Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Cash flows from operating activities:
Net income	$ 715,170	$ 523,380
Adjustments to reconcile net income to net cash (used in) provided by operating activities:
Depreciation and amortization	320,791	238,984
Deferred income taxes	(5,452)	143,991
Provision for bad debts	(32,700)	1,826
Other operating non-cash items	1,076	974
Changes in assets and liabilities:
Trade accounts receivable	(1,001,849)	(41,156)
Receivables due from affiliated companies	(470,895)	325,150
Inventories	(439,011)	(897,157)
Prepaid expenses and other current assets	(79,447)	(37,503)
Accounts payable - trade	114,678	121,899
Accrued expenses payable	271,394	142,085
Net cash (used in) provided by operating activities	(606,245)	522,473
Cash flows from investing activities:
Purchases of property, plant and equipment	(303,901)	(571,720)
Net cash used in investing activities	(303,901)	(571,720)
Cash flows from financing activities:
Payments on long-term debt	(111,346)	(66,239)
Proceeds from exercise of stock options	13,799
Net cash used in financing activities	(97,547)	(66,239)
Effect of exchange rate on cash	421	(748)
Net decrease in cash and restricted cash	(1,007,272)	(116,234)
Cash and restricted cash at beginning of period	3,733,924	5,165,844
Cash and restricted cash at end of period	2,726,652	5,049,610
Supplemental disclosure of cash flow information:
Cash paid for interest during period	38,065	6,374
Cash paid for income taxes during period
Cash paid under operating lease	23,700	23,700
Cash	563,426	2,294,648
Restricted cash	2,163,226	2,754,962
Total cash and restricted cash	2,726,652	5,049,610
Noncash lease activities:
Operating lease right to use asset exchanged for operating lease liability	432,466
Finance lease right to use assets exchanged for finance lease liabilities	44,979
Total lease right to use assets exchanged for lease liabilities	$ 477,445