Why do we get washboarding effect on Corrugated Board ? What is the remedy ?
	Which functional properties of the adhesives are important to Corrugated Board manufacturers ?
	How can the adhesive help in reducing the curing time of the Corrugated Board ?
	What is the net increase in weight of paper after it is being converted into Corrugated Box by use of gum.
	Why do we get washboarding effect on Corrugated Board ? What is the remedy ?
	Ans :- The reasons for washboarding effect on Corrugated Board are as follow :
	1. The adhesive is applied to the sides of the flutes rather than only on the tips. This adhesive pulls the liner down between the flutes when it dries, creating a washboard tendency.
	2. Linear which are absorbent, weak or of less bulk can cause washboard tendency.
	3. Excessive pressure on the corrugating machine can also cause washboard tendency.
	The remedies are as follows :
	1. When making 2 ply liners on corrugating machine the glue applicator roll should run at the same speed as the paperweb speed to avoid the wiping action which causes the adhesive to spread to the sides of the flutes. When making Corrugated Board on the pasting machine the pressure roll should be adjusted correctly and adhesive of correct viscosity should be used to prevent adhesive from spreading to the sided of the flutes.
	2. Paper of suitable thickness and strength should be used on the facings of the Corrugated Board. Generally the facings should be thicker and stronger compared to the medium.
	3. Correct pressure on Corrugating machine should be maintained.
	Which functional properties of the adhesives are important to Corrugated Board manufacturers ?
	Ans :- The following functional properties of the adhesives are important :
	1. Corrugating adhesive.:-
	a) Solid content.
	b) Quality of starch.
	c) Viscosity.
	d) Gel point.
	e) Avility of the adhesive to remain homogeneous.
	f) Adhesive should be bacteria and fungus free.
	g) pH value should not be more than 9.
	2. Pasting Adhesive:-
	a) Solid content.
	b) Viscosity.
	c) Tackiness.
	d) Drying time.
	e) Should be bacteria and fungus free when stored for a few days.
	f) pH value should not be more than 9.
	How can the adhesive help in reducing the curing time of the Corrugated Board ?
	Ans :- During 2 ply corrugating process the curing takes place quickly as the heat present evaporates the water from the adhesive. This curing process cab be further hastened by using higher solids (20%-25%), and high quality starch of minimum 45 viscosity when we make a 3 Ply/ 5 Ply board on the pasting machine considerable moisture is introduced in the corrugated board is the pasting gum leading to delayed curing time especially under humid climatic conditions.
	Use of adhesive having below mentioned properties can reduce curing time:
	1. Good Tackiness.
	2. Solid content. (25% - 30%)
	3. Viscosity (19 - 25 seconds)
	Regulated amount of adhesive should be released( Generally about 40 grams per square metre).
	What is the net increase in weight of paper after it is being converted into Corrugated Box by use of gum.
	Ans :- When a average Quality of Paper i.e. Semikraft & Kraft combination is used generally this is an 5% - 7% increase in the weight of Paper, this increase in weight is generally equaled by wastage during converted into Box having optimum moisture content the output weight of Corrugated Boxes will be approximately more or less in same.