurities are removed.  It is a long fibre which is used to create strength and helps in making a softer tissue which in turn will help to produce a better quality product.

   Typical Chemical pulp fibre

image4.jpg

Along with these two obvious sources of fibre, there is also the waste paper market where the fibres have already been used to make other papers. The advantage is obviously price as a waste product, but the disadvantage is that each paper contains unknown fibre mixes and this can cause problems when trying to make characteristic-specific products.

Now for the machinery ………..

Image5.jpg
Big

Image 6.jpg
Bigger 

Image 7.jpg
Biggest

THE PROCESS
In order to manufacture pulp we require 6 litres of water to make 1 kilo of pulp hence the reason all paper mills are based by rivers or water outlets.   Purer water gives a softer tissue/pulp.

Having decided on the product to be made, the pulp or waste and sometimes a mix of both, is added to the papermaking machine in set quantities (like baking a cake). The pulp is then mixed with enormous quantities of water and at this stage it will be 99.9% water, and now looks like "porridge".

At this stage the fibres are about 99.9% water. They then travel through a series of cleaners and after that they are formed onto a wire at differing speeds, depending on the required paper - slower for a dense sheet, faster for a more open sheet. The fibre tends to run in one direction, called the 'machine direction'; they have to be forced to lie across the flow, which makes the pulp expensive. This operation is called cross flow. The normal way always means that the tissue is weaker in one direction.

After forming the sheet, the water is removed at a high rate until the sheet meets the large heated drying cylinder where the water content reduces from 95% to 3%, when it becomes recognisable as tissue paper.

Wet strength papers have resins added at the mixing stage in order to stop them decomposing when wet, the more reside the harder and less decomposable the paper.  What gives the tissue its characteristics is the way the paper is scraped off the drying cylinder, in terms of crepe and other attributes like softness, thickness, etc.

DEFINITIONS OF PULP & PAPER TERMS

BHKP: Bleached hardwood kraft pulp

BKP:
Bleached kraft pulp {includes all softwood & hardwood kraft pulp}

BSKP: Bleached softwood kraft pulp

CWF: Coated woodfree printing & writing paper {see woodfree paper}

UWF: Uncoated woodfree printing & writing paper {see woodfree paper}

Kraft paper: Paper made from kraft pulp-bleached or unbleached. It is a strong paper used principally for wrapping or packaging

Kraft pulp: The kraft process is the world's predominant chemical pulping process; the name is derived from the German word for "strong". The method involves cooking [digesting] wood chips in an alkaline solution for several hours during which time the chemicals attack the lignin in the wood, the dissolved lignin is later removed leaving behind the cellulose fibres. Unbleached kraft pulp is dark brown in colour, so before it can be used in many papermaking applications it must undergo a series of bleaching processes.

LWC: Light Weight Coated, a grade of mechanical printing paper usually weighing less then 60gsm, used mainly as a publication paper where surface quality and weight are important.

NBSK: Northern Bleached Softwood Kraft pulp, the industry's benchmark grade of pulp, market NBSK is produced in Canada and the Nordic counties, some NBSK is also produced in North- Western USA and Russia.

Newsprint: Paper made for the purpose of printing newspaper, varieties of newsprint are also used for directories [when it is described as directory paper] and for some magazines and comics. In parts of Asia, newsprint also finds an end-use in school exercise books. The furnish of newsprint is mainly mechanical pulp and/or recycled fiber.

Woodfree paper: A printing and writing paper which contains little or no mechanical woodpulp, for statistical purposes any paper which contains less then 10% mechanical pulp is categorized as woodfree, if the proportion is greater then 10% it is categorized as mechanical paper. Woodfree paper is coated {CWF} or uncoated {UWF} woodfree paper is sometimes known as "fine paper" in the USA woodfree paper is known as "free sheet".

Pulp Making Process - a 99% water mix with fibrous material 

Image8.jpg

A pile of Pulp!

