Folding and sealing
A Wellplast package is either self-sealing or a tool is used for folding and sealing (welding tape, glue, staples, etc).
The picture shows an example of a box where the short sides are double folded and locked with tabs at the bottom of the box.
Non self-sealing design
The picture shows an example of a “corner support” box held together by with plastic sleeves.
The two methods above can be folded by hand or automatically. The choice of folding method mostly depends on the number of packages to be folded. It is impossible to generalize at which quantity of packages it is worthwhile to use an automatic folding equipment. Wellplast AB helps the customers find the best solution. At automatizations Wellplast AB offers through partners folding equipment for all types of packaging.
Products and methods for sealing
In order to seal boxes and other packages often tape, glue, staples or self-sealing constructions are used. All those methods work for Wellplast® packages with one exception – cold glue. Apart from the traditional methods, also welding works as an effective sealing method when no added material is required. Below various methods are described where also tested products are recommended.
Depending on in which environment the Wellplast® package is to be used we here recommend various tapes
|Normal conditions||3M/Scotch 313||Transparent PP|
|Humid and cold conditions||3M/Scotch 375E||Transparent PP|
|Extreme conditions||Stokvis PC8105050||Transparent reinforced PP|
N.B.! Boards or packages can be delivered pre-taped with double-sided tape.
PP plastic usually requires other adhesive than paper based packages, why special hotmelts for this purpose have been developed. With Technomelt Supra HT 325 from Henkel Norden AB a very strong glue joint will be obtained. This glue gives a joint that by far exceeds the normal strength of for example hot glued corrugated cardboard. Also Jowat Toptherm 25650 from Arne Lundquist & Partners AB gives satisfying strength, but requires a somewhat higher pressure and about 15 degrees higher temperature than normal in tank, hose and mouthpiece.
In automatic folding machines there usually are vacuum mouthpieces that pick or handle the sheets and boxes. In many cases standard vacuum mouthpieces made in nitril rubber or equivalent work very well. In more extreme applications we recommend a softer mouthpiece of silicone rubber which gives a much better and stronger grip of Wellplast®. The Duraflex® series from PIAB AB is an example of such tested, durable and well functioning vacuum suction cups.
Since Wellplast® to 45% consists of polypropen plastic, welding is an effective method for sealing of packages when other material does not have to be added. We offer both manual and automatic solutions.