Kappa is a measure for relative hardness, the bleachability and the digestion degree of pulp. As other methods for the determination of the digestion degree, the determination of the Kappa-measure is based on the oxidation of the lignin rests. The consumption of oxidizer (here potassium permanganate) is a measure for the lignin concentration. The Kappa-measure is therefore a method for determination of pulp.

As the Kappa-measure refers to pulp as raw material and our raw material for the products KÖHLERBOX SPECIAL, KÖHLERBOX S SPECIAL and KÖHLERBOOK SPECIAL (according to ISO 9706) is waste paper, Kappa as method of measure is not relevant (see our datasheets).

The pH-value indicates the hydrogen ion concentration in an aqueous solution. Aqueous solutions with a pH-value underneath 7 are acid. Aqueous solutions with a pH-value = 7 are neutral and more than 7 alkaline. Many vital processes take place within certain pH-limits.

The term “pH-value” is explained in the following way:

The “p” means “potential”, the “H” stands for the symbol hydrogen. “pH” also means “potential hydrogenii” (latin) which signifies “potency of the hydrogen concentration”.

Permanent measurements reveal a neutral value of our products of aprox. pH 7,0. By using the raw material unsorted waste paper (1.02) we are unfortunately not able to guarantee the pH-value indicated. Due to the raw material there can be fluctuations. This is valid for all KÖHLER products which are manufactured of 100 % unsorted waste paper. 

Our product KÖHLERLIGHT 400 which is made of 100 % wood pulp the permanent measurements revealed a neutral value of aprox. pH 7,0. The fluctuation due to this kind of raw material is very little so that you can assume a neutral range.

Products made of paper have a strong interdependence with the ambient air.

Responsible is the hygroscopic characteristics of the (natural) paper fibre that means the capability to absorb humidity or to pass it to a dryer surrounding. Only when there is a balance of humidity between air and paper or cardboard the fibre comes to rest and stops “working”.

It is ideal that cardboards are stored and processed under the same standardised climate conditions.

The temperatures in the storage and processing areas should have 21° Celsius. The relative humidity should be 50-55%.

When cardboard is brought from a cold storage room to a heated processing room the pallets must have enough time to warm up before the humidity resistant stretch wrap will be removed.

When cold cardboard is unpacked in a warm and humid environment, water condenses on the cutting lines of the cardboard and this leads to the bending of the edges, wavy cardboard and change of the dimensions (length, width, strength).

The European paper industry produces aprox. 40 million tons paper and cardboard for packing purposes which are in a large part used for the packing of food. Most of the time they are made of recycling fibres. As raw material newspapers, magazines and waste packing of cardboard are used. 

The production is according to the particular legal regulations which are adjusted to the state of the art and the latest scientific research. 

Recent analytic studies detected oil which originates from the printing colours used in newspapers also in paper and cardboard based on waste paper as well as in food which is packed in them. 

Our company is as a member of the VDP (German Pulp and Paper Association) in close contact with the manufacturers of printing colours, the printing industry, publishing houses and the packing industry in order to solve this problem. All parties involved are responsible for products which are non-hazardous to health and for securing a sustainable recycling management of paper and cardboard.

For the manufacturing of our recycling and wood cardboards we do not use material which is mentioned in the SVHC-lists or in the REACH-regulations.

If such material was in the used waste paper, it would be possible that after our processing of fibres there could be traces of them in the end product.

These traces are in all cases under the limit of the REACH-regulations so that our products are conform to REACH.

In the course of the years our raw material unsorted waste paper (1.02) has changed its gross density (specific weight) negatively due to the recycling process . As the gross density adjusts to this situation the smoothness of the smoothed version will be less.

Our qualities KÖHLERBOARD, KÖHLERBOX and KÖHLERPAC were tested in our laboratory for their reaction to temperatures. We can assure that our cardboard is suitable up to a temperature of max. 200 °C for a direct contact with corresponding materials.