Image 9.jpg

RAW MATERIALS

WASTE PAPER

Advantages
Cheaper
Better for heavy papers
Packaging

Stationery 

Writing

 

Disadvantages
Inconsistent

Poor dye colouration
Holes in base sheet
Ink spots/dirt
Light gsm
Gives open sheet
What is it made from?
1-11 waste grade of tissue
Toilet tissue won't always break down if higher waste grade is used
Less weight control
Unknown fibre mix
Generally weaker

 

VIRGIN PAPER

Advantages
Softness
Better dye colouration
Higher bulk
Breaks down better when wet
Consistency
Wet strength is consistent when needed
Thickness in gsm consistent
Better embossing when plying together
Colour
Better for micro embossing
Better base sheet
More absorbency
Better weight control

Disadvantages
Price

 

GSM
A good deal is talked about GSM (grammas per square metre). This is the weight of paper per m- per ply; and gives a good indication as to the amount of water absorption available e.g. higher GSM = more water absorption. However, virgin fibres of specific nature may well disprove this theory as in the manufacturing of the tissue, we can make a more dense fibre than we can with recycled pulp, hence giving an even base sheet and therefore providing more absorption.

What we must also watch out for is the weight of the finished product. 2ply toilet tissue can be from 14.5gsm - 16.5gsm, if both rolls are 200m in lengths one will be lighter, but it doesn't mean that the lighter roll is not 200m, we must also consider the width of the rolls, as these can be from 88mm - 100mm.

Due to tissue weight and new manufacturing processes at the pulp mills and converting plants, the only way to tell roll lengths is by rolling out the roll or counting the sheets.

To calculate the weight of a roll, we have to multiply the grammage per m² by the total surface of the roll (number of sheets x perforation length x width) + core weight.

Example  : A roll of : 1000 sheets
width : 24 cm
gsm : 19
perforation : 27 cm
number of plies : 2

 

Roll total Weight:   2.46 kg

1000 x 0.24 x 0.27 x 19 x 2 =

        2.46kg _1000


PLY
All paper is made one ply then wound together to make two, three or four plys. The plys are put together in order to increase strength without losing softness, two plys of say 17gsm will generally be stronger and softer than a 34gsm one ply.

WET STRENGTH
Papers have resins added in order to prevent decomposition when wet: the more resin, the harder and less decomposable the paper; it is therefore not used for toilet tissue as it's not flushable.

ABSORPTION
Absorption speed and absorbtion capacity are two different notions.
Absorption speed relates to how quickly a product can absorb a given amount of liquid.

Absorption capacity is the amount of liquid the product can absorb. For paper, absorption speed is the most important.  Paper is not meant to absorb litres of liquids!
Absorption depends on the grammage, on the number of plys of the product and also on the quality of the wood pulp and how well it is refined.

Absorption is related to :

BIODEGRADABLE
All paper is biodegradable but this term should not be confused with flushable.

SUSTAINABLE ENVIRONMENT

Paper millers focus on environment friendly processes during manufacture so as to ensure a continuous supply of raw materials - sustainable forest management is the key!

Image10.jpg

CREPE
The peaks and troughs in paper when viewed from the side:

Flat crepe : low bulk tissue
Image11.jpg

High crepe : heavyweight paper products

Image12.jpg
Normal Crepe:   High bulk tissue

Image13.jpg

Thickness is caused by the curve. This is very crucial on high metreage products.

RANGE
The main product that is used in the away from home market for soft disposable tissue is toilet tissue. The UK population is approximately 61 million and one is happy to report that we all use toilet tissue every day of the week and women use more than men!

We must also be aware that there is two types of market, the home market and the away from home market. The home market is cash & carry/supermarkets and the away from home is industrial / commercial / medical -  the list is endless.

Toilet tissue comes in all types of packaging and sheet sizes within our market. The range consists of the following:

Conventional rolls
Luxury 111mmx139mm sheet size x 12 twin and 10 x 4roll x 220/260 sheet
Industrial 100mmx125mm sheet size x 18 twin and 10 x 4roll x 280/320 sheet
Contract 95mmx111mm sheet size x 18 twin and 10 x 4roll x 200 sheets

When contract cleaners focus on price, they normally buy the contract products.

