GB637411A - Tear tape - Google Patents

Abstract

637,411. Package tear-tapes. WING- FOOT CORPORATION. Oct. 28, 1947, No. 28733. Convention date, March 28. [Class 94(i)] A tear tape is composed of an elongated ply of a plastic of a class of plastics suited for use as film wrapping materials, united to a ply of a plastic, of a greater tensile strength than the plastic. As applied to packaging a box of cigarettes (Fig. 6), the tear tape 6 (shown in cross section in Fig. 1), comprises a ply a of regenerated cellulose united by a suitable adhesive (not shown), to a ply b of rubber hydrochloride. The tape 6 is heat-sealed to the inner face of a rubber hydrochloride wrapper 1, so that when the box is wrapped, the outer surface of the regenerated cellulose ply a lies against the surface of the box. In order that the ply a (which is non-heat sealable), may be secured to the inner edge 4 of the wrapper seam 4, 5, either the ply a or the wrapper is provided with a spot of wax 7, preferably before the wrapping operation. The outer edge 5 may be nicked at 9, 9, to initiate a tear. An exposed end of the tape may form a tear tab 8 which may be united by wax to the wrapper but is preferably left free. In a second form of tape (Fig. 2, not shown) the outer edges of the tape of Fig. 1 are turned inwards and secured by adhesive to 'the outer face of the ply a leaving a central exposed surface of regenerated cellulose. Instead of adhesive the surfaces may be coated with nitro-cellulose and then heat-sealed. In a third form (Fig. 3, not shown) each half of the tape of Fig. 1 is folded about a central longitudinal axis so that the outer surfaces of the ply a are brought together and secured as before. In a fourth form (Fig. 4, not shown) the tape has a single ply of regenerated cellulose sandwiched between outer plies of rubber hydrochloride. The ply a may alternatively be of paper, cloth, scrim, thread &c., while the ply b may alternatively be of polyethylene or copolymer of vinylchloride and vinylidene chloride, but is of the same plastic material as that of the wrapper. The thickness of the wrapper, which is preferably unplasticized, may vary between .0007 in. and .0025 in. The thickness of the ply a when of regenerated cellulose may vary between .001 in. to .002 in. and in a preferred form is .0015 in., the ply b of rubber hydrochloride then being .001 in. Regenerated cellulose, when used, may be coated on one or both sides with a moisture-proof lacquer. Rubber hydrochloride when used may be of different composition and gauge for the wrapper and tape and the proportions of stabilizer, and plasticizer and the quantities of pigment may be different.