Finger Jointing of Plantation Timbers using indigenously developed Finger-Jointing and Finger Shaping Machine

 

With the increasing consciousness preservation of natural rain forests, large girth logs of exotic species like teak, rose-wood etc. are no more available in required quantities. The future has to be processing of plantation timbers like rubber wood and poplar wood. Plantation timbers are small girth logs and the trees are usually felled when still immature.

 
Plantation

The juvenile timber leads to growth stresses which manifest themselves in the form of misbehaviour of timber even after drying. It is therefore necessary to end join smaller sections of plantation timbers to make them up to usable lengths.


Recognising the need for such a process, BMTPC has developed a complete line of finger jointing and shaping machine. This new generation of wood processing machinery, finger-jointing machine (FJM) offer a financially viable approach to maximize wood recovery and using FJM it is possible to efficiently turn a large proportion of wood waste materials into valuable products. Finger jointing short length sawn timber, particularly from warp prone plantation species can facilitate production of higher quality solid wood products.

 

 

A study was conducted to evaluate the strength of Finger joined timbers from plantation grown species. It was found that finger jointed timbers from plantation grown species such as Eucalyptus, Silver oak and Rubber wood gave finger joint efficiency in the range of 60 - 73% of the original defect free wood of the species. In addition the finger jointed wood is found to have greater dimensional stability.

 

The license for commercial production of the indigenously developed finger jointing and shaping machine has already been issued and subsequently machine is also installed at Indian Plywood Industries Research and Training Institute (IPIRTI), Bangalore for demonstration and Research &Training.  In India, use of finger-jointing technique is now bound to increase exponentially which otherwise was severely restricted due to high cost of imported finger-jointing machines.
 

PROJECT OBJECTIVES
To indigenously design and develop a set of machines for finger jointing treated and seasoned plantation timber to obtain long and usable lengths. These machines are available at the lowest possible cost so that this technology can be propagated to even the smallest of processors of plantation timbers.
 

 

Manufacturing Process

Following are the steps involved in the production of finger-jointed timber.
 

  1. Selection of Sawn timber, Preparation for Seasoning, Trimming of ends, Planing and Squaring.

  2. Formation of Finger Profile

  3. Glue Application

  4. Assembly of Joint

  5. Curing of Adhesive

  6. Laminating wherever necessary

 

While manufacturing finger-jointed timber, attention has to be paid to factors such as Grade of timber, Moisture Content, Selection of Finger Profile, Choice of Adhesive, Alignment and Fitting of Finger-Joints, which affect the efficiency of products made from finger-jointed timber.
 

Finger-Jointing machinery

Finger Jointing line comprises of the following machines

i) Processing machines

1. Finger Shaping machine          2. Glue applicator           3. Finger Pressing machine

ii) Auxiliary Equipments

1. Dust Extractor                        2.  Air Compressor.

 

1. Finger Shaping machine

The capabilities of the finger-shaping machine are:

  •  Can process both softwoods and hardwoods.

  •  Can process a maximum dimension of 100 mm thickness and 150 mm width.

  •  Can produce both horizontal and vertical fingers.
 

Specifications :

  • Max.timber section                  : 100 mmx155 mm
    (thick x wide)

  • Finger cutting diameter            : 160 mm

  • Power requirement                  : 1x7.5 kw (10 HP)

  • Air pressure                           : 6 kg/cm 2

  • Air requirement (@6 cyl./min)    : 300 l/min.

  • Dimensions (HxWxD)                : 1300x750x650 mm

  • Net weight (approximate)         : 300 kgs
     
2. Glue applicator

The adhesive is applied to finger sections to be joined using a Glue applicator machine or manually using a Brush.The types of adhesives employed or making finger joints are:

 

 

1. Phenol Resorcinol Formaldehyde (PRF)

2. Phenol Formaldehyde (PF)

3. Urea Formaldehyde (UF)

4. Polyvinyl Acetates (PVAc)

 

 

 

3. Finger Pressing machine

The capabilities of the finger-pressing machine are:

·      Can process maximum length of 2500 mm.

·      Can exert maximum Specific end pressure of 12 N/mm After the fingers are applied  with adhesive, cut end of timber is aligned and  external pressure of 6-8 N/mm is normally applied to keep the joint accurately meshed In the finger pressing machine pressure on glued assembly is applied by hydraulic system.

 

 Specifications

  • Timber pressing length               : 2500 mm (standard)

  • Max.timber section (thick x wide) : 100 mm x 155 mm

  • Max.pressing power                    :  10 tons

  • Power requirement                      : 1 x 2 hp,1 x 3 hp

  • Diameter of cross cut saw blade    : 305 mm

  • Saw blade bore diameter             : 25 mm

  • Air pressure                               : 6 kg/cm 2

  • Air requirement                          : 60 l/min.

  • Dimensions (HxWxL)                  : 1350x1220x3150 mm

  • Net weight (approximate)            : 700 kgs

 

 

Project Cost

1. Installed Capacity      : 2.8 m (100 cft)/Shift

2. Land and Building

a) Land             : 2400 sq.m.

b) Built up area   : 300 sq.m.

3. Power Requirement    : 16 k.w.(Approx)

4. Capital Investment     : Rs. 12 lakhs (approx)

Potential Applications

Panelling, Partitions, Panel Doors, Flush Doors, Furniture, Joinery etc.

 

Advantages

Utilization of low-grade wood, Removal of defects and rejoining, Less wastage of wood, Less consumption of glue, High productivity, Joint Strength upto 75 % of clear wood

 

For further details please contact

Executive Director
Building Materials and Technology Promotion Council
Core 5A,First Floor,India Habitat Centre,Lodhi Road
New Delhi 110 003

Tel :91-11-2301 9367,2463 8097,2463 6747;
Fax:91-11-2301 0145,2464 2849;

E-Mail: bmtpc@del2.vsnl.net.in  or feedback@bmtpc.org

Web Site :http://www.bmtpc.org