At 200 °C - no discolouration observable

At 250 °C - slight brownish colouring

At 300 °C - strong brownish colouring

Until September 2003 we were certified according to DIN EN ISO 9002:1994. The certificate was not renewed. The order processing and the production are conform with the regulations of the original certification documents.

A certification according to the latest norm is not planned at the moment.

Recommendation XXXVI “Paper and cardboards for food packing” of the Federal Ministry of Health:

We herewith confirm that our cardboards are manufactured according to the acknowledged rules of technology and that they correspond to the requirements of the Law for Food and Commodities of 08.07.1993, revised on 09.09.1997, used as intended in contact with dry and non-greasing food.

We manufactured our cardboard according to the recommendation XXXVI of the Federal Institute for the health protection of consumers and veterinary medicine. The recommendation is called “Paper and cardboards for food packing”. Thus the requirements of §§ 30 and 31 of the laws for health protection and the transfer of substance to food are respected.

Our cardboards correspond with regards to the concentration of antimony, arsenic, barium, lead, cadmium, chromium, mercury and selenium the requirements of DIN EN 71, part 3.

Primary sulphur is not used for the manufacturing of cardboard. Inorganic (sulphuric acid, aluminum sulphate, dithionite) and organic sulphur compounds (formamidine sulphinic acid) are used for the adjustment of the pH-value, as a sizing material for cardboard or for bleaching of waste paper fibres. Most of the part of this organic and inorganic sulphur compounds can be found in the waste water of a cardboard production plant. In water purification plants organic sulphur compounds are transferred into sulphate.

The concentration of organic and inorganic sulphur compounds in cardboard produced is low. 

Phthalate are used for example as plasticizer for plastics, but not in the production of paper and cardboard. In researches on baby food very small amounts of phthalate were found. It turned out that this substance did not originate of the packing, but can be found anywhere - also in other food, even in human breast milk. (Source: C.Böhme: “Toxicity and exposition of some substances of food packings”, Federal Health Paper 10/97, pages 392-393).

As phthalate can be found in all substances and products, we cannot exclude that it can also be found in the cardboard we manufacture.

In recommendation XXXXVI (LMBG) for paper and cardboard for food packing orthophenyl phenol is explicitly authorized for contact with food in the paper industry.

Nevertheless we do not use it in our production. This does not exclude that due to our raw material waste paper (1.02) traces of orthopenyl phenol in an analytic detection limit can be found in our products. 

Furthermore, we would like to point out that orthophenyl phenol is authorized as a preservative for oranges and citrus fruits.

Perfluorooctanesulfonic acid is utilized for the manufacturing of perfluorinated products which are used in the galvanic industry. As we use unsorted waste paper (1.02) as a raw material, we cannot exclude that this substance is found in our products. However, the percentage is under the limit value of 0,1 % (1000 ppm). The so-called perfluorinated lipophobic surfactants mentioned in the recommendation XXXVI which are used in the paper industry do not contain perfluorooctanesulfonic acid either in the limit value mentioned above.

Nonylphenol is a primary product of nonylphenoletoxylate which is the most important subgroup of the alkylphenol ethoxylate used as surfactants. In the environment nonylphenoletoxylate turn again into toxic nonylphenol. Alkylphenol ethoxylate can be found in pesticides, detergent and disinfection agents as well as in packing for food e.g. PV foils. It is also part of print and wall colours or chemicals for crude oil extraction. Furthermore it is used for the production of plastic, textiles, leather and paper. 

Nonyphenol and nonylphenolethoxylate are substances which are especially used in detergents. 

We herewith confirm that neither nonylphenol nor nonyphenolethoxylate is used in our production. Therefore, a diffusion of these substances to our cardboard is not possible.

Lignin is a substance which besides of cellulose and further components is part of wood. It is responsible for the additional rigidity of the fibres. There is an unwanted component which is the reason that paper turns yellow rapidly. At the production of pulp it is separated chemically from cellulose. Our cardboard is produced to 100 % from unsorted waste paper of the quality 1.02. For this reason we cannot give any guarantee for the contents. Therefore we cannot exclude that our cardboard contains traces of lignin.