JUMBO ROLLS
These come in all sizes.  However, in today's market we have to take great care for the following reasons:

•   Mini jumbo: these can be anything from a 120m - 200m x 88mm - 100mm wide
•   Midi jumbo: these can be anything from a 215m - 250m x 88mm - 100mm wide
•   Maxi jumbo: these can be anything from a 250m - 430m x 88mm - 100mm wide

This is why we have to be careful. The only real way of telling is by the price the customer is paying and on top of this; we have to remember that jumbos come in 1 and 2 ply on a 76mm core as well as a 60mm core. Also, believe it or not, there is a correct way and an incorrect way of loading jumbos into its dispenser. Always make sure that the tail end is close to the toilet seat area and not away from it.

The other thing we need to watch out for is the number of rolls per case as not every manufacturer packs in the same way.

Other forms of toilet tissue are flat packs, bulk pack (1 and 2ply), without cores, with bungs, sulphite and out of all of these variant types of toilet wiping paper, the most hygienic is sulphite.

HAND TOWELS
These towels come in 1ply, 2ply and 3ply tissue and also some air-laid non woven.

The most popular towel in the UK market is C-fold  for industry.  A 1ply heavyweight paper: 46/48gsm is used. For offices, doctors' surgeries, etc. you will need a 1ply softer towel: 40/42gsm or a 2ply.   Again, there is a correct way of putting these into the dispenser, always make sure that the ends of the tissue are pointing down and not upward. 

The other popular towel is the interfold or V-fold  which comes in a lightweight and heavyweight paper. This is sold through School, Medical Centres and Hospitals.

With interfold towels, when one tissue is pulled out the next sheet will present itself unlike a c-fold which will remain in the dispenser.

The new 'in-word' for hand towels is the multi/Z-fold.  These are like an interfold but with an extra fold included.

The 'very new in-word' for hand towels is W-fold  or multi-fold these are like an interfold but with an extra fold in and will, long term, replace C-folds, as when opened they are the same size as a  C-fold open.

ROLLER TOWELS
Roller towels come in all types of different tissue and packaging.

Heavyweight: This is normally a 1ply 46/48gsm green/blue roll towel 20cmx76m box 16 rolls. It can also be 40cmx76m box 8 rolls.  Along with this, there is an embossed system on the market. 2ply tissue is also available made 1ply 20gsm and the other 30gsm, or it can be 2 x 20gsm which is the most popular, available in blue or white.

Re-inforced: This is a 40gsm tissue with nylon running through. This product goes into a continuous towel dispenser.

Soft tissue: A mine field, you can obtain these products in: 1, 2 and 3ply, 18 - 28 gsm:   90 sheet counts to 135 sheets:  packed in 9-24's:   perforated 35-45mm from 60cm-25cm wide.  It is therefore very important, indeed crucial, to find out what you are selecting, as most of these products are sold through the healthcare industry, available in blue or white.

CENTREFEED
One could write a book the size as 'War & Peace' on this product! These products are available in 1, 2 or 3 ply and can be anything from 17gsm to 60gsm, 18.5cm - 30cm wide from 57m - 247m.

The product range runs from washroom wipes to specialist wipes and found in markets in all types of industry.

INDUSTRIAL ROLLS
This range of products mainly goes on to floor stands. One of the biggest markets is engineering, excluding the garage trade. Once again, there is a very mixed range of 1, 2, 3 or 4ply products, ranging from 20cm x 40cm wide and from 145m - 1800m long.

OTHER PRODUCTS
There is another range of products of kitchen towels, serviettes and facial tissues - all sold through the catering trade.

NEW TECHNOLOGY

Our new DESL (Double Embossing Synchronised Lamination) way of marrying sheets together consists in gluing the ply's together and not embossing them (mechanical pinching). This is an improved technology giving our products superior characteristics and performance when compared with a standard 2 ply embossed product. 

DESL is a new way of producing tissue which is two 1ply tissues are glued together and then embossed.  This will give the finished product a higher dry strength, higher wet strength and higher speed absorption.

The advantage of DESL over a classic product is that it does not separate, does not shed and it also retains its softness even when glued and, most importantly, it is more environmentally friendly as  less paper is used.

Double Embossing Synchronised Lamination  - 
 DESL where less is more efficient

Image14.jpgImage15.jpg

CONCLUSION
Wherever there is a roof with people underneath,  a need for paper products will exist and it is up to us to find that need, and to recommend the tissue that will meet the customer's requirements in the most environmentally friendly and cost effective way possible.

Copyright:  pd-Tissues

To discuss any of the above Contact Peter Digby