INCOME TAXES (Details) (USD $)	12 Months Ended
	Jan. 31, 2013		Jan. 31, 2012	Jan. 31, 2011
Current [Abstract]
Federal	$ 2,488,953		$ 2,010,929	$ 2,106,753
State	311,905		290,461	299,616
Foreign	163,921		201,565	135,327
Total current tax expense (benefit)	2,964,779		2,502,955	2,541,696
Deferred [Abstract]
Federal	790,748		1,112,827	429,442
State	42,539		98,191	37,892
Foreign	22,392		(13,364)	(28,265)
Total deferred tax expense (benefit)	855,679		1,197,654	439,069
Provision for taxes	3,820,458		3,700,609	2,980,765
Deferred tax assets [Abstract]
Inventory cost capitalization	155,301		110,306
Pension cost	3,577,115		3,964,282
Management incentive	34,131		262,612
Stock options	656,650		458,468
Interest rate swap	111,191		135,526
Other	434,910		446,576
Total deferred tax assets	4,969,298		5,377,770
Deferred tax liabilities [Abstract]
Property, plant and equipment	2,396,065		2,348,541
Inventory - LIFO	318,222		320,759
Prepaid expenses	266,431		205,501
Goodwill	4,106,338		3,839,091
Total deferred tax liabilities	7,087,056		6,713,892
Net deferred tax liabilities	(2,117,758)		(1,336,122)
Undistributed earnings of foreign subsidiaries	3,500,000
Reconciliation of the federal taxes and the Company's effective taxes [Abstract]
Computed expected federal tax expense	4,034,330		3,683,665	3,100,765
Manufacturing exemption	(271,862)		(205,457)	(207,968)
State income taxes, net of federal income tax benefit	282,226		289,895	235,638
Research and development tax credits	(153,689)		(149,728)	(143,361)
Stock option tax expense	75,880		78,473	20,076
Stock option modification	(110,311)		0	0
Other	(36,116)		3,761	(24,385)
Effective income taxes	3,820,458		3,700,609	2,980,765
Reconciliation of the federal tax rate and the Company's effective tax rate [Abstract]
Computed expected federal tax expense (in hundredths)	34.00%		34.00%	34.00%
Manufacturing exemption (in hundredths)	(2.30%)		(1.90%)	(2.30%)
State income taxes, net of federal income tax benefit (in hundredths)	2.30%		2.70%	2.60%
Research and development tax credits (in hundredths)	(1.30%)		(1.40%)	(1.50%)
Stock option tax expense (in hundredths)	0.70%		0.70%	0.20%
Stock option modification (in hundredths)	(0.90%)		0.00%	0.00%
Other (in hundredths)	(0.30%)		0.00%	(0.30%)
Effective income taxes (in hundredths)	32.20%		34.10%	32.70%
Unrecognized tax benefits [Roll Forward]
Balance at beginning of period	49,000
Increase in tax positions for prior years	0
Decrease in tax positions for prior years	(49,000)
Increase in tax positions for current year	0
Balance at end of period	$ 0		$ 49,000
Federal [Member]
Open Tax Year [Line Items]
Examination in Progress		[1]
Examination Not Yet Initiated	2010 - 2013
State [Member]
Open Tax Year [Line Items]
Examination in Progress		[1]
Examination Not Yet Initiated	2008 - 2013
Canada [Member]
Open Tax Year [Line Items]
Examination in Progress		[1]
Examination Not Yet Initiated	2007 - 2013
The Netherlands [Member]
Open Tax Year [Line Items]
Examination in Progress		[1]
Examination Not Yet Initiated	2008 - 2013
People's Republic of China [Member]
Open Tax Year [Line Items]
Examination in Progress		[1]
Examination Not Yet Initiated	2011 - 2013
Chile [Member]
Open Tax Year [Line Items]
Examination in Progress		[1]
Examination Not Yet Initiated	2012 - 2013

[1] n